基于BIM技术的斗栱三维参数化设计研究

为更好地传承和发扬中国古建筑文化,使现代建筑技术能够服务于古建筑文化保护,以清式斗栱为例,在古建筑模数制的基础上,利用BIM技术,以斗口为基本变量,建立斗栱的各组成构件的标准库,通过斗栱各构件的参数化控制以及斗栱模型的参数联动,实现了斗栱的参数化设计,极大提高设计工作效率,为古建筑的保护与传承提供了一种新的思路和方法.     

泵水力设计方法的研究现状

泵是流体输送系统的核心动力源,开展泵优化设计、实现节能降耗一直是流体机械领域的研究热点。文章回顾了基于一元、二元、三元流动理论进行水力设计的各种方法,总结了各个水力设计方法的优缺点;概括了近年来在叶轮、导叶、蜗壳水力设计方面的研究热点和主流方法,为今后泵设计方法的发展奠定了基础。以数值模拟结合三元流动理论和优化算法的设计方法已成为当前开展泵水力设计的主流手段,可以预期,随着计算机计算能力的进一步提高和优化算法的快速发展,泵的水力设计水平将会有大幅度提升并会促进泵行业的整体技术进步。     

DanHong Injection inhibits the development of primary abdominal aortic aneurysms in apoE knockout mice

Clinical observations indicate that DanHong Injection （DHI） can increase blood flow and reduce various syndromes in patients with cardiovascular disease. How- ever, it still needs to define the function of DHI and the involved mechanisms in details, such as the protective effect on the development of primary abdominal aortic aneurysms （AAAs）. In this study, we determined whether DHI is able to inhibit AAA in apoE knockout （apoE-/-） mice. Thirty apoE-/- male mice on high-fat diet （0.5 % cholesterol, 21% fat） were randomly divided into two groups and received i.p. injection of saline （100 μL/day） and DHI （100 μL/day）, respectively, for 16 weeks. At the end of experiment, we determined the development of atherosclerosis in en face aorta and aneurysms,pathological morphology of arterial wall, and serum lipid levels. We also determined the expression of monocyte chemoattractant protein-1 （MCP-1）, MMP-2, and MMP-9 mRNA in aortic wall using real-time RT-PCR. Our results indicated that high-fat diet induced the development of AAAs in apoE-/- mice, but the induction was totally blocked by DHI （P 〈 0.01）. The result of staining of abdominal aortic cross sections showed that DHI main- tained the collagen content in arterial wall, thereby pre- venting the animals from the development of AAA. Although DHI had little effect on serum total- and LDL- cholesterol levels, it reduced the expression of MCP-1, MMP-2, and MMP-9 mRNA in aortic wall （P 〈 0.01）. Taken together, our study suggests that DHI can inhibit the high-fat diet-induced AAA formation. The inhibitory effects may be related to the maintenance of the collagen content and inhibition of expression of AAA-related genes. Our study may suggest a new application of DHI in clinics.     

Deep cleaning of a metallurgical zinc leaching residue and recovery of valuable metals

Huge quantities of zinc leaching residues (ZLRs) generated from zinc production are dumped continuously around the world and pose a potential environmental threat because of their considerable amounts of entrained heavy metals (mainly lead). Most ZLRs have not been properly treated and the valuable metals in them have not yet been effectively recovered. Herein, the deep cleaning of a ZLR and recovery of valuable metals via a hydrometallurgical route were investigated. The cleaning process consists of two essential stages:acid leaching followed by calcium chloride leaching. The optimum conditions for extracting zinc, copper, and indium by acid leaching were a sulfuric acid concentration of 200 g·L-1, a liquid/solid ratio of 4:1 (mL/g), a leaching time of 2 h, and a temperature of 90℃. For lead and silver extractions, the optimum conditions were a calcium chloride concentration of 400 g·L-1, a pH value of 1.0, a leaching time of 1 h, and a temperature of 30℃. After calcium chloride leaching, silver and lead were extracted out and the lead was finally recovered as electrolytic lead by electrowinning. The anglesite phase, which poses the greatest potential environmental hazard, was removed from the ZLR after deep cleaning, thus reducing the cost of environmental management of ZLRs. The treatment of chlorine and spent electrolyte generated in the process was discussed.     

R-Gorenstein内射模的忠实平坦余基变换

探究了R-Gorenstein内射模的忠实平坦余基变换.设R是交换环,S是忠实平坦R-代数,在一些额外的条件下,证明了R-模N是R-Gorenstein内射模，当且仅当N是强余挠R-模且Hom R(S,N)是R′-Gorenstein内射 S-模.     

概念精准与逻辑严密视角下对"密度"概念教学思路的再认识

"密度"作为初中物理引入最早、抽象程度最高的概念,历来都是教学的重点和难点,针对"密度"在日常教学中存在的症结,联系学生朴素认识,导入密度物理意义;直接比较物体质量,成功引发认知冲突;找出谬误产生根源,合理修正先前假设;结合具体实验数据,尝试诠释比值内涵;巧妙安排问题顺序,完成密度学习进阶4个环节,并对教学效果进行了相关的实证分析,教学效果很好.     

察哈素煤矿31303工作面煤矿破碎煤柱高温区域治理实践

察哈素煤矿31303工作面回采期间,受相邻工作面开采矿山压力的影响,辅助回风顺槽煤柱变形破碎、产生漏风,辅助回风顺槽煤柱出现高温氧化现象。根据现场自然发火隐患情况,加强了气体及温度变化监测,对辅助回风顺槽隔离煤柱采取了灭火、降温、惰化、漏风通道封闭等措施,消除了火灾隐患。     

网络舆情及其应对与上市公司的信息效率

网络舆情的兴起给资本市场带来了深远影响,对监管层和上市公司的舆情管理工作也提出了新的挑战.借助于监管部门对深市上市公司网络舆情应对状况的调查,实证检验了网络舆情及其应对与上市公司的信息效率的关系.研究发现,网络舆情危机会造成当年度股价崩盘,且来自自媒体的转载会增大股价崩盘的幅度,网络舆情重视和应对程度良好的公司在面对舆情危机时的股价崩盘幅度更低.上市公司对网络舆情的重视及投入能够向资本市场传递公司特质信息,提高资本市场的信息效率,进而降低未来股价崩盘风险和股价同步性.结论表明,上市公司加强网络舆情应对并非是满足监管要求和投资者诉求的面子工程,而是一项切实有效的求是工作,结论对完善资本市场信息传播管理制度,提高资本市场信息效率具有一定的参考价值.     

动力电池用纳米LiCoPO_4正极材料的合成与电化学性能

研究了动力电池用5V纳米正极材料磷酸钴锂(LiCoPO4)的喷雾裂解合成技术及其电化学性能.研究中使用喷雾干燥法获得前驱体,通过高温裂解等一系列手段获得LiCoPO4纳米正极材料,使用X射线衍射仪(XRD)、扫描电子显微镜(SEM)等分析手段对LiCoPO4样品进行分析表征和性能测试.结果发现,裂解温度是影响LiCoPO4合成的主要因素,650℃以上温度煅烧获得纯相LiCoPO4.纯相LiCoPO4的电化学性能不甚理想,而掺杂Fe元素部分取代Co能够提高LiCoPO4的初始容量和循环性能,使得该材料具有很好的应用前景.