Characterization of V-modules by Relative Quasi-continuity

§ 1.Ｉｎｔｒｏｄｕｃｔｉｏｎ　ＬｅｔＲｂｅａｒｉｎｇｗｉｔｈｉｄｅｎｔｉｔｙａｎｄＭａｌｅｆｔＲ ｍｏｄｕｌｅ .ＡｌｅｆｔＲ ｍｏｄｕｌｅＵｉｓｃａｌｌｅｄＭ ｉｎｊｅｃｔｉｖｅｉｆ,ｆｏｒｅｖｅｒｙｓｕｂｍｏｄｕｌｅＮｏｆＭａｎｄｅｖｅｒｙｈｏｍｏｍｏｒｐｈｉｓｍ :Ｎ→Ｕ ,ｃａｎｂｅｅｘｔｅｎｄｅｄｔｏａｈｏｍｏｍｏｒｐｈｉｓｍ ψ :Ｍ→Ｕ .ＡｌｅｆｔＲ ｍｏｄｕｌｅＭｉｓｃａｌｌｅｄａＶ ｍｏｄｕｌｅｂｙＲａｍａｍｕｒｔｈｉ[1]ａｎｄＴｏｍｉｎａｇａ[2 ](ａｎｄｉｓｃａｌｌｅｄａｃｏ ｓｅｍｉｓ…     

Magnetic Resonance of Chromium (V) with 2–Hydroxy–2–Ethylbutyrates

A complex of Cr (V) with 2–hydroxy–2–ethylbutyric acid (EHBA) has been studied experimentally by the method of electron spin resonance (ESR). The tensor components of the g–factor, the dependences of the ESR line widths on the concentration of paramagnetic centers, and the SHF power of saturation are determined. It is shown that the main mechanism of dynamic polarization of nuclei in the EHBACr^V complex in a propanediol solution is the mechanism of dynamic cooling with a burnt hole. It has been established that the ESR spectra of the EHBACr^V solutions in deuterated and ordinary propanediol display practically the same behavior, which is indicative of the good solubility of the complex in deuterated alcohols.     

双极谱峰指示催化动力学极语法测定痕量钒

在硫酸介质中,以酒石酸为活化剂,痕量机对溴酸钾氧化乙基极的反应具有极强的催化作用,研究了最佳反应条件,且发现在氨性缓冲溶液中乙基橙及其氧化产物具有良好的极谱峰,以极谱法监测催化反应过程中乙基橙及其氧化产物浓度的变化,建立了催化动力学极谱法测定痕量帆的新方法。方法的线性范围为０．２５～３．５μｇ／Ｌ,检出限为０．１２μｇ／Ｌ。应用于食品中痕量钒的测定,结果满意。     

4-(5-溴-2-噻唑偶氮)间苯二酚反相阳离子对HPLC测定痕量铌、钒、铑、铬

本文报道新试剂4-(5-溴-2-噻唑偶氮)间苯二酚(5-Br-TAR)为柱前衍生试剂,以阳离子表面活性剂作为对离子试剂,用含15 mmol／L的pH 5.8的乙酸-乙酸钠缓冲溶液、0.05 mmol／L溴化钠、10 mmol／L TBA·Br的乙腈-甲醇-水(42 : 13：45,V／V／V)三元体系为流动相,在C8柱上25min内HPLC测定了Nb(V)、V(V)、Rh(Ⅲ)和Cr(Ⅵ)的5-BR-TAR螯合物。当SNR=2时,检出限分别为Nb(V)1.0、V(V)1.6、Rh(Ⅲ)0.9和Cr(Ⅵ)1.9μg／L。该方法用于测定污水中的铬和钒,结果良好。     

Carbene Complexes of Pnictogen Pentafluorides and Boron Trifluoride

Summary.  Synthesis, characterization, and solid state X-ray crystallographic structures for 12-Pn-6 complexes derived from carbene 4,5-dichloro-1,3-dimesitylimidazol-2-ylidene and phosphorus, arsenic, or antimony pentafluoride are reported. The adducts show octahedral geometries at the pnictogen centers with C-Pn bond distances of 189.8 (P), 199.9 (As), and 217.5 (Sb) pm. The structures are those of internal zwitterions with imidazolium ion character in the heterocyclic ring and a pentafluoropnictanide anion bonded to C². Adducts of BF₃ with 1,3-dimesitylimidazol-2-ylidene and 4,5-dichloro-1,3-dimesitylimidazol-2-ylidene are also reported for comparison. Although the reactivity of chlorinated and non-chlorinated carbenes varies considerably, the spectroscopic and structural properties of analogous adducts are remarkably similar. Received September 6, 1999. Accepted (revised) October 20, 1999     

电力市场环境下计及V2G和多类型需求响应的综合能源系统多目标优化模型

园区综合能源系统(Park integrated energy system,PIES)是满足用户多种用能需求的一种重要途径,但由于内部分布式能源机组出力具有不确定性,且与负荷在时间维度上存在一定的不匹配性,限制了能源利用效率和经济效益的提升.因此,本文首先在构建耦合热电的PIES的基础上,构建了多类型需求响应模型;其次,构建了考虑风光机组出力不确定性的以系统净收益、清洁能源弃能率为多目标函数的优化模型;然后,构建了"不确定性处理-多目标处理-单目标处理"的三阶段求解模型,最后,以V2G和需求响应为考虑条件,设计多情景.算例结果表明:V2G可以为清洁能源不稳定发电提供有效备用,在一定程度上提供清洁能源利用效率;引入电热需求响应,能够改变用户负荷,增加经济效益.     

数控高精度PWM调制特种电源

介绍了两种斯特林制冷机数控驱动源,分析了单极性驱动方式与双极性驱动方式对红外探测芯片产生的干扰情况,并根据与系统的联试比较了两种数控驱动源的优缺点.说明了数字滤波技术、PID控制算法及V/F转换电路在提高温控精度和减少电源对探测芯片干扰中的优势.     

Structural,Optical, and Electrical Characteristics of Zinc Oxide and Copper Oxide Films and Their Heterojunctions

In this paper, n-Zinc oxide/p-copper oxide heterojunctions were fabricated by RF-sputtering on indium tin oxide-covered glass substrates. The structural and optical properties of the copper oxide and zinc oxide films were analyzed by X-ray diffraction, Fourier transform infrared, scanning electronic microscopy and ultraviolet-visible spectroscopy. The electrical junction properties were investigated by current–voltage (I–V) characteristics. Additionally, both capacitance (C) and conductance (G) versus frequency (f) measurements were realized at room temperature. The junctions showed a rectifying behavior, and C and G varied with both voltage and frequency.     

Effect of V cut in perforated twisted tape insert on heat transfer and fluid flow behavior of tube flow: An experimental study

ABSTRACT

Present study investigates the heat transfer and friction characteristics of heat exchanger tube fitted with perforated twisted tape (PTT) insert having V cuts. A copper tube of 1 m length and 0.032 m inner diameter is used as test section to collect the experimental data by varying the twist ratio of PTT from 2 to 6 for the Reynolds number range of 2,700–23,400. V cuts are introduced in the PTT and the V-cut relative pitch ratio is varied from 1 to 2. The maximum thermo-hydraulic performance parameter is found to be 1.58.