Synthesis of graphene/methylene blue/gold nanoparticles composites based on simultaneous green reduction,in situ growth and self-catalysis

The novel composites based on reduced graphene oxide/methylene blue/gold nanoparticles (rGO/MB/AuNPs) were synthesized by a green and easy method. This synthesis was realized through a one-step green reduction of graphene oxide and chloroauric acid by ascorbic acid, with MB as the assistant reductant and formed AuNPs as the self-catalyst. Except for electroactive substance, MB, which was firmly coated onto the surface of rGO through π–π stacking non-covalent interactions, also serves as the anchor for AuNPs in situ growth due to the electrostatic attraction between positively charged MB and negatively charged chloroauric ions. The characteristics of rGO/MB/AuNPs composites were investigated by various optical and electrical methods. These composites exhibit excellent electrochemical properties and promising prospects for practical application in electrochemical analysis.     

市级社保卡管理服务平台建设研究与实现

社保卡发行范围很广,但不能充分得到应用是各地普遍存在的问题。本文主要探讨了在市级数据资源中心的基础上,建立社保卡管理服务平台,开展跨部门多领域的社保卡应用,从而解决社保卡应用单一问题,为持卡人开展多方位服务。     

高性能9%~12%Cr转子钢发展现状及锻件国产化概况

概括了火电机组汽轮机转子用铁素体耐热钢的发展现状,以及国内外生产与应用情况。介绍了首支COST-FB2国产化锻件的生产试制情况,并将国产锻件性能与国外报道的数据以及进口转子性能进行对比,结果表明,国产锻件能够达到国外水平,但距少数企业的高水平锻件仍存在差距。以国内现有的技术现状为基础,讨论了现阶段高性能转子锻件国产化存在的部分问题,未来需要在电渣冶炼与组织均匀化等多个方面进行技术攻关。     

全自动总氮在线分析仪的研制

将在线加热消解、在线冷却、镉柱还原与偶氮比色法相结合,并采用流动注射分析技术实现了全自动总氯分析仪的研制工作。该系统可在无人干预的情况下,自动地执行从环境采样、预处理、测定、数据分析和最终传输的全过程。实验证明,此系统消耗试剂量少,测定范围宽（0～100mg／L）,检出限低（0．042mg／L）,测定快速（3样／时）,精密度高（RSD〈0．45％）,实际水样的加标回收率均在93．3％～105．O％之内,可用于在线快速测定总氮。     

铅暴露对发育期大鼠肾脏超微结构影响

目的:从光镜和电镜水平观察铅暴露对发育期雄性大鼠肾组织的形态学影响.方法:3周龄SD雄性大鼠,随机分为对照组和染铅组.染铅组腹腔注射0.2%乙酸铅溶液(0.2 mL/100 g体质量),隔日1次,共20次,对照组同时注射生理盐水.实验结束后,测量各组动物血铅和血中游离原卟啉,取肾组织作光镜和透射电镜观察.结果:与对照组...     

Fractions and Bioavailability of Soil Inorganic Phosphorus in the Loess Plateau of China under Different Vegetations

Plants play an important role in soil phosphorus nutrition. However, the effect of plants on phosphorus nutrition in soils of the Loess Plateau of China is not well understood. This study was conducted to reveal the relationships between plants and phosphorus' fractions and availability in the Loess Plateau of China. Twenty-two plant communities were surveyed and soil samples under different plant canopies were collected for the determination of soil properties and inorganic phosphorus fractionation. The results showed that Leguminosae and Lilaceae reduced pH and increased organic matter, cation exchange capacity, total and Olsen phosphorus in soils under their canopies, while Labiatae and Rosaceae increased pH and decreased organic matter, cation exchange capacity, total and Olsen phosphorus in soils under their canopies. The contents of Ca2P, CasP, AI-P and Fe-P were highly related with soil Olsen phosphorus. They were all higher in soils under Leguminosae and Lilaceae and lower in soils under Labiatae and Rosaceae. The results of this study indicate that Leguminosae and Lilaceae improved phosphorus nutrition in soils, yet Labiatae and Rosaceae impeded the improvement of phosphorus nutrition in soils under their canopies, which will be of more help to instruct vegetation restoration in the region and provide information for soil development.     

热处理温度对海水循环泵叶轮用双相不锈钢冲击性能的影响

针对海水循环泵叶轮的服役条件,利用烟台台海玛努尔核电设备有限公司提供的材料,研究了热处理工艺对GX2GrNiMoN22-5-3双相不锈钢冲击性能的影响。结果表明,双相不锈钢的冲击性能在常温下随固溶温度的升高而逐渐下降,并且在1120～1160℃固溶温度范围内下降明显,在1160～1200℃温度范围内下降趋势缓慢。铁素体含量测试表明,随固溶温度的升高,铁素体的变化趋势与冲击功的变化趋势具有良好一致性,表明固溶温度升高铁素体含量降低,是冲击功减小的重要原因。对冲击断口形貌进行观察,冲击断口以韧窝型断裂为主。     

A modified Johnson–Cook constitutive model for Mg–Gd–Y alloy extended to a wide range of temperatures

In this paper, a new phenomenological and empirically based constitutive model was proposed to change the temperature term in the original Johnson–Cook constitutive model. The new model can be used to describe or predict the stress–strain relation of the metals deformed over a wide range of temperatures even though the current temperatures were lower than the reference temperature. Based on the impact compression data obtained by split Hopkins pressure bar technique, the material constants in the new model can be experimentally determined using isothermal and adiabatic stress–strain curves at different strain rates and temperatures. Good agreement is obtained between the predicted and the experimental stress–strain curves for a hot-extruded Mg–10Gd–2Y–0.5Zr alloy at both quasi-static and dynamic loadings under a wide range of temperatures ever though the current temperatures were lower than the reference temperature.     

某工厂利用热泵技术回收工业余热的技术改造

本文以某工厂生活热水及采暖系统为研究对象,提出了利用热泵技术回收工艺冷却水余热,并从节能、经济及环保方面分析了技术改造方案的可行性。     

基于BIM的建设工程柔性管理模式分析

BIM技术将在未来引发建筑业新的革命,相较于当前仅仅重视BIM技术方面的优势,将BIM技术与柔性管理相结合,以工程项目管理模式变化为视角分析BIM对建筑业带来的深刻影响,从计划职能柔性化、组织职能柔性化、领导职能柔性化和控制职能柔性化4个角度分析BIM带来的项目管理模式创新。