期刊文献+
共找到174,307篇文章
< 1 2 250 >
每页显示 20 50 100
Key technologies and practice for gas field storage facility construction of complex geological conditions in China 被引量:6
1
作者 MA Xinhua ZHENG Dewen +3 位作者 SHEN Ruichen WANG Chunyan LUO Jinheng SUN Junchang 《Petroleum Exploration and Development》 2018年第3期507-520,共14页
In view of complex geological characteristics and alternating loading conditions associated with cyclic large amount of gas injection and withdrawal in underground gas storage(UGS) of China, a series of key gas storag... In view of complex geological characteristics and alternating loading conditions associated with cyclic large amount of gas injection and withdrawal in underground gas storage(UGS) of China, a series of key gas storage construction technologies were established, mainly including UGS site selection and evaluation, key index design, well drilling and completion, surface engineering and operational risk warning and assessment, etc. The effect of field application was discussed and summarized. Firstly, trap dynamic sealing capacity evaluation technology for conversion of UGS from the fault depleted or partially depleted gas reservoirs. A key index design method mainly based on the effective gas storage capacity design for water flooded heterogeneous gas reservoirs was proposed. To effectively guide the engineering construction of UGS, the safe well drilling, high quality cementing and high pressure and large flow surface injection and production engineering optimization suitable for long-term alternate loading condition and ultra-deep and ultra-low temperature formation were developed. The core surface equipment like high pressure gas injection compressor can be manufactured by our own. Last, the full-system operational risk warning and assessment technology for UGS was set up. The above 5 key technologies have been utilized in site selection, development scheme design, engineering construction and annual operations of 6 UGS groups, e.g. the Hutubi UGS in Xinjiang. To date, designed main indexes are highly consistent with actural performance, the 6 UGS groups have the load capacity of over 7.5 billion cubic meters of working gas volume and all the storage facilities have been running efficiently and safely. 展开更多
关键词 gas field storage trap dynamic SEALING capacity key index design effective storage volume drilling and COMPLETION in ultra-deep and ultra-low pressure formation ALTERNATING load surface engineering core equipment risk assessment and control
下载PDF
Comparing of Hydrogen On-Board Storage by the Largest Car Companies, Relevance to Prospects for More Efficient Technologies
2
作者 Yu. S. Nechaev V. G. Makotchenko +3 位作者 M. B. Shavelkina M. Yu. Nechaev A. Veziroglu T. N. Veziroglu 《Open Journal of Energy Efficiency》 2017年第3期73-79,共7页
It presented a comparative consideration of General Motors long-term activities on the current subject of fuel-cell-powered electric vehicles vs Toyota Mirai recent results, relevant to prospects on more efficient and... It presented a comparative consideration of General Motors long-term activities on the current subject of fuel-cell-powered electric vehicles vs Toyota Mirai recent results, relevant to prospects on more efficient and safe technologies of the hydrogen on-board storage. It also presented a call on the project International cooperation. The main aim of this paper is to attract attention of General Motors, Toyota and/or other large car companies to a real possibility of developing and using, in the nearest future, of the break-through hydrogen on-board storage technology based on the solid H2 intercalation into graphite nanostructures. 展开更多
关键词 GM Activities vs TOYOTA Mirairesults PROSPECTS on Developing of a Break-Through HYDROGEN ON-BOARD storage Technology The Solid H2 INTERCALATION into Graphite Nanostructures Call on the Project International Cooperation
下载PDF
Storage time affects the level and diagnostic efficacy of plasma biomarkers for neurodegenerative diseases
3
作者 Lifang Zhao Mingkai Zhang +4 位作者 Qimeng Li Xuemin Wang Jie Lu Ying Han Yanning Cai 《Neural Regeneration Research》 SCIE CAS 2025年第8期2373-2381,共9页
Several promising plasma biomarker proteins,such as amyloid-β(Aβ),tau,neurofilament light chain,and glial fibrillary acidic protein,are widely used for the diagnosis of neurodegenerative diseases.However,little is k... Several promising plasma biomarker proteins,such as amyloid-β(Aβ),tau,neurofilament light chain,and glial fibrillary acidic protein,are widely used for the diagnosis of neurodegenerative diseases.However,little is known about the long-term stability of these biomarker proteins in plasma samples stored at-80°C.We aimed to explore how storage time would affect the diagnostic accuracy of these biomarkers using a large cohort.Plasma samples from 229 cognitively unimpaired individuals,encompassing healthy controls and those experiencing subjective cognitive decline,as well as 99 patients with cognitive impairment,comprising those with mild cognitive impairment and dementia,were acquired from the Sino Longitudinal Study on Cognitive Decline project.These samples were stored at-80°C for up to 6 years before being used in this study.Our results showed that plasma levels of Aβ42,Aβ40,neurofilament light chain,and glial fibrillary acidic protein were not significantly correlated with sample storage time.However,the level of total tau showed a negative correlation with sample storage time.Notably,in individuals without cognitive impairment,plasma levels of total protein and tau phosphorylated protein threonine 181(p-tau181)also showed a negative correlation with sample storage time.This was not observed in individuals with cognitive impairment.Consequently,we speculate that the diagnostic accuracy of plasma p-tau181 and the p-tau181 to total tau ratio may be influenced by sample storage time.Therefore,caution is advised when using these plasma biomarkers for the identification of neurodegenerative diseases,such as Alzheimer's disease.Furthermore,in cohort studies,it is important to consider the impact of storage time on the overall results. 展开更多
关键词 Alzheimers disease amyloid-β diagnostic ability glial fibrillary acidic protein NEURODEGENERATION neurofilament light chain plasma biomarkers single molecule array storage time tau
下载PDF
Hydrocarbon generation and storage mechanisms of deepwater shelf shales of Ordovician Wufeng Formation–Silurian Longmaxi Formation in Sichuan Basin, China 被引量:11
4
作者 GUO Xusheng LI Yuping +5 位作者 BORJIGEN Tenger WANG Qiang YUAN Tao SHEN Baojian MA Zhongliang WEI Fubin 《Petroleum Exploration and Development》 2020年第1期204-213,共10页
As the hydrocarbon generation and storage mechanisms of high quality shales of Upper Ordovician Wufeng Formation– Lower Silurian Longmaxi Formation remain unclear, based on geological conditions and experimental mode... As the hydrocarbon generation and storage mechanisms of high quality shales of Upper Ordovician Wufeng Formation– Lower Silurian Longmaxi Formation remain unclear, based on geological conditions and experimental modelling of shale gas formation, the shale gas generation and accumulation mechanisms as well as their coupling relationships of deep-water shelf shales in Wufeng–Longmaxi Formation of Sichuan Basin were analyzed from petrology, mineralogy, and geochemistry. The high quality shales of Wufeng–Longmaxi Formation in Sichuan Basin are characterized by high thermal evolution, high hydrocarbon generation intensity, good material base, and good roof and floor conditions;the high quality deep-water shelf shale not only has high biogenic silicon content and organic carbon content, but also high porosity coupling. It is concluded that:(1) The shales had good preservation conditions and high retainment of crude oil in the early times, and the shale gas was mainly from cracking of crude oil.(2) The biogenic silicon(opal A) turned into crystal quartz in early times of burial diagenesis, lots of micro-size intergranular pores were produced in the same time;moreover, the biogenic silicon frame had high resistance to compaction, thus it provided the conditions not only for oil charge in the early stage, but also for formation and preservation of nanometer cellular-like pores, and was the key factor enabling the preservation of organic pores.(3) The high quality shale of Wufeng–Longmaxi Formation had high brittleness, strong homogeneity, siliceous intergranular micro-pores and nanometer organic pores, which were conducive to the formation of complicated fissure network connecting the siliceous intergranular nano-pores, and thus high and stable production of shale gas. 展开更多
关键词 hydrocarbon generation and storage mechanism Upper ORDOVICIAN Wufeng FORMATION Lower SILURIAN Longmaxi FORMATION deep-water SHELF siliceous shale Sichuan Basin pore preservation
下载PDF
桑天牛卵长尾啮小蜂的繁殖生物学研究 被引量:12
5
作者 黄大庄 刘辉芳 +2 位作者 王志刚 杨忠岐 李会平 《林业科学》 EI CAS CSCD 北大核心 2005年第2期195-200,共6页
The reproduction characteristics of Aprostocetus prolixus, which is a new parasitioid on Apriona germarii, were studied. It demonstrated that the female adult can generate offspring by either sex reproduction or parth... The reproduction characteristics of Aprostocetus prolixus, which is a new parasitioid on Apriona germarii, were studied. It demonstrated that the female adult can generate offspring by either sex reproduction or parthenogenesis, but all the offspring were male if they were from the mode of parthenogenesis. The sex ratio, with investigating in nature, was 2.38∶1. The environmental conditions had notable influence on sex ratio, survival ratio and fecundity. Its sex ratio increased to 3.48∶1 by feeding complementary nutrition that adding with 20% honey. The temperature has great effect on Aprostocetus prolixus in terms of system research, of which adult longevity decreased with temperature from 17.5 ℃ to 35 ℃ and its ability of reproduction increased between 25 ℃ and 30 ℃ but the acme at 27.5 ℃. Without the feeding complementary nutrition, on the other hand, the female adult will both lose the ability of fecundity at the temperature below 17.5 ℃ and over 35 ℃. With humidity increasing from 40% to 80%, its fecundity increased significantly. It also showed that there was no significant influence of temperature on fecundity between the 4 ℃ to 8 ℃ when cold storage( i.e. the matured larvae for 90 d, the adults for 10 d and the host egg for 40 d). 展开更多
关键词 ratio research storage with nature system the and great The SEX for mode acme over With cold host was ITS new can all ITS in
下载PDF
In situ atomic-scale observation of size-dependent (de) potassiation and reversible phase transformation in tetragonal FeSe anodes
6
作者 Ran Cai Lixia Bao +12 位作者 Wenqi Zhang Weiwei Xia Chunhao Sun Weikang Dong Xiaoxue Chang Ze Hua Ruiwen Shao Toshio Fukuda Zhefei Sun Haodong Liu Qiaobao Zhang Feng Xu Lixin Dong 《InfoMat》 SCIE CAS CSCD 2023年第1期161-171,共11页
Potassium-ion batteries(PIBs)are considered promising alternatives to lithium-ion batteries owing to cost-effective potassium resources and a suitable redox potential of-2.93 V(vs.-3.04 V for Li+/Li).However,the explo... Potassium-ion batteries(PIBs)are considered promising alternatives to lithium-ion batteries owing to cost-effective potassium resources and a suitable redox potential of-2.93 V(vs.-3.04 V for Li+/Li).However,the exploration of appro-priate electrode materials with the correct size for reversibly accommodating large K+ions presents a significant challenge.In addition,the reaction mecha-nisms and origins of enhanced performance remain elusive.Here,tetragonal FeSe nanoflakes of different sizes are designed to serve as an anode for PIBs,and their live and atomic-scale potassiation/depotassiation mechanisms are revealed for the first time through in situ high-resolution transmission electron micros-copy.We found that FeSe undergoes two distinct structural evolutions,sequen-tially characterized by intercalation and conversion reactions,and the initial intercalation behavior is size-dependent.Apparent expansion induced by the intercalation of K+ions is observed in small-sized FeSe nanoflakes,whereas unexpected cracks are formed along the direction of ionic diffusion in large-sized nanoflakes.The significant stress generation and crack extension originating from the combined effect of mechanical and electrochemical interactions are elucidated by geometric phase analysis and finite-element analysis.Despite the different intercalation behaviors,the formed products of Fe and K_(2)Se after full potassiation can be converted back into the original FeSe phase upon depotassiation.In particular,small-sized nanoflakes exhibit better cycling perfor-mance with well-maintained structural integrity.This article presents the first successful demonstration of atomic-scale visualization that can reveal size-dependent potassiation dynamics.Moreover,it provides valuable guidelines for optimizing the dimensions of electrode materials for advanced PIBs. 展开更多
关键词 elucidated by geometric phase analysis and finite-element analysis. Despite the different intercalation behaviors the formed products of Fe and K 2 Se after full potassiation can be converted back into the original FESE phase upon depotassiation. In particular small-sized nanoflakes exhibit better cycling perfor- mance with well-maintained structural integrity. This article presents the first successful demonstration of ATOMIC-SCALE visualization that can reveal size- dependent potassiation dynamics. Moreover it provides valuable guidelines for optimizing the dimensions of electrode materials for advanced PIBs. KEYWOR DS in situ transmission electron microscopy potassium-ion batteries potassium-ion storage mechanism SIZE-DEPENDENT effects TETRAGONAL FESE
原文传递
Battery Technologies for Grid-Level Large-Scale Electrical Energy Storage 被引量:16
7
作者 Xiayue Fan Bin Liu +8 位作者 Jie Liu Jia Ding Xiaopeng Han Yida Deng Xiaojun Lv Ying Xie Bing Chen Wenbin Hu Cheng Zhong 《Transactions of Tianjin University》 EI CAS 2020年第2期92-103,共12页
Grid-level large-scale electrical energy storage(GLEES) is an essential approach for balancing the supply–demand of electricity generation, distribution, and usage. Compared with conventional energy storage methods, ... Grid-level large-scale electrical energy storage(GLEES) is an essential approach for balancing the supply–demand of electricity generation, distribution, and usage. Compared with conventional energy storage methods, battery technologies are desirable energy storage devices for GLEES due to their easy modularization, rapid response, flexible installation, and short construction cycles. In general, battery energy storage technologies are expected to meet the requirements of GLEES such as peak shaving and load leveling, voltage and frequency regulation, and emergency response, which are highlighted in this perspective. Furthermore, several types of battery technologies, including lead–acid, nickel–cadmium, nickel–metal hydride, sodium–sulfur, lithium-ion, and flow batteries, are discussed in detail for the application of GLEES. Moreover, some possible developing directions to facilitate efforts in this area are presented to establish a perspective on battery technology, provide a road map for guiding future studies, and promote the commercial application of batteries for GLEES. 展开更多
关键词 BATTERY TECHNOLOGIES Grid-level LARGE-SCALE ELECTRICAL energy storage Peak shaving and load leveling Voltage and frequency regulation Emergency response
下载PDF
小麦粉储藏品质变化规律研究 被引量:26
8
作者 孙辉 姜薇莉 +2 位作者 田晓红 林家永 凌家煜 《中国粮油学报》 EI CAS CSCD 北大核心 2005年第3期77-82,共6页
本文研究了不同类型的小麦粉样品在38℃和70%相对湿度的密闭条件下储藏过程中品质的变化规律,结果表明:储藏2个星期之后,样品的淀粉酶活性急剧下降;面筋的含量和质量以及面团的流变学特性均呈现出一定的规律性变化。包括面筋吸水量下降... 本文研究了不同类型的小麦粉样品在38℃和70%相对湿度的密闭条件下储藏过程中品质的变化规律,结果表明:储藏2个星期之后,样品的淀粉酶活性急剧下降;面筋的含量和质量以及面团的流变学特性均呈现出一定的规律性变化。包括面筋吸水量下降;面团粉质吸水率增加;吹泡P值增大,L值减小,P/L值增大;RVA特征粘度值增大。其中,吹泡曲线的特征值变化最为明显。但是这些指标的变化与原料小麦粉的质量有很大的关系,因储藏而造成的品质差异无法超越样品间原有的品质差别。馒头品质随储藏时间的延长而变劣,但这种变化的速度在不同的样品间存在差异,原因尚需要进一步探索。 展开更多
关键词 湿 RVA L
下载PDF
Effects of Preparation and Storage of Agar Media on the Sensitivity of Bacterial Forward Scattering Patterns
9
作者 Mélissa Mialon Yanjie Tang +2 位作者 Atul K. Singh Euiwon Bae Arun K. Bhunia 《Open Journal of Applied Biosensor》 2012年第3期26-35,共10页
Recent worldwide foodborne outbreaks emphasize the need for the development of rapid and accurate method for pathogen detection. To address such issues, a new colony based label-free detection method working on the pr... Recent worldwide foodborne outbreaks emphasize the need for the development of rapid and accurate method for pathogen detection. To address such issues, a new colony based label-free detection method working on the principles of elastic light scattering was introduced. In order to build libraries of scattering images for bacterial pathogens, it is pertinent to determine the effect of preparation and storage of the agar media on the scatter patterns. Scatter patterns of three Escherichia coli serovars (O26, O111 and O157) were studied and used in a model system, after growth on Sorbitol-MacConkey agar plates that were prepared and stored at different conditions in the laboratory. Quantitative image processing software was used to analyze variation in scatter patterns of the same serovar on media prepared under various standard laboratory conditions and to generate a cross-validation matrix for comparison. Based on the results, it was determined that attention should be given during preparation of media so that the agar plates are not air-dried more than 10 - 20 min after solidification at room temperature. The plates could be stored in sealed bags in cold room (4oC - 10oC) for up to a month before use. The findings of this study should provide guidelines in preparation, storage, and handling of media for generation of reproducible scatter patterns of bacterial colonies with the light scattering sensor for pathogen detection. 展开更多
关键词 Optical Biosensor Pathogen Light Scattering AGAR MEDIA PREPARATION and storage Surface Water E. coli SEROVARS O157 O111 O26
下载PDF
Numerical Assessment on Fin Design Parameters Employed for Augmentation of Natural Convection and Fluid Flow in a Horizontal Latent Heat Thermal Energy Storage Unit 被引量:1
10
作者 Mohammad Khan Nan Zhao Tianhao Xu 《Engineering(科研)》 2019年第7期407-428,共22页
The present work focus on the thermal performance of a horizontal concentric heat exchanger, which is numerically investigated to evaluate the heat transfer enhancement process by adding fins with different configurat... The present work focus on the thermal performance of a horizontal concentric heat exchanger, which is numerically investigated to evaluate the heat transfer enhancement process by adding fins with different configurations. As a part of this investigation, the melting process is simulated from the onset of phase change to the offset involving physics of natural convection in PCM fluid pool. The investigation is carried out by ANSYS Fluent code, which is an efficient numerical analysis tool for investigating fluid flow and convective heat transfer phenomena during PCM melting process. The attention is mainly focused on the extension of contact area between the PCM body and cylindrical capsule to enhance heat transfer rates to PCM bodies during the melting process by employing longitudinal fins in the enclosed capsule. Two commercial PCMs: RT50 and C58, are introduced in a 2D cylindrical pipe with their thermo-physical properties as input for modelling. The selected modelling approach is validated against experimental result with respect to the total enthalpy changes that qualify our model to run in the proceeding calculation. It is ensured that an isothermal boundary condition (373 K) is applied to the inner pipe throughout the series of simulation cases and the corresponding Rayleigh number (Ra) ranges from 104 - 105 and Prandtl number (Pr) 0.05 - 0.07. Finally, parametric study is carried out to evaluate the effect of length, thickness and number of longitudinal fins on the thermal performance of PCM-LHTES (Latent Heat Thermal Energy Storage) system associated with the physics of natural convection process during PCM melting. 展开更多
关键词 Phase Change Materials (PCM) Natural Convection THERMAL ENERGY storage (TES) CFD Simulation Latent Heat Based THERMAL ENERGY storage (LHTES) ENTHALPY
下载PDF
Ensuring Security, Confidentiality and Fine-Grained Data Access Control of Cloud Data Storage Implementation Environment 被引量:1
11
作者 Amir Mohamed Talib 《Journal of Information Security》 2015年第2期118-130,共13页
With the development of cloud computing, the mutual understandability among distributed data access control has become an important issue in the security field of cloud computing. To ensure security, confidentiality a... With the development of cloud computing, the mutual understandability among distributed data access control has become an important issue in the security field of cloud computing. To ensure security, confidentiality and fine-grained data access control of Cloud Data Storage (CDS) environment, we proposed Multi-Agent System (MAS) architecture. This architecture consists of two agents: Cloud Service Provider Agent (CSPA) and Cloud Data Confidentiality Agent (CDConA). CSPA provides a graphical interface to the cloud user that facilitates the access to the services offered by the system. CDConA provides each cloud user by definition and enforcement expressive and flexible access structure as a logic formula over cloud data file attributes. This new access control is named as Formula-Based Cloud Data Access Control (FCDAC). Our proposed FCDAC based on MAS architecture consists of four layers: interface layer, existing access control layer, proposed FCDAC layer and CDS layer as well as four types of entities of Cloud Service Provider (CSP), cloud users, knowledge base and confidentiality policy roles. FCDAC, it’s an access policy determined by our MAS architecture, not by the CSPs. A prototype of our proposed FCDAC scheme is implemented using the Java Agent Development Framework Security (JADE-S). Our results in the practical scenario defined formally in this paper, show the Round Trip Time (RTT) for an agent to travel in our system and measured by the times required for an agent to travel around different number of cloud users before and after implementing FCDAC. 展开更多
关键词 CLOUD Computing CLOUD DATA storage CLOUD Service PROVIDER Formula-Based CLOUD DATA Access Control Multi-Agent System and Secure Java Agent Development Framework
下载PDF
Mineralogical and Geochemical Characteristics of Caprock Formations Used for Storage and Sequestration of Carbon Dioxide
12
作者 Hedi Jedli Hachem Hedfi +2 位作者 Abdessalem Jbara Souhail Bouzgarrou Khalifa Slimi 《Journal of Minerals and Materials Characterization and Engineering》 2015年第5期409-419,共11页
The main objective of the present study is to characterize cap rock formation used for geological storage of carbon dioxide (CO2). The petrophysical properties of several rocks were studied before CO2 injection. This ... The main objective of the present study is to characterize cap rock formation used for geological storage of carbon dioxide (CO2). The petrophysical properties of several rocks were studied before CO2 injection. This step is necessary for an understanding of CO2-brine-rock interactions. The mineralogical composition of several clay samples collected from real storage sites located in the south of Tunisia was determined by X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM) coupled to a probe EDS, infrared spectroscopy, thermal analysis and fluorescence spectra. The obtained experimental results reveal that illite, calcite and quartz are the dominant clay minerals. Dolomite and albite are also present. Besides, SEM analysis shows laminated structure for these samples which suggests low crystallinity. This sample contains a higher content of Fe, Cl, Ca and O. The clay cover may also be useful in storage process by immobilizing the migration of CO2 outer of the geological site and activating the process of mineral sequestration. 展开更多
关键词 Carbon Dioxide storage CAP Rock CLAY X-Ray Diffraction Scanning Electron Microscopy Thermal Analysis Infrared Spectroscopy Fluorescence Spectra
下载PDF
Battery Energy Storage System and Demand Response Based Optimal Virtual Power Plant Operation
13
作者 Ya-Chin Chang Rung-Fang Chang 《Journal of Applied Mathematics and Physics》 2017年第4期766-773,共8页
With certain controllability of various distribution energy resources (DERs) such as battery energy storage system (BESS), demand response (DR) and distributed generations (DGs), virtual power plant (VPP) can suitably... With certain controllability of various distribution energy resources (DERs) such as battery energy storage system (BESS), demand response (DR) and distributed generations (DGs), virtual power plant (VPP) can suitably regulate the powers access to the distribution network. In this paper, an optimal VPP operating problem is used to optimize the charging/discharging schedule of each BESS and the DR scheme with the objective to maximize the benefit by regulating the supplied powers over daily 24 hours. The proposed solution method is composed of an iterative dynamic programming optimal BESS schedule approach and a particle swarm optimization based (PSO-based) DR scheme approach. The two approaches are executed alternatively until the minimum elec-tricity cost of the whole day is obtained. The validity of the proposed method was confirmed with the obviously decreased supplied powers in the peak-load hours and the largely reduced electricity cost. 展开更多
关键词 Battery ENERGY storage System Distributed ENERGY RESOURCE DEMAND Response ITERATIVE Dynamic PROGRAMMING Particle SWARM Optimization Virtual Power Plant
下载PDF
白马鸡繁殖早期栖息地选择和空间分布 被引量:29
14
作者 贾非 王楠 郑光美 《动物学报》 SCIE CAS CSCD 北大核心 2005年第3期383-392,共10页
2003年1-6月和2004年4-6月考察了分布于四川省稻城县著杰寺周围的白马鸡(Crossoptiloncrossop-tilon)种群,分析繁殖早期白马鸡繁殖对的栖息地选择和空间分布特征。雌雄个体配对前,对整个研究区域进行系统取样并测量若干环境变量的参数... 2003年1-6月和2004年4-6月考察了分布于四川省稻城县著杰寺周围的白马鸡(Crossoptiloncrossop-tilon)种群,分析繁殖早期白马鸡繁殖对的栖息地选择和空间分布特征。雌雄个体配对前,对整个研究区域进行系统取样并测量若干环境变量的参数。配对后,利用随机样线调查繁殖对出现的位置和数量。有繁殖对出现的栅格定义为探测栅格,反之为非探测栅格。水源距离、灌木盖度、灌木高度和草本高度等变量在探测和非探测栅格间差异显著。将显著差异变量及这些变量间的一级互作经单变量逻辑斯蒂回归进行筛选,以保留变量为自变量进行向前筛选的逐步逻辑斯蒂回归,最后选择具有最小AICC值的回归等式为最佳的回归模型。模型表明繁殖对的栖息地选择与水源距离负相关,与灌木盖度正相关。2004年进行了重复调查,获得实际的探测和非探测栅格与模型预测值之间无显著差异。计算繁殖对在0°(东-西),45°(东北-西南),90°(南-北)和135°(西北-东南)4个方向上的变异函数。结果表明:繁殖对的方向性变异函数可用球状模型来拟合,拟合曲线和实验曲线间的拟合程度达到显著水平,繁殖对呈明显的各向异性聚集分布[动物学报51(3):383-392,2005]。 展开更多
关键词 2004 2003 线 线 AIC
下载PDF
Measurement of Thermophysical Property of Energy Storage System (CaCl<sub>2</sub>&#46NH<sub>3</sub>System) 被引量:2
15
作者 Yuki Sakamoto Hideki Yamamoto 《Natural Resources》 2014年第12期687-697,共11页
In order to measure the thermophysical properties of ammoniated salt (CaCl2.mNH3: m = 4, 8) as an energy storage system utilizing natural resources, the measurement unit was developed, and the thermophysical propertie... In order to measure the thermophysical properties of ammoniated salt (CaCl2.mNH3: m = 4, 8) as an energy storage system utilizing natural resources, the measurement unit was developed, and the thermophysical properties (effective thermal conductivity and thermal diffusivity) of CaCl2.mNH3 and CaCl2.mNH3 with heat transfer media (Ti: titanium) were measured by the any heating method. The effective thermal conductivities of CaCl2.4NH3 + Ti and CaCl2.8NH3 + Ti were 0.14 - 0.17 and 0.18 - 0.20 W/(m.K) in the measuring temperature range of 290 - 350 K, respectively, and these values were approximately 1.5 - 2.2 times larger than those of CaCl2.4NH3 and CaCl2.8NH3. The effective thermal diffusivities were 0.22 - 0.24 × 10-6 and 0.18 - 0.19 × 10-6 m2/sin the measuring temperature range of 290 - 350 K, respectively, and these values were approximately 1.3 - 1.5 times larger than those of CaCl2.4NH3 and CaCl2.8NH3. The obtained results show that the thermophysical properties have a dependence on the bulk densities and specific heats of CaCl2.mNH3 and CaCl2.mNH3 + Ti. It reveals that the thermophysical properties in this measurement would be the valuable design factors to develop energy and H2 storage systems utilizing natural resources such as solar energy. 展开更多
关键词 Energy storage SYSTEM Thermophysical Property Calcium Chloride (CaCl2) Ammonia (NH3) Ammoniated Salt AMMONIATION Heat Transfer Media
下载PDF
Modern Corrosion Mapping of Storage Tank Bottoms--Notable Advancements in Critical Zone Coverage,Inspection Efficiency and Data Integrity
16
作者 Andrew J.Simpson Matthew A.Boat 《Journal of Civil Engineering and Architecture》 2024年第3期148-153,共6页
Every day,an NDT(Non-Destructive Testing)report will govern key decisions and inform inspection strategies that could affect the flow of millions of dollars which ultimately affects local environments and potential ri... Every day,an NDT(Non-Destructive Testing)report will govern key decisions and inform inspection strategies that could affect the flow of millions of dollars which ultimately affects local environments and potential risk to life.There is a direct correlation between report quality and equipment capability.The more able the equipment is-in terms of efficient data gathering,signal to noise ratio,positioning,and coverage-the more actionable the report is.This results in optimal maintenance and repair strategies providing the report is clear and well presented.Furthermore,when considering tank floor storage inspection it is essential that asset owners have total confidence in inspection findings and the ensuing reports.Tank floor inspection equipment must not only be efficient and highly capable,but data sets should be traceable and integrity maintained throughout.Corrosion mapping of large surface areas such as storage tank bottoms is an inherently arduous and time-consuming process.MFL(magnetic flux leakage)based tank bottom scanners present a well-established and highly rated method for inspection.There are many benefits of using modern MFL technology to generate actionable reports.Chief among these includes efficiency of coverage while gaining valuable information regarding defect location,severity,surface origin and the extent of coverage.More recent advancements in modern MFL tank bottom scanners afford the ability to scan and record data sets at areas of the tank bottom which were previously classed as dead zones or areas not scanned due to physical restraints.An example of this includes scanning the CZ(critical zone)which is the area close to the annular to shell junction weld.Inclusion of these additional dead zones increases overall inspection coverage,quality and traceability.Inspection of the CZ areas allows engineers to quickly determine the integrity of arguably the most important area of the tank bottom.Herein we discuss notable developments in CZ coverage,inspection efficiency and data integrity that combines to deliver an actionable report.The asset owner can interrogate this report to develop pertinent and accurate maintenance and repair strategies. 展开更多
关键词 storage tank tank bottom CZ MFL stars CORROSION corrosion-mapping EFFICIENCY COVERAGE paperless reporting data traceability
下载PDF
Phase Structure and Electrochemical Properties of Rare Earth Based Hydrogen Storage Alloys 被引量:1
17
作者 Chen Weidong Liu Xiangdong Liu Xiao Che Guangdong 《Journal of Rare Earths》 SCIE EI CAS CSCD 2004年第z1期228-231,共4页
The rare earth based hydrogen storage alloys MmxM1 1 - x ( Ni3.55 Co0.75 Mn0.4 A10.3 ) ( x = 0 ~ 0.5 ) were investigated in this work.Adjusted Ml: Mm ratio to change the content of La,Ce,Pr and Nd in the alloys and t... The rare earth based hydrogen storage alloys MmxM1 1 - x ( Ni3.55 Co0.75 Mn0.4 A10.3 ) ( x = 0 ~ 0.5 ) were investigated in this work.Adjusted Ml: Mm ratio to change the content of La,Ce,Pr and Nd in the alloys and then to change the phase structure, the influences of phase structure on the electrochemical properties were analyzed.The results indicate that the main phase of all alloys is LaNi5 with CaCu5 type structure and the crystal lattices constants of LaNi5 are changed with increasing x value, i.e, decreased a-axis, increased c-axis and axis ratio and nonlinear decreased crystal volume.The crystal volume of the alloy with x = 0.3 is larger than others.There is second phase A1LaNi4 in alloys when x≥0.3, which decrease the discharge capacity, but increase the cycling stability and high rate discharge ability.Compared comprehensively, the alloy with x = 0.3 shows the higher discharge capacity and the better cycling stability. 展开更多
关键词 RARE earth BASED hydrogen storage alloy phase structure activation DISCHARGE capacity CYCLING stability high rate DISCHARGE ability
下载PDF
Power management in co-phase traction power supply system with super capacitor energy storage for electrified railways 被引量:4
18
作者 Xiaohong Huang Qinyu Liao +2 位作者 Qunzhan Li Sida Tang Ke Sun 《Railway Engineering Science》 2020年第1期85-96,共12页
Increasing railway traffic and energy utilization issues prompt electrified railway systems to be more economical,efficient and sustainable.As regenerative braking energy in railway systems has huge potential for opti... Increasing railway traffic and energy utilization issues prompt electrified railway systems to be more economical,efficient and sustainable.As regenerative braking energy in railway systems has huge potential for optimized utilization,a lot of research has been focusing on how to use the energy efficiently and gain sustainable benefits.The energy storage system is an alternative because it not only deals with regenerative braking energy but also smooths drastic fluctuation of load power profile and optimizes energy management.In this work,we propose a co-phase traction power supply system with super capacitor(CSS_SC)for the purpose of realizing the function of energy management and power quality management in electrified railways.Besides,the coordinated control strategy is presented to match four working modes,including traction,regenerative braking,peak shaving and valley filling.A corresponding simulation model is built in MATLAB/Simulink to verify the feasibility of the proposed system under dynamic working conditions.The results demonstrate that CSS_SC is flexible to deal with four different working conditions and can realize energy saving within the allowable voltage unbalance of 0.008%in simulation in contrast to 1.3%of the standard limit.With such a control strategy,the performance of super capacitor is controlled to comply with efficiency and safety constraints.Finally,a case study demonstrates the improvement in power fluctuation with the valley-to-peak ratio reduced by 20.3%and the daily load factor increased by 17.9%. 展开更多
关键词 Electrified railway Co-phase TRACTION POWER supply system Energy storage Peak SHAVING VALLEY FILLING POWER quality Super capacitor
下载PDF
运用ActiveX技术开发炼钢物流可视化仿真平台 被引量:7
19
作者 李云 高小强 +5 位作者 郑忠 何腊梅 赵克文 宋国菊 张大德 陈小平 《计算机应用研究》 CSCD 北大核心 2005年第5期181-182,207,共3页
基于工位、作业和作业规则的炼钢物流细胞自动机仿真模型,运用ActiveX技术开发了具有计算机图形化建模、仿真和分析功能的炼钢物流仿真平台。该仿真平台使用了面向对象的软件设计方法和图形窗口环境,界面友好,使用简便。以攀钢提钒炼钢... 基于工位、作业和作业规则的炼钢物流细胞自动机仿真模型,运用ActiveX技术开发了具有计算机图形化建模、仿真和分析功能的炼钢物流仿真平台。该仿真平台使用了面向对象的软件设计方法和图形窗口环境,界面友好,使用简便。以攀钢提钒炼钢厂的实例仿真检验了仿真平台组态建模、捆绑仿真核心算法、仿真运行和仿真结果处理等功能的有效性。仿真平台具有优良的扩展性,通过扩展工位组件以及选择适当的仿真算法,可用于整个钢铁制造流程的仿真。 展开更多
关键词 ACTIVEX 仿 仿 仿 仿 仿
下载PDF
Applications of Lithium-Ion Batteries in Grid-Scale Energy Storage Systems 被引量:11
20
作者 Tianmei Chen Yi Jin +5 位作者 Hanyu Lv Antao Yang Meiyi Liu Bing Chen Ying Xie Qiang Chen 《Transactions of Tianjin University》 EI CAS 2020年第3期208-217,共10页
In the electrical energy transformation process,the grid-level energy storage system plays an essential role in balancing power generation and utilization.Batteries have considerable potential for application to grid-... In the electrical energy transformation process,the grid-level energy storage system plays an essential role in balancing power generation and utilization.Batteries have considerable potential for application to grid-level energy storage systems because of their rapid response,modularization,and flexible installation.Among several battery technologies,lithium-ion batteries(LIBs)exhibit high energy efficiency,long cycle life,and relatively high energy density.In this perspective,the properties of LIBs,including their operation mechanism,battery design and construction,and advantages and disadvantages,have been analyzed in detail.Moreover,the performance of LIBs applied to grid-level energy storage systems is analyzed in terms of the following grid services:(1)frequency regulation;(2)peak shifting;(3)integration with renewable energy sources;and(4)power management.In addition,the challenges encountered in the application of LIBs are discussed and possible research directions aimed at overcoming these challenges are proposed to provide insight into the development of grid-level energy storage systems. 展开更多
关键词 LITHIUM-ION batteries Grid-level ENERGY storage system Frequency regulation and peak SHAVING RENEWABLE ENERGY integration Power management
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部