明清时代的鄱阳商业与商人

文章利用方志与墓志中的商业与商人史料,分析了明清时代鄱阳县本地商业状况与外来商帮构成,以及鄱阳商人的经营行业和商贸地域.透过商人的传记资料,可以看到士人为商人写传,大力肯定商人的志业,商人则高度认同士人所代表的儒学主流价值观;方志为商人立传,商人为桑梓与国家效力,体现的是士商之间、商人与国家和社会之间相得益彰、"美美与共"的良性互动.     

螺栓连接大变形梁非线性振动特性的实验研究

柔性机械臂、大型可展开天线等机械结构的动作精度受运动过程中大变形几何非线性和连接处接触非线性的影响十分显著。以含螺栓连接结构的大变形梁作为研究对象，针对动力学建模和振动特性开展了实验研究，通过数值计算验证了实验发现的非线性振动特性。搭建了含螺栓连接柔性大变形梁的实验台架，开展了敲击和正弦激振的实验测试。实验结果表明，螺栓连接的柔性梁较连续梁的（无螺栓连接）模态频率降低，阻尼增加，反映出随着激励能量增大，模态频率降低的非线性模态特征。改变螺栓连接位置会显著影响结构的模态频率，其变化规律可由求解线性矩阵特征值定性反映。     

南城县景观生态风险评价及预测研究

基于南城县2010年、2013年、2016年与2019年4期遥感解译数据,将土地利用类型重分类为8类,利用Fragstats4.2软件计算景观指数,分析景观生态风险时空变化特征,并基于FLUS模型预测南城县土地利用结构,进行南城县景观生态风险预测研究.     

多弧离子镀制备的耐事故燃料包壳铬涂层晶粒结构研究

本文通过从几十微米到几埃的多尺度表征展示了多弧离子镀制备铬涂层的详细结构.经XRD, SEM, FIB, TEM和HRTEM表征，结果显示该涂层是一种多重结构，包括表面上的微米级颗粒、缺陷带钉扎的微米或次微米级液滴、以堆垛层错为晶界的柱状晶、以刃位错和螺型位错为区分的微晶、位错末端的原子畸变以及原子排列无序化的区域.这些结构通过改变涂层的结晶度，影响了晶格常数、表面粗化和FIB溅射裂纹.此外，通过分析HTEM照片，确定了这些堆垛层错和位错的类型.最后，讨论了沉积参数对这些晶粒结构的影响.     

烟支硬度检测结果影响因素分析

为探究烟支硬度检测结果的影响因素,对烟支物理指标检测方案进行优化,提升卷烟质量监督水平.本试验以3类卷烟泰山(东方)为试验材料,分别设计不同检测方案、挡烟板位置、预压时间、压缩时间、压缩速度、环境湿度、贮存时间来对烟支硬度进行测定.烟支检测全项时硬度明显高于单独检测出的硬度;随挡烟板位置的增加,烟支硬度检测值先下降再上升;预压时间、压缩速度对烟支硬度检测结果影响不显著;不同的测试环境湿度会引起烟支水分变化,进而导致烟支硬度检测值产生变化;1个月内硬度不会发生明显变化,但是随着贮存时间延长而增长.应适当优化烟支物理指标检测顺序或方案,设置挡烟板位置为距离接嘴端55 mm,降低测定环境湿度为60％±2％,减少烟支贮存时间或控制贮存环境湿度,及时维护测定设备,以提升质量监督水平.     

Side-Channel Attacks in a Real Scenario

Existing Side-Channel Attacks(SCAs) have several limitations and, rather than to be real attack methods,can only be considered to be security evaluation methods. Their limitations are mainly related to the sampling conditions, such as the trigger signal embedded in the source code of the encryption device, and the acquisition device that serves as the encryption-device controller. Apart from it being very difficult for an attacker to add a trigger into the original design before making an attack or to control the encryption device, there is a big gap in the capacity of existing SCAs to pose real threats to cipher devices. In this paper, we propose a new method, the sliding window SCA(SW-SCA), which can be applied in scenarios in which the acquisition device is independent of the encryption device and for which the encryption source code requires no trigger signal or modification. First,we describe the main issues in existing SCAs, then we theoretically analyze the effectiveness and complexity of our proposed SW-SCA —a method that can incorporate a sliding-window mechanism into almost all of the existing non-profiled SCAs. The experimental results for both simulated and physical traces verify the effectiveness of the SW-SCA and the appropriateness of its theoretical complexity.     

双辊薄带连铸低碳微合金钢的铸态组织

采用双辊薄带连铸技术制备了低碳微合金钢薄带，利用OM，SEM和TEM对铸态凝固组织、室温组织、析出及位错进行观察和分析.结果表明:低碳微合金钢铸带的凝固组织中二次枝晶间距约为12~15μm，相对于传统厚板坯和薄板坯连铸，铸带组织得到了明显细化.铸带的原奥氏体晶粒尺寸比较粗大，约为250~410μm，其组织由魏氏铁素体、珠光体和不规则铁素体组成.铸带组织中存在纳米级TiC析出和短棒状的渗碳体.TiC析出没有被薄带连铸的凝固过程及二次冷却过程明显抑制.铸带组织由于铸轧力及二次冷却速率不均匀导致大量位错的产生.     

Defining G protein-coupled receptor peptide ligand expressomes and signalomes in human and mouse islets

Introduction

Islets synthesise and secrete numerous peptides, some of which are known to be important regulators of islet function and glucose homeostasis. In this study, we quantified mRNAs encoding all peptide ligands of islet G protein-coupled receptors (GPCRs) in isolated human and mouse islets and carried out in vitro islet hormone secretion studies to provide functional confirmation for the species-specific role of peptide YY (PYY) in mouse islets.

Materials and methods

GPCR peptide ligand mRNAs in human and mouse islets were quantified by quantitative real-time PCR relative to the reference genes ACTB, GAPDH, PPIA, TBP and TFRC. The pathways connecting GPCR peptide ligands with their receptors were identified by manual searches in the PubMed, IUPHAR and Ingenuity databases. Distribution of PYY protein in mouse and human islets was determined by immunohistochemistry. Insulin, glucagon and somatostatin secretion from islets was measured by radioimmunoassay.

Results

We have quantified GPCR peptide ligand mRNA expression in human and mouse islets and created specific signalomes mapping the pathways by which islet peptide ligands regulate human and mouse GPCR signalling. We also identified species-specific islet expression of several GPCR ligands. In particular, PYY mRNA levels were ~ 40,000-fold higher in mouse than human islets, suggesting a more important role of locally secreted Pyy in mouse islets. This was confirmed by IHC and functional experiments measuring insulin, glucagon and somatostatin secretion.

Discussion

The detailed human and mouse islet GPCR peptide ligand atlases will allow accurate translation of mouse islet functional studies for the identification of GPCR/peptide signalling pathways relevant for human physiology, which may lead to novel treatment modalities of diabetes and metabolic disease.

     

基于Unity 3D的多机协同化纤长丝生产线工艺仿真

将化纤长丝生产线按功能特点分成生产、检测、包装和仓储4个子系统,基于Unity 3D分别在4台电脑上进行协同仿真和显示。生产子系统使用数据化驱动可以仿真任意生产规模的场景,检测子系统与智能检测模块联合可以仿真基于视觉处理的真实生产线产品质量检测,包装子系统可以对质量合格的丝饼按规格打包,仓储子系统根据订单需求对已打包的丝饼进行存储并完成进出库操作。对各子系统需要通信的数据制定了协议,使用基于TCP/IP(transmission control protocol/internet protocol)的Socket通信完成多台电脑协同仿真。试验表明,多机协同仿真可以更高效地设计和优化化纤长丝生产线。     

分离式微通道热管低风量下换热性能模拟研究

为了降低数据中心的运行能耗，分离式热管冷却系统会根据实际负载降低风扇转速，造成换热性能的衰减. 为了对低风量和低负载下分离式微通道热管的换热性能进行研究和分析，建立了适用于预测低风量下分离式微通道热管换热性能的一维稳态模型，并与试验结果对比，验证了模型的准确性，其最大预测平均偏差为6.3%. 利用该模型研究了运行参数对分离式微通道热管的换热性能和数据中心热安全的影响. 不同风量下，服务器排风温度从27 ℃上升至39 ℃时，系统换热量均有超过60%的提升；冷冻水供水温度从6 ℃提升至18 ℃会导致系统换热量最高下降41.8%. 在200～1 400 m3/h风量下，增加蒸发器和冷凝器的高度差可有效提升系统换热量和制冷剂质量流量，风量越大，换热量增长率越高. 但在相同风量下，随着高度差的逐渐增大，换热量增长率逐渐降低. 研究结果对分离式微通道热管在数据中心的设计优化和节能运行有一定促进作用.