期刊文献+
共找到820,090篇文章
< 1 2 250 >
每页显示 20 50 100
Petrogenetic and geochemical characteristics of some auriferous granitoids in the Kumasi Basin, Ghana: Implications for geodynamic settings and controls of orogenic gold mineralization in the Edikan Gold Mine
1
作者 Emmanuel D.Sunkari Obed Oppong Theophilus K.Agbenyezi 《Deep Underground Science and Engineering》 2025年第3期406-421,共16页
The Edikan Mine,which consists of Fobinso and Esuajah gold deposits,lies within the Asankrangwa Gold Belt of the Birimian Supergroup in the Kumasi Basin.The metasedimentary rocks in the Basins and the faulted metavolc... The Edikan Mine,which consists of Fobinso and Esuajah gold deposits,lies within the Asankrangwa Gold Belt of the Birimian Supergroup in the Kumasi Basin.The metasedimentary rocks in the Basins and the faulted metavolcanic rocks in the Belts that make up the Birimian Supergroup were intruded by granitoids during the Eburnean Orogeny.This research aims to classify granitoids in the Edikan Mine and ascertain the petrogenetic and geochemical characteristics of some auriferous granitoids in the wider Kumasi Basin,Ghana,to understand the implications for geodynamic settings.A multi-methods approach involving field studies,petrographic studies,and whole-rock geochemical analysis was used to achieve the goal of the study.Petrographic studies revealed a relatively high abundance of plagioclase and a low percentage of K-feldspars(anorthoclase and orthoclase)in the Fobinso samples,suggesting that the samples are granodioritic in nature,while the Esuajah samples showed relatively low plagioclase abundance and a high percentage in K-feldspars,indicating that they are granitic.The granitoids from the study areas are co-magmatic.The granitoids in Esuajah and Fobinso are generally enriched in large ion lithophile elements and light rare earth elements than high field strength elements,middle rare earth elements,and heavy rare earth elements,indicating mixing with crustal sources during the evolution of the granitoids.The granitoids were tectonically formed in a syn-collisional+VAG setting,which implies that they were formed in the subduction zone setting.Fobinso granodiorites showed S-type signatures with evidence of extensive crustal contamination,while the Esuajah granites showed I-type signatures with little or no crustal contamination and are peraluminous.Gold mineralization in the study area is structurally and lithologically controlled with shear zones,faulting,and veining as the principal structures controlling the mineralization.The late-stage vein,V3,in the Edikan Mine is characterized by a low vein angle and is mineralized. 展开更多
关键词 Edikan Mine geodynamic setting GRANITOIDS lithologically controlled structurally controlled subduction zone
原文传递
A matrix metalloproteinase-responsive hydrogel system controls angiogenic peptide release for repair of cerebral ischemia/reperfusion injury
2
作者 Qi Liu Jianye Xie +5 位作者 Runxue Zhou Jin Deng Weihong Nie Shuwei Sun Haiping Wang Chunying Shi 《Neural Regeneration Research》 SCIE CAS 2025年第2期503-517,共15页
Vascular endothelial growth factor and its mimic peptide KLTWQELYQLKYKGI(QK)are widely used as the most potent angiogenic factors for the treatment of multiple ischemic diseases.However,conventional topical drug deliv... Vascular endothelial growth factor and its mimic peptide KLTWQELYQLKYKGI(QK)are widely used as the most potent angiogenic factors for the treatment of multiple ischemic diseases.However,conventional topical drug delivery often results in a burst release of the drug,leading to transient retention(inefficacy)and undesirable diffusion(toxicity)in vivo.Therefore,a drug delivery system that responds to changes in the microenvironment of tissue regeneration and controls vascular endothelial growth factor release is crucial to improve the treatment of ischemic stroke.Matrix metalloproteinase-2(MMP-2)is gradually upregulated after cerebral ischemia.Herein,vascular endothelial growth factor mimic peptide QK was self-assembled with MMP-2-cleaved peptide PLGLAG(TIMP)and customizable peptide amphiphilic(PA)molecules to construct nanofiber hydrogel PA-TIMP-QK.PA-TIMP-QK was found to control the delivery of QK by MMP-2 upregulation after cerebral ischemia/reperfusion and had a similar biological activity with vascular endothelial growth factor in vitro.The results indicated that PA-TIMP-QK promoted neuronal survival,restored local blood circulation,reduced blood-brain barrier permeability,and restored motor function.These findings suggest that the self-assembling nanofiber hydrogel PA-TIMP-QK may provide an intelligent drug delivery system that responds to the microenvironment and promotes regeneration and repair after cerebral ischemia/reperfusion injury. 展开更多
关键词 angiogenesis biomaterial blood-brain barrier cerebral ischemia/reperfusion injury control release drug delivery inflammation QK peptides matrix metalloproteinase-2 NEUROPROTECTION self-assembling nanofiber hydrogel
暂未订购
Generative Artificial Intelligence in Judicial Applications:Functions,Risks,and Controls
3
作者 Hong Wenxiao 《Contemporary Social Sciences》 2025年第1期142-155,共14页
The application of generative artificial intelligence(GAI)in the judicial domain represents an innovative approach to achieving digital justice.GAI’s functionalities are primarily exhibited in the enhancement of judi... The application of generative artificial intelligence(GAI)in the judicial domain represents an innovative approach to achieving digital justice.GAI’s functionalities are primarily exhibited in the enhancement of judicial efficiency,improving the accuracy and fairness of adjudications,promoting the uniform application of the law,and enhancing transparency and engagement in judicial processes.However,these advancements are accompanied by potential risks and challenges in technology,adjudication,and ethics.It is thus essential to strengthen privacy protection during the processing and transmission of data,ensure data security and confidentiality,and establish and refine clear legal norms regarding the roles,responsibilities,and legal obligations of GAI in judicial settings.In addition,ethical guidelines that delineate the behavioral boundaries and value orientations of GAI need to be formulated.Collectively,these elements can form a trinary model of technical controls,legal norms,and ethical constraints,to facilitate the modernization and intelligent development of the judicial system. 展开更多
关键词 GAI application functions RISKS technical controls legal norms ethical constraints
在线阅读 下载PDF
Analysis of key therapeutic elements in acupuncture therapy and placebo acupuncture controls
4
作者 Jian-fei NIU Guan-qun WANG +3 位作者 Xiao-long XIE Shuo DU Bi-hui PENG Ji-ping ZHAO 《World Journal of Acupuncture-Moxibustion》 2025年第2期145-151,共7页
Identifying key acupuncture elements is essential for optimizing sham acupuncture controls.Based on the characteristics and current state of acupuncture therapy,this paper categorizes key acupuncture elements into typ... Identifying key acupuncture elements is essential for optimizing sham acupuncture controls.Based on the characteristics and current state of acupuncture therapy,this paper categorizes key acupuncture elements into types and contents.Taking the former as a clue,it examines the current understanding of key acupuncture elements and underscores the need for further refinement to ensure that sham acupuncture controls more closely approximate physiological inertness.Additionally,it explores strategies and methodologies for advancing the understanding of key acupuncture elements from both the type and content perspectives.Key acupuncture elements should expand the number of included element types.Elements such as acupuncture needles,point selection,point combination,needle insertion,needle manipulation,and needle withdrawal should all be included,and they should be reported in a standardized manner in the trials.Regarding element content,improvements should be made in three key areas to enhance selection accuracy:1.Strengthening the comprehensiveness of relevant theoretical frameworks.2.Emphasizing the role of Traditional Chinese Medicine(TCM)diagnosis and acupoint palpation methods in trial application and reporting.3.Continuously investigating the mechanisms underlying both the specific efficacy and the placebo efficacy of acupuncture. 展开更多
关键词 Key acupuncture elements Placebo acupuncture Sham acupuncture Explanatory randomized controlled trials
原文传递
A New Inversion-free Iterative Method for Solving the Nonlinear Matrix Equation and Its Application in Optimal Control
5
作者 GAO Xiangyu XIE Weiwei ZHANG Lina 《应用数学》 北大核心 2026年第1期143-150,共8页
In this paper,we consider the maximal positive definite solution of the nonlinear matrix equation.By using the idea of Algorithm 2.1 in ZHANG(2013),a new inversion-free method with a stepsize parameter is proposed to ... In this paper,we consider the maximal positive definite solution of the nonlinear matrix equation.By using the idea of Algorithm 2.1 in ZHANG(2013),a new inversion-free method with a stepsize parameter is proposed to obtain the maximal positive definite solution of nonlinear matrix equation X+A^(*)X|^(-α)A=Q with the case 0<α≤1.Based on this method,a new iterative algorithm is developed,and its convergence proof is given.Finally,two numerical examples are provided to show the effectiveness of the proposed method. 展开更多
关键词 Nonlinear matrix equation Maximal positive definite solution Inversion-free iterative method Optimal control
在线阅读 下载PDF
Osteocytic vinculin controls bone mass by modulating Mef2c-driven sclerostin expression in mice
6
作者 Yishu Wang Jianmei Huang +7 位作者 Sixiong Lin Lei Qin Dingyu Hao Peijun Zhang Shaochuan Huo Xuenong Zou Di Chen Guozhi Xiao 《Bone Research》 2025年第5期1282-1294,共13页
The focal adhesion(FA)is the structural basis of the cell-extracellular matrix crosstalk and plays important roles in control of organ formation and function.Here we show that expression of FA protein vinculin is dram... The focal adhesion(FA)is the structural basis of the cell-extracellular matrix crosstalk and plays important roles in control of organ formation and function.Here we show that expression of FA protein vinculin is dramatically reduced in osteocytes in patients with aging-related osteoporosis.Vinculin loss severely impaired osteocyte adhesion and dendrite formation.Deleting vinculin using the mouse 10-kb Dmp1-Cre transgenic mice causes dramatic bone loss in the weight-bearing long bones and spine,but not in the skull,in both young and aged mice by impairing osteoblast formation and function without markedly affecting bone resorption.Vinculin loss impairs the anabolic response of skeleton to mechanical loading in mice.Vinculin knockdown increases,while vinculin overexpression decreases,sclerostin expression in osteocytes without impacting expression of Mef2c,a major transcriptional regulator of the Sost gene,which encodes sclerostin.Vinculin interacts with Mef2c and retains the latter in the cytoplasm.Thus,vinculin loss enhances Mef2c nuclear translocation and binding to the Sost enhancer ECR5 to promote sclerostin expression in osteocytes and reduces bone formation.Consistent with this notion,deleting Sost expression in osteocytes reverses the osteopenic phenotypes caused by vinculin loss in mice.Finally,we find that estrogen is a novel regulator of vinculin expression in osteocytes and that vinculin-deficient mice are resistant to ovariectomy-induced bone loss.Thus,we demonstrate a novel mechanism through which vinculin inhibits the Mef2c-driven sclerostin expression in osteocytes to promote bone formation. 展开更多
关键词 focal adhesion fa mef c driven sclerostin expression aging related osteoporosis osteocytic vinculin osteocyte adhesion bone loss control organ formation functionhere focal adhesion
暂未订购
Target Seeker Gyro and Controls 被引量:2
7
作者 汪渤 高洪民 +1 位作者 郝爱芳 董明杰 《Journal of Beijing Institute of Technology》 EI CAS 2002年第1期10-13,共4页
A composite target seeker gyro with dual spectral range infrared rays and millimeter waves, and the associated control methodology are developed. The static pressure air floated ball bearing is used to sustain the ou... A composite target seeker gyro with dual spectral range infrared rays and millimeter waves, and the associated control methodology are developed. The static pressure air floated ball bearing is used to sustain the outer frame, the optical fiber and wave guide are used to transmit these two kinds of signals to the rear part of the gyro, and the stator coils are used to get non contact angular measurement. Composite guiding, scanning, tracing and controlling can be achieved, the maximum tracing angular velocity can be as high as 16(°)/s. 展开更多
关键词 angle detecting scanning and tracing controls target seeker gyro
在线阅读 下载PDF
Time-varying Sliding Mode Controls in Rigid Spacecraft Attitude Tracking 被引量:19
8
作者 靳永强 刘向东 +1 位作者 邱伟 侯朝桢 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2008年第4期352-360,共9页
To solve the problem of attitude tracking of a rigid spacecraft with an either known or measurable desired attitude trajectory, three types of time-varying sliding mode controls are introduced under consideration of c... To solve the problem of attitude tracking of a rigid spacecraft with an either known or measurable desired attitude trajectory, three types of time-varying sliding mode controls are introduced under consideration of control input constraints. The sliding surfaces of the three types initially pass arbitrary initial values of the system, and then shift or rotate to reach predetermined ones. This way, the system trajectories are always on the sliding surfaces, and the system work is guaranteed to have robustness against parameter uncertainty and external disturbances all the time. The controller parameters are optimized by means of genetic algorithm to minimize the index consisting of the weighted index of squared error (ISE) of the system and the weighted penalty term of violation of control input constraint. The stability is verified with Lyapunov method. Compared with the conventional sliding mode control, simulation results show the proposed algorithm having better robustness against inertia matrix uncertainty and external disturbance torques. 展开更多
关键词 attitude tracking control time-varying sliding mode control input constraint genetic algorithm
在线阅读 下载PDF
Sensitivity analysis of surface ozone to emission controls in Beijing and its neighboring area during the 2008 Olympic Games 被引量:14
9
作者 Yi Gao Meigen Zhang 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2012年第1期50-61,共12页
The regional air quality modeling system RAMS (Regional Atmospheric Modeling System)-CMAQ (Community Multi-scale Air Quality modeling system) is applied to analyze temporal and spatial variations in surface ozone ... The regional air quality modeling system RAMS (Regional Atmospheric Modeling System)-CMAQ (Community Multi-scale Air Quality modeling system) is applied to analyze temporal and spatial variations in surface ozone concentration over Beijing and its surrounding region from July to October 2008.Comparison of simulated and observed meteorological elements and concentration of nitrogen oxides (NOx) and ozone at one urban site and three rural sites during Olympic Games show that model can generally reproduce the main observed feature of wind,temperature and ozone,but NOx concentration is overestimated.Although ozone concentration decreased during Olympics,high ozone episodes occurred on 24 July and 24 August with concentration of 360 and 245 μg/m 3 at Aoyuncun site,respectively.The analysis of sensitive test,with and without emission controls,shows that emission controls could reduce ozone concentration in the afternoon when ozone concentration was highest but increase it at night and in the morning.The evolution of the weather system during the ozone episodes (24 July and 24 August) indicates that hot and dry air and a stable weak pressure field intensified the production of ozone and allowed it to accumulate.Process analysis at the urban site and rural site shows that under favorable weather condition on 24 August,horizontal transport was the main contributor of the rural place and the pollution from the higher layer would be transported to the surface layer.On 24 July,as the wind velocity was smaller,the impact of transport on the rural place was not obvious. 展开更多
关键词 chemical smoke tropospheric ozone emission control CMAQ process analysis
原文传递
Temporal and Spatial Variations in the Climate Controls of Vegetation Dynamics on the Tibetan Plateau during 1982–2011 被引量:6
10
作者 Ting HUA Xunming WANG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2018年第11期1337-1346,共10页
The ecosystem of the Tibetan Plateau is highly susceptible to climate change. Currently, there is little discussion on the temporal changes in the link between climatic factors and vegetation dynamics in this region u... The ecosystem of the Tibetan Plateau is highly susceptible to climate change. Currently, there is little discussion on the temporal changes in the link between climatic factors and vegetation dynamics in this region under the changing climate.By employing Normalized Difference Vegetation Index data, the Climatic Research Unit temperature and precipitation data,and the in-situ meteorological observations, we report the temporal and spatial variations in the relationships between the vegetation dynamics and climatic factors on the Plateau over the past three decades. The results show that from the early 1980s to the mid-1990s, vegetation dynamics in the central and southeastern part of the Plateau appears to show a closer relationship with precipitation prior to the growing season than that of temperature. From the mid-1990s, the temperature rise seems to be the key climatic factor correlating vegetation growth in this region. The effects of increasing temperature on vegetation are spatially variable across the Plateau: it has negative impacts on vegetation activity in the southwestern and northeastern part of the Plateau, and positive impacts in the central and southeastern Plateau. In the context of global warming, the changing climate condition(increasing precipitation and significant rising temperature) might be the potential contributor to the shift in the climatic controls on vegetation dynamics in the central and southeastern Plateau. 展开更多
关键词 VEGETATION dynamics CLIMATE control TEMPORAL and spatial VARIATIONS TIBETAN PLATEAU
在线阅读 下载PDF
Food safety controls in different governance structures in China's vegetable and fruit industry 被引量:13
11
作者 ZHOU Jie-hong LI Kai LIANG Qiao 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2015年第11期2189-2202,共14页
Food safety issues constitute an international topic discussed by many scholars. Although there is an extensive body of literature on comparisons of food safety control practices across different governance structures... Food safety issues constitute an international topic discussed by many scholars. Although there is an extensive body of literature on comparisons of food safety control practices across different governance structures, these studies have been conducted mainly in terms of qualitative and descriptive analysis. In addition, little attention has been given to family farms. This study addresses the food safety control practices adopted by firms with different governance structures in China. Food safety control is expressed by the following aspects, i.e., pollution-free, green, organic, and/or geographical indication prod- ucts certification, establishment of production records, and pesticide residue testing. Three types of governance structures that engage in agricultural production are distinguished: farmer cooperatives, agricultural companies, and family farms. The food safety control practices of various governance structures are investigated based on a database that comprises 600 vegetable and fruit enterprises in Zhejiang, China. The results show that (1) pesticide residue testing is adopted by the most firms, followed by products certification, and production records are adopted by the fewest firms, and (2) agricul- tural companies adopt more food safety control practices than family farms, while farmer cooperatives adopt the fewest food safety control practices. Governance structure features of a cooperative in terms of ownership, decision-making, and income distribution are the main reasons for the low level of food safety control in the cooperative. 展开更多
关键词 food safety control governance structure farmer cooperative agricultural company family farm
在线阅读 下载PDF
Numerical modelling of structural controls on fluid flow and mineralization 被引量:14
12
作者 J.Robinson P.M.Schaubs 《Geoscience Frontiers》 SCIE CAS 2011年第3期449-461,共13页
This paper presents the results of a set of numerical models focussing on structural controls on hydrothermal mineralization. We first give an overview of natural phenomena of structurally-controlled ore formation and... This paper presents the results of a set of numerical models focussing on structural controls on hydrothermal mineralization. We first give an overview of natural phenomena of structurally-controlled ore formation and the background theory and mechanisms for such controls. We then provide the results of a group of simple 2D numerical models validated through comparison with Cu-vein structure observed near the Shilu Copper deposit (Yangchun, Guangdong Province, China) and finally a case study of 3D numerical modelling applied to the Hodgkinson Province in North Queensland (Australia). Two modelling approaches, discrete deformation modelling and continuum coupled deformation and fluid flow modelling, are involved. The 2D model-derived patterns are remarkably consistent with the Cu-vein structure from the Shilu Copper deposit, and show that both modelling approaches can realistically simulate the mechanical behaviours of shear and dilatant fractures. The continuum coupled deformation and fluid flow model indicates that pattern of the Cu- veins near the Shilu deposit is the result of shear strain localization, development of dilation and fluid focussing into the dilatant fracture segments. The 3D case-study models (with deformation and fluid flow coupling) on the Hodgkinson Province generated a number of potential gold mineralization 展开更多
关键词 Structural control DILATION Fluid flow MINERALIZATION Numerical modelling Shilu Cu-deposit Hodgkinson Province
在线阅读 下载PDF
Deep Learning Based Hand Gesture Recognition and UAV Flight Controls 被引量:11
13
作者 Bin Hu Jiacun Wang 《International Journal of Automation and computing》 EI CSCD 2020年第1期17-29,共13页
Dynamic hand gesture recognition is a desired alternative means for human-computer interactions.This paper presents a hand gesture recognition system that is designed for the control of flights of unmanned aerial vehi... Dynamic hand gesture recognition is a desired alternative means for human-computer interactions.This paper presents a hand gesture recognition system that is designed for the control of flights of unmanned aerial vehicles(UAV).A data representation model that represents a dynamic gesture sequence by converting the 4-D spatiotemporal data to 2-D matrix and a 1-D array is introduced.To train the system to recognize designed gestures,skeleton data collected from a Leap Motion Controller are converted to two different data models.As many as 9124 samples of the training dataset,1938 samples of the testing dataset are created to train and test the proposed three deep learning neural networks,which are a 2-layer fully connected neural network,a 5-layer fully connected neural network and an 8-layer convolutional neural network.The static testing results show that the 2-layer fully connected neural network achieves an average accuracy of 96.7%on scaled datasets and 12.3%on non-scaled datasets.The 5-layer fully connected neural network achieves an average accuracy of 98.0%on scaled datasets and 89.1%on non-scaled datasets.The 8-layer convolutional neural network achieves an average accuracy of 89.6%on scaled datasets and 96.9%on non-scaled datasets.Testing on a drone-kit simulator and a real drone shows that this system is feasible for drone flight controls. 展开更多
关键词 Deep learning neural networks hand gesture recognition Leap Motion controllers DRONES
原文传递
RESEARCH ON MECHANICAL MEASUREMENT-ORIENTED INTELLIGENT VIRTUAL CONTROLS 被引量:7
14
作者 TangBaoping QinShuren 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2004年第3期356-359,共4页
Intelligent virtual control (IVC) is an intelligent measurement instrumentunit with the function of actual measurement instruments, and the unit can be used as basic buildingblock for a variety of more complex virtual... Intelligent virtual control (IVC) is an intelligent measurement instrumentunit with the function of actual measurement instruments, and the unit can be used as basic buildingblock for a variety of more complex virtual measurement instruments on a PC. IVC is a furtheradvancement from virtual instrument (VI), and it fuses the function modules and the controls modulesso that the relationship between the functions and controls of an instrument is imbedded in one ormore units. The design, implementation and optimization methods of IVCs are introduced. The computersoftware representation of IVCs is discussed. An example of an actual VI constructed with thebuilding blocks of IVCs is given. 展开更多
关键词 Mechanical measurement Intelligent virtual control (IVC) Virtualinstrument(VI)
暂未订购
Validation of housekeeping genes as internal controls for studying the gene expression in Pyropia haitanensis(Bangiales, Rhodophyta) by quantitative real-time PCR 被引量:6
15
作者 LI Bing CHEN Changsheng +2 位作者 XU Yan JI Dehua XIE Chaotian 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2014年第9期152-159,共8页
Pyropia haitanensis is an economically important mariculture crop in China and has a high research value for several life phenomena, for example environmental tolerance. To explore the mechanisms underlying these char... Pyropia haitanensis is an economically important mariculture crop in China and has a high research value for several life phenomena, for example environmental tolerance. To explore the mechanisms underlying these characteristics, gene expression has been investigated at the whole transcriptome level. Gene expression studies using quantitative real-time PCR should start by selecting an appropriate internal control gene; therefore, the absolute expression abundance of six housekeeping genes (18S rRNA (18S), ubiquitin-conju-ating enzyme (UBC), actin (ACT), β-tubulin (TUB), elongation factors 2 (EF2), and glyceraldehyde-3-phos- phate dehydrogenase (GAPDH) examined by the quantitative real-time PCR in samples corresponding to different strains, life-cycle stages and abiotic stress treatments. Their expression stabilities were assessed by the comparative cycle threshold (Ct) method and by two different software packages: geNorm and NormFinder. The most stable housekeeping gene is UBC and the least stable housekeeping is GADPH. Thus, it is proposed that the most appropriate internal control gene for expression analyses in P. haitanensis is UBC. The results pave the way for further gene expression analyses of different aspects of P. haitanensis biology including different strains, life-history stages and abiotic stress responses. 展开更多
关键词 Pyropia haitanensis quantitative real-time PCR internal control genes gene expression
在线阅读 下载PDF
Geological Controls on the CBM Productivity of No.15 Coal Seam of Carboniferous–Permian Taiyuan Formation in Southern Qinshui Basin and Prediction for CBM High-yield Potential Regions 被引量:5
16
作者 ZHANG Zheng QIN Yong +2 位作者 ZHUANG Xinguo LI Guoqing LIU Donghai 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2018年第6期2310-2332,共23页
Coalbed methane(CBM) resources in No.15 coal seam of Taiyuan Formation account for 55% of the total CBM resources in southern Qinshui Basin(SQB), and have a great production potential. This study aims at investigating... Coalbed methane(CBM) resources in No.15 coal seam of Taiyuan Formation account for 55% of the total CBM resources in southern Qinshui Basin(SQB), and have a great production potential. This study aims at investigating the CBM production in No.15 coal seam and its influence factors. Based on a series of laboratory experiments and latest exploration and development data from local coal mines and CBM companies, the spatial characteristics of gas production of No.15 coal seam were analyzed and then the influences of seven factors on the gas productivity of this coal seam were discussed, including coal thickness, burial depth, gas content, ratio of critical desorption pressure to original coal reservoir pressure(RCPOP), porosity, permeability, and hydrogeological condition. The influences of hydrological condition on CBM production were analyzed based on the discussions of four aspects: hydrogeochemistry, roof lithology and its distribution, hydrodynamic field of groundwater, and recharge rate of groundwater. Finally, a three-level analytic hierarchy process(AHP) evaluation model was proposed for predicting the CBM potentials of the No.15 coal seam in the SQB. The best prospective target area for CBM production of the No.15 coal seam is predicted to be in the districts of Panzhuang, Chengzhuang and south of Hudi. 展开更多
关键词 coalbed methane gas productivity controlling factors production potential Taiyuan Formation southern Qinshui Basin
在线阅读 下载PDF
Preventions and Controls on Congenital Transmissions of Zika: Mathematical Analysis 被引量:1
17
作者 Nita H. Shah Zalak A. Patel Bijal M. Yeolekar 《Applied Mathematics》 2017年第4期500-519,共20页
Vector-borne diseases threat lives of millions of people in many countries of the world. Zika is one of the vector-borne diseases which initially spread by the bite of an infected Aedes species mosquito (Ae. aegypti a... Vector-borne diseases threat lives of millions of people in many countries of the world. Zika is one of the vector-borne diseases which initially spread by the bite of an infected Aedes species mosquito (Ae. aegypti and Ae. albopictus) and then it transmits vertically from a pregnant woman to her fetus or from an infected human to their sexual partners. The congenital transmission of Zika virus (ZIKV) results in new born with microcephaly and other neurological abnormalities. The control of infected mosquitos is the best efficient way to control spread of ZIKV. Spraying insecticide is the safest and easiest way to control mosquitos, but sometimes it is cost worthy for long period of spraying. Controlled prevention from the vector bites can also help to control disease spread. To control congenital transmission and sexual transmission of ZIKV, preventions should be taken to reduce/stop pregnancy rate and safe heterosexual transmission among adults. Also, there is no specific treatment available for Zika disease. Treatment is aimed at relieving symptoms with rest, fluids and medications. Controlled combinations of rest, fluids and medications will help to recover early. As costs are incorporated with spraying, preventions and treatment, our aim is to minimise the total cost associated by controlling spraying, preventions and treatment. To fulfil this purpose a mathematical model is developed with disease dynamics in nine compartments namely Susceptible human child, Susceptible human male, Susceptible human female, Infected human child, Infected human male, Infected human female, Recovered human, Susceptible vector and Infected vector including vertical transmission of Zika disease. Numerical simulations have been carried out to optimise controls, and basic reproduction number and stability are calculated. 展开更多
关键词 Zika VERTICAL TRANSMISSION DYNAMICAL System control STABILITY
暂未订购
Timing and structural controls on skarn-type and vein-type mineralization at the Xitian tin-polymetallic deposit, Hunan Province, SE China 被引量:5
18
作者 Miao He Quanlin Hou +4 位作者 Qing Liu Jiheng Zhang Jinfeng Sun Shichong Wu Haofeng Zhu 《Acta Geochimica》 EI CAS CSCD 2018年第2期295-309,共15页
Xitian tin-polymetallic deposit, located in the eastern Hunan Province, SE China, hosts quartz vein and skarn in the contact zone between carbonate and two stages granites. Critical geodynamic questions for South Chin... Xitian tin-polymetallic deposit, located in the eastern Hunan Province, SE China, hosts quartz vein and skarn in the contact zone between carbonate and two stages granites. Critical geodynamic questions for South China are whether different types of mineralization form in the same time and how the magmatism–tectonic system controls the ore-forming process. Based on the distribution of the orebodies, six cassiterite samples from different types of mineralization are collected for dating. In-situ LA-MCICP-MS U–Pb isotopic data yielded concordia low intercept ages between 154 and 157 Ma, indicating that different types of mineralization belong to the same magmatism–mineralization system. Coupled with the study of the kinematic indicators, it suggests that the structural control of the wall rocks constrain the types of mineralization. These results provide further evidence of a close temporal link between the structure and the tin-polymetallic mineralization in Xitian deposit. Considering the structure in the district, granite dome plays an important role in the ore-forming process. The age and structural signatures in Xitian deposit are the response to the subduction of Pacific Plate. 展开更多
关键词 LA-MC-ICP-MS U-Pb dating Structure control Tin-polymetallic deposit SE China
在线阅读 下载PDF
Drivability improvements for a single-motor parallel hybrid electric vehicle using robust controls 被引量:4
19
作者 Hu ZHANG Cun-lei WANG Yong ZHANG Jun-yi LIANG Cheng-liang YIN 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2014年第4期291-301,共11页
For a single-motor parallel hybrid electric vehicle, during mode transitions (especially the transition from electric drive mode to engine/parallel drive mode, which requires the clutch engagement), the drivability ... For a single-motor parallel hybrid electric vehicle, during mode transitions (especially the transition from electric drive mode to engine/parallel drive mode, which requires the clutch engagement), the drivability of the vehicle will be signifi- cantly affected by a clutch torque induced disturbance, driveline oscillations and jerks which can occur without adequate controls. To improve vehicle drivability during mode transitions for a single-motor parallel hybrid electric vehicle, two controllers are proposed. The first controller is the engine-side controller for engine cranking/starting and speed synchronization. The second controller is the motor-side controller for achieving a smooth mode transition with reduced driveline oscillations and jerks under the clutch torque induced disturbance and system uncertainties. The controllers are all composed of a feed-forward control and a robust feedback control. The robust controllers are designed by using the mu synthesis method. In the design process, control- oriented system models that take account of various parameter uncertainties and un-modeled dynamics are used. The results of the simulation demonstrate the effectiveness of the proposed control algorithms. 展开更多
关键词 Hybrid electric vehicle DRIVABILITY Mode transition Robust control Mu synthesis
原文传递
Suppression of Amplitude Decoherence in Arbitrary n-Level Atom in -Configuration with Bang-Bang Controls 被引量:2
20
作者 WANG Yan-Hui LIU Xiao-Shu LONG Gui Lu 《Communications in Theoretical Physics》 SCIE CAS CSCD 2008年第6期1432-1434,共3页
In this paper, we give Bang-Bang (BB) decoupling schemes to suppress the amplitude decoherence in the five-and six-level atom systems in ≡-configuration. We generalize this scheme to the arbitrary level atom system... In this paper, we give Bang-Bang (BB) decoupling schemes to suppress the amplitude decoherence in the five-and six-level atom systems in ≡-configuration. We generalize this scheme to the arbitrary level atom system in ≡-configuration. The corresponding decoupling operators are given explicitly. 展开更多
关键词 Bang-Bang control amplitude decoherence ≡-configuration
在线阅读 下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部