bluuebunny/crossref_metadata_2025 huggingface dataset:
Real-Time Observations of Fracturing Processes of Brittle Rock in Compression by X Ray Computed Tomography
Authors: Cao Guang Zhu , Qiang Yi , Li Feng
Published: October 2011

In present，a series of uniaxial compressive experiments on sandstone samples have been conducted in the laboratory by using jointed devices of triaxial loading equipment and medical SOMTOM-plus CT scanner. Based on CT value, expression of density damage variables and density damage increments (DDI) of brittle rock and the method to determine the rock initial damage variables have been worked out. From real-time CT observations of sandstone sample under uniaxial compression condition and the analysis on CT digital images and the relation curve between sandstone density damage increment (DDI)and stress, the evolution process of fracturing in brittle rock sample can be divided into five stages, i.e. initial densification stage, crack occurrence-propagation, crack merging-bifurcation, crack rebifurcation-propagation, and crack cut-through-massive failure stage. Crack occurrence-propagation is a local phenomenon and the whole rock is still in the densification stage. Therefore, the rock failure process under compression is mainly including three stages, namely initial damage densification, local dilatation-bulk dilatation, and massive failure. The use of CT images and relation curve between density damage increment and stress in analyzing the meso-damage evolution processes of brittle rock sample is an important and effective method. As an important mechanics index in rock meso-mechanics, the density damage increment can be used to analyze the quantitative fracturing process in brittle rock under compressive condition, as well as being an important factor in a rock fracturing process model to be constructed.
Spatial Strategic Orientation and Distribution of the Tourism Development in Minority Areas — A Case of Linxia Hui Autonomous Prefecture
Authors: Wang Zhi Ping , Yan Jiang Ping , Li Wei
Published: October 2011

On the basis of analysis the tourism developing background in Linxia, this paper puts forward the spatial strategic orientation. According to the conditions of tourism resources, traffic, market, regional functions etc, we establish the tourism spatial distribution of “one center, two poles, two belts, three districts”and the developmental thinking, for the purpose of developing the tourism scientifically in Linxia.
Analysis of Soil Nutrient Content Characteristic for Inductive Transformed Low-Quality Forest in Greater Higgnan Mountains
Authors: Ji Hao , Dong Xi Bin
Published: October 2011

In This paper, the miscellaneous tree low-quality forest and Oak low-quality forest in the Greater Hinggan Mountains region were transformed inductively by planting Siberian Korean pine, Mongolica, and Larch, respectively. With the method of using different bandwidth and gap area, the soil nutrient characteristics were changed. The results indicated that the pH of soil increased slightly by different ways of induced transformation, but the variance was not significant (P﹤0.05). After reforming the induced soil organic matter content was balanced, while the basic content of hydrolysable nitrogen increased, and the availiable phosphorus decreased. Soil rapidly-available potassium content in Oak coppice was reduced but raised in the region of secondary performed miscellaneous wood. The variation coefficient of Siberia Korean pine was the largest with different soil pH value of various bandwidth and soil nutrient content (except for availiable phosphorus). Content of soil organic matter and hydrolysis nitrogen, phosphorus and potassium content are significantly positive correlated. At the same time, clear-cutting bandwidth and soil organic matter and hydrolysis nitrogen content are significantly negative correlated. During the transformation of forest gap in the sunny and shady slope, smaller area of forest gap owed the larger soil nutrient content. Generally, soil nutrient content in sunny slope is higher than the shady one.
The Evaluations and Suggestions of Current Implement Situation of Financial Support Policies in China
Authors: Jia Qiao , Yang Ping , Wang Jia Bao , Lan Qiang Gao
Published: October 2011

Our major objective is to discuss the development of and understand how the policies have be implemented .The analysis of rural financial support based on surveys of hundreds of farmers in China.Some of the major problems in Chinese rural financial support are the phenomena of replacement, selective, cheating. Hence, if policy makers want minimize the impacts, there needs to be an effort to minimize the effect on these households either by enhancing policy makers from the knowledge and mental qualities, or by sounding policy implementation process system, or by improving communication and coordination mechanism for policy implementation, or by optimizing the environment for policy implementation.
Economic Analysis about Big Consumers Purchasing Electricity Directly
Authors: Zhang Li Dong , Zheng Nan , Yu Ting Li , Wang Kun Yu
Published: October 2011

If the big users electricity consumption kept the same, while comparing through grid direct-purchasing power with building the power plant and purchasing the power by grid, and then establish the profit and loss model and point to point mode. Finally, we need to demonstrate the economy of direct power purchase through the example and value.
New Development of the Oriented Design against a Background of Low-Carbon Society
Authors: Mo Wei , Sun Wen Juan
Published: October 2011

It is no doubt that the spotlight of all sectors of today’s society has been focusing on the energy and environment conservation as well as the low carbon living. Such ideas are not only guidance to social development, but also a great influence to every aspect of people’s life. As a basic mode of space guide, the way-finding system is closely bound up with the livelihood of people. Moreover, there is no substitute for its function. This paper is trying to illustrate the influences which resulted in the object-oriented design system and to elaborate the innovations in the setup mode under the low-carbon social background.
Test Study on the Multi-Pulse Loading Fracturing Technology for Development of Shallow CBM
Authors: Wu Jin Jun , Chu Xiao San , Liu Li Cai , Zhao Guo Hua
Published: October 2011

In China, the coal gas formation is characterized as low permeability, low pressure and low water saturation. The coal bed methane (CBM) has strong adsorption and is difficult to develop. Hydraulic fracture is currently the main measure to improve its permeability, drain the liquid and lower the pressure, which promotes desorption of CBM. But it is not efficient. Based on the principle of high energy gas fracturing (HEGF) and the study of new methods, we proposed the test application of the multi-pulse loading fracturing technology for development of shallow CBM. The mechanism of the technology is that it generates high-temperature and high-pressure gas in the target coal bed to produce a long multi-fracture system with effects of multi-pulse loading. It can also produce strong impulse oscillation acting on formation matrix to loose formation pressure, improve the pore connectivity and permeability of coal bed, which promotes pressure drawdown and desorption of CBM. Thus, the goal of increasing the yield of CBM wells is achieved. This paper focuses on the research ideas, mechanism, process design and feasibility. We carried out analysis combined with field test applications. The study provides a new direction to explore new technologies for China’s CBM development.
Optic Method to Measure the Density of Gas and the Analysis on Uncertainty of Measurement
Authors: Guo Chang Li , Zhang Yan Qing
Published: October 2011

A optic method to measure the density of gas is put forward. That is, by using the optical Wedge structure to build air chamber and chamber for gas under test, and by measuring the differences of the optical Wedge interference fringes of the two rooms, the density of gas has been measured. The interference theory of Wedge has been theoretical analyzed, and a formula which can be used to measure the refractive index of gas is put forward, and the uncertainty of the measurement has been analyzed. The parameters of gas density, refractive index and gas thickness have been used in the formula. The results show that the method of optical Wedge interference is practical, and high measurement accuracy is achievement when the density of gas is high.
Study on Mining Techniques for Improving Lump Coal Rate of Anthracite
Authors: Zhang Wei , Zhang Dong Sheng , Chen Jian Ben
Published: October 2011

Based on the decisive impact of mining techniques on lump coal formation, according to the specific mining conditions of 2206# coalface in Xinqiao Mine, the turning direction of rollers in coal winning machine had been changed, the cutting coal ways of coal winning machine had been transformed, the supporting strength of hydraulic supports had been reduced and the presplit short-delay blasting had been implemented for improving the lump coal rate of anthracite. The application results show that those mining techniques could greatly improve the quantity and rate of lump coal and make better technical and economic benefits.
Research on the Further Floatation of the Low-Grade Polymetallic Ore
Authors: Liu Zhi Lin , Zhou Xiao Wen
Published: October 2011

According to the nature of a polymetallic ore and on the basis of the main separation of the molybdenum minerals, the low-grade bismuth, tungsten minerals with be associated are to be recycled. The beneficiation process of Mo-Bi bulk floatation separation and tailings bulk floatation followed by scheelite floatation was determined through a lot of testing. The indexes of small-scale closed circuit test were obtained: the molybdenum concentrate grading at 52.82% with a recovery of 95.01%, the bismuth concertrate grading at 15.26% with a recovery of 53.94%, the scheelite concerntrate with WO3 31.5% and recovery 37.27%. The result of research laid a technical foundation for the raising the comperhensive utilization ratio of mineral resources in the mine.
The Development of Preconcentration Technology in Low-Grade Magnetite’s Beneficiation
Authors: Xu Chun Hong
Published: October 2011

Exhaustion of high-grade magnetite resources and large demand for iron ore in the rapidly developing steel industry promotes the mining enterprises to exploit low-grade magnetite. Low-grade magnetite with a low content of valuable minerals is hard to be separated with the conventional separation process flow because of its high beneficiation costs. By preconcentration technology, enriching valuable minerals and discarding large amounts of gangue as soon as possible before grinding, low beneficiation costs can be achieved in low-grade magnetite’s beneficiation. After continuous researches and production practices and the development of relevant efficient crushing and separating equipments, preconcentration technology has made great progress: from crushing-dry magnetic separation technology to grinding-wet magnetic separation technology, then to ultrafine crushing-wet magnetic separation technology. Now preconcentration has become an indispensable stage in low-grade magnetite’s beneficiation.
Recognition of Fracturing by Stimulated Reservoir Volume (SRV) in Shale Gas Wells
Authors: Kou Hui Hui , Liu Wei Dong , Hou Dong Dong , Sun Ling Hui
Published: October 2011

Ultra-low permeability shale reservoir require a large fracture network to maximal well performance. In conventional reservoirs and tight gas sands, single fracture length and conductivity are the key drivers for stimulation performance. In shale reservoirs, where complex fracture network are created, single fracture length and conductivity are insufficient to stimulate. This is the reason for the concept of using stimulated reservoir volume as a correlation parameter for well performance. This paper mainly illustrates perforation with interlaced row well pattern and multi-fracture fracturing technology and refracturing applied in vertical wells. Moreover, it establishes the seepage differential equation of multi-fracture.
A New Estimation of Water-Drive Reservoir Production Performance Prediction Based on Radial Fluid Flow
Authors: Liu Xiao Juan , Huang Rui , Wang Rui He
Published: October 2011

Due to deposition sequence, reservoir can be approximately considered as formation vertically consisting of many small layers with different physical properties. Meanwhile, the property distribution of these small layers, e.g. heterogeneity of the formation, has a great impact on reservoir development and its production performance. No matter how fine grid to be used, it is always difficult for traditional numerical simulation to couple the impact of vertical heterogeneity of the formation, that will inevitably result in significant calculation error. Therefore in order to overcome this defect and deliver better calculation results which are consistent along with real production performance, this paper derives a math model combined both analysis approach and numerical approach, which has a better description for vertical heterogeneity of formation by overlapping small layers and could deliver better calculation results by fine-gridding strata profile. The model could be applied to either predict further field production performance or conduct history match based on production history of field. This method has applied in actual production analysis and reservoir evaluation, and good results have been achieved.
Comparative Study on Inflow Performance Model of Short Horizontal Wells
Authors: Ruan Min , Wang Jing , Li Xiang Fang
Published: October 2011

High yields and higher efficiency can be acquired by using horizontal well as it has a lager contact area reservoir. So the horizontal well has become a better choice to gas fields all over the world, especially to low permeability oil fields in the world. There are several inflow performance models for horizontal wells. This paper studies several horizontal well models currently widely used in the word through an example of Chinese oil field. These include steady state model of Giger model, Joshi model and Renard and Dupuy model. And pseudo steady model of Babu and Odeh model. The results show that Giger model give greater production rate from our procedure and calculation.
A Streamline-Based Model of Wuliwan Oil Field Injecting Polymer Microspheres to Enhance Sweep Efficiency of Water Flooding
Authors: Fan Zhao Qi , Cheng Lin Song , Dai Fu , Shen Jian
Published: October 2011

Polymer microsphere is a deep profile control agent which has been developed in recent years. Microsphere’s excellently elastic property makes it possible to be injected, or to penetrate deep into formation, and plug high permeable layers. Many laboratory investigations have been carried out on polymer microspheres by researchers, and field tests also have been done in some oilfields. The laboratory and field test results show that polymer microspheres can plug pore throats effectively, decrease permeability of high permeable channels, thus force injected water to change it’s direction and enhance water-flood sweep efficiency. In this paper, based on the mechanisms of profile modifying and plugging of polymer microsphere, Streamline models have been build abstractly to simulate the profile controlling progress of polymer microspheres, observe the transformation of streamline field, and analyze its impact on the pressure of water injection wells and performance of oil wells. In the end, the mechanisms of profile modifying and plugging of polymer microspheres have been interpreted based on the streamline field.
Experimental and Theoretical Study on Slag MTC Improving the Cementing Quality of the Second Interface
Authors: Liu Hua Jie , Bu Yu Huan , Li Fei
Published: October 2011

In view of the complicated issue that how to improve the cementing quality of the second interface in cementing engineering, experimental and theoretical research on slag MTC slurry improving the quality of the second interface was carried out in the paper. Experimental study shows that slag MTC and mud cake can achieve overall cementing; the volume shrinkage ratio of slag MTC is far less than the cement slurry system; and the strength of slag MTC cannot be affected by the presence of mud cake and is greater than low-density cement slurry. Theoretical analysis shows that the alkali activator and Ca(OH)2 produced by hydration can react with SiO2 which exists in mud cake and dead mud to get C-S-H gel with a low ratio of calcium to silicon, and improving the quality of the second interface. The study on the chemical shrinkage ratio of the products of slag MTC hydration was made by using the method of chemical analysis, and low-shrinkage mechanism of MTC was revealed. The results show that mud cake solidification, dead mud solidification and low-shrinkage ratio are fundamental to improve the cementing quality of slag MTC and formation.
Characteristics and Distribution of Insulating Layer and Interlayer in Funing Formation of Gaoji Oilfield
Authors: Zhang Peng Hui , Zhang Jin Liang , Wang Shan Zhang
Published: October 2011

The insulating layer and interlayer are the main factors to form the heterogeneity in the Continental reservoir. According to the reservoir geological features in Funing Formation of Gaoji Oilfield, combined with characteristics of sedimentary environment and diagenesis, we carry out classification and feature description for the insulating layer and interlayer in the research area. The spatial distribution of insulating layer and the interlayer is on the basis of analyzing the log response characteristics of the single well. With the impact of reservoir heterogeneity, we further elaborate the distribution of insulating layer and the interlayer and remaining oil in the relationship.
Investigating Particle-Size Effect on Uplift Mechanism of Pipes Buried in Sand Using Distinct Element Method
Authors: Jiang Ming Jing , Zhang Wang Cheng , Liu Fang , Shen Zhi Fu
Published: October 2011

Uplift of pipeline due to buckling deformation and the resultant soil resistance are key concerns in its design. This paper investigates the particle-size effect on uplift resistance of a pipe buried in sand and the ground deformation mechanism using the distinct element method (DEM). Two granular grounds, one for coarse-sand ground and the other for fine-sand ground, were examined in this simulation. The results show that both cases exhibit similar deformation mechanism of four featured stages: mobilization of peak uplift resistance, infilling of soils beneath pipe, formation of shear bands, and flow of soils around pipe. The uplift resistances in both cases gradually increase to a peak and then drop to a constant value with the upward displacement of the pipe. However, higher peak resistance and shear bands with gentler slope are observed in the coarse case.
The Influence of Surfactant Concentration on Rheology and Proppant-Carrying Capacity of VES Fluids
Authors: Wang Zhi Guo , Wang Shu Zhong , Sun Xiao
Published: October 2011

Polymer-free VES fluids are used to minimize damage to the proppant pack to efficiently transport proppants into fractures. Proper investigation of the rheological properties and the proppant settling of the fluids play an important role in fracturing enginering.In this paper,the rheology and viscosity-temperature properties of the VES fracturing fluid were researched at the range of 1wt% to 6wt% of VES concentration using the HAAKE RS300 Stress-Controlled Rheometer. Proppant settling experiments are performed in static VES fluid. The results show that VES system behaves as a non-Newtonian shear-thinning fluid and the power law model can be used to describe fluid rheology within a certain range of shear rate and temperature. However, with the increase of shear rate and temperature, the fluid trends to Newtonian fluid. Apparant viscocity of the fluid first increases slightly with the temperature rising from 28°C, then，It would drastically reduce after reaching a peak. The temperature correspongding to the peak value increases with the concentration of VES,as well as the shear rates. When VES concentration is 4wt%, the fluid may generates stable micro-mesh wormlike micelle structure, which results in good viscoelasticity and high proppant-carrying capacity.
Real Gas Effect on Unsteady Flow of Natural Gases in Shock Tubes
Authors: Dai Yu Qiang , Zou Jiu Peng , Zhu Che , Wu Jin Tao , Hu Da Peng
Published: October 2011

The unsteady flow behaviors in devices like gas wave machines, wave rotor refrigerators and so on are complex due to real gas effect at high operational pressure and low temperature. In this work, a detail computational model for unsteady flow analysis of real natural gases is established. The real effect on unsteady behaviors of natural gases in shock tubes have been studied extensively. Results show that the non-classical flow of the gases will not exist. The discipline of reflection and refraction of various gas waves or discontinuities remain unchanged for natural gases. Attention should be paid only to the deviations between perfect gas model and real gas model for gasdynamic waves.
Numerical Simulation of Airflow in Wet Rotating Reticular Plate Electrostatic Precipitator
Authors: Bai Ming Hua , Liu Zhi Qiang , Zhang Zhi Min , Liu Jing Jing
Published: October 2011

Wet rotating reticular plate electrostatic precipitator gathers the advantages of moving electrode type electrostatic precipitator technology and wet electrostatic precipitator technology, and utilizes reticular plate, which significantly increases the dust collecting area. In this paper, airflow distribution boards were simplified as porous jump model, and empirical equation was used to get the inertial resistance factors of airflow distribution boards. FLUENT was used to simulate the internal flow field under the condition of without guide plates and with guide plates. Regular skewed airflow was formed through introducing guide plates, which improved the internal flow field significantly.
A Network Intrusion Detection Model Based on Artificial Immune
Authors: Xiao Xin , Zhang Rui Rui
Published: October 2011

For the existing artificial immune systems applied to network intrusion detection have some shortages, an improved network intrusion detection model based on the dynamic clone selection algorithm which was put forward by Kim is proposed. The model introduces the concept of self group, which is obtained by the clustering algorithm AiNet and represents common features of normal data. The self group deals with network data before they are tested by detectors. In addition, the model adopts a design of distributed network intrusion detection, and a central server manages all the immune cells, receives vaccines and vaccinats the whole network detection hosts. Experimental results show that the number of selves and detectors are reduced, the process of affinity maturation for the detector population is speeded up, and the model achieves higher detection rate and lower false positive rate with the evolution generation increases.
Effect of Fluid inside Casing on Resistivity Logging Response through Casing
Authors: Liu Fu Ping , Wang An Ling , Zhang Ming Chang
Published: October 2011

With the help of the transmission line measure method of formation resistivity through casing, we have presented a calculated approach of potential distribution on the metal casing and in the fluid inside casing, realized the calculation of the resistivity logging response(RLR)of formation, and made inspection for two measure methods of formation resistivity. The numerical computing results show that the fluid in casing hardly has influence on the RLR of formation, but, when there are different kinds of fluids in casing, the interface of fluids has an obvious logging response for RLTA, and the response range of fluid interface is about the length of tool electrode spacing. The calculating examples also show that the measure and computation methods of formation resistivity for logging response have a larger effect when inside casing with fluid.
Identiﬁcation and Characteristics of Lactic Acid Bacteria Isolated from Stylosanthes guianensis sw.
Authors: Zhai Hai Rui , Zhou Han Lin , Yang Jin Song , Wang Qian , Tan Hai Sheng , Li Mao , Cai Yi Min
Published: October 2011

Four lactic acid bacteria (LAB) strains named HN78, HN87, HN91 and HN113 were separated fromStylosanthes guianensis SW. of Hainan province, which were identified bacterially using the classical classification and the sequences of 16S rDNA. The results showed that four strains wereEnterococcus hirae,Enterococcus faecalis,Lactococcus lactisandLactobacillus plantarum. The capability of lactic acid production of HN113 and HN91 were better than HN78 and HN87.
Experimental Study on the Temperature Variation of a New Tobacco Curing Barn with Double-Way Ventilation
Authors: Fang Shun Li , Jin Shi Ping , Huang Su Yi , Wen Wu Qi , Li Yue Ping
Published: October 2011

In China, there is a vast area of tobacco producing, and the production condition in various regions is different. It is difficult for the traditional bulk tobacco curing barns with air rising to adjust the area with all conditions, and the intrinsic quality of cured tobacco is difficult to guarantee. We study on a new tobacco curing barn with double-way ventilation, and we analyze its performance through experiments. We tested the change of the temperature field in both the new tobacco curing barn with double-way ventilation and the traditional tobacco curing barn with air rising, the result shows: (1) Air moves in the new tobacco curing barn with double-way ventilation from top to bottom, compared with the traditional bulk tobacco curing barn with air rising, the new tobacco curing barn has a smaller amount of airflow, and it also has a small temperature difference on the same horizontal plane and a reasonable temperature difference on vertical direction, this is good for the curing of different maturity tobacco leaves; (2) Fuel of the new tobacco curing barn with double-way ventilation is one-time added, so the heat supply is stable, and the temperature changes quite gentle, but fuel of the traditional tobacco curing barn with air rising is many-time added, the temperature changes dramatic. (3) The new tobacco curing barn with double-way ventilation has forced ventilation channel and enhanced moisture channel to strengthen the ability of natural ventilation, so when power outages and other emergency situations happen, there is natural air convection in the tobacco curing barn, but the simple tobacco curing barn with air rising totally could not avoid the harm caused by power outages and other emergency situations. This research could provide reference for the design and application of new curing barn later.
Analysis of Aquathermal Pressuring Based on Equation of Liquid State
Authors: Guo Zhi Feng , Liu Zhen , Fang Da Zhi , Lin Lu , Chen Jie
Published: October 2011

Mechanisms of overpressure generation is key issue for fluid dynamics and hydrocarbon accumulation in sedimentary basin exploration. The contribution of aquathermal pressuring to overpressure generation is always focus problem. The equation of liquid state would describe internal relations of temperature, pressure and volume of pore fluid in thermodynamic system. The contribution ratio of overpressure generation by auqathermal pressuring and undercompaction based on equation of liquid state would obtain quantitative assessment of these two geological processes leading to generation of overpressure. The contribution ratio was expressed by function of formation porosity and temperature. The mechanism of overpressure generation of well ST36-1-1 was studied by this method, which developed overpressure in Qiongdongnan basin of northern South China Sea, research shows that contribution of overpressure generation from auqathermal pressuring is treble of undercompaction, and with increasing of formation porosity, contribution of auqathermal pressuring would increases gradually comparing with undercompaction
Knowledge Spillovers, Absorptivecapacity, Technology Innovation and Agricultural Network Structure
Authors: Wang Yan Rong , Liu Ye Zheng
Published: October 2011

From the perspective of agricultural cluster to explore network structure, knowledge spillovers, absorptive capacity for technical innovation of the agglomeration. Studies have shown that dense network structure will enhance the knowledge spillovers and promote the actual absorptive capacity of agriculture cluster members, absorptive capacity is conducive to the enhancement of knowledge diffusion, the network structure, knowledge spillovers and absorptive capacity is directly related to agricultural technology innovation.
Optimization of Processing Parameters for the Blitzkrieg Extraction of Noni (Morinda citrifolia L) Seed Oil
Authors: Bai Xin Peng , Zhao Xiao Lei , Guo Zhi Yong , Liu Xiao Qin
Published: October 2011

A simple and rapid blitzkrieg extraction procedure has been developed and optimized for hexane extraction yield from the noni (Morinda citrifolia L) seed. Several variables that could potentially affect the extraction efficiency, namely, solid: liquid ratio (g /mL), blitzkrieg extraction voltage (V), extracting time (s) have been optimized by means of response surface methodology (RSM). The optimum conditions were the ratio of material to liquid 95g/500mL, blitzkrieg extraction voltage 148V and extracting time 79s. Under the optimum operating conditions, the extraction yield was 10.42 %, a drastic reduction of the blitzkrieg extraction time (79 s vs. 8 h) was achieved, comparable with the reflux extraction.
Current Situation of Tight Sand Gas in China
Authors: Li Shi Zhen , Qiao De Wu
Published: October 2011

Unconventional natural gas because of a huge amount of resources has been received extensive attention in the world. Based on the present technology in China, tight sand gas as one type of unconventional gas, has become the most realistic energy resources, and has reached a certain development scale. Low porosity and permeability of tight sand gas reservoirs are widely distributed in China's major basins, the proved reserves of tight sand gas reservoirs in the proportion of reserves increases significantly year by year. Tight sand gas exploration in unconventional natural gas is most realistic, the concept of tight sand gas, reservoir characteristics, formation mechanism of unconventional tight sand gas, distribution in China are reviewed in the essay, exploration direction and some suggestions are pointed out at the end.
Interactive Effects of Salinity and Elevated CO2 on Ecophysiological Function of Euhalophyte Suaeda salsa
Authors: Han Zhao Xiang , Han Gui Quan , Meng Zhang , Lv Chun Xia
Published: October 2011

This study was aimed at obtaining detailed information about the interaction of NaCl salinity and elevated atmospheric CO2concentration in the halophyte S.salsa, which was irrigated with five different salinity levels under ambient and elevated (530 ppm) CO2. The results show that total soluble sugar concentration was significantly increased by salt-treatments in both leaves and roots, and that the most progressive sugar increments were observed in leaves and roots of S. salsa under the elevated CO2. The Na+ concentration in the leaves and roots increased with the increased NaCl concentration, the K+ accumulation gradually decreaed by increasing salinity levels in leaves and roots. Proline increased in response to salt stress along with incremental NaCl concentration. The GB concentrations of leaves were significantly raised as NaCl levels increased. Electrolyte leakage increased in the leaves of S. salsa grown under NaCl stress. ψs of leaves and roots decreased as the NaCl concentration increase, and that elevated CO2both had markedly greater effects on ψs of leaves and roots. The osmotic adjustment values ascended with elevated CO2concentration in both leaves and roots.
Promotional Effect of Cr on Catalytic Performance of Fe/γ-Al2O3 for Ethylbenzene Dehydrogenation in the Presence of N2O
Authors: Chen Shu Wei , Jia Xiao Fei , Cui Xing Yu , Li Rui Feng
Published: October 2011

This work shows that N2O, which causes global warming, could be effectively utilized as a soft oxidant in the oxidative dehydrogenation of ethylbenzene over alumina-supported iron oxide catalysts. The modification of the catalytically active iron oxide component with appropriate amounts of chromium oxide led to higher styrene yield (48.1%) with high styrene selectivity ( > 90%) at 500 °C and suppressed the catalyst deactivation for EB dehydrogenation under N2O. The improved catalytic behavior was attributed to the enhanced dispersion and redox properties of iron active species.
The Study of Renewable Oceanic Energy Used on Island
Authors: Wang De Gang , Yang Yi Ju , Tan Yong Hua , Yu Miao
Published: October 2011

Due to the unique geographic location and natural environment, island energy supply seems complicated. But the stored oceanic energy around island makes important practical significance to maintain island energy sustainable usage. This paper explored main oceanic energy category, its distribution and reserves based on the status of oceanic energy usage, and also summarized the three main factors which restrict island oceanic energy usage-technique and cost, ecological environment and national planning. Then, the paper gives suggestion on island oceanic energy development and forecasts the future of island oceanic energy usage.
Research on the Energy Consumption Structure Based on Low Carbon Economy in China
Authors: Wang Feng Yun
Published: October 2011

As the biggest developing country in the world, with sustainable and fast development of economy, the fossil energy consumption and carbon emission increases so quickly that the problem of energy security and carbon emission is more and more prominent In China. Therefore, building the sustainable energy supply system and energy consumption mode is the important guarantee for constructing harmonious society. This paper analyses the status of the gross energy consumption and its structure change in China, and then researches the problems of the energy consumption structure. In the end, the paper puts forward the specific countermeasures on optimizing the energy consumption structure, such as striving to develop new energy, improving the using of energy efficiency, promoting the development of low-carbon economy and so on.
A New Method to Remove the Calcium and Magnesium from the Sea Water with CO2
Authors: Yu Hui , Gao Xue Li , Su Bao Wei , Gao Cong Jie
Published: October 2011

Sea water desalination methods are widely used. Thermal process and membrane process are the commonly used methods .However, both thermal and membrane processes are faced scaling trend. In this study, a new approach for the management of sea water and capture of CO2, where ammoniated sea water is reacted with carbon dioxide, has been investigated. The effects of reaction temperature, reaction time, and excess ammonia were assessed. The experimental results indicated that the optimum reaction temperature was about 20 °C and the optimum NH3H2O used amount was 4.8g/200ml. The results indicated that the new approach can reduce the sea water hardness and at the same time, contribute to reducing CO2 emissions.
Imaging Acute Appendicitis: State of the Art
Authors: Gaitini Diana
Published: October 2011

The goal of this review is to present the state of the art in imaging tests for the diagnosis of acute appendicitis. Relevant publications regarding performance and advantages/disadvantages of imaging modalities for the diagnosis of appendicitis in different clinical situations were reviewed. Articles were extracted from a computerized database (MEDLINE) with the following activated limits: Humans, English, core clinical journals, and published in the last five years. Reference lists of relevant studies were checked manually to identify additional, related articles. Ultrasound (US) examination should be the first imaging test performed, particularly among the pediatric and young adult populations, who represent the main targets for appendicitis, as well as in pregnant patients. A positive US examination for appendicitis or an alternative diagnosis of possible gastrointestinal or urological origin, or a negative US, either showing a normal appendix or presenting low clinical suspicion of appendicitis, should lead to a final diagnosis. A negative or indeterminate examination with a strong clinical suspicion of appendicitis should be followed by a computed tomography (CT) scan or alternatively, a magnetic resonanace imaging (MRI) scan in a pregnant patient. A second US examination in a patient with persistent symptoms, especially if the first one was performed by a less experienced imaging professional, is a valid alternative to a CT.
Moisture and dynamical interactions maintaining decoupled Arctic mixed-phase stratocumulus in the presence of a humidity inversion
Authors: Solomon A. , Shupe M. D. , Persson P. O. G. , Morrison H.
Published: October 2011

Abstract. Observations suggest that processes maintaining subtropical and Arctic stratocumulus differ, due to the different environments in which they occur. For example, specific humidity inversions (specific humidity increasing with height) are frequently observed to occur near cloud top coincident with temperature inversions in the Arctic, while they do not occur in the subtropics. In this study we use nested LES simulations of decoupled Arctic Mixed-Phase Stratocumulus (AMPS) clouds observed during the DOE Atmospheric Radiation Measurement Program's Indirect and SemiDirect Aerosol Campaign (ISDAC) to analyze budgets of water components, potential temperature, and turbulent kinetic energy. These analyses quantify the processes that maintain decoupled AMPS, including the role of humidity inversions. Key structural features include a shallow upper entrainment zone at cloud top that is located within the temperature and humidity inversions, a mixed layer driven by cloud-top cooling that extends from the base of the upper entrainment zone to below cloud base, and a lower entrainment zone at the base of the mixed layer. The surface layer below the lower entrainment zone is decoupled from the cloud mixed-layer system. Budget results show that cloud liquid water is maintained in the upper entrainment zone near cloud top (within a temperature and humidity inversion) due to a down gradient transport of water vapor by turbulent fluxes into the cloud layer from above and direct condensation forced by radiative cooling. Liquid water is generated in the updraft portions of the mixed-layer eddies below cloud top by buoyant destabilization. These processes cause at least 20% of the cloud liquid water to extend into the inversion. The redistribution of water vapor from the top of the humidity inversion to its base maintains the cloud layer, while the mixed layer-entrainment zone system is continually losing total water. In this decoupled system, the humidity inversion is the only source of water vapor for the cloud system, since water vapor from the surface layer is not efficiently transported into the mixed layer. Sedimentation of ice is the dominant sink of moisture from the mixed layer.
Temporal co-registration for TROPOMI cloud clearing
Authors: Genkova I. , Robaidek J. , Roebeling R. , Sneep M. , Veefkind P.
Published: October 2011

Abstract. The TROPOspheric Monitoring Instrument (TROPOMI) is planed for launch in 2014 on board of the Sentinel 5 Precursor (S5P) and is anticipated to provide high-quality and timely information on the global atmospheric composition for climate and air quality applications. TROPOMI will observe key atmospheric constituents such as ozone, nitrogen dioxide, sulfur dioxide, carbon monoxide, methane, formaldehyde and aerosol properties. The retrieval algorithms for the anticipated products require cloud information on a pixel basis. Most of them will use the cloud properties derived from TROPOMI's own measurements, such as the O2 A-band measurements. However, the methane and the aerosol retrievals require very precise cloud clearing, which is difficult to achieve at the TROPOMI spatial resolution (7 × 7 km2) and without thermal IR measurements. The current payload of the Sentinel 5 Precursor (S-5P) does not include a cloud imager, thus it is planned to fly the S5P mission in a constellation with another instrument yielding an accurate cloud mask. The cloud imagery data will be provided by the US NPOESS Preparatory Project (NPP) mission which will have the Visible Infrared Imager Radiometer Suite (VIIRS) on board (Scalione, 2004). VIIRS will have 22 bands in the VIS and IR spectral ranges, and will deliver data with two spatial resolutions: imagery resolution bands with a nominal pixel size of 370 m at nadir, and moderate resolution bands with nominal pixel size 740 m at nadir. The instrument is combining fine spatial resolution with high-accuracy calibration similar or superior to AVHRR. This paper presents results from investigating the temporal co-registration requirements for suitable time differences between the VIIRS measurements of clouds and the TROPOMI methane and aerosol measurements, so that the former could be used for cloud clearing. The temporal co-registration is studied using Meteosat Second Generation (MSG) Spinning Enhanced Visible and Infrared Imager (SEVIRI) data with 15 min temporal resolution (Veefkind, 2008a), and with data from the Geostationary Operational Environmental Satellite-10 (GOES-10) having 1 min temporal resolution. The aim is to understand and assess the relation between the amount of allowed cloud contamination and the required time difference between the two satellites' overflights. Quantitative analysis shows that a time difference of approximately 5 min is sufficient (in most conditions) to use the cloud information from the first instrument for cloud clearing in the retrievals using data from the second instrument. In recent years the A-train constellation demonstrated the benefit of flying satellites in formation. Therefore this study's findings will be useful and applicable for designing future Low Earth Orbit (LEO) satellite constellations.
Forest cover influence on regional flood frequency assessment in Mediterranean catchments
Authors: Preti F. , Forzieri G. , Chirico G. B.
Published: October 2011

Abstract. The paper aims at evaluating to what extent the forest cover can explain the component of runoff coefficient as defined in a regional flood frequency analysis based on the application of the rational formula coupled with a regional model of the annual maximum rainfall depths. The analysis is addressed to evaluate the component of the runoff coefficient which cannot be captured by the catchment lithology alone. Data mining is performed on 75 catchments distributed from South to Central Italy. Cluster and correlation structure analyses are conducted for distinguishing forest cover effects within catchments characterized by hydro-morphological similarities. We propose to improve the prediction of the runoff coefficient by a linear regression model, exploiting the ratio of the forest cover to the catchment critical rainfall depth as dependent variable. The proposed regression enables a significant bias correction of the runoff coefficient, particularly for those small mountainous catchments, characterised by larger forest cover fraction and lower critical rainfall depth.
A Scalable GeoWeb Tool for Argumentation Mapping
Authors: Sani Aaron , Rinner Claus
Published: October 2011

Public participation geographic information systems (PPGIS) support collaborative decision-making in the public realm. PPGIS provide advanced communication, deliberation, and conflict resolution mecha nisms to engage diverse stakeholder groups. Many of the functional characteristics of Web 2.0 echo basic PPGIS functions including the authoring, linking, and sharing of volunteered geographic information. However, with the increasing popularity of geospatial applications on the Web comes a need to develop concepts for scalable, reliable, and easy-to-maintain tools. In this paper, we propose a cloud computing implementation of a scalable argumentation mapping tool. The tool also illustrates the opportunities of applying a Web 2.0 model to PPGIS. The searching, linking, authoring, tagging, extension, and signalling (SLATES) functions are associated with PPGIS functionality to produce a participatory GeoWeb tool for deliberative democracy.
Engineering Surveying for the Construction of Railway Tunnels in Hong Kong
Authors: Lam Steve , Chan Albert
Published: October 2011

This paper provides an overview of the accuracy standards, specifications, and recent advances of engineering survey operations for the design and construction of railway tunnels in Hong Kong. It covers geodetic control, deformation monitoring surveys, detail mapping, geometric modelling, setting-out, asbuilt surveys and total quality management (TQM). Recent advances include an integrative approach to: (1) combine measurements collected by geodetic and geotechnical systems including interferometric synthetic aperture radar (InSAR) in monitoring ground displacements and structural deformation at local and regional scales; (2) map geospatial data into computer aided design (CAD) formats and geographic information systems (GIS) by both conventional and mobile surveying systems; (3) collect as-built data of railway tracks and tunnels by positioning instruments, track sensors and laser scanners together; (4) incorporate Outsource Plan into the TQM system under ISO 9001:2008.
Interventions to Prevent Falls in Older Adults
Authors: Guirguis-Blake Janelle M. , Perdue Leslie A. , Coppola Erin L. , Bean Sarah I.
Published: June 2024

Importance

Falls are the most common cause of injury-related morbidity and mortality in older adults.

Objective

To systematically review evidence on the effectiveness and harms of fall prevention interventions in community-dwelling older adults.

Data Sources

MEDLINE, Cumulative Index for Nursing and Allied Health Literature, and Cochrane Central Register of Controlled Clinical Trials for relevant English-language literature published between January 1, 2016, and May 8, 2023, with ongoing surveillance through March 22, 2024.

Study Selection

Randomized clinical trials of interventions to prevent falls in community-dwelling adults 65 years or older.

Data Extraction and Synthesis

Critical appraisal and data abstraction by 2 independent reviewers. Random-effects meta-analyses with Knapp-Hartung adjustment.

Main Outcomes and Measures

Falls, injurious falls, fall-related fractures, hospitalizations or emergency department visits, people with 1 or more falls, people with injurious falls, people with fall-related fractures, and harms.

Results

Eighty-three fair- to good-quality randomized clinical trials (n = 48 839) examined the effectiveness of 6 fall prevention interventions in older adults. This article focuses on the 2 most studied intervention types: multifactorial (28 studies; n = 27 784) and exercise (37 studies; n = 16 117) interventions. Multifactorial interventions were associated with a statistically significant reduction in falls (incidence rate ratio [IRR], 0.84 [95% CI, 0.74-0.95]) but not a statistically significant reduction in individual risk of 1 or more falls (relative risk [RR], 0.96 [95% CI, 0.91-1.02]), injurious falls (IRR, 0.92 [95% CI, 0.84-1.01]), fall-related fractures (IRR, 1.01 [95% CI, 0.81-1.26]), individual risk of injurious falls (RR, 0.92 [95% CI, 0.83-1.02]), or individual risk of fall-related fractures (RR, 0.86 [95% CI, 0.60-1.24]). Exercise interventions were associated with statistically significant reductions in falls (IRR, 0.85 [95% CI, 0.75-0.96]), individual risk of 1 or more falls (RR, 0.92 [95% CI, 0.87-0.98]), and injurious falls (IRR, 0.84 [95% CI, 0.74-0.95]) but not individual risk of injurious falls (RR, 0.90 [95% CI, 0.79-1.02]). Harms associated with multifactorial and exercise interventions were not well reported and were generally rare, minor musculoskeletal symptoms associated with exercise.

Conclusions and Relevance

Multifactorial and exercise interventions were associated with reduced falls in multiple good-quality trials. Exercise demonstrated the most consistent statistically significant benefit across multiple fall-related outcomes.