电力工程项目管理的三要素分析

现今社会经济正在迅速发展中，电力工程领域也得到了较为良好的发展。但在此领域发展中，项目管理问题较为突显。文章主要是对电力工程项目管理的三要素进行了分析研究，以此帮助有效提升电力项目的管理工作效率及质量。     

3种现场快速水质检测仪的性价对比

选择了市场上口碑好、占有率高的3款便携式水质现场应急检测设备,通过准确度、精密度、检测时长及价格等指标,以权重积分法对3款仪器进行了比选,结果表明德国MN公司的PF-12型便携式多参数分光光度计的综合性能最优.     

触摸技术及测量研究

针对电容、电阻和红外触摸技术原理进行了介绍,分析了不同触摸技术的定位原理以及优缺点.在此基础上,对不同触模产品的特性进行了探讨,从而引出主要触摸功能的验证方法,以及触摸性能的测量方法,最后对触摸产品显示性能的测量进行了探讨.     

超声波辅助萃取同位素稀释质谱法测定聚氯乙烯中6种邻苯二甲酸酯

采用超声波辅助萃取同位素稀释质谱法测定聚氯乙烯中6种邻苯二甲酸酯的含量。以四氢呋喃为溶剂对样品进行超声波辅助提取后,加入甲醇对聚合物进行沉淀,取上清液,经冷冻离心后进行气相色谱一质谱分析,并采用氘代邻苯二甲酸酯为内标,单点校正法定量。该方法应用于中、日、韩计量比对的样品测定中,两天进行的6次测定结果相对标准偏差为0．7％～3．0％。最终比对结果显示3个国家的数据取得很好的一致性,除DEP相对标准偏差为2．4％以外,其它5种邻苯二甲酸酯相对标准偏差为0．7％～1．2％,测定结果的相对扩展不确定度为1．8％～4．9％,证明该方法准确、可靠。     

Electrogenerated Fe(I) Porphyrins: Efficient Electrocatalysts for Reductive Dechlorination of DDT in N,N′‐Dimethylformamide

Two iron(I) porphyrins were electrogenerated and then utilized as catalysts for the reductive dechlorination of 1,1‐bis(4‐chlorophenyl)‐2,2,2‐trichloroethane (DDT) in N,N′‐dimethylformamide. No reaction is observed between DDT and the Fe(III) or Fe(II) forms of the porphyrin, but the electrogenerated Fe(I) porphyrin efficiently catalyzes the electroreduction of DDT to give (1,1‐bis(4‐chlorophenyl)‐2,2‐dichloroethane) DDD, (1,1‐bis(4‐chlorophenyl)‐2,2‐dichloroethylene) DDE and (1,1‐bis(4‐chlorophenyl)‐2‐dichloroethane) DDMU as determined by GC‐MS analysis. The reductive dechlorination was monitored by electrochemistry, controlled potential electrolysis and spectroelectrochemistry and a mechanism for the reaction involving the reduced porphyrins and DDT is proposed. Comparisons are also made between the catalytic properties of metalloporphyrins containing iron, cobalt and manganese central metal ions under the same solution conditions.     

Theoretical studies on the structures, heats of formation, energetic properties and pyrolysis mechanisms of nitrogen-rich difurazano[3,4-b:3′,4′-e]piperazine derivatives and their analogues

The molecular structure, heats of formation, energetic properties, strain energy and thermal stability for a series of substituted difurazano[3,4-b:3′,4′-e]piperazines and their analogues were studied using density functional theory. The results show that it is a useful way to increase the heat of formation values of energetic compounds by incorporating a five- or six-membered aromatic heterocycle to construct a fused ring system. The calculated detonation properties reveal that introducing one heterocycle to construct a fused ring structure greatly enhances their detonation properties. The substitution of the –NF₂, –NO₂ or –NHNO₂ group is very useful for enhancing the detonation performance for the substituted derivatives. According to molecular structure and natural bond orbital analysis, the introduction of the –NO₂, –NF₂ or –NHNO₂ group decreases the stability of the substituted derivative. There is a weak N–NO₂ bond conjugation in the NO₂-substituted derivatives. An analysis of the bond dissociation energies for several relatively weak bonds suggests that all the unsubstituted derivatives have good thermal stability, but the substitution of –NO₂ or –NF₂ remarkably decreases their stability. Considering the detonation performance and thermal stability, eight compounds may be considered as the potential candidates of high-energy density materials with less sensitivity.     

Direct Blue 71 staining as a destaining‐free alternative loading control method for Western blotting

In Western blotting, a suitable loading control is indispensable for correcting errors in the total amount of loaded protein. Immunodetection of housekeeping proteins and total protein staining have traditionally been used as loading control methods. Direct Blue 71 (DB71) staining—a novel, sensitive, dye‐binding staining method compatible with immunodetection—may offer advantages over these traditional loading control methods. Three common neuroscientific samples (human plasma, human oligodendrocytes, and rat brain) were employed to assess DB71 staining as a loading control method for Western blotting. DB71, CBB, one traditional housekeeping protein, and one protein of interest were comparatively assessed for reliability and repeatability and linear dynamic range over 2.5–40 μg of protein loaded. DB71's effect on the reliability and repeatability and linear dynamic range of immunoreaction were also assessed. Across all three sample types, DB71 was either equivalent or superior to CBB and housekeeping protein‐based methods in terms of reliability and repeatability and linear dynamic range. Across all three sample types, DB71 staining did not impair the reliability and repeatability or linear dynamic range of immunoreaction. Our results demonstrate that the DB71 staining can be used as a destaining‐free alternative loading control method for Western blotting.     

The ambient gamma dose-rate and the inventory of fission products estimations with the soil samples collected at Canadian embassy in Tokyo during Fukushima nuclear accident

In this study, soil samples were collected at Canadian embassy in Tokyo (about 300 km from Fukushima) on 23 March and 23 May of 2011 for purposes of estimating concentrations of radionuclides in fallout, the total fallout inventory, the depth distribution of radionuclide of interest and the elevated ambient gamma dose-rate at this limited location. Some fission products and actinides were analyzed using gamma-ray spectrometry, alpha spectrometry and liquid scintillation counting. The elevated activity concentration levels of ¹³¹I, ¹³²I, ¹³⁴Cs, ¹³⁷Cs, ¹³⁶Cs, ¹³²Te, ¹²⁹mTe, ¹²⁹Te, ¹⁴⁰Ba and ¹⁴⁰La were measured by the gamma-ray spectrometer in the first sample collected on 23 March. Two months after the accident, the ¹³⁴Cs and ¹³⁷Cs became only detectable nuclides. A mass relaxation depth of 3.0 g/cm² was determined by the activities on the depth distribution of ¹³⁷Cs in a soil core. The total fallout inventory was thus calculated as 225 kBq/m² on March sampling date and 25 kBq/m² on May sampling date. The ambient gamma dose-rates in the sampling area estimated by the fallout fission products inventory and ¹³⁷Cs depth distribution ranged from 184 to 38 nGy/h. There was no detectable americium or plutonium in the soil samples by alpha spectrometry. Although ⁹⁰Sr or ⁸⁹Sr were detected supposedly as a result of this accident, it was less than the detection limit, which was about 0.4 Bq/kg in the soil samples.     

Three Isomeric Chiral Metal-organic Frameworks Determined by Different Halogen Ions

Three isomeric metal-organic frameworks,[Cd2（X）（btc）（DMA）3]n（X = Cl（1）,Br（2）,I（3）,H3btc =1,3,5-benzenetricarboxylic acid and DMA = N,Nˊ-dimethylacetamide）,have been synthesized and characterized by elemental analysis,infrared spectra（IR）,thermogravimetric（TG） analyses and single-crystal X-ray diffraction.Single-crystal X-ray analysis reveals that compounds 1–3 crystallize in the orthorhombic P212121 space group,and feature a three-dimensional（3D） extended framework containing dinuclear [Cd2（COO）3] units as the secondary building units（SBUs）.Topological analysis reveals that compounds 1–3 can be simplified into a 3-connected srs topological network.