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。     

基于DQEM的分层流体饱和热弹性多孔介质轴对称问题的动力响应分析

研究了分层不可压流体饱和热弹性多孔介质轴对称问题的动力响应问题,基于多孔介质理论(PMT),给出了该问题的数学模型.在空间域内采用微分求积单元法(DQEM)设置离散的控制微分方程、边界条件和连接条件,在时间域内采用二阶向后差分格式处理时间导数.在离散化的初始条件下,运用Newton-Raphson法进行迭代求解,得到各离散点处未知物理量的数值结果.研究表明:该方法有效、可靠,且具备精度较高、计算量较小、数值稳定等优点.     

结合过完备字典与PCA的小样本语音情感识别方法

针对稀疏表示识别方法需要大量样本训练过完备字典且特征冗余度较高的问题,提出了结合过完备字典学习与PCA降维的小样本语音情感识别算法.该方法首先用PCA降维方法将特征降维,再将处理后的特征用于过完备字典训练与稀疏表示识别方法,从而给出了语音情感特征的稀疏表示方法,并确定了新算法的具体步骤.为验证其有效性,在同等特征维数下,将方法与BP、SVM进行比较,并对比、分析语音情感特征稀疏化前后对语音情感识别率、时间效率以及空间效率的影响.试验结果表明,所提出方法的识别率比SVM与BP高;与采用稀疏化前的特征相比,稀疏化后的特征向量更便于处理,平均识别率提高约15%,时间效率提高近原来的1/2,空间效率提升近原来的1/3.     

带多重临界指数和Hardy项的椭圆方程组解的存在性

研究了一类带有多重临界指数和Hardy位势项的椭圆方程组,运用变分原理和分析技巧,证明了当参变量范围较大时,该方程非平凡解的存在性.     

茶树油脂内生真菌检测及产油脂性状研究

通过培养、染色、显微观察及生化提取与分析,对茶树产油脂内生真菌种类及产油脂性状进行了研究.结果表明:茶树内生真菌中大多数菌株能产生油脂类代谢产物,其产油脂真菌资源较丰富;产油真菌菌株所占比例与真菌种类相关,高产油真菌集中存在于拟茎点霉属(Phomopsis)及镰刀菌属(Fusarium)菌株中,供试的青霉菌各菌株均不产生油脂.茶树内生真菌油脂为棕黄色黏稠液体,具芳香气味,茶叶提取液可促进内生真菌油脂的合成.     

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.