点雨量和面雨量的最优估计

降雨量系随空间位置变化的一种区域化变量,既有随机性,又有一定的结构性。本文应用克里格法对点雨量和面雨量进行了最优估计。由该法得到的估计值符合无偏性,且估计方差最小,因此它比传统常规方法具有较高的可靠性。     

Stress and deformation analysis on deep surrounding rock at different time stages and its application

Based on the characteristics of the deep circular tunnel, the surrounding rock was divided into three regions: the cracked region, the plastic region and the viscoelastic region. The process of rock stress deformation and change was divided into three stages after the roadway excavation. By using the elastic–plastic mechanics theory, the analytical solutions of the surrounding stress and displacement at different stages and the radii of cracked and plastic regions were formulated. We additionally explained the surrounding rock stress and displacement which appeared in practical project. Simultaneously, based on the problem which emerged from a mine in Xuzhou during the excavating process of rock roadway’s transport, we got the theoretical solutions for the stress and displacement in the process of rock roadway’s excavation and considered that the broken area of rock roadway was largely loosing circle. The results indicate that according to the rheological characteristics of surrounding rock, in the primeval excavation of rock roadway, we should increase the length of anchor bolt and cooperate it with anchor nets cable-U steel supporting frame. In addition, when the deformation rate of the surrounding rock is descending after the 15 days’ excavation, we should use the “three anchor” supporting method (anchor bolt spray, anchor note and anchor rope) and set aside about 20 cm as the reserved deformation layer.     

化工冶金学家陈家镛

1958年中国科学院化工冶金研究所(现过程工程研究所)的创建,与建国初期的国家经济发展和国防建设的需求紧密相关。1956年陈家镛受到世界著名冶金学家叶渚沛的邀请,到正在筹建中的化工冶金研究所工作。作为国内该领域开拓者和学术带头人,陈家镛院士的学术经历是本文主线。以他带领同事们开展湿法冶金研究为案例,分析了国家重大战略需求与科学技术研究之间的关系。重点介绍了他在冶金、化工、材料等研究领域做出的重要学术贡献,以及将代表性科研成果经过中间试验应用于实际生产、解决企业所面临的技术难题的情况。藉此反映了以过程工程研究所为代表的国立科研机构,围绕国家重大战略需求开展科技攻坚的历程与成果。     

山东省某测井公司放射工作人员职业健康状况分析

分析了山东省某测井公司放射工作人员职业健康检查结果。结果表明:(1)放射工作人员的血压异常率与年龄、工龄有关,随着年龄、工龄的增加而增高,差异显著;(2)不同年龄段间比较,肾功能异常率差异显著;(3)不同工龄段间比较,胸部X射线摄影异常率差异显著。结论认为,从事测井工作的放射工作人员长期接触低剂量辐射,应提高防护意识,...     

Analysing the shielding effect of a concrete wall reinforced with steel plate using generalised surface integral equations

The electromagnetic shielding effect of a two-dimensional concrete wall reinforced with steel plate is analysed using a generalised surface integral equation (GSIE) method developed from Huygens? equivalence principle. The wall is divided into small blocks. Each block is analysed independently at first, and its electromagnetic characteristics are expressed by an associated generalised transition matrix defined on the reference surface of that block. In order to find the electromagnetic characteristics of the whole system, a GSIE formulation is established on the reference surface of all blocks, which can be solved efficiently using characteristic basis functions.     

Studied on a novel human keratinocyte membrane delivery system in vitro

The culture of keratinocytes on flexible membranes has been proposed as a means to simplify, accelerate and improve the efficiency with which proliferating cells are delivered to full thickness or non-healing skin defects. The purpose of this article was to study the ability of chitosan-gelatin manbranes to facilitate the growth of human keratinocytes. The membranes with different chitosan contents were studied. The surface properties of chitosan-gelatin membranes were investigate by SEM, and water contact angle test. The mechanical property of the membranes was tested. Data implied that gelatin could make the membranes more flexible and hydrophilic than chitosan membranes, which may regulate the seeded cells behavior. Loading human keratinocytes on chitosan-gelatin membranes, cells attachment, spread, and growth were investigated by light microscopy, SEM, and MTT test. The results suggested that the adhesion and proliferation of keratinocytes seeded on chitosan-gelatin membranes were same as on tissue culture plate, in which gelatin could modify the interaction between keratinocytes and chitosan membranes. Therefore, chitosan-gelatin membrane is a good candidate for keratinocytes delivery system.     

Molecular Mechanisms of Parthanatos and Its Role in Diverse Diseases

Differential evolution of apoptosis, programmed necrosis, and autophagy, parthanatos is a form of cell death mediated by poly(ADP-ribose) polymerase 1 (PARP1), which is caused by DNA damage. PARP1 hyper-activation stimulates apoptosis-inducing factor (AIF) nucleus translocation, and accelerates nicotinamide adenine dinucleotide (NAD⁺) and adenosine triphosphate (ATP) depletion, leading to DNA fragmentation. The mechanisms of parthanatos mainly include DNA damage, PARP1 hyper-activation, PAR accumulation, NAD⁺ and ATP depletion, and AIF nucleus translocation. Now, it is reported that parthanatos widely exists in different diseases (tumors, retinal diseases, neurological diseases, diabetes, renal diseases, cardiovascular diseases, ischemia-reperfusion injury...). Excessive or defective parthanatos contributes to pathological cell damage; therefore, parthanatos is critical in the therapy and prevention of many diseases. In this work, the hallmarks and molecular mechanisms of parthanatos and its related disorders are summarized. The questions raised by the recent findings are also presented. Further understanding of parthanatos will provide a new treatment option for associated conditions.     

Recursive identification for Hammerstein–Wiener systems with dead-zone input nonlinearity

A new recursive algorithm is proposed for the identification of a special form of Hammerstein–Wiener system with dead-zone nonlinearity input block. The direct motivation of this work is to implement on-line control strategies on this kind of system to produce adaptive control algorithms. With the parameterization model of the Hammerstein–Wiener system, a special form of model estimation error is defined; and then its approximate formula is given for the following derivation. Based on these, a recursive identification algorithm is established that aims at minimizing the sum of the squared parameter estimation errors. The conditions of uniform convergence are obtained from the property analysis of the proposed algorithm and an adaptive setting method for a weighted factor in the algorithm is given, which enhances the convergence of the proposed algorithm. This algorithm can also be used for the identification of the Hammerstein systems with dead-zone nonlinearity input block. Three simulation examples show the validity of this algorithm.     

一种基于重心法的连锁经营企业区域物流配送中心选址模型

提出了配送中心吸引力指数的概念,建立了以吸引力指数最大为目标函数的选址理论模型.考虑了模型解决具体问题的实用性,引入交通区位和地价2个权重因素对不同候选地址的吸引力指数进行加权,实现连锁经营企业区域物流配送中心的选址优化.通过具体算例表明算法能够获得更切合实际的目标解,且搜索时间短、效率较高.