检索结果-南通市图书馆

Budget constrained flow interception location model for congested systems

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Engineering and Electronics 2009年第6期20卷 1255-1262页

作者： hu dandan yang chao yang jun Dept. of Management Science and Engineering Huazhong Univ. of Science and Technology Wuhan 430074 P. R. China

To study location problems with congestion demand, a bi-objective model based on flow intercep-tion problem is *** model is formulated from the view of M/M/m queuing *** quantity and quality are simultaneously considered as objectives, with constraint on total *** quality includes deviation distance from preplanned trips and customers＇ waiting *** quantity is the number of intercep-tion customers.A multi-objective evolutionary algorithm combined with greedy heuristic is *** a computational experiment is given, and the algorithm is proved to be efficient.

关键词： location flow interception bi-objective heuristic.

Insight into crystal growth and upconversion luminescence property of tetragonal Ba_(3)Sc_(2)F_(12) nanocrystals

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2021年第1期40卷 113-122页

作者： Juan Xie Guang-chao Zheng yang-Ming hu Farhat Nosheen Zhi-Cheng Zhang Er-jun Liang School of Physics and Microelectronics Zhengzhou UniversityZhengzhou 450001China Division of Science and Technology Department of ChemistryUniversity of EducationLahore 54770Pakistan Tianjin Key Laboratory of Molecular Optoelectronic Sciences Department of ChemistrySchool of ScienceTianjin University and Collaborative Innovation Center of Chemical Science and EngineeringTianjin 300072China

Sc-based nanomaterials have attracted considerable attention due to their unique optical properties different from those of Ln/Y-based ***,studies on Sc-based nanomaterials are far from ***,nanoscale alkaline(Ca,Sr and Ba)scandium fluorides were almost ignored for their stringent synthetic ***,we synthesize high-quality tetragonal phase Ba_(3)Sc_(2)F_(12) nanocrystals with uniform morphology and good dispersibility by carefully tailoring the reaction conditions,such as the molar ratio of reactants,temperature and reaction ***,the upconversion(UC)luminescence property of Ba_(3)Sc_(2)F_(12):Yb/Er(Ho)samples is investigated in *** doping concentrations of sensitizer(Yb^(3+))and activator(Er^(3+)and Ho^(3+))are optimized for the strongest UC luminescence,of which the corresponding energy transfer processes are also ***,tetragonal Ba_(3)Sc_(2)F_(12) nanocrystals can gradually transform into hexagonal Ba_(4)Yb_(3)F_(17) nanocrystals with the increase in Yb^(3+)doping *** work provides a novel type of Sc-based nanomaterials with strong red UC emissions which are promising in high-resolution 3-dimensional color displays,laser,bioimaging and biolabels.

关键词： Ba_(3)Sc_(2)F_(12)nanocrystals Crystal growth Upconversion Sc-based nanomaterials

Seed dormancy,germination and storage behavior of Magnolia sinica,a plant species with extremely small populations of Magnoliaceae

在线全文

学校读者我要写书评

暂无评论

Plant Diversity 2022年第1期44卷 94-100页

作者： Liang Lin Lei Cai Lei Fan jun-chao Ma Xiang-Yun yang Xiao-Jian hu The Germplasm Bank of Wild Species Kunming Institute of BotanyChinese Academy of SciencesKunming650201YunnanChina Yunnan Key Laboratory for Integrative Conservation of Plant Species with Extremely Small Populations Key Laboratory far Plant Diversity and Biogeography of East AsiaKunming Institute of BotanyChinese Academy of SciencesKunming650201YunnanChina

Magnolia sinica is one of the most endangered Magnoliaceae species in *** biology information concerning its long-term ex situ conservation and utilization is *** study investigated dormancy status,germination requirements and storage behavior of *** matured seeds germinated to ca.86.5%at 25/15℃but poorly at 30℃;GA3 and moist chilling promoted germination significantly at 20℃.Embryos grew at temperatures(alternating or constant)between 20℃and 25℃,but not at 5℃or 30℃.Our results indicate that *** seeds possibly have non-deep simple mor-phophysiological dormancy(MPD).Seeds survived desiccation to 9.27%and 4.85%moisture content(MC)as well as a further 6-month storage at-20℃and in liquid nitrogen,including recovery in vitro as excised *** established protocol ensured that at least 58%of seedlings were obtained after both cold storage and *** results indicate that both conventional seed banking and cryopreservation have potential as long-term ex situ conservation methods,although further optimized approaches are recommended for this critically endangered magnolia species.

关键词： Magnolia sinica Seed Dormancy Storage behavior Cryopreservation Excised embryo

Toxic Effects of Atrazine on Reproductive System of Male Rats

在线全文

学校读者我要写书评

暂无评论

Biomedical and Environmental Sciences 2014年第4期27卷 281-288页

作者： SONG yang JIA Zhen chao CHEN Jin Yao hu jun Xiang ZHANG Li Shi Department of Nutrition and Food Hygiene West China School of Public Health Sichuan University

Objective This study was designed to evaluate the toxic effects of Atrazine （ATZ） on the reproductive system of male rats. 〈br〉 Methods Male Sprague-Dawley rats were exposed to ATZ by gavage at dosages of 0, 38.5, 77, and 154 mg/kg bw/day for 30 d. The toxic effects of ATZ to rats were assessed through histopathologcal observation, spermatozoa quality evaluation, testicular marker enzyme indicators, antioxidant capacity and reproductive hormone levels. Results Significant adverse effects on reproductive system were observed in rats exposed to ATZ at different dosages compared with 0 mg/kg group, including an irregular and disordered arrangement of the seminiferous epithelium in 154 mg/kg group;a decreased spermatozoa number and an increased spermatozoa abnormality rate in 77 and 154 mg/kg groups;decreased levels of acid phosphatase （ACP）, alkaline phosphatase （AKP）, lactic dehydrogenase （LDH）, and succinate dehydrogenase （SDH） with the increasing of ATZ concentration; a decreased level of total antioxidant capacity （TAC） in a dose-dependent manner, and a decreased reduced glutathione （GSH） level and an increased malondialdehyde （MDA） content in 154 mg/kg group;and decreased serum levels of testosterone （T） and inhibin-B （INH-B） and an increased serum level of follicle stimulating hormone （FSH） in 77 and 154 mg/kg groups, and an increased serum level of luteinizing hormone （LH） in 154 mg/kg group. Conclusion These results suggested that relatively high doses of ATZ could exert reproductive toxicity of male rats.

关键词： Atrazine Reproductive toxicity Oxidative stress Endocrine disrupter

Therapeutic efficiency of tissue-engineered human corneal endothelium transplants on rabbit primary corneal endotheliopathy

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2011年第6期12卷 492-498页

作者： Ting-jun FAN jun ZHAO Xiu-zhong hu Xi-ya MA Wen-bo ZHANG chao-zhong yang Key Laboratory for Corneal Tissue Engineering College of Marine Life Sciences Ocean University of China Qingdao 266003 China Qingdao Dongfang Eye Hospital Qingdao 266110 China

To evaluate the therapeutic efficiency of tissue-engineered human corneal endothelia (TE-HCEs) on rabbit primary corneal endotheliopathy (PCEP),TE-HCEs reconstructed with monoclonal human corneal endothelial cells (mcHCECs) and modified denuded amniotic membranes (mdAMs) were transplanted into PCEP models of New Zealand white rabbits using penetrating *** TE-HCEs were examined using diverse techniques including slit-lamp biomicroscopy observation and pachymeter and tonometer measurements in vivo,and fluorescent microscopy,alizarin red staining,paraffin sectioning,scanning and transmission electron microscopy observations in *** corneas of transplanted eyes maintained transparency for as long as 200 d without obvious edema or immune *** corneal thickness of transplanted eyes decreased gradually after transplanting,reaching almost the thickness of normal eyes after 156 d,while the TE-HCE non-transplanted eyes were turbid and showed obvious corneal *** polygonal corneal endothelial cells in the transplanted area originated from the TE-HCE *** intact monolayer corneal endothelium had been reconstructed with the morphology,cell density and structure similar to those of normal rabbit corneal *** conclusion,the transplanted TE-HCE can reconstruct the integrality of corneal endothelium and restore corneal transparency and thickness in PCEP *** TE-HCE functions normally as an endothelial barrier and pump and promises to be an equivalent of HCE for clinical therapy of human PCEP.

关键词： Tissue-engineered human corneal endothelium New Zealand white rabbits Penetrating keratoplasty Primary corneal endotheliopathy Transparency

Design of a Sector Cascade Applied in the Middle Stage of a Compressor Test Rig

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2022年第2期31卷 485-494页

作者： WANG Jiayu hu jun JIANG chao LI jun College of Energy and Power Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China Jiangsu Province Key Laboratory of Aerospace Power System Nanjing 210016China

A compressor test platform was designed in the purpose of easy assembly and cost-saving *** design concepts were firstly used on the test platform and iterative revisions were conducted to verify the effects,which decrease the risk of applying to the full annulus *** platform was a sector cascade that can be inserted into an otherwise full stator annulus,with a set of exchangeable endwall casing and blades manufactured by 3-D *** platform can create an operating condition which is closer to engine-realistic flow conditions than traditional cascade *** flow field of the prototype stator was tested in detail at the operating point and showed some flow defects in the tip region,and then three design plans were conducted to experimentally investigate which design concept could improve the blade tip *** concept of casing endwall profiling was the most effective one which markedly depressed the separation of the tip region and decreased the total pressure loss *** test results show that the design of the test platform was successful and promising,which could be used to conduct more researches on the flow mechanism of the middle stage.

关键词： sector cascade compressor test platform 3-D printing

Targeting ASIC1a Promotes Neural Progenitor Cell Migration and Neurogenesis in Ischemic Stroke

在线全文

学校读者我要写书评

暂无评论

Research 2024年第1期2023卷 369-387页

作者： Hongfei Ge Tengyuan Zhou chao Zhang Yupeng Cun Weixiang Chen yang yang Qian Zhang huanhuan Li jun Zhong Xuyang Zhang hua Feng Rong hu Department of Neurosurgery and Key Laboratory of Neurotrauma Southwest HospitalThird Military Medical University(Army Medical University)400038 ChongqingChina Medical Research Center Southwest HospitalThird Military Medical University(Army Medical University)400038 ChongqingChina Pediatric Research Institute Ministry of Education Key Laboratory of Child Development and DisordersNational Clinical Research Center for Child Health and DisordersChildren’s Hospital of Chongqing Medical University400014 ChongqingChina

Cell replacement therapy using neural progenitor cells(NPCs)has been shown to be an effective treatment for ischemic ***,the therapeutic effect is unsatisfactory due to the imbalanced homeostasis of the local microenvironment after *** acidosis is a common imbalanced homeostasis in the penumbra and could activate acid-sensing ion channels 1a(ASIC1a),a subunit of proton-gated cation channels following ischemic ***,the role of ASIC1a in NPCs post-ischemia remains ***,our results indicated that ASIC1a was expressed in NPCs with channel functionality,which could be activated by extracellular *** evidence revealed that ASIC1a activation inhibited NPC migration and neurogenesis through RhoA signaling-mediated reorganization of filopodia formation,which could be primarily reversed by pharmacological or genetic disruption of *** vivo data showed that the knockout of the ASIC1a gene facilitated NPC migration and neurogenesis in the penumbra to improve behavioral recovery after stroke.

关键词： ASIC1a homeostasis inhibited

HNCO hydrolysis performance in urea-water solution thermohydrolysis process with and without catalysts

维普期刊数据库评论

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 Zhejiang University-Science A(Applied Physics & Engineering) 2010年第11期11卷 849-856页

作者： Zhen-chao CHEN Wei-juan yang jun-hu ZHOU Hong-kun LV Jian-zhong LIU Ke-fa CEN State Key Laboratory of Clean Energy Utilization Zhejiang University Hangzhou 310027 China

The thermolysis of urea-water solution and its product, HNCO hydrolysis is investigated in a dual-reactor system. For the thermal decomposition below about 1073 K, the main products are ammonia (NH3) and isocyanic acid (HNCO) whereas at higher temperatures the oxidation processes take effect and the products include a low concentration of nitric oxide (NO) and nitrous oxide (N2O). The gas HNCO is quite stable and a high yield of HNCO is observed. The ratio of NH3 to HNCO increases from approximately 1.2 to 1.7 with the temperature. The chemical analysis shows that H radical is in favor of HNCO hydrolysis by instigating the reaction HNCO+H·→·NH2+CO and high temperature has positive effect on H radical. The hydrolysis of HNCO over an alumina catalyst made using a sol-gel process (designated as γ-Al2O3) is investigated. The conversion of HNCO is high even at the high space velocities (6×105 h-1) and low temperatures (393–673 K) in the tests with catalysts, which enhances HNCO hydrolysis and raises the ratio of NH3 to HNCO to approximately 100. The pure γ-Al2O3 shows a better catalytic performance than CuO/γ-Al2O3. The addition of CuO not only reduces the surface area but also decreases the Lewis acid sites which are recognized to have a positive effect on the catalytic activity. The apparent activation energy of the hydrolysis reaction amounts to about 25 kJ/mol in 393–473 K while 13 kJ/mol over 473 K. The overall hydrolysis reaction rate on catalysts is mainly determined by external and internal mass-transfer limitations.

关键词： Urea-water solution Sol-gel method γ-Al2O3 HNCO hydrolysis

Air-core characteristics in a swirling tunnel flow

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2022年第4期34卷 634-646页

作者： jun-hu Nan huan Gao chao-qun Wang Kang-ning Ma James yang Jia-fang Wei Guo-dong Li State Key Laboratory of Eco-hydraulics in Northwest Arid Region Xi'an University of TechnologyXi'an 710048China College of Energy and Power Engineering Lanzhou University of TechnologyLanzhou 730050China Department of Civil and Architectural Engineering Royal Institute of Technology(KTH)StockholmSweden

A cost-effective technique to dissipate the energy in hydropower systems is the formation of a swirling flow within a *** such flows,an air core with a significant cross section usually *** reveal the air-core features in the horizontal tunnel of a high-head shaft spillway,laboratory tests,numerical modeling,and prototype observations are performed,to examine issues such as the formation of the air core,the interjacent air motion,the air-carrying capacity,and the scale *** is shown that the shape of the air core varies greatly in the axial and radial directions along the tunnel and that the center of the core deviates from the axis of the *** motion of the air within the core is caused by the combined action of the water entrainment on the inner surface of the swirling flow and the axial pressure difference in the air *** aeration process can be divided into five processes with respect to the changes of the gate openings.A theoretical expression is established for the air-carrying capacity of the swirling *** vacuum degree is the similarity condition of the air-carrying capacity of the swirling flow between the model and prototype tests based on the Froude law of the similitude,and this similarity condition is verified by both the model and prototype *** work provides a reference for the application of the swirling flows in horizontal hydropower tunnels.

关键词： Horizontal tunnel swirlingflow air core air-carrying capacity scale effect