检索结果-南通市图书馆

Gyrokinetic Particle Simulation of Compressional Electromagnetic Modes

在线全文

学校读者我要写书评

暂无评论

Communications in Computational Physics 2008年第8期4卷 519-536页

作者： H.qu Z.lin Department of Physics and Astronomy University of CaliforniaDivineCA 92697USA

A gyrokinetic particle simulation model is developed for simulations of the compressional electromagnetic turbulence driven by the mirror *** of the linear simulations of mirror modes agree well with the analytic dispersion *** simulations of a single mode find that the mirror instability saturates via a phase-space trapping due to the nonlinear wave-particle interaction when the instability drive is weak.

关键词： Mirror instability compressional electromagnetic turbulence particle-in-cell simulation

Aerobic exercise combined with huwentoxin-I mitigates chronic cerebral ischemia injury

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2017年第4期12卷 596-602页

作者： hai-feng Mao Jun Xie Jia-qin Chen Chang-fa Tang Wei Chen Bo-cun Zhou Rui Chen Hong-lin qu Chu-zu Wu Key Laboratory of Physical Fitness and Exercise Rehabilitation of Hunan Province Hunan Normal University College of Physical Education Yichun University

Ca2＋ channel blockers have been shown to protect neurons from ischemia, and aerobic exercise has significant protective effects on a variety of chronic diseases. The present study injected huwentoxin-I （HWTX-I）, a spider peptide toxin that blocks Ca2＋ channels, into the caudal vein of a chronic cerebral ischemia mouse model, once every 2 days, for a total of 15 injections. During this time, a subgroup of mice was subjected to treadmill exercise for 5 weeks. Results showed amelioration of cortical injury and improved neurological function in mice with chronic cerebral ischemia in the HWTX-I ＋ aerobic exercise group. The combined effects of HWTX I and exercise were superior to HWTX-I or aerobic exercise alone. HWTX-I effectively activated the Notch signal transduction pathway in brain tissue. Aerobic exercise up-regulated synaptophysin mRNA expression. These results demonstrated that aerobic exercise, in combination with HWTX-I, effectively relieved neuronal injury induced by chronic cerebral ischemia via the Notch signaling pathway and promoting synaptic regeneration.

关键词： nerve regeneration chronic cerebral ischemia aerobic exercise huwentoxin-I Notch signaling pathway calcium overload neuralregeneration

Preparation of sulfur-doped graphene fibers and their application in flexible fibriform micro-supercapacitors

在线全文

学校读者我要写书评

暂无评论

Frontiers of Materials Science 2019年第2期13卷 145-155页

作者： Bin CAI Changxiang SHAO Liangti qu Yuning MENG lin JIN School of Chemistry and Chemical Engineering Zhoukou Normal University Zhoukou 466001 China Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials Key Laboratory of Cluster Science (Ministry of Education)School of Chemistry and Chemical Engineering Beijing Institute of Technology Beijing 100081 China The Key Laboratory of Rare Earth Functional Materials and Applications Zhoukou Normal University Zhoukou 466001 China

A novel type of sulfur-doped graphene fibers (S-GFs) were prepared by the hydrothermal strategy, the in situ interfacial polymerization method and the annealing method. Two S-GFs were assembled into an all-solid-state fibriform micro-supercapacitor (micro-SC) that is flexible and has a high specific capacitance (4.55 mF·cm^-2) with the current density of 25.47 pA·cm^-2. The cyclic voltammetry (CV) curve of this micro-SC kept the rectangular shape well even when the scan rate reached 2 V·s^-1. There is a great potential for this type of S-GFs used in flexible wearable electronics.

关键词： graphene fiber sulfur doping wearable electronics flexible supercapacitor micro-supercapacitor

Advances in the study of directed evolution for cellulases

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Environmental Science & Engineering 2011年第4期5卷 519-525页

作者： hailong lin Weiguang LI Changhong GUO Sihang qu Nanqi REN State Key Laboratory of Urban Water Resource and Environment Harbin Institute of TechnologyHarbin 150090China College of Life Science and Technology Harbin Normal UniversityHarbin 150080China

If cellulose can be effectively hydrolyzed intoglucose by cellulase,the production costs of hydrogen,ethanol or other chemicals from cellulosic materials will begreatly decreased,and economically viable production ofbiohydrogen and bioethanol will become *** degraded into glucoses by multi-component *** cellulases are widely used in brewing,food,bioenergy,fodder,textiles,paper,pharmaceuticals,environmental protection and other ***,existing cellulases have several problems that limit theirwider applications,including the low turnover number forsolid cellulosic materials,and low stability in adapting tovarious application *** example,high temperature,low pH,and so *** of directedevolution technology may be one of the most effectiveways for improving the characteristics of *** presents a brief review of the cellulases hydrolysismechanism by cellulase,advances in cellulases(endoglucanaseandβ-glucosidase)improvement by directedevolution for several characteristics(for instance,thermalstability,pH adaptability and enzyme activity),limitationsof directed evolution for cellulases,and the outlook fordirected evolution for cellulase.

关键词： biohydrogen bioethanol cellulase cellulose directed evolution

Applying systematic conservation planning to constitute a protection strategy for broad-leaved Korean pine forests in Changbai Mountains, China

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Mountain Science 2016年第3期13卷 493-507页

作者： MA lin SUN Gong-qi qu Yi LI Jun-qing Beijing university of civil engineering and architecture library Beijing 100044China Key Laboratory for Silviculture and Conservation of Ministry of Education Forest College Beijing Forestry University Beijing 100083 China Nature conservation College Beijing Forestry University Beijing 100083 China National and Local Joint Engineering Laboratory of Wetland and Ecological Conservation Heilongjiang Academy of sciences - Institute of Nature and Ecology Harbin 150040 China

The broad-leaved Korean pine(Pinus koraiensis) forest is one of the most biodiverse zonal communities in the North Temperate Zone and an important habitat for many endangered ***-leaved Korean pine forests(BKPFs) are shrinking quickly due to deforestation and rapid urbanization. Thus, scientific protection strategies are urgently needed to change this status. Changbai Mountains contains one of the largest BKPFs and is considered a priority biodiversity conservation area in China. Guided by systematic conservation planning(SCP) methods and procedures, we chose representative species and communities in BKPFs ecosystem as priority conservation objects, and set quantitative conservation target, which is in the light of the biodiversity characteristic of BKPFs. The watershed area is used as planning unit. We used CPlan software to calculate the irreplaceability(Ir)value of each planning unit and the contribution value(Ti) of each conservation object to(1) assess the conservation efficiency;(2) identify the conservation gap of the existing conservation network. Then wecalculated a human disturbance index(HDI) for planning units in the conservation gaps and combine this with the Ir value to design three conservation scenarios to optimize the conservation *** show that planning units with high conservation value 14.16% of the total area, with3084.36 km2 were covered by the existing conservation network. 79.28% of planning units with high conservation value have not been protected which were concentrated mainly in the eight gap *** 25.3% of protection objects achieved their conservation target with the existing conservation network. Conservation efficiency is low. Three conservation scenarios are constituted, each prioritizing a different aim:(1) ecological value;(2)species rescue; and(3) economical avoidance. The three conservation schemes potentially enable 93%,88% and 51% of conservation objects, respectively, to achieve identified conservatio

关键词： Korean Pine Changbai Mountain Systematic conservation planning Conservation network Protection strategy Conservation efficiency

Modified physiological and operative score for the enumeration of mortality and morbidity risk assessment model in general surgery

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2007年第38期13卷 5090-5095页

作者： Lian-An Ding Li-qun Sun Shuang-Xi Chen lin-lin qu Dong-Fang Xie Department of General Surgery Affiliated Hospital of Medical College Qingdao University Qingdao 266003 Shandong Province China Department of ICU Haici Hospital of Medical College Qingdao University Qingdao 266003 Shandong Province China

AIM: To establish a scoring system for predicting the incidence of postoperative complications and mortality in general surgery based on the physiological and operative severity score for the enumeration of mortality and morbidity (POSSUM), and to evaluate its efficacy. METHODS: Eighty-four patients with postoperative complications or death and 172 patients without postoperative complications, who underwent surgery in our department during the previous 2 years, were retrospectively analyzed by logistic regression. Fifteen indexes were investigated including age, cardiovascular function, respiratory function, blood test results, endocrine function, central nervous system function, hepatic function, renal function, nutritional status, extent of operative trauma, and course of anesthesia. Modified POSSUM (M-POSSUM) was developed using significant risk factors with its efficacy evaluated. RESULTS: The significant risk factors were found to be age, cardiovascular function, respiratory function, hepatic function, renal function, blood test results, endocrine function, nutritional status, duration of operation, intraoperative blood loss, and course of anesthesia. These factors were all included in the scoring system. There were significant differences in the scores between the patients with and without postoperative complications, between the patients died and survived with complications, and between the patients died and survived without complications. The receiver operating characteristic curves showed that the M-POSSUM could accurately predict postoperative complications and ***: M-POSSUM correlates well with postoperative complications and mortality, and is more accurate than POSSUM.

关键词： Physiological and operative severity score for the enumeration of mortality and morbidity Postoperative morbidity Mortality Preoperative assessment General surgery Critical illness

On‑Ramp Merging for Highway Autonomous Driving:An Application of a New Safety Indicator in Deep Reinforcement Learning

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Automotive Innovation 2023年第3期6卷 453-465页

作者： Guofa Li Weiyan Zhou Siyan lin Shen Li Xingda qu College of Mechanical and Vehicle Engineering Chongqing UniversityChongqing 400044China Institute of Human Factors and Ergonomics College of Mechatronics and Control EngineeringShenzhen University3688 Nanhai AvenueShenzhen 518060Guangdong ProvinceChina School of Civil Engineering Tsinghua UniversityBeijing 100084China

This paper proposes an improved decision-making method based on deep reinforcement learning to address on-ramp merging challenges in highway autonomous driving.A novel safety indicator,time difference to merging(TDTM),is introduced,which is used in conjunction with the classic time to collision(TTC)indicator to evaluate driving safety and assist the merging vehicle in finding a suitable gap in traffic,thereby enhancing driving *** training of an autonomous driving agent is performed using the Deep Deterministic Policy Gradient(DDPG)*** action-masking mechanism is deployed to prevent unsafe actions during the policy exploration *** proposed DDPG+TDTM+TTC solution is tested in on-ramp merging scenarios with different driving speeds in SUMO and achieves a success rate of 99.96%without significantly impacting traffic efficiency on the main *** results demonstrate that DDPG+TDTM+TTC achieved a higher on-ramp merging success rate of 99.96%compared to DDPG+TTC and DDPG.

关键词： Autonomous driving On-ramp merging Deep reinforcement learning Action-masking mechanism Deep Deterministic Policy Gradient(DDPG)

Fabrication of micro-fine high Nb-containing TiAl alloyed powders by fluidized bed jet milling

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Rare Metals 2012年第1期31卷 1-6页

作者： Lu, Xin Zhu, Langping Liu, Chengcheng Zhang, lin Wu, Mao qu, Xuanhui State Key Laboratory for Advanced Meials and Materials School of Materials Science and Engineeing University of Science and Technology Beijing Beijing 100083 China

A fluidized bed jet milling process was used to make micro-fine high Nb-containing TiAl alloyed powders from the chippings obtained by crushing the Ti-45Al-8.5Nb-(W,B,Y) *** influences of classifier frequency on powder characteristics were *** results show that the powders with controlled average particle size can be prepared on a large *** powders with different sizes are all dominated by γ with aminor amount of α*** particle size significantly decreases with the classifier frequency *** a classifier frequency higher than 38 Hz,the average particle size of the ground powders is lower than 25μ*** powders are composed of two differ-ent sizes of particles:shaped particles and some clastic particles,and both particle sizes meet the log-normal *** the classifier frequency increasing,the both sizes decrease;meanwhile,the proportion of the clastic particles gradually increases,and the size distribution span value of the ground powders increases correspondingly.

关键词： high Nb-containing TiAl alloys powder preparation fluidized bed jet milling powder characteristics classifier frequency

Promising Electrode and Electrolyte Materials for High-Energy-Density Thin-Film Lithium Batteries

在线全文

学校读者我要写书评

暂无评论

Energy & Environmental Materials 2022年第1期5卷 133-156页

作者： Jie lin Liang lin Shasha qu Dongyuan Deng Yunfan Wu Xiaolin Yan Qingshui Xie Laisen Wang Dongliang Peng College of Materials State Key Laboratory for Physical Chemistry of Solid SurfacesFujian Key Laboratory of Materials GenomeCollaborative Innovation Center of Chemistry for Energy MaterialsXiamen UniversityXiamen 361005China

All-solid-state thin-film lithium batteries(TFLBs)are the ideal wireless power sources for on-chip micro/nanodevices due to the significant advantages of safety,portability,and *** the bottleneck for increasing the energy density of TFLBs,the key components of cathode,electrolyte,and anode are still underway to be *** this review,a brief history of TFLBs is first outlined by presenting several TFLB *** on the state-of-the-art materials developed for lithium-ion batteries(LIBs),the challenges and related strategies for the application of those potential electrode and electrolyte materials in TFLBs are *** the advanced manufacture and characterization techniques,the recent advances of TFLBs are reviewed for pursuing the high-energy-density and long-termdurability demands,which could guide the development of future TFLBs and analogous all-solid-state lithium batteries.

关键词： all-solid-state high-energy-density lithium battery physical vapor deposition thin film