决定晶体硅太阳电池工作状态的独立参量的确定

从晶体硅太阳电池功率全微分方程出发,结合开路电压和功率随温度、日照变化的实验事实,研究 影响晶体硅太阳电池工作状态的各参量的独立性。从数学上确定出其独立变量为日照强度、电池温度和负载, 并得出了串联内阻是温度的函数的结论。串联内阻的实验数据验证了理论分析结果的正确性。     

黄河下游滩地土地利用/覆盖现状及影响因素分析

以黄河下游滩地为研究对象, 根据2015—2017年卫星遥感影像, 采取人工解译方法, 利 GIS技术,得到研究区土地利用/覆盖的类型分布。结合社会经济统计数据, 分析影响黄河下游桃花峪至高村段宽滩区土地利用/覆盖的因素。结果表明, 黄河下游滩区土地利用/覆盖以非设施耕地为主, 占77.99%, 其次是居民点自然村, 占6.63%。游荡段河道的平均宽度、滩区面积与自然村、工矿仓储地等土地利用面积均大于过渡段与窄河段, 窄河段设施农业与鱼塘面积大于过渡段。黄河下游土地利用类型整体上较少, 结构单一, 其分布受黄河大堤和河槽的双重胁迫作用。影响宽滩区土地利用/覆盖的主要因素是滩区的面积、周边城市发展的吸引力和滩区的水利设施。自然村、工矿仓储地、设施农业和砖瓦窑面积与滩区面积正相关; 鱼塘和工矿仓储地倾向于出现在经济发展更高的区域, 设施农业与工矿仓储地倾向于出现在离县城更近的滩区。     

灰枣和酸枣叶绿体trnL-trnF基因序列分析

以灰枣和酸枣叶片为材料,用改良的CTAB法提取总DNA,用通用引物对枣叶绿体trnL基因内含子和trnL-trnF间隔区进行PCR扩增,得到了trnL基因内含子和trnL-trnF间隔序列片段,并对trnL-trnF间隔序列片段回收测序,测序结果符合植物叶绿体基因trnL-trnF间隔序列特征,用DNAMAN软件进行同源性分析,结果表明灰枣和酸枣trnL-trnF基因序列同源性为94．78％.枣和酸枣的分类学地位是一个长期争议的问题,初步开展了灰枣和酸枣叶绿体基因序列分析的研究,为研究枣和酸枣分子系统进化提供参考.     

分散式钢棒混凝土柱非线性数值模拟研究

 针对实腹式型钢混凝土柱施工难度大、造价高的特点,文中基于核心区钢骨含钢量相同的原则给出了一种低工程造价、低施工难度的分散式钢棒核心钢骨混凝土柱,初步试验已验证两种柱的力学性能相近,该论文则是更深入地研究这种新型截面柱的抗震性能。通过考虑材料本构关系的非线性以及P-Δ效应,应用有限元软件（ABAQUS）建立分散式钢棒核心钢骨混凝土柱的非线性有限元模型,开展轴压比、含钢率、混凝土强度以及核心钢棒屈服强度等对分散式钢棒核心钢骨混凝土柱荷载位移曲线、水平极限承载力及延性系数影响的研究,结果表明：分散式钢棒核心钢骨混凝土柱水平极限承载力受轴压比和混凝土强度的影响明显,而含钢率和核心钢棒屈服强度对水平极限承载力影响很小;延性系数是一个比较敏感的指标,受各种因素的影响均较明显。     

高校开设少数民族体育项目的可行性研究

文章通过文献资料法、逻辑判断法、归纳总结法、数理统计法,从少数民族体育与高校体育的互补性来阐述高校开设少数民族体育的可行性;又从课程改革、体育全球化、大学生民族教育的缺失等多角度对高校体育教育与少数民族体育运动发展的相关性、互补性进行了分析研究,旨在促进我国高校体育教育事业的发展.     

Effect of light response on the photocatalytic activity of BiOCl x Br1−x in the removal of Rhodamine B from water

BiOClxBr1-x catalysts were synthesized through an alcoholysis method and characterized by X-ray diffraction （XRD）, transmission electron microscopy （TEM）, high-resolution transmission electron microscopy （HRTEM）, and diffuse reflectance spectroscopy （DRS）. The as-prepared photocatalysts were found to be tetragonal crystal structure and lamellar plate morphology. Their band gaps were between 3.44 and 2.83 eV. The effect of light response on the photocatalytic activity of BiOClxBrl-x was investigated by degradation of Rhodamine B （RhB）. Complete removal of RhB from water was realized under simulated sunlight irradiation for 50 min with BiOC10.5Br0.5. Mechanism studies showed that photo- generated holes and superoxide anion radicals played important roles in RhB photodegradation. The results of chemical oxygen demand （COD） confirmed RhB mineralization. The effect of light response on the activity of BiOClxBr1-x was further investigated under monochromatic light irradiation, and BiOCl0.5Br0.5 catalyst exhibited the highest activity. Furthermore, BiOC10.5Br0.5 exhibited high stability, suggesting its practical application for the removal of RhB pollutant from water.     

Human embryonic stem cells-derived endothelial cell therapy facilitates kidney regeneration by stimulating renal resident stem cell proliferation in acute kidney injury

Endothelial cell therapy has been implicated to enhance tissue regeneration and vascularization in ischemic kidney. However, no published study has yet examined direct effects of endothelial cell treatment in kidney recovery. This study investigated the therapeutic efficacy of endothelial cells in a mouse model with acute kidney injury (AKI). Thus, human embryonic stem cells-derived endothelial cells (hESC-ECs) labeled with a reporter system encoding a double fusion reporter gene for firefly luciferase (Fluc) and green fluorescent protein (GFP) were characterized by Fluc imaging and immunofluoresence staining. Cultured hESC-ECs (1×106) were injected into ischemic kidney shortly after AKI. Survival of the transplanted hESC-ECs was monitored in vivo from day 1 to 14 after endothelial cell transplantation and potential impact of hESC-EC treatment on renal regeneration was assessed by histological analyses. We report that a substantial level of bioluminescence activity was detected 24 h after hESC-EC injection followed by a gradual decline from 1 to 14 d. Human ESC-ECs markedly accelerated kidney cell proliferation in response to ischaemia-induced damage, indicated by an elevated number of BrdU+ cells. Co-expression of Sca-1, a kidney stem cell proliferation marker, and BrdU further suggested that the observed stimulation in renal cell regeneration was, at least in part, due to increased proliferation of renal resident stem cells especially within the medullary cords and arteriole. Differentiation of hESC-ECs to smooth muscle cells was also observed at an early stage of kidney recovery. In summary, our results suggest that endothelial cell therapy facilitates kidney recovery by promoting vascularization, trans-differentiation and endogenous renal stem cell proliferation in AKI.     

Recent progress in immobilization of late-transition-metal complexes with diimine ligands for olefin polymerization

Late-transition-metal(LTM) catalysts are a family of very flexible ethylene polymerization catalysts because their catalytic performance can be easily adjusted by modifying the ligand structure.Their less oxyphilicity character,which may promote the production of copolymers from ethylene and polar comonomers,is another aspect that attracts much attention in both academic and industrial fields.The immobilization of LTM catalysts on spherical supports is a crucial step prior to their use in the industrial processes of gas-phase or slurry polymerizations.This paper reviews recent developments in supported LTM catalysts for olefin polymerization,and summarizes loading methods and mechanisms of the immobilization of LTM catalysts on inorganic,organic,and inorganic-organic materials,and the effects of immobilization on catalytic activity,polymerization mechanism,and polymer morphology.     

基于知识流优化的业务流程重组

基于业务流程和其内部知识特征,提出一种从知识流优化角度进行流程重组的方法.通过识别业务流程及流程知识,构造基于业务流程的知识地图及流程角色关系网,挖掘业务流程和组织结构的知识流潜在联系,并提出不同的知识流优化原则,对业务流程和组织结构进行优化,实现业务流程重组.通过实例说明利用知识流的业务流程重组方法能改善业务性能,促使组织结构更加合理化及组织知识水平提高.     

基于PROCAST软件的铸锭形状仿真分析

目前对于硅锰合金的主流生产方式为坑池铸造,但该方法易产生严重粉尘污染并造成资源浪费.为了解决该问题,当前硅锰合金行业设计并制造了一种连铸粒化设备,利用锭模铸造方法加工硅锰合金,能够有效减少污染、节约材料并提高生产效率.为了对锭模铸造方法进行更全面的认识,利用PROCAST仿真软件,对半球体和半球圆柱体铸锭的铸造进行仿真...