mlsa-iai-msu-lab/ru_sci_bench_zho_cite_reranking huggingface dataset:
Regulation of Light Energy Utilization and Distribution of Photosynthesis in Five Subtropical Woody Plants

The adaptations and responses of photosynthesis to long- and short-term growth light gradient treatments were investigated in five subtropical forest plants, namely Pinus massoniana Lamb., Schima superba Gardn. et Champ., Castanopsis fissa (Champ. ex Benth.) Rehd. et Wils., Acmena acuminatissima (BI.) Merr et Perry, and Cryptocarya concinna Hance. With diurnal changes in sunlight and air temperature, the de-epoxidation state and lutein content in the five woody plants under three light intensifies first increased and then decreased during the day. However,maximal photochemical efficiency (F_v/F_m; where F_m is the maximum fluorescence yield and F_v is variable fluorescence) and the photochemical quantum yields of photosystem (PS) Ⅱ (Φ_(PSII)) of the species examined changed in the opposite manner, with those in plants grown under 100% natural light changing the most. After long-term treatment (21 months), anti-oxidant capacity (1,1-diphenyl-2-picrylhydrazyl radical (DPPH·)-scavenging capacity) and utilization of excitation energy showed differences in modulation by different light intensities. It was shown that A.acuminatissima and C. concinna, as dominant species in the late succession stage of a subtropical forest in Dinghu mountain, South China, were better able to adapt to different light environments. However, P. massoniana, the pioneer species of this forest, exhibited less adaptation to Iow light intensity and was definitely eliminated by the forest successlon process.
Simulation of Soil Organic Carbon Dynamics in Chinese Rice Paddies from 1980 to 2000

Changes in soil organic carbon (SOC) of rice paddies in China were simulated from 1980 to 2000 by linking a coupled bio-physical model to GIS database. The coupled model consists of two sub-models including Crop-C for simulating net primary productivity and hence residue retention and Soil-C for computing the turnover rates of SOC. The GIS database included parameters of climate, soils and agricultural activities with the resolution of 10 km × 10 km. Model simulation indicated that Chinese rice paddies covering 22.6 Mha sequestrated a considerable amount of C, about 0.15 ± 0.07 Pg C from 1980 to 2000. Annual sequestration rate increased sharply from -180 ± 45 kg C ha~(-1) year~(-1) in 1980 to 440 ± 170kg C ha~(-1) year~(-1) in 1989. Thereafter, a steady sequestration rate of 460 ± 170 kg C ha~(-1) year~(-1) occurred till 1994 and declined since then. Approximately 84% of the Chinese rice paddies sequestrated carbon, while 15% lost carbon and 1% kept balance over the 20 years. Great SOC sequestration occurred in eastern, southern and central China, while a slight decline of SOC existed in some regions of northeastern and southwestern China.
Assessment of Genetic Stability Among In Vitro Plants of Arachis retusa Using RAPD and AFLP Markers for Germplasm Preservation

Arachis retusa Krapov. et W. C. Gregory et Valls is endemic in the West-central region of Brazil, occurring in areas endangered by human actions. The establishment of in vitro preservation methods for wild species of Arachis isan alternative to seed banks for germplasm storage, multiplication and distribution. The risk of genetic changesinduced by tissue culture and the monitoring of the genetic stability of the biological material before, during andafter storage must be considered in the context of conservation. Random amplified polymorphic DNA (RAPD) andamplified fragment length polymorphism (AFLP) fingerprinting were used to evaluate the genetic stability of invitro plants originated from cotyledons and embryo axes of A. retusa. Cotyledons originated shoots through directorganogenesis and embryo axes displayed multishoot formation induced by 110 mmol/L and 8.8 mmol/L BAP,respectively. Ninety genomlc regions (loci) generated from RAPD and 372 from AFLP analyses were evaluated. Allamplified fragments detected by both techniques in plants derived from the two explant types were monomorphic.The results indicate that the recovered shoots are genetically stable at the assessed genomic regions.
Age Structure and Growth Pattern of an Endangered Species, Amentotaxus formosana Li

Amentotaxus formosana Li is a native, tolerant, and under-wood species in Taiwan. This particular species is only distributed around the Chachayalaishan and Dawushan areas. Because of its rarity, and the endangered and native properties of the species, we explored the regeneration process of the species in the native environment. This paper, therefore, aims to outline the age distribution and growth characteristics of A. formosana in the native stand using the techniques of tree ring analysis. An inventory was conducted in a site at the Chachayalaishan area from 2004 to 2006. According to the inventory, there are 67 trees in the sampling plot among which 16 individual A.formosana trees were counted. This is roughly 24% of the total population. This particular species is distributed around the understory space, while other species such as Litsea spp., Meliosma squamulata Hance, Schefflera octophylla Harms, Elaeocarpus japonicus Sieb et Zucc and Cleyera japonica Thunb are the major species whose canopy occupying the upperstory space of the stand. Results of tree-ring analysis suggest that the age of most of the trees in the sampling plot is between 31 and 90 years old with an average of 56. For the endangered species, A.formosana, age of the individuals varied from 14 and 126 years old and the average was 58 years old. Age distribution of the species was modeled using the Weibull probability density function and was statistically assessed using Sigmaplot statistical software. The estimate of shape parameter is 1.404 5 indicating a medium regeneration situation. The diameter growth rate of A. formosana is 0.32 cm and ranks 20th among the 26 species in the sampling plot. Using the age as a regressor variable, we can predict the diameter increment of A. formosana efficiently. The coefficient of determination, R~2, is 0.832 2. The diameter growth among the trees of the upperstory and understory was competitive. Relationship between the growth change percentage of A. formosana and the surrounding hardwoods is negative.
An Overview of the Biology of Reaction Wood Formation

Reaction wood possesses altered properties and performs the function of regulating a tree's form, but it is a serious defect in wood utility. Trees usually develop reaction wood in response to a gravistimulus. Reaction wood in gymnosperms is referred to as compression wood and develops on the lower side of leaning stems or branches.In arboreal, dicotyledonous angiosperms, however, it is called tension wood and is formed on the upper side of the leaning. Exploring the biology of reaction wood formation is of great value for the understanding of the wood differentiation mechanisms, cambial activity, gravitropism, and the systematics and evolution of plants. After giving an outline of the variety of wood and properties of reaction wood, this review lays emphasis on various stimuli for reaction wood induction and the extensive studies carried out so far on the roles of plant hormones in reaction wood formation. Inconsistent results have been reported for the effects of plant hormones. Both auxin and ethylene regulate the formation of compression wood in gymnosperms. However, the role of ethylene may be indirect as exogenous ethylene cannot induce compression wood formation. Tension wood formation is mainly regulated by auxin and gibberellin. Interactions among hormones and other substances may play important parts in the regulation of reaction wood formation.
Growth Rings of Roots in Perennial Forbs in Duolun Grassland, Inner Mongolia, China

Annual growth rings of roots in perennial forbs have been used in studies of climate change and the ecology of grasslands. However, little has been done in this aspect of research in China. In this study, we report the characteristics of growth rings in the main roots of 13 herb species sampled in Duolun of the Inner Mongolia grassland in northern China. The results show that around two thirds of the species possess clearly demarcated annual rings in the root xylem. Some species of the same genera show different patterns in anatomical structure of the root xylem. Standardized annual ring widths of three species, Potentilla anserine L., Cymbaria dahurica L. and Lespedeza daurica (Laxm.) Schindl., show a common linear trend, indicating a continued favorable growth condition in the sampling sites. Our results provide evidence that growth rings in roots of some perennial forbs in the Inner Mongolia grassland can serve as a new and useful indicator of past changes in the grassland environment.
A Role for Auxin in Flower Development

Auxin has long been implicated in many aspects of plant growth and development including flower development. However, the exact roles of auxin in flower development have not been well defined until the recent identification of auxin biosynthesis mutants. Auxin is necessary for the initiation of floral primordia, and the disruption of auxin biosynthesis, polar auxin transport or auxin signaling leads to the failure of flower formation. Auxin also plays an essential role in specifying the number and identity of floral organs. Further analysis of the relationship between the auxin pathways and the known flower development genes will provide critical information regarding mechanisms of organogenesis and pattern formation in plants.
无线网络的攻击技术与安全防护研究

结合当前实际中应用比较广泛的IEEE 802.11无线网络技术,从攻与防两个角度较为全面地分析了无线网络所面对的安全威胁和相应的安全防护机制,并提出了增强无线网络安全性的方案.
相位检测系统中误差的消除

论述了相位检测系统的原理和引起误差的原因,提出了消除误差的方法,着重对影响相位测量精度的零点漂移、幅度因素、闸门时间设置等问题进行了分析,提出了相应的解决措施,并给出了具体的设计电路.
液晶屏数字识别中分割算法的研究

介绍了一种基于图像处理的针对液晶显示数字进行分割识别的方法.在滤波算法中采用增强型的高斯高通滤波器,较好地解决了因光照不均而引起的大面积背景干扰.根据图像的特点,构造了滤波模板并经过进一步滤波、二值化后,提出了一种统计基础上的水平扫描线去除杂点干扰的算法.试验结果表明,该算法能较好地去除背景分割出数字,识别率高.
直接数字频率合成器DDS的优化设计

在深入理解DDS基本原理的基础上,采用多级流水线控制技术对DDS的VHDL语言实现进行了优化,并进行了异步接口的同步化设计,给出了DDS系统的时序仿真结果及其在FPGA中的资源占有率.
Effects of Aging and Self-organized Criticality in a Pulse-Coupled Integrate-and-Fire Neuron Model Based on Small World Networks

Effects of aging and self-organized criticality in a pulse-coupled integrate-and-fire neuron model based on small world networks have been studied. We give the degree distribution of aging network, average shortest path length, the diameter of our network, and the clustering coefficient, and find that our neuron model displays the power-law behavior, and with the number of added links increasing, the effects of aging become smaller and smaller. This shows that if the brain works at the self-organized criticality state, it can relieve some effects caused by aging.
Vector and Spinor Decomposition of SU(2) Gauge Potential, Their Equivalence, and Knot Structure in SU(2) Chern-Simons Theory

In this paper, spinor and vector decompositions of SU(2) gauge potential are presented and their equivalence is constructed using a simply proposal. We also obtain the action of Faddeev nonlinear O(3) sigma model from the SU(2)massive gauge field theory, which is proposed according to the gauge invariant principle. At last, the knot structure in SU(2) Chern-Simons filed theory is discussed in terms of the φ-mapping topological current theory. The topological charge of the knot is characterized by the Hopf indices and the Brouwer degrees of φ-mapping.
Multi-indicator assessment of water environment in government environmental auditing

This study focuses on a multi-indicator assessment methodology for governmental environmental auditing of water protection programs. The environmental status of Wuli Lake in China was assessed using the global indicators (driver-status-response) developed by the CSD, and four additional indicators proposed by the author- water quality, pollution load, aquatic ecosystem status and lake sediment deposition. Various hydrological, chemical, biological and environmental parameters were used to estimate the values of the indicators for assessment of environmental status of the lake based on time series data sets for twenty years. The indicators proposed can be customized to meeting the needs for particular assessment of water protection programs. This method can be used to evaluate the performance of national environmental protection programs and provide technical support for environmental auditors.
Adaptation of Nitraria sphaerocarpa to wind-blown sand environments at the edge of a desert oasis

This study addresses the adaptation of Nitraria sphaerocarpa to blown sand at the edge of a desert oasis with regard to the aspects of soil seed banks, seedlings, and population. Horizontally, the total number of seeds per unit area decreased from the shrub canopy center to intershrub areas, and most seeds were found under shrub canopies. Vertically, the highest proportion of seeds was found at depths of 5-10 cm. The emergence percentage, seedling mass, and seedling height, which were significantly affected by both burial depth and seed size, were highest at the optimal burial depth of 2 cm, and decreased with increasing burial depth in each seed size-class. Although seedling mass was usually greatest for large seeds and least for small seeds at each burial depth, little difference was observed in seedling height at shallow burial depths of 0-3 cm. The population shows a patchy and discontinuous distribution pattern. Population height increases with increasing sand depth. Also the density increases with increasing depth of sand in the desert; however, there is a steady decrease when the depth of sand is more than 100 cm. This result indicates that the depth of sand that is most suitable for the growth of Nitraria sphaerocarpa is 100 cm. The size of the population is significantly correlated with the sand depth, which increases with increasing depth in the desert.
Electrochemical process of titanium extraction

A wide variety of processes are being pursued by researchers for cost effective extraction of titanium metal. Electrochemical processes are promising due to simplicity and being less capital intensive. Some of the promising electrochemical processes of titanium extraction were reviewed and the results of laboratory scale experiments on electrochemical reduction of TiO2 granules were brought out. Some of the kinetic parameters of the reduction process were discussed while presenting the quality improvements achieved in the experimentation.
Identification of anthropogenic influences on water quality of rivers in Taihu watershed

Surface water bodies are progressively subjected to stress as a result of anthropogenic activities. This study assesses and examines the impact of human activities on spatial variation in the water quality of 19 rivers in the Taihu watershed. Concentrations of physico-chemical parameters of surface water quality were determined at the mouth of each river during the period of 2000-2004. Multivariate statistical techniques were applied to identify characteristics of the water quality in the studied rivers. The results show that rivers strongly influenced by household wastewater have the highest concentrations of nutrients (TN and TP). Moreover, rivers in the vicinity of a metropolis presented low dissolved oxygen (DO) levels. However, organic-chemical pollution (petroleum and volatile phenolics) was identified with high localization. Two rivers influenced by sewage from industry and ships were distinguished from other rivers with high values of petroleum. The Taige Channel, a river located in Changzhou City that is strongly influenced by wastewater from industry, was characterized with an extraordinarily high value of volatile phenolics. Rivers passing through countries, especially through hilly countries were characterized with high DO contents and low nutrient and organic-chemical pollution, suggesting that agriculture puts less pressure on water quality in adjacent rivers. Therefore, more effort should be made in controlling point pollution to restore water quality in rivers adjacent to cities.
Evaluation of ambient air quality in Guangzhou, China

On the basis of the reported air quality index (API) and air pollutant monitoring data provided by the Guangzhou Environment Monitoring Stations over the last twenty-five years, the characteristics of air quality, prominent pollutants, and variation of the average annual concentrations of SO_2, NO_2, total suspended particulate(TSP), fine particulates (PM_(10)), CO and dustfall in Guangzhou City were analyzed. Results showed that TSP was the prominent pollutant in the ambient air environment of Guangzhou City. Of the prominent pollutants, TSP accounted for nearly 62%, SO_2 12.3%, and NOx 6.4%, respectively. The average API of Guangzhou over 6 years was higher than that of Beijing, Tianjin, Nanjing, Hangzhou, Suzhou and Shanghai, and lower than that of Shenzhen, Zhuhai and Shantou. Concentrations of air pollutants have shown an downward trend in recent years, but they are generally worse than ambient air quality standards for USA, Hong Kong and EU. SO_2 and NO_x pollution were still serious, impling that waste gas pollution from all kinds of vehicles had become a significant problem for environmental protection in Guangzhou. The possible causes of worsening air quality were also discussed in this paper.
A novel acidophile community populating waste ore deposits at an acid mine drainage site

Waste ore samples (pH 3.0) were collected at an acid mine drainage (AMD) site in Anhui, China. The present acidophilic microbial community in the waste ore was studied with 16S rRNA gene clone library and denaturing gradient gel electrophoresis (DGGE). Eighteen different clones were identified and affiliated with Actinobacteria, low G + C Gram-positives, Thermomicrobia, Acidobacteria, Proteobacteria, candidate division TM7, and Planctomycetes. Phylogenetic analysis of 16S rRNA gene sequences revealed a diversity of acidophiles in the samples that were mostly novel. It is unexpected that the moderately thermophilic acidophiles were abundant in the acidic ecosystem and may play a great role in the generation of AMD. The result of DGGE was consistent with that of clone library analysis. These findings help in the better understanding of the generation mechanism of AMD and in developing a more efficient method to control AMD.
Preparation of helicopter rotor counterbalance component by means of permanent-mold casting

Copper alloy was adopted to prepare helicopter rotor counterbalance component by means of permanent-mold casting. Process parameters were determined on the basis of theory calculation and computer numerical simulation. Through controlling mould temperature, pouring temperature and speed, the defects, such as gas cavity, shrinkage porosity, cold shut, can be effectively avoided. The results show that the best process parameters for smelting are as follows: pouring temperature is 1 100 ℃, pouring time is 14 s and opened mould time is 6 min. Mixture of 90% charcoal powder and 10% fluorite were selected as covering agent and 0.01% phosphorus copper acts as oxidizer. The density of rotor counterbalance component after casting in permanent-mold is 99.91% of its theory density. Mechanical properties are as follows: σ_b=315 MPa, σ_(0.2)=143 MPa, δ=25%, HB=950. The mass deviation is between -5 g and +5 g, the curved surface distortion is less than 0.20 mm, and the largest tolerance of sectional thickness can be controlled between -0.10 mm and +0.10 mm.
Property measurements on spray formed Si-Al alloys

A novel Si-Al alloy was prepared by spray forming process for electronic packaging. Property measurements on spray-formed Si-Al alloys after hot pressing were carried out. The results indicate that the alloys (Si-(30%-40%)Al) have advantageous physical and mechanical characteristics, including low coefficient of thermal expansion (6.9×10~(-6)-8.7×10~(-6)/K), high thermal conductivity (118-127 W/(m·K)), low density (2.421×10~3-2.465×10~3 kg/m~3), high ultimate flexural strength (180-220 MPa) and Brinell hardness (162-261). The alloys are easy to machine to tight tolerances using standard machine tools and they can be electroplated with gold finishes and soldered with Sn-Pb alloy without any difficulty.
Effect of extrusion wheel angular velocity on continuous extrusion forming process of copper concave bus bar

The continuous extrusion forming process for producing large section copper concave bus bar under different extrusion wheel angular velocities was studied by three-dimensional finite element technology based on software DEFORM-3D. The rigid-viscoplastic constitutive equation was employed in the model. The numerical simulation results show that the deformation body flow velocity in the die orifice increases gradually with the increase of the extrusion wheel angular velocity. But slippage between the rod and extrusion wheel occurs when the extrusion wheel angular velocity is high. The effective stress near the die orifice enhances gradually with increasing extrusion wheel angular velocity. High stress is concentrated in adjacent regions of the flash gap. The effective strain gradient is greater near the abutment than that near the die orifice. The effective strain of the product increases gradually with increasing extrusion wheel angular velocity. In the deformation process, the deformation body temperature increases remarkably due to friction and deformation. So the cooling is necessary in the region of the die and tools.
Internal oxidation thermodynamics and microstructures of Ag-Y alloy

The thermodynamic data of pure Ag and Y were calculated. The phase constitution, composition of micro-region and microstructures of Ag-Y alloy after internal oxidation were investigated by X-ray diffractometry(XRD), energy dispersion spectrometry(EDS) and scanning electron microscopy(SEM). The results show that the internal oxidation behavior of Ag-Y alloy is feasible from the view of thermodynamics. The upper limit of oxygen partial pressure of Ag-Y alloy oxidation is a function of temperature. Two phases (Ag and Y_2O_3) appear in Ag-Y alloy after the internal oxidation. The surface of Ag-Y alloy is convex because of the volume expansion of oxide in the alloy and the composition of the convex part is Ag. In Ag-Y_2O_3 sintered bulk Y_2O_3 particles are distributed inhomogeneously and conglomerated seriously, but they are dispersed uniformly in the Ag matrix after severe plastic deformation.
Laser surface alloying fabricated porous coating on NiTi shape memory alloy

Laser surface alloying technique was applied to fabricate a metallic porous coating on a solid NiTi shape memory alloy. By laser surface alloying a 40%TiH2-60%NiTi powder mixture on the surface of NiTi alloy using optimized laser process parameters, a porous but crack-free NiTi layer can be fabricated on the NiTi substrate. The porous coating is metallurgically bonded to the substrate NiTi alloy. The pores are uniformly distributed and are interconnected with each other in the coating. An average pore size of less than 10 μm is achieved. The Ni content of the porous layer is much less than that of the original NiTi surface. The existence of the porous coating on the NiTi alloy causes a 37% reduction of the tensile strength and 55% reduction of the strain as compared with the NiTi alloy. Possible biomedical or other applications for this porous surface with good mechanical strength provided by the substrate are prospective.