2011—2015年秦山核电基地周围环境沉降物总α、总β放射性水平监测

报道2011—2015年浙江省辐射环境监测站对秦山核电基地周围环境沉降物总α、总β放射性水平的监测工作。监测结果表明, 2011—2015年, 秦山核电基地周围环境沉降物中总α活度浓度范围为0.07～0.92 Bq·m^-2d^-1, 平均值为0.28 Bq·m^-2d^-1;总β活度浓度范围为0.24～1.70 Bq·m^-2d^-1, 平均值为0.58 Bq·m^-2d^-1;总α/总β值范围为0.26～0.83;监测结果与对照点(杭州市)监测值处同一水平。     

浅圆仓仓顶钢结构支撑的设计与施工探讨

本文介绍一种大直径浅圆仓装配整体式钢筋混凝土锥形仓顶施工过程中 ,采用的设计与施工方法。该方案利用仓壁滑模操作平台作为仓顶安装用钢结构支撑的底层拉杆 ,同时兼作钢结构支撑自身的施工安装平台 ,解决了类似工程钢结构支撑易失稳的技术难题 ,对同类工程的施工很有参考价值     

转包和违法分包等违法行为自查及纠正方案

近期,住房城乡建设部就工程质量治理问题密集出台多项文件,就建筑行业的转包、违法分包等顽疾进行严查、整治,本文根据数十年的建设工程法律服务经验,深入解析文件要点,并结合建筑企业实际情况提出自查及纠正方案,从项目管理机构及人员关系、资质证书、合同文件、资金往来关系4方面进行针对性策略,以期对建筑企业规范自身管理、防范风险有所裨益。     

不同坡角斜坡动力响应频谱特征研究

 斜坡频谱特征曲线与斜坡形态密切相关,若入射地震波主频接近频谱曲线中极大谱比值所对应的卓越频率,就会放大斜坡动力响应,甚至造成斜坡失稳。以汶川极震区青川狮子梁斜坡为典型实例,根据青川3次余震作用下斜坡不同高程实测地震记录及地脉动测试结果,通过单点谱比法,获得斜坡地震动和地脉动的频谱特征曲线,通过对比分析曲线发现：坡顶卓越频率最小;同时,实测水平地震加速度峰值放大系数随高程增加表现出先减小后增加的“凹型”特征,坡顶的放大系数甚至达到坡底的1.25。如果从斜坡形态因素进行分析,坡顶存在低频但较高放大系数的现象可能与斜坡高差与入射波波长之比密切相关,在比值为0.2时,坡顶放大效应达到最大。为进一步确定斜坡形态对频谱特征影响,利用实测汶川地震卧龙波拟合成多频率地脉动作为动力输入,在FLAC有限差分软件中建立3种不同坡角均质斜坡模型,经动力计算后发现,3种模型坡顶、坡中及坡脚的卓越频率基本一致,该结果与输入单一频率Ricker子波时斜坡动力响应一致,说明斜坡角度改变不会影响斜坡的卓越频率。研究结论有助于增强斜坡自身频谱与动力响应之间关系的认识。     

Promoting effect of W doped in electrodeposited Co–P catalysts for hydrogen generation from alkaline NaBH4 solution

Amorphous Co–W–P catalysts were prepared on Cu substrates by electrodeposition, which have been investigated as the catalyst for hydrogen generation from alkaline NaBH₄ solution. The surface morphology and chemical composition of the as-prepared Co–W–P catalysts were analyzed in relation to the cathodic current density and the electrodeposition time. The hydrogen generation rate for the optimized Co–W–P catalyst is measured to be 5000 mL (min g-catalyst)⁻¹ at 30 °C. From hydrogen generation tests in solutions with the various concentrations of NaBH₄ and NaOH, there were optimum concentrations for both NaBH₄ and NaOH, above or below which the hydrogen generation rate decreased. Furthermore, the as-prepared catalyst also showed good cycling capability and the activation energy for hydrolysis of NaBH₄ by the Co–W–P catalyst was calculated to be 22.8 kJ/mol, which was lower than other reported Co-based catalysts.     

双中台架构用电信息采集系统研究

因采用垂直信息传输方式,现有用电信息采集系统难以满足能源互联网多能流信息采集、设备即插即用及信息互联共享的要求.文章提出采用双中台架构建立物理与信息深度融合的综合用电信息采集系统,通过融合数据中台和业务中台形成数据采集共享平台,采用共享服务分级组件化和服务化组装方式,优化了垂直式信息传输方式,解决电力业务数据采集难、应...     

毒理学关注阈值方法在食品接触材料风险评估中的应用

食品接触材料中包含诸多有意添加的化学助剂,在生产和使用过程中还会引入大量非有意添加物。食品接触材料中的有意和非有意添加物质种类繁多,难以得出所有物质完整的毒理学数据;而且食品接触材料中存在一些低暴露量的物质,它们对人体造成的风险较小而不必要进行传统的风险评估。毒理学关注阈值（threshold oftoxicological concern,TTC）方法作为一种新的风险评估工具,可以对缺乏完整毒理学数据且暴露量较低的化学物质进行风险评估。本文综述TTC方法对食品接触材料中的物质（结构确定和结构未知的物质）进行风险评估的具体应用。对结构已知的物质,可以参照欧洲国际生命科学学会（European International Life Sciences Institute,ILSI）专家组提出的TTC决策树方法;对于未鉴定结构的物质,可以引用一个分步分析的方法,得出未知物质是否需要进行安全关注。本文还指出了TTC方法在食品接触材料风险评估中应用的难点和今后需解决的问题,可为食品接触材料中缺乏毒性数据物质的风险评估提供依据。     

N‐ICE plasmids for generating N‐terminal 3 × FLAG tagged genes that allow inducible,constitutive or endogenous expression in Saccharomyces cerevisiae

PCR‐mediated homologous recombination is a powerful approach to introduce epitope tags into the chromosomal loci at the N‐terminus or the C‐terminus of targeted genes. Although strategies of C‐terminal epitope tagging of target genes at their loci are simple and widely used in yeast, C‐terminal epitope tagging is not practical for all proteins. For example, a C‐terminal tag may affect protein function or a protein may get cleaved or processed, resulting in the loss of the epitope tag. Therefore, N‐terminal epitope tagging may be necessary to resolve these problems. In some cases, an epitope tagging strategy is used to introduce a heterologous promoter with the epitope tag at the N‐terminus of a gene of interest. The potential issue with this strategy is that the tagged gene is not expressed at the endogenous level. Another strategy after integration is to excise the selection marker, using the Cre‐LoxP system, leaving the epitope tagged gene expressed from the endogenous promoter. However, N‐terminal epitope tagging of essential genes using this strategy requires a diploid strain followed by tetrad dissection. Here we present 14 new plasmids for N‐terminal tagging, which combines two previous strategies for epitope tagging in a haploid strain. These ‘N‐ICE’ plasmids were constructed so that non‐essential and essential genes can be N‐terminally 3 × FLAG tagged and expressed from an inducible promoter (GAL1), constitutive promoters (CYC1 or PYK1) or the endogenous promoter. We have validated the N‐ICE plasmid system by N‐terminal tagging two non‐essential genes (SET1 and SET2) and two essential genes (ERG11 and PKC1). Copyright © 2016 John Wiley & Sons, Ltd.     

天然植物染料染色存在的问题及其解决措施

天然染料因其绿色环保成为发展的方向,但在应用中存在许多问题。在实践的基础上,对天然植物染料的染色对象、染液制备、助剂的使用、染色方法以及工艺、染色色相、牢度和资源8个方面的实际应用情况进行了分析总结,并对存在的问题提出了一些解决措施。     

钢件渗碳层碳浓度直读光谱分层分析方法的探讨

渗碳层各层次碳浓度测定历来采用车削剥层法,铁屑经化验测定碳量,这一办法要求用精密车床加工及繁琐化学分析过程。 试验证明可以利用直读光谱测定法,快而精确地测定各深度梯度合碳量。本文分别对气体渗碳和固体渗碳的零件为对象,用磨床磨出不同深度,选用合适的控样,用直读光谱仪分别测得不同深度的碳含量,得出渗碳件碳浓度梯度分布。