Modeling of the pharyngeal muscle in Caenorhabditis elegans based on FitzHugh-Nagumo equations

The pharyngeal pumping motion to send food to the bowel is a rhythmic movement in Caenorhabditis elegans. This paper proposes a simulation-based approach to investigate the mechanisms of rhythm phenomena in the pharyngeal pumping motion. To conduct the simulations, first, we developed a pharyngeal muscle model including 29 cell models which simulate the activity of each cell as a membrane potential based on FitzHugh-Nagumo equations. Then, to compare the response of the model with that of C. elegans, we calculated the electropharyngeogram (EPG), which represents the electrophysiological responses of the pharyngeal cells, using the simulated membrane potentials. The results confirmed that our model could generate the EPG similar to that measured from C. elegans. We proposed a computer simulation of the pumping motion to investigate the mechanisms of rhythm phenomena in living organisms.     

一种基于EPID的安全OA系统

文章对OA系统中存在的安全问题进行了讨论,引人了一种新的基于远程匿名身份认证EPID模式,它能通过保存设备拥有者私密信息的硬件设施进行身份鉴定。一个嵌入EPID私密的硬件设备可以向远程机构证实它的有效性,而不必暴露自己的身份和其他私密信息。可以撤消一个签名的EPID私钥,即使不知道密钥的身份。同时,把EPID和其它的一些方法进行了对比。     

小型储气罐火灾工况数值模拟分析

以某输气管线气液联动执行机构中的储气罐为例,利用Ansys Fluent软件建立同比例三维模型,模拟火灾工况下,外部热量不断输入,罐内压力和罐体温度随时间的变化情况。利用Aspen Hysys软件模拟计算该小型储气罐在火灾工况下安全泄放所需的最小安全阀口径。结果表明,当钢制储气罐外部发生火灾时,罐体温度和罐内压力急剧升高,在很短的时间内就能达到储气罐坍塌温度和储气罐设计压力;达到钢制储气罐坍塌温度的时间滞后于达到储气罐设计压力的时间;从安全的角度,设置安全阀可安全有效泄放气体,即使储气罐发生坍塌,也有助于降低事故发生的危害程度;确定的安全阀最小口径为0.03 cm²,建议选型的安全阀口径不低于0.05 cm²。     

CMS环境下基于智能优化算法的单元间布局问题研究*

研究了单元制造系统(CMS)设计中单元间布局设计问题,从单元制造系统的实际出发,提出了一种基于割树(Slicing-tree)的单元间布局设计模型.该模型考虑了单元形状约束、单元I/O点位置优化等诸因素对布局结果的影响.针对基于割树的描述形式,采用遗传算法求解,提出了一种新的割树编码方案,克服了以往编码方案易产生非法子串、不能覆盖整个解空间以及实现困难等缺点.计算结果表明,该算法是有效的、可行的.     

Photocatalytic syngas synthesis from CO2 and H2O using ultrafine CeO2-decorated layered double hydroxide nanosheets under visible-light up to 600 nm

The rational design of photocatalyst that can effectively reduce CO₂ under visible light(l>400 nm),and simultaneously precise control of the products syngas(CO/H2)ratio is highly desirable for the Fischer-Tropsch reaction.In this work,we synthesized a series of CeO₂-decorated layered double hydroxides(LDHs,Ce-x)samples for photocatalytic CO₂ reduction.It was found that the selectivity and productivity of CO and H₂ from photoreduction of CO₂ in conjunction with Ru-complex as photosensitizer performed an obvious“volcano-like”trend,with the highest point at Ce-0.15 and the CO/H₂ ratio can be widely tunable from 1/7.7 to 1/1.3.Furthermore,compared with LDH,Ce-0.15 also drove photocatalytic CO₂ to syngas under 600 nm irradiation.It implied that an optimum amount of CeO₂ modifying LDH promoted the photoreduction of CO₂ to syngas.This report gives the way to fully utilize the rare earth elements and provides a promising route to enhance the photo-response ability and charge injection efficiency of LDH-based photocatalysts in the synthesis of syngas with a tunable ratio under visible light irradiation.     

不同类型避雷针雷击接闪效能差异的实验评价方法

探讨一种直观、易于理解且反映雷击放电机理的实验方法,以评价不同类型避雷针的雷击接闪效能差异,对雷电防护领域形成共识显得尤为重要.为此,论文首先分析了雷电环境下地面目标物上避雷针的雷击接闪过程,指出不同类型避雷针接闪效能的差异主要体现在对迎面放电过程的影响上;接着,提出了如下实验评价方法:采用针-板间隙的放电实验布置,对4m及以上间隙施加1.2/50μs标准雷电波模拟迎面流注放电过程,对6m及以上间隙施加250/2500μs标准操作波模拟迎面先导放电过程;然后,通过比较非传统避雷针与传统避雷针的放电起始时刻与平均发展速度2个指标,以评价不同类型针的接闪效能差异;最后,利用所提方法对典型提前放电(early streamer emission,ESE)非传统避雷针与传统避雷针开展了接闪效能差异的评价实验.实验结果表明:ESE针与传统避雷针的评价指标基本一致,不具备研发商所宣称的引雷增效作用.     

高压并联电容器补偿装置的元件选择及其运行分析

阐述了高压并联电容器补偿装置的组成、接线方式,依据现行国家标准及有关技术资料分析了高压并联电容器补偿装置中电容器、放电线圈、电抗器、熔断器及过电压保护器等主要电气元件的作用、选择规范及安装运行时应注意的问题;同时介绍了电容器分组容量及电容器组在各种容量组合投切时遵循的原则,确保高压并联电容器补偿装置的安全经济运行.     

Synthesis and characterization of poly acrylic acid/graphite oxide nanocomposite

1　INTRODUCTIONOrganic intercalatedlayeredsolidshavebeenstudiedbyscientistsindifferentfieldsformanyyearsbecauseoftheirnew physicalandchemicalpropertiessuchaselectricalproperties[1] ,mechanicalproper ties ,thermalbehavior[2 ] ,surfaceandinterfacialproperties[3] .Graphiteoxide (GO)hasbeenstudiedformany years ,itsstructuralmodel[4 6 ] ,formationprocessandkinetics[7,8] havebeenstudiedindetail.IthasbeenreportedthatGOpossessesC OHande poxidefunctionalgroups[9] whichmakegraphiteox ideeasilyabs…     

炼厂硫腐蚀的典型案例分析及解决措施

通过硫在不同温度与环境下对金属材料腐蚀的典型案例分析，简述其腐蚀机理与解决,工对今后炼厂高硫油加工提出进一步建议。     

氟化铝生产废水处理工艺的研究

对氟化铝生产废水的处理方法进行了研究。结果表明，一级中和沉淀法和二级中和二级沉淀法均不宜用于氟化铝生产废水的结果，理想的处理方法是碱过量中和酸回调法，辅加氯化钙的石灰乳中和法也可考虑采用。