带约束拉杆方形钢管混凝土短柱偏压工作机理

为研究带约束拉杆方形钢管混凝土短柱偏压的工作机理,采用考虑材料泊松比变化、钢管和核心混凝土界面作用及钢管残余应力的有限元模型,利用有限元软件ABAQUS对其偏压受力全过程进行分析.从横向变形、荷载-竖向位移曲线、核心混凝土纵向应力分布、钢管与核心混凝土的相互作用、约束拉杆的影响等方面讨论了带约束拉杆方形钢管混凝土短柱偏压工作机理.结果表明:有限元计算结果与试验结果吻合较好;设置约束拉杆可减小构件的横向挠曲变形,改变截面的变形模态,增强钢管对核心混凝土的约束效应,提高短柱的偏压承载力和延性;约束拉杆间距越小,短柱的延性越好,偏压承载力越大;泊松比对短柱偏压承载力具有一定影响,残余应力则对其几乎无影响.     

两种聚类模型在城市垃圾清运路径规划中的应用

基于广东省深圳市南山区的实地调查,提出了一种新的城市垃圾处理设备的分布设计和清运方案。在厨余垃圾处理设备的分布设计时,建立了两种数学模型,即最短距离聚类模型和k-Means聚类模型。通过对两者的比较得出k-Means聚类模型更适合垃圾清运路径的规划。本文提出的方法对解决深圳市南山区垃圾处理的路径规划具有较高的准确性,可用于全国其他各大城市的垃圾处理方案设计中。     

高压脉冲对岩混材料击穿效应的仿真研究

为了研究高压脉冲对岩混材料目标的击穿规律,该文通过计算机仿真软件模拟高压脉冲对岩混材料块的作用过程,研究电子束运动轨迹及其能量密度分布的变化。结果表明:趋于临界击穿条件下,电极端自由电子的倍增效应越发显著,输入端发生雪崩击穿并表现出电子束呈现边界收窄的趋势,同时电极尖端能量密度分布趋于聚焦,与实验所测输出电流峰值越高,波形脉宽越窄的现象一致。该研究可为高效破碎岩混材料相关应用提供技术依据。     

镁水泥钢筋混凝土盐卤侵蚀下的耐久性试验

针对研发青海省格尔木市的察尔汗盐湖地区耐腐蚀混凝土研发的迫切要求,结合察尔汗盐湖地区的实际情况,设计盐卤侵蚀单因素试验条件,通过相对质量、相对动弹性模量、裂缝与变形及钢筋的锈蚀情况来研究镁水泥钢筋混凝土在盐卤侵蚀单因素下的耐久性问题.通过研究发现:经长期盐卤侵蚀试验后,镁水泥混凝土性能未出现明显劣化;镁水泥混凝土的抗腐蚀性能优越,钢筋均存在一定程度的腐蚀.     

白龙浮标数据全球通信系统共享的解决方案

为实现白龙浮标数据按照标准格式全要素参与国际交换,设计了从浮标数据测量、卫星传输、岸站接收、实时数据质量控制、云服务器存储到FTP数据上传中国气象局的数据传输链路;采用WMO推荐的标准BUFR格式对原始数据进行格式转换和重新编报,并按照全球通信系统(GTS)的规则进行封装和编发,实现了白龙浮标气象和海洋观测数据实时向GTS的分发共享,全球用户可以通过GTS收集数据并进行分拣后,按照报头识别并解码得到白龙浮标实时数据。白龙浮标成为我国第一个实时数据共享到GTS的锚系浮标,表明我国锚系浮标数据提供能力达到世界先进水平。     

铅基钙钛矿太阳能电池界面工程的研究

在wxAMPS太阳能电池数值模拟软件微平台上,对ITO/ZnO/界面层(IFL)/MAPbI₃/Sprio-OMeTAD/Au结构的钙钛矿太阳能电池(PSCs)的电子传输层(ETL)/吸收层的界面工程进行研究。结果表明:在界面层缺陷密度低于1014 cm-3时,PSCs的电池性能几乎不变,当缺陷密度高于1014 cm-3时,PSCs的电池性能急剧下滑。当界面层与吸收层亲和势差(Δχ)在-0.7~-0.1 eV范围时,各项电池性能参数均随Δχ的增大而增大;当Δχ在-0.1~0.5 eV范围时,各项电池性能呈平缓增长;当Δχ大于0.5 eV时,电池的短路电流(J_SC)呈平缓增长趋势,而开路电压(V_OC)、填充因子(FF)及光电装换效率(PCE)快速降低。当带隙E_g在0.9~1.4 eV范围内增大时,PSCs的V_OC、FF和PCE均上升;当带隙E_g大于1.4 eV,PSCs的各项性能参数基本不变。     

Protein arginine deiminase 4: a target for an epigenetic cancer therapy

The recent approvals of anticancer therapeutic agents targeting the histone deacetylases and DNA methyltransferases have highlighted the important role that epigenetics plays in human diseases, and suggested that the factors controlling gene expression are novel drug targets. Protein arginine deiminase 4 (PAD4) is one such target because its effects on gene expression parallel those observed for the histone deacetylases. We demonstrated that F- and Cl-amidine, two potent PAD4 inhibitors, display micromolar cytotoxic effects towards several cancerous cell lines (HL-60, MCF7 and HT-29); no effect was observed in noncancerous lines (NIH 3T3 and HL-60 granulocytes). These compounds also induced the differentiation of HL-60 and HT29 cells. Finally, these compounds synergistically potentiated the cell killing effects of doxorubicin. Taken together, these findings suggest PAD4 inhibition as a novel epigenetic approach for the treatment of cancer, and suggest that F- and Cl-amidine are candidate therapeutic agents for this disease.     

A Note on the Property of ψ-Function

About the accurate value of ψ ( x ) = Γ′ ( x ) / Γ ( x), we know only ψ (1)and ψ (1/ 2).In this paper, by calculating the accurate values of some series expansion of a function and applying some skills of complex analysis, we prove that the expression of the ψ-function admits a finite expression in elementary function for rational number z. As an application, some examples are given.     

(±)-二氢猕猴桃内酯的合成研究(Ⅱ)

以柠檬醛为原料，经环化、羟腈化、水解关环和脱水４步反应，以３１４％的总产率合成了（±）－二氢猕猴桃内酯     

The role of endosomal-recycling in long-term potentiation

Long-term potentiation (LTP) defines persistent increases in neurotransmission strength at synapses that are triggered by specific patterns of neuronal activity. LTP, the most widely accepted molecular model for learning, is best characterised at glutamatergic synapses on dendritic spines. In this context, LTP involves increases in dendritic spine size and the insertion of glutamate receptors into the post-synaptic spine membrane, which together boost post-synaptic responsiveness to neurotransmitters. In dendrites, the material required for LTP is sourced from an organelle termed the endosomal-recycling compartment (ERC), which is localised to the base of dendritic spines. When LTP is induced, material derived from the recycling compartment, which contains α-amino-3-hydroxy-5-methyl-4-isoxazole propionate-type glutamate receptors (AMPARs), is mobilised into dendritic spines feeding the increased need for receptors and membrane at the spine neck and head. In this review, we discuss the importance of endosomal-recycling and the role of key proteins which control these processes in the context of LTP.