铜(Ⅱ)、铁(Ⅲ)、铅(Ⅱ)和锌(Ⅱ)同时分光光度测定的研究

Cu(Ⅱ)、Fe(Ⅲ)、Pb(Ⅱ)、Zn(Ⅱ)与 PAR 络合物的吸收光谱严重重叠,用 CPA 法对它们的混合物的吸收光谱数据进行了计算。CPA 法与 AKC 法、LP 法相比,其准确度高,抗随机误差能力强。本文还研究了最佳实验条件,测量波长的选择以及计算程序设计的改进问题。CPA 法已满意地用于循环冷却水中 Cu、Fe、Pb、Zn 的同时测定。     

On the predictive capabilities of CPA for applications in the chemical industry: Multicomponent mixtures containing methyl-methacrylate,dimethyl-ether or acetic acid

The predictive performance of the CPA (Cubic-Plus-Association) equation of state for applications relevant to the chemical industry is illustrated in this work. Three such applications inspired by industrial requests/interest are illustrated here, all of which involve aqueous multicomponent mixtures exhibiting vapor–liquid (VLE) and/or liquid–liquid (LLE) equilibrium. The first two cases include mixtures of methyl-methacrylate with acetone or methanol and dimethyl-ether with ethanol, respectively. In these two cases, the classical form of CPA is used. The third case involves aqueous mixtures with acetic acid, esters, ethers and alcohols, and in this case for water–acetic acid the CPA-Huron Vidal (CPA-HV) version of the model is used. For the latter binary mixture, new CPA-HV binary parameter sets are estimated using, among others, data for activity coefficients at infinite dilutions. The modeling approach is similar in all three cases, i.e. the binary parameters are solely fitted to binary data and thus all multicomponent calculations are considered predictions.It is shown that CPA correlations for binary systems are excellent in all cases using temperature independent parameters except for the acetic acid–water system for which different parameter sets at different temperatures can be recommended. Even with the use of CPA-HV mixing rules, modeling of the acetic acid–water system with few interaction parameters remains a challenging task. Excellent simultaneous VLE and LLE correlation is obtained for complex systems such as aqueous mixtures with ethers and esters. The multicomponent results are, with a few exceptions, very satisfactory, especially for the vapor–liquid equilibrium cases. For the demanding aqueous acetic acid–water containing systems, one parameter set is recommended at the end for modeling ternary or multicomponent mixtures containing acetic acid and water.     

Cyclical Parthenogenesis Algorithm for guided modal strain energy based structural damage detection

In this paper, a newly developed multi-agent meta-heuristic method, named Cyclical Parthenogenesis Algorithm (CPA), is incorporated into a guided modal strain energy based structural damage detection technique. A modal strain energy based index is used to guide the structural damage identification process, which is formulated as an inverse optimization problem. Generalized Flexibility Matrix (GFM) of the structure is used to define the objective function of the optimization problem. Three numerical examples are provided in order to examine the viability of the proposed method. The results indicate that the proposed method is capable of locating and quantifying structural damage using only the first few modes of the structure. The results are also compared with those of three other meta-heuristic algorithms in order to show the efficiency of CPA in solving the problem.     

针对ECC密码芯片的CPA分析研究

相关性功率分析（CPA）方法可有效地对加密的集成电路芯片进行攻击解密,它绕过了加解密算法繁琐的数学分析,从而获取密码和信息。应用CPA分析攻击嵌有椭圆曲线算法的芯片,搭建实验平台,获取加密时的电磁数据,并用统计学、密码分析学和信号处理的方法推导分析得出结论,从而成功破解加密系统。     

Electronic properties of Cu–Zn–Al alloys

The stability of Cu–Zn–Al was studied by total-energy calculations using the KKR–CPA method. Mixing and elastic and chemical energies, solubility lines, and Fermi surfaces were computed for the fcc and bcc structure. We find that the martensitic transformation can be considered as a transition from a disordered bcc to a disordered fcc structure. Fermi-surface nesting leads to DO₂₃ ordering while the van Hove singularities contribute to the instability of the fcc structure.     

水泥净浆结粒水筛检测方法研究

由水筛法得到启示，提出了一套水泥净浆结粒的检测方法。通过研究水泥称量、水化温度、水泥细度、水灰比、石膏掺量和水化时间对结粒量的影响，探讨了该检测方法的可行性，并计算了结粒量的标准偏差。结果表明：该净浆结粒检测方法可靠性高，检测结果具有很好的稳定性和重现性；同时对于不同条件下的变化，能够充分反映水泥净浆结粒的变化规律，是研究净浆结粒的有效方法。     

DES密码相关性功率分析中最小样本量计算

样本量是可以衡量设备抵 CPA攻击的重要指标,因此建立一种计算样本量的模型是很重要的.选择用统计学的方法通过计算样本量测定硬件的防护效果,这就可以让设计者在设计过程中通过计算了解设备抵御CPA的能力,还可以很容易地比较不同的防护方法,避免了由于产品不能有效抵 CPA攻击而进行的代价高昂的重复设计.     

入世后我国会计师事务所发展战略研究

加入WTO后,我国会计师事务所将面临严峻的挑战已不可避免,从会计市场、服务领域、人才培养等方面论述了我国会计师事务所迎战国际会计公司的对策。     

注册会计师审计鉴证失真的成因及对策

由于审计制度本身的缺陷、对注册会计师监管不力、民事赔偿制度不完善、会计信息失真严重等多方面因素的影响，使得注册会计师审计鉴汪失真成为一个严重的社会问题。要解决注册会计师审计鉴征失真问题，需要采取不断完善审计制度、建立行业信用体系、执业规范、健全民事赔偿制度、提高会计信息质量等有力的措施，以提高审计质量。     

In vivo Mutational Analysis of Highly Conserved Amino Acid Residues of the Small Subunit Cpa1p of the Carbamylphosphate Synthetase of Saccharomyces cerevisiae

The role of selected amino acid residues located in the putative catalytic domain and of two conserved histidine residues within the small subunit of the carbamylphosphate synthetase (CPS) specific to the arginine biosynthesis pathway of the yeast Saccharomyces cerevisiae was studied using site-directed mutagenesis to change all residues to aspartic acid. Carbamylphosphate synthesis catalysed by modified CPS was tested in vivo. The C264D, H307D and H349D mutants were unable to grow on minimal medium, indicating the importance of these three residues for efficient CPS activity, whereas, four other mutated residues located in the catalytic site (including a proline residue) do not affect the growth rate. These results in comparison to those obtained with the CPS of Escherichia coli, implicate residues Cys 264 and His 349 in the glutaminase catalytic activity, and His 307 in the binding of glutamine to the active site. Using these three defective mutants, we investigated the in vivo utilization of ammonia by CPS. C264D and H307D mutants are able to use ammonia as a substrate when provided in sufficiently high concentrations (up to 200 mm). The H349D mutant, however, did not grow even at ammonium sulfate concentrations above 400 mm, suggesting that this substitution is critical to NH₃-dependent CPS activity although the ammonia binding site is presumably located within the large subunit of the enzyme. © 1997 by John Wiley & Sons, Ltd.