bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on design method of composite arch-cover excavation for super shallow-buried long-span metro station
Authors: Jiang Qichen , Li Kexian , Liu Peng , Wang Zhenjun
Published: November 2019

Arch-cover method is an effective construction method in upper-soft lower-hard strata, but its applicability in large-span excavation is still problematic. Based on a large-span and super-shallow-buried underground station excavation project of Qingdao Metro, a composite arch-cover method featured with double-layer lining and two-lining was proposed. The whole process of arch-cover excavation was simulated by finite difference method FLAC2D, and the evolution law of structural stress and stratum deformation were obtained. The results show that the stress of the arch cover can be evenly distributed by the interaction of the inner and outer lining, and the formation of concentrated stress zone can be avoided. The bearing capacity of arch cover can be improved, and the generation of lining cracks can be effectively reduced. Stress at the skewback of composite arch cover method should be strengthened. The maximum stress and displacement of rock and soil in the upper part of the station cavern should occur in the process of removing the middle pillar and applying the second initial support. Correspondingly, the monitoring frequency should be increased, and the support should be timely processed. This method is reasonable and feasible, and can provide reference for similar projects.
Nonlinear buckling analysis of arch structure to initial defect sensitivity
Authors: Yang Fan , Feng Tao , Xie Yan
Published: November 2019

Due to the more and more prominent nonlinear buckling problems of large-span arch structures in engineering applications, and the lack of special design methods of large-span arch structures in existing specifications, this paper establishes a simplified mechanical model for the stability of arch structures with initial geometric defects. The finite element model of arch structure is established by using finite element software, and the characteristic value buckling analysis and geometric nonlinear analysis are carried out to find out the buckling mode of arch structure, and the sensitivity of defects to arch structure is studied. The results show that the existence of defects will reduce the bearing capacity of the structure, and the increase of defects will change the deformation form of the structure.
Static and dynamic analysis the influence of underlying tunnel construction on surrounding rock of existing tunnel-type anchorages
Authors: Lianbin Wang , Dayong Shu
Published: November 2019

Due to the constraints of construction period and site conditions, it is necessary to study the influence of construction of underlying tunnel on the surrounding rock of the existing tunnel-type anchorages. Through static excavation and dynamic blasting, this paper systematically analyzes the influence of underpass tunnel construction on the surrounding rock of the tunnel-type anchorages from the aspects of stress, deformation, plastic zone, velocity and loose circle of the surrounding rock. The results show that the effect of excavation of underlying tunnel on the maximum principal stress around the tunnel-type anchorages is small. The maximum relative displacement of the tunnel-type anchorages is smaller than the allowable relative displacement of the code. The distribution of plastic zone around the tunnel-type anchorages is not affected by the excavation of underlying tunnel. When underlying tunnel blasting, the peak velocity of monitoring points of the top arch in each section of the right underlying tunnel is largest. From the area closer to the explosion source to the far area, the reduction of peak velocity in all directions is large. Based on the elasto-plastic theory, Hoek-Brown strength criterion is used to calculate the thickness of the loose circle.
Beam-Truss Model of Steel-Concrete Composite Box-Girder Bridges I: theory and calculation
Authors: Liu Ang , Zhang Zhen-Dong , Li Xuan , Ma Guan-Ling
Published: November 2019

In this paper, modeling strategy for member and section level is firstly established based on shear-flexible grillage theory cellular decks. In addition, modal analysis and static analysis under the dead and live load are conducted for composite simply supported and continuous box girder bridges, the alignment of which includes straight and curve. High accuracy and good applicability of beam-truss model of composite box-girder bridge can be verified due to good correlation of numerical results between elaborate and beam FE model. The research in this paper has laid the foundation for the further application of beam-truss models in the design analysis of actual composite box-girder bridge.
Mechanics of Inhomogeneous Deformation of Concrete Pavement under Temperature Effect
Authors: Nan Chen
Published: November 2019

For the concrete pavement, it has a significant characteristics of Principle of Expand on Heating and Contract on Cooling, which probably causes a bending stress for the slabs. The temperature of upper slab waves a lot rather than the lower part for the effect of fluctuation of environmental temperature. And inhomogeneous deformation of the slab will be caused by the temperature difference, which relates to several typical defects of the concrete pavement. A theoretical analysis as well as a numerical analysis have been made in this paper. According to result of the numerical simulation, the maximum voiding length cmax is 2.176mm. And the result of theoretical analysis is 2.343mm. The error of both results is 7.12%, which proved the reliability of both methods.
Study on Sunshine Temperature Field of Concrete Box Girder Based on Meteorological Parameters
Authors: Lv Shuangshuang , Zhu Liming , Xing Shiling , Wang Chenglong
Published: November 2019

In order to analyze the variation law of sunshine temperature field of low height concrete box girder, Tangshan second ring road cable-stayed bridge was used as the engineering background, the finite element method combined with the field temperature measurement is used to analyze the sunshine temperature field of the concrete box girder by using the weather observation data at the bridge site. The results show that: the temperature field of sunshine in the box girder can be directly analyzed using the meteorological observation data at the bridge site, and the calculation precision can meet the engineering requirements.
Study on Surface Vibration Characteristics of Composite Shallow-buried Tunnel Blasting Construction
Authors: Wu Bo , Lan Yangbin , Peng Yiyong , Meng Guowang , Wei Han
Published: November 2019

Based on the background of the construction of the mining section at the southern end of Yangli Station of Fuzhou Metro Line 2 project, in order to study the ground surface vibration law during the blasting construction of tunnels in the upper soft and lower hard composite strata, the vibration velocity data were obtained through field tests, and the traditional and modified Sadowski formulas were used to fit and analyze the vibration velocity respectively, which were verified by numerical simulation. The results show that under the condition of composite stratum, the peak value of radial vibration velocity of blasting construction on the surface of cave-forming area is the largest, and the peak value of vertical vibration velocity on the surface of non-cave-forming area is the largest; the ground vibration of shallow-buried tunnel excavation area in composite stratum has void effect, and the larger the distance between the blasting centers, the more obvious the void effect; the fitting degree of traditional Sadowski formula is lower than that of modified Sadowski formula V=KQaRb
; because of the existence of soft-hard interface, the attenuation rate of vertical vibration velocity is the sharpest relative to the radial and tangential vibration velocities on the surface of composite shallow-buried tunnels. At the same time, the feasibility of numerical software to simulate such engineering blasting construction is verified.
Nonlinear Finite Element Analysis of CSGR Dyke Engineering on Soft Foundation
Authors: Wang Sha , Jia Jinsheng , Yang Huichen , Zheng Cuiying
Published: November 2019

In order to obtain the optimal section of the cemented sand, gravel and rock (CSGR) dyke on the soft foundation of sand and gravel, this paper designs three different plans to analyze the vertical normal stress of the foundation, comprehensive stability, settlement, maximum and minimum principal stresses, and the foundation stress by adopting the finite element method and the finite element equivalent stress method. Based on the finite element calculation results of the optimal plan, this paper analyzes the safety situation of various parts of the dyke and proposes engineering measures accordingly. Sensitivity analysis of the soft foundation parameters shows that the foundation parameters have a great influence on the stress and deformation of the fending groyne and the seepage proof wall. The analysis in this paper can provide some reference for the design of similar projects.
Research on simulation of anchor concrete frame beam reinforcement in slope
Authors: Tian Xiao , Meng Jiangpeng , Wang Zhaokun
Published: November 2019

The anchor concrete frame beam is a kind of slope protection structure. Based on the project of a road cutting slope from Havelian to Thakot highway in China-Pakistan Economic Corridor, the reinforced effect of anchor concrete frame beam is studied by using the strength reduction finite element method. The safety coefficents are obtained from the stability analysis of slopes with different coefficents in similar geo-environmental settings. The results show that the anchor concrete frame beam can decrease the horizontal displacement significantlly and increase the slope stability. The slope stability reduces as the slope coefficent increases in the same engineering settings. The results can provide reference for the design and construction in the project of high road cutting slope.
Research on sustainable development of construction industry
Authors: Zhao Weiwei , Ye Ruyi
Published: November 2019

In recent years, with the emergence of ecological environment crisis, the topic of sustainable development has attracted people’s attention, and it is also the common goal. With the rapid development of the construction industry, there are many problems to be solved because of the lack of social responsibility. For example, frequent engineering quality and safety accidents, huge resource consumption, inadequate utilization of construction waste, and so on. These actions of construction enterprises not only harm the interests of stakeholder, but also seriously disrupt the order of the construction market. With the improvement of social transparency and the enhancement of citizens’ awareness of safeguarding their rights, the voice of society requiring construction enterprises to fulfill their social responsibilities is rising day by day. From the view of social responsibility, this paper puts forward some suggestions on promoting the sustainable development of construction industry in the aspects of organizational governance, the environment protection, labor practice and so on.
Review of Studies on Risk Early Warning of Public-Private Partnership Projects in Characteristic Town
Authors: Lai Yihong , Wu Shulian
Published: November 2019

Under the new normal background of China’s economy, the construction of characteristic towns is of great significance for promoting the supply-side reform and also the sustainable development of regional economy. In recent years, the construction of characteristic towns is in full swing, and the PPP financing–model has been introduced to various places due to the difficulty of financing. However, the projects combining a characteristic town with a PPP model are more likely to create risks. Based on literature analysis, this paper summarized the current status of risk identification, risk assessment and risk early warning research of PPP infrastructure projects, in order to draw on the existing research results, construct a theoretical framework for risk analysis and early warning of PPP projects in characteristic towns, which might benefit the future research.
Research on Restoring Force Model of Prefabricated Concrete Beam-column Joint
Authors: Shufeng Li , Qingning Li , Di Zhao , Jiaolei Zhang , Dawei Yuan , Huajing Zhao
Published: November 2019

Starting from the research of fabricated concrete frame structure system, the bolt-end plate connection applied in the steel structure and the combined structure is extended into the reinforced concrete structure to form a frame structure with a high-strength bolt-end plate connection. The quasi-static test was carried out. The test results show that the nodes exhibit good ductility and energy dissipation. In order to further explore the seismic performance of this type of structure, according to the experimental fitting method and the “fixed point pointing” law, on the basis of the skeleton curve’ s dimensionless treatment, the resilience model of this kind of nodes is established, and compared with the experimental results, the two agree well, which can be provides a certain reference for elasto-plastic seismic response analysis of this type of structure.
Study on Recycled Concrete Powders as Mineral Admixture in Recycled Concrete
Authors: Chen Xi , Li Ying , Kang Xiaoming , Fan Yaohu
Published: November 2019

The process of recycling waste concrete generated fine powders with a particle size of less than 0.16mm; it contains a large amount of hardened cement and unhydrated cement and has high activity. In order to meet the requirement of sustainable development in concrete industry, this study aims to improve the recycle use level of these fine powders in concrete. First, the properties of the recycled concrete powder were analyzed, and compared with one normal mineral admixture such as fly ash. Then the workability and compressive strength test of the concrete which mixed by different replacement ratio of the recycled concrete powder and fly ash were performed. The results show that the the content of SiO2 in recycled concrete powder is more than cement and fly ash. The replacement rate of RCP has little influence on the slump of fresh recycled concrete compared to fly ash. When the replacement rate of the recycled concrete powder is 20 %, the compressive strength of corresponding concrete at each age is close to that of control concrete, especially at 56d, the compressive strength of concrete reach to 90% of that of control concrete. So the application of the recycled concrete powder can save cement and has certain environmental and economic benefits.
Study on Limit Scouring of Maliuzhou Waterway: A Case Study of the Cross Gate Tunnel Project
Authors: Huang Pengfei , Wang Hua , Wu Tiansheng , Wang Hua
Published: November 2019

Based on the analysis of the water and sediment characteristics of the Maliuzhou Waterway, this paper establishes a local physical model near the project and a mathematical model of two-dimensional tidal sediment with reasonable hydro-logical and sediment parameters of river scouring so as to simulate the river scouring under the extreme conditions of the Maliuzhou Waterway. Based on the calculation results, this paper divides the fracture surface and longitudinal section of the river near the project and analyzes its fracture surface, section and channel layout so as to explore the characteristics of the river scouring under the extreme conditions of the Maliuzhou Waterway. This study shows that under extreme conditions, the deepest scouring of the Maliuzhou Waterway is in the main channel, and the hydrodynamic axis and the talweg of the river channel show little change.
The application of three new technologies in water remediation: taking Pearl River Delta as an analysis sample
Authors: Lu Wenyun
Published: November 2019

The problem of water pollution has always been a concern for people from all over the world. In recent years, due to the enhancement of people’s awareness of environmental protection and the rapid development of science and technology, the solution to water pollution has been put on the agenda. More and more water remediation technologies are constantly being discovered and applied in solving pollution. In this article, the author will give an introduction to three popular water remediation technologies which are Nanofibrous membrane, Biofiltration, and Electrodialysis remediation, discuss the advantages and disadvantages of them, as well as give suggestions to the real application of the three technologies taking Pearl River Delta as a sample.
Hydrological Simulation of Taizi River Basin with HSPF Model
Authors: Zhang Peiqi , Zhang Jing , Song Yongyu
Published: November 2019

With the development of economy and the increase of population, water resources are becoming more and more scarce. The total amount of water resources in the Taizi River Basin of Liaoning Province, China is 5.120 billion m3, and the per capita water resources amount is 845 m3. According to the United Nations standards, it is classified as a water shortage area.In order to better manage and protect water resources, this paper uses Hydrological Simulation Program-Fortran (HSPF) model to simulate runoff in the Taizi River Basin. The Parameter Estimation (PEST) procedure was used to calibrate the hydrological parameters. The results showed that the Nash-Sutcliffe efficiency (NSE) of the calibration period (2009-2011) was 0.78, the correlation coefficient (R2) was 0.89; the Nash-Sutcliffe efficiency of the validation period (2012-2013) was 0.68, and the correlation coefficient was 0.85. It indicates that the HSPF hydrological model has good applicability in the Taizi River basin which will provide useful reference for future modeling research.
Study on failure mechanism of red clay slope under dry and wet cycles
Authors: Wang Lei , Chen Kaisheng
Published: November 2019

In order to study the failure characteristics and mechanism of red clay slope under dry-wet cycling conditions, a model slope similar to engineering slope was established. The test slope was monitored by testing elements, and the variation laws of moisture content, temperature, pore water pressure, soil pressure and displacement were analyzed respectively under the alternating conditions of dry-wet cycling. The failure characteristics and mechanism of slope are obtained. With the increase of dry-wet cycles, the overall water content of slope increases, pore water pressure decreases, lateral displacement increases, and vertical displacement remains unchanged to a certain extent. After five dry-wet cycles, the water content of the top and top of the slope is the largest, the water content of the bottom and foot of the slope is the smallest, the horizontal displacement of the slope is the largest, and the horizontal displacement of the top of the slope is the smallest. The range of temperature change increases with the number of dry-wet cycles, and tends to be stable after the third dry-wet cycle. The earth pressure is the largest at the top of the slope, followed by the foot of the slope and the smallest at the slope surface, and the first two dry-wet cycles have the greatest impact on the earth pressure. In the process of dry-wet cycling, the surface cracks of slope undergo the cyclic process of cracking, healing and re-cracking. The width and depth of cracks increase gradually. The surface failure characteristics represented by gully weathering and spalling gradually change into shallow failure characteristics represented by collapse and slump.
Integrated Water Quality Model and Its Application in Baihe River Basin
Authors: Ma Sijie , Zhang Jing , Song Yongyu
Published: November 2019

The integrated watershed water quality model is an important tool for studying the water environment of the basin. This study explores several comprehensive watershed water quality models, analyzes the development history, structural principle, characteristics and application of the model. This paper preliminary applied SWAT model in the Baihe River Basin, Beijing, China to analyze the water quality changes. Finally, this study briefly analyzes the development trend of the basin comprehensive water quality model.
Control of methane gas concentration in sewage tank reactor
Authors: Wu Xiaowu , Zhao Dongfang , You Xueyi
Published: November 2019

In order to solve the safety hazard of methane gas explosion in dry toilets, the control of methane gas concentration in sewage tank reactor was carried out. The numerical simulation method was applied to study the concentration field of methane gas in the dry septic tank reactor. The main influence parameters considered here are the ventilation pipe diameter and the fan pressure drop. The optimum ventilation condition found by Fluent software is that the diameter of ventilation pipe is 300 mm and the pressure drop of draining fan is 20 Pa.
Analysis of River System Structure and Runoff Evolution of Typical Section in Ziya River Plain
Authors: Si-yan Hou , He Xu , Li-feng Guo
Published: November 2019

In this study, by interpretation method, the density, quantity, length and variation of rivers in Ziya River Plainincreased in the 1960s and 1980s, mainly related to the excavation of small tributaries and canals. By comparing the series of years before and after 1980, the amount of surface water resources in the study area has decreased in the past 30 years. By using cumulative anomaly method and Kendall trend test method, it is found that the annual average runoff of typical cross-section decreases obviously, and the time series sudden change occurs in the late 1970s. The situation of the trunk runoff cut-off and drying-up caused by the river system structure and runoff evolution is evaluated, and the interannual evolution of the eco-hydrological system in Ziya River Plain is obtained.These can provide scientific support for water environment research and water ecological restoration in plain areas.
Fundamental Study on the Rapid Detection Method of Indoor Airborne Microbes and its Applicability to Food Plants for Quality and Safety Improvement
Authors: Liu Ze , Tanaka Takehiro
Published: November 2019

Airborne microbes are examined generally by sampling them on culture media and counting the number of their colonies formed. However, because it takes at least two days for bacteria to be cultivated and five days for fungi, reliable results may not be obtained for a time of need. Therefore, the development of a simple and quick detection method is required. A rapid detection method of indoor airborne microbes is examined and a fundamental study on its applicability to food plants for the purpose of improving quality and safety is introduced in this study.
The variation and influencing factors of the runoff and sediment entering sea in the Yellow River
Authors: Yan Cai
Published: November 2019

This paper analyzes the trend of runoff and sediment entering the Bohai Sea using the streamflow and sediment data of the Yellow River estuary hydrological station. The results shows that runoff and sediment into sea in the Yellow River both reduce in the recent 60 years, there is significant positive correlation between the two. And the influencing factors of runoff and sediment are also researched, it is found that there is no significant correlation between runoff and precipitation, or between sediment and precipitation. The increase of the water intake quantity from the river is the main reason of runoff reduction entering the sea. And soil and water conservation measures and water storage projects result in the decrease of sediment in the river estuary.
Research on monitoring and prevention technology of rock burst in junde coal mine
Authors: Jing Suolin , Jiang Pengfei , Huang Gang , He Xue , Zhang Jingkai
Published: November 2019

Rock burst, a dynamic phenomenon in coal mine, is a special manifestation form of the rock pressure. In brief, rock burst is a kind phenomenon of catastrophic failures of the coal and rock mass. Without any obvious macroscopic premonitory symptoms, a large amount of energy is released when the rock burst occurs, thus causing enormous casualties and equipment damages. Since 2004, rock burst accidents have occurred many times in Junde Coal Mine, resulting in damages of mining roadways, suspension of mining activities, or worse still, abandonment of mining roadways and casualties. Over these years, Junde Coal Mine has formed a set of systematic methods and measures which have achieved good result in filed practice.
Mining pressure analysis and accident prevention on deep working face
Authors: Jing Suolin , Jiang Pengfei , Huang Gang , He Xue , Zhang Jingkai
Published: November 2019

In recent years, with the increasing depth of coal mines, mining pressure accidents impose a serious threat to mining safety. Through the observation and analysis of the mining pressure of the 11301 fully-mechanized caving working face in Zhaolou Coal Mine. In the paper, the main factors affecting the mining pressure of deep working faces were identified, and combined the existing methods for selection of fully-mechanized supports and roof management technology, aiming to prevent mining pressure accidents in deep working face.
Factorial experiment of slope stability under slope-top loading and heavy rainfall
Authors: Feng Xu , Li Ming , Ma Pengjie , Li Yong
Published: November 2019

Because the slope-top loading and heavy rainfall are both important factors inducing slope landslides and another geologic hazard. it is necessary to analyze factorial experiment of the slope stability under the slope-top loading and heavy rainfall. Taking a lope engineering of a municipal roads as an example, the stability of the slope was calculated based on the strength reduction method with FEM and Midas-GTS (SRM), and then the double-factor factorial experiment with repeated tests was used to analyze the stability of the slope. The stability results show that, when rainfall conditions remain unchanged, the slope-top loading is applied, and the safety coefficient is reduced by 16%∼21%. When the slope-top loading remains unchanged and the rainfall is strengthened, the security coefficient decreases by 10%∼19%.The analysis shows that the maximum shear strain of the slope is significantly affected by the slope- top loading and rainfall on the top of the slope. The effect of the slope-top loading on the maximum horizontal displacement of the slope is not significant. The effect of heavy rainfall on the maximum displacement of slope is very significant. The combined effect of slope-top loading and heavy rainfall on the maximum horizontal displacement of the slope is significant. Generally speaking, heavy rainfall is the main factor affecting the slope safety. Under the interaction of two factors, the slope stability is poor. In the future, attention should be paid to some local projects such as slope drainage in landslide control and prevention.
Research Progress of Removal of Pollutants from Wastewater by Zero-valent Aluminum
Authors: Yang Jinhui , Li Chuanshu , Dai Yanghong , Yang Bin , Lei Zengjiang , Luo Yi
Published: November 2019

In recent years, the use of zero-valent metals (ZVMs) to treat environmental pollutants has been a research hotspot in the field of environment.Zero valent aluminium (ZVAl) has attracted much attention due to its lower redox potential and amphoteric properties (reaction pH can be extended to alkaline) than other metals. In this paper, zero-valent aluminium and its composite materials are used to treat pollutants in wastewater, including phenols, organic halides, azo dyes organic pollutants and perchlorate, Cr(VI), As(III) inorganic pollutants. The removal effect and reaction mechanism were also clarified. The existing problems and bottlenecks of this method are further discussed, and the development direction and application prospect of zero-valent metal aluminium redox technology are prospected.
The Study of Evaluation and Prediction of China’s Crude Oil’s Safety Based on the Degree of Foreign Dependence
Authors: Yong Zhu , Tong Chen
Published: November 2019

As the blood of industry, crude oil, to a large extent, determines the security and development of a country. China has been importing very much overseas crude oil for a long time, making it strongly necessary to study China’s crude oil safety. Therefore, based on the degree of foreign dependence, the regular curves of overseas import crude oil and China’s crude oil consumption are computed by numerical fitting to evaluate and predict the safety of China’s crude oil, and the results show that (1)the degree of foreign dependence of China’s crude oil is higher than the international average value, 20%, for a long time, and (2)it has exceeded the international high security warning line by 50% since 2009 and reached nearlly 70% at 2017, probably soaring to 90% in 2020. So, China’s overseas crude oil has been in a highly dangerous state for a long time. Therefore, it is necessary to reduce the degree of foreign dependence of China’s crude oil to improve the safety of China’s crude oil with the following aspects: (1)developing and making use of alternative green energy, and (2)improving the efficiency of crude oil utilization and strengthening secondary and multiple use of the crude oil.
Economic performance evaluation of an active solar heat storage-release system for heating Chinese Solar Greenhouses
Authors: Lu Wei , Zhang Yi , Fang Hui , Zhou Bo , Cheng Ruifeng , Yang Qichang
Published: November 2019

In this study, the economic and environmental performance of four active solar heat storage-release (AHS) systems compared with four other conventional heating systems (as practical options in northern China) were investigated in an experimental test of their ability to store energy during the daytime and heat a Chinese solar greenhouse (CSG) at night during the cold winter in northern China. The case-4 AHS performed best in terms of economic performance compared with the other three designs and four other conventional heating systems. However, future investigations of the long-term performance and environmental impact of AHS heating in greenhouses are needed and further improvements must be developed.
Effects of continuous grafting on nutrient absorption of cutting seedlings of Nasturtium officinale
Authors: Zheng Yangxia , Li Keqiang , Liao Ming’an , Lin Lijin
Published: November 2019

A pot experiment was conducted to study the effects of continuous grafting on nutrient absorption of cutting seedlings of Nasturtium officinale. The result showed that the N content of root, stem, leaf and shoot of N. officinale of one time grafting could significantly improve compared with the ungrafted. The content P and K of stem, leaf and shoot of N. officinale of one time grafting could significantly improve the content of P and K compared with the ungrafted. And N, P and K content in different parts of N. officinale of two times grafting and three times grafting was lower than the ungrafted. Therefore, the stem, leaf and shoot of N. officinale of one time grafting could significantly improve the nutrient absorption of cutting seedlings of N. officinale.
Evaluation of Energy Consumption Status and Energy-Saving Effect in the Industry of Transportation in China
Authors: Wang Chengjie , Zhang Yunpeng
Published: November 2019

This paper has analyzed the trends of total energy consutmption and energy consumption structure in the industy of transport in China since 2005. Energy saving quantity in the industry of transportation since the “11th Five-Year Plan” has been measured, combined with energy-saving policies and key energy-saving measurement introduced by the transportation industry, and based on the trend of energy consumption which are derived from the unit turnover and comprehensive turnover under the four modes of transportation of roads, railways, waterways and civil aviation since 2005.The research results provide a comprehensive and systematic analysis of energy consumption and energy saving in the industry of transportation, which provide reference for relevant research by government and related industry workers.
Preparation of VCAP/AMPS/DMDAAC/AM Quaternary Copolymer Filtrate Reducer for Drilling Fluids
Authors: Zhuang Wei , Wang Xin , Ma Zhongyong , Jiao Yongming , Wang Zhibin , Cao Weiqiang , Dai Zhiwen
Published: November 2019

It is difficult for existing filtrate reducer to meet oilfield application requirements. Based on the molecular structure design principle of temperature-resistant vinyl copolymer, a quaternary copolymer filtrate reducer has been developed with VCAP, AMPS, DMDAAC and AM as monomers through water solution copolymerization using redox initiation system. The optimum synthesis conditions were as follows: the mole ratio of monomer was VCAP/AMPS/DMDAAC/AM=1:1:1:9, reaction temperature was 70°C, reaction time was 6 h, initiator mass ratio was 0.2% and total monomer mass ratio was 20%. The filtration loss of base slurry with 1wt% optimum synthetic product after aging at 150 °C for 16 h was 5.2 mL.
Study on the flocculation condition of Poly-Silicate-Aluminum-Ferric (PSiAF) coagulant prepared with coal gangue as raw material
Authors: Yang Yuping , Zeng Furong , Zhao Qingcai , Zhang Yuanfei
Published: November 2019

Si, Al, Fe were leached from coal gangue to prepare Poly-silicate-aluminum-ferric (PSiAF) coagulant. The optimal dosage and the most adaptive pH value was explored when PSAF was used to treat simulated wastewater, simulated dyeing wastewater and domestic sewage respectively. The flocculation conditions of PSiAF were investigated with the removal efficiency of turbidity, CODCr or chrominance as the inspecting parameters. The experiment results show that, when PSiAF was usede to treat the three kinds of water sample, the optimal dosage is 1.2ml/L, and the most adaptive pH is 8 for simulation wastewater, under this condition, the turbidity removal ratio was 76.04%, the CODCr removal ratio was 58.33%. There is no decolorization effect for simulation dyeing wastewater, and PSiAF is not suitable for simulation dyeing wastewater. the optimal dosage is 8.0ml/L, and the most adaptive pH is 6 for domestic sewage, under this condition, the turbidity removal ratio was 67.25.04%, the CODCr removal ratio was 46.15%.
Preparation of Portland cement with high compressive and tensile strength by the synergistic effect between micron-size green silicon carbide and micro steel fiber
Authors: Li Hao , Shi Yongmin , Jiao Zhiyi , Chen Jiahui
Published: November 2019

A composite material was prepared with high compressive and tensile strength,which was composed primarily of Class G oil well cement,superfine cement,and microfine cement,using a simple mixing method.The compressive strength of the material was maintained by the micron-size green silicon carbide, and the tensile strength was enhanced by the micro steel fiber. The strength test results on day 28 showed that the compressive and tensile strength of the material increased from 44 MPa to 74 MPa and from 3.6 MPa to 18.3 MPa compared with the material without the addition of micron-size green silicon carbide. In addition, the composite material was characterized by various techniques, including scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric (TG) analysis, and measurement of physical adsorption porosity and specific surface area. We also analyzed the sliding contact angle and the work of adhesion of the material. We found that the micron-size green silicon carbide was adsorbed to the surface of calcium hydroxide (the hydration product of cement) by intermolecular forces. The hydration of cement in the later stage and the hardened structure of the cement were improved, thus increasing the strength of the cement.
Research Status of Polyvinyl Alcohol-Based Chelating Materials
Authors: Wu Qiang , Wang Yuansheng
Published: November 2019

This paper reviewed the research status of polyvinyl alcohol (PVA)-based chelating materials. The preparation methods of PVA chelating materials was introduced including graft copolymerization,blending precipitation, interpenetrating network crosslinking and mechanical melting. The adsorption characteristics of PVA chelating materials were analyzed while the development was proposed.
Effects of different drying conditions on volatile components of Pericarpium Arecae
Authors: Yuan Yuan , Liu Yang-yang , Gong Xiao , Zhou Wei
Published: November 2019

In the present study, the different drying temperatures and time on volatile components of Pericarpium Arecae (PA) were quantitatively and qualitatively analysed by headspace solid phase micro extraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS). The matching similarity retrieval libraries and retention index (RI) were used to characterize the unknown compounds; and the contents of each component were determined by internal standard method. Finally, the significance among groups was inspected by through ANOVA and Duncan’s multiple range tests. As the results showed, 23 main characteristic volatile compounds were separated and identified, including esters, organic acids, aldehydes, alcohols and alkaloids. It was found that drying at different temperatures had a great impact on esters, organic acids, aldehydes and alcohols. And there was a significant difference among the groups. Therefore, through the accurate qualitative and quantitative analysis of volatile components in PA dry products, it is helpful to evaluate and judge the whole process, and provide a theoretical basis for its further development and utilization.
Quantitative Identification of Urban Functional Areas in Downtown Area of Changchun Based on POI Data
Authors: Zhen Quan
Published: November 2019

In the information era, the distribution pattern of point of interest (POI) data points in urban space is of great reference significance in urban infrastructure planning and urban spatial analysis, providing a basis for studying the identification of urban functional areas. With the downtown area of Changchun as the research object, the POI data was quantified according to the classification of the urban functional areas, identifying the urban functional areas in the downtown area of Changchun. The experimental results were compared with the current urban land use maps in Changchun to demonstrate the feasibility of the experimental method. Compared with traditional methods, this method features fast analysis speed and digital attributes, which is of certain value for urban geospatial planning.
Semantic segmentation network of uav image based on improved U-net
Authors: Liu Ziyi , Huang Jin
Published: November 2019

The u-net, which is popular in the field of deep learning, is improved on the basis of the Fully Convolutional Network (FCN) [1]. U-net [2] was first published in the field of medical image, because the network has many advantages, so many scholars put their migration to use on the other computer vision problems, finding its on different problems still show the excellent performance. In this paper, U-net is applied to the problem of uav image processing, and the semantic segmentation of uav images at pixel level is carried out to identify the types of ground objects and the pixels contained in them. In order to increase the recognition accuracy of neural network, this paper proposes an improved network model based on u-net, and applies it to this problem. By training, verifying and testing the same small sample data set, it is found that the improved network has better recognition accuracy than U-net.
An Emerging Clone, Klebsiellapneumoniae Carbapenemase 2–Producing K. pneumoniae Sequence Type 16, Associated With High Mortality Rates in a CC258-Endemic Setting
Authors: Andrey Diego O , Pereira Dantas Priscila , Martins Willames B S , Marques De Carvalho Fabíola , Almeida Luiz Gonzaga Paula , Sands Kirsty , Portal Edward , Sauser Julien , Cayô Rodrigo , Nicolas Marisa F , Vasconcelos Ana Tereza R , Medeiros Eduardo A , Walsh Timothy R , Gales Ana C
Published: November 2019

Background

Carbapenemase-producing Klebsiella pneumoniae has become a global priority, not least in low- and middle-income countries. Here, we report the emergence and clinical impact of a novel Klebsiella pneumoniae carbapenemase–producing K. pneumoniae (KPC-KP) sequence type (ST) 16 clone in a clonal complex (CC) 258–endemic setting.

Methods

In a teaching Brazilian hospital, a retrospective cohort of adult KPC-KP bloodstream infection (BSI) cases (January 2014 to December 2016) was established to study the molecular epidemiology and its impact on outcome (30-day all-cause mortality). KPC-KP isolates underwent multilocus sequence typing. Survival analysis between ST/CC groups and risk factors for fatal outcome (logistic regression) were evaluated. Representative isolates underwent whole-genome sequencing and had their virulence tested in a Galleria larvae model.

Results

One hundred sixty-five unique KPC-KP BSI cases were identified. CC258 was predominant (66%), followed by ST16 (12%). The overall 30-day mortality rate was 60%; in contrast, 95% of ST16 cases were fatal. Patients’ severity scores were high and baseline clinical variables were not statistically different across STs. In multivariate analysis, ST16 (odds ratio [OR], 21.4; 95% confidence interval [CI], 2.3–202.8; P = .008) and septic shock (OR, 11.9; 95% CI, 4.2–34.1; P < .001) were independent risk factors for fatal outcome. The ST16 clone carried up to 14 resistance genes, including blaKPC-2 in an IncFIBpQIL plasmid, KL51 capsule, and yersiniabactin virulence determinants. The ST16 clone was highly pathogenic in the larvae model.

Conclusions

Mortality rates were high in this KPC-KP BSI cohort, where CC258 is endemic. An emerging ST16 clone was associated with high mortality. Our results suggest that even in endemic settings, highly virulent clones can rapidly emerge demanding constant monitoring.
Simultaneous Evaluation of Diagnostic Assays for Pharyngeal and Rectal Neisseria gonorrhoeae and Chlamydia trachomatis Using a Master Protocol
Authors: Doernberg Sarah B , Komarow Lauren , Tran Thuy Tien T , Sund Zoe , Pandori Mark W , Jensen David , Tsalik Ephraim L , Deal Carolyn D , Chambers Henry F , Fowler Vance G , Evans Scott R , Patel Robin , Klausner Jeffrey D
Published: November 2019

Background

Pharyngeal and rectal Neisseria gonorrhoeae and Chlamydia trachomatis play important roles in infection and antibacterial resistance transmission, but no US Food and Drug Administration (FDA)–cleared assays for detection at these sites existed prior to this study. The objective was to estimate performance of assays to detect those infections in pharyngeal and rectal specimens to support regulatory submission.

Methods

We performed a cross-sectional, single-visit study of adults seeking sexually transmitted infection testing at 9 clinics in 7 states. We collected pharyngeal and rectal swabs from participants. The primary outcome was positive and negative percent agreement for detection of N. gonorrhoeae and C. trachomatis for 3 investigational assays compared to a composite reference. Secondary outcomes included positivity as well as positive and negative predictive values and likelihood ratios. Subgroup analyses included outcomes by symptom status and sex.

Results

A total of 2598 participants (79% male) underwent testing. We observed N. gonorrhoeae positivity of 8.1% in the pharynx and 7.9% in the rectum and C. trachomatis positivity of 2.0% in the pharynx and 8.7% in the rectum. Positive percent agreement ranged from 84.8% to 96.5% for different anatomic site infection combinations, whereas negative percent agreement was 98.8% to 99.6%.

Conclusions

This study utilized a Master Protocol to generate diagnostic performance data for multiple assays from different manufacturers in a single study population, which ultimately supported first-in-class FDA clearance for extragenital assays. We observed very good positive percent agreement when compared to a composite reference method for the detection of both pharyngeal and rectal N. gonorrhoeae and C. trachomatis.

Clinical Trials Registration

NCT02870101.
Does Addition of Intravenous Metronidazole to Oral Vancomycin Improve Outcomes in Clostridioides difficile Infection?
Authors: Wang Ying , Schluger Aaron , Li Jianhua , Gomez-Simmonds Angela , Salmasian Hojjat , Freedberg Daniel E
Published: November 2019

Background

Guidelines recommend adding intravenous (IV) metronidazole to oral vancomycin for fulminant Clostridioides difficile infection (CDI). In this study, we compared dual therapy with IV metronidazole and vancomycin vs vancomycin monotherapy. We assessed prevalence of use and effectiveness of dual therapy in nonfulminant and fulminant CDI.

Methods

This was a 2-center retrospective study conducted from 2010 to 2018. Adult inpatients were included if they had a positive C. difficile polymerase chain reaction (PCR) performed on an unformed stool and received vancomycin within 2 days of testing. Patients were classified as having received dual therapy if IV metronidazole was given within the same time window, and otherwise classified as vancomycin monotherapy. The primary outcome was death or colectomy within 90 days after the index test. Logistic regression modeling was used to adjust for CDI severity and other established predictors of CDI outcomes. CDI recurrence was examined as a secondary outcome, adjusting for death as a competing risk.

Results

The study included 2114 patients (dual therapy, 993; monotherapy, 1121); 23% met the primary outcome. There was no association between dual therapy and the primary outcome (adjusted odds ratio [aOR], 1.07; 95% confidence interval [CI], .79–1.45), which remained true when the analysis was restricted to patients with fulminant CDI (aOR, 1.17; 95% CI, .65–2.10). There was also no association between dual therapy and CDI recurrence.

Conclusions

Dual therapy with IV metronidazole and vancomycin was common for nonfulminant and fulminant CDI but was not associated with improved outcomes compared with vancomycin alone.
BUILDING CAPACITY TO CARE FOR OLDER PEOPLE! HOW IS CARE OF THE OLDER PERSON TAUGHT IN AUSTRALIAN SCHOOLS OF NURSING?
Authors: Fetherstonhaugh Deirdre M , Rayner Jo-anne , Beattie Elizabeth , Harrington Ann , Jeon Yun-Hee , Moyle Wendy , Parker Deborah , Toye Chris
Published: November 2019

As the Australian population ages the demand for nursing care which focuses on responding to the needs of the older person will increase. Few newly graduated Registered Nurses (RNs) currently enter the aged care workforce and few select a career in caring for older people; yet older people are the largest patient group in most health care environments. This research, conducted by the Australian Hartford Consortium of Gerontological Nursing Excellence (Aus-HCGNE), explored how care of the older person is currently taught in Australian schools of nursing (SoN). The interview guide included questions about: whether care of the older person is taught in separate subjects or integrated across the curriculum; academics’ qualifications; subject content; and aged care clinical placements. The head of each of the 33 Australian schools of nursing was contacted, invited to participate and asked to nominate the appropriate academics (undergraduate/curriculum co-ordinators) who would be the most appropriate person to participate in the interview. These academics were then contacted, written informed consent was obtained, interviews were scheduled and completed. This research is timely given the current Royal Commission into Aged Care Quality and Safety in Australia, one focus of which is nurses in residential aged care in respect to numbers, education and competence. This research will be completed by mid-2019. The results will be fed back to SoN to inform the development of their curricula and the preparation of future RNs who will undoubtably need to be expert in the care of older people across the health sector.