基于回归模型的CPU超频仿真软件设计

为了帮助认识CPU超频问题并熟悉超频设置操作,进行CPU超频仿真软件设计的全面研究。分析CPU超频的影响因素,介绍超频的方法和操作流程;讨论软件的功能模块结构、模块的运行流程和样本数据的存储方法;重点研究CPU超频后的性能测试结果估计问题,并为此提出了建立回归模型的解决之道;详细探讨了VB.NET与Matlab混合编程的接口与实现途径,并以此种方式完成了程序代码的编写。试用表明,该软件功能完整、界面直观、使用简便,能够为理解超频理论和熟悉超频操作提供有效帮助。     

Biomimetic strain hardening in interpenetrating polymer network hydrogels

In this paper, we present the systematic development of mechanically enhanced interpenetrating polymer network (IPN) hydrogels with Young's moduli rivaling those of natural load-bearing tissues. The IPNs were formed by synthesis of a crosslinked poly(acrylic acid) (PAA) network within an end-linked poly(ethylene glycol) (PEG) macromonomer network. The strain-hardening behavior of these PEG/PAA IPNs was studied through uniaxial tensile testing and swelling measurements. The interaction between the independently crosslinked networks within the IPN was varied by (1) changing the molecular weight of the PEG macromonomer, (2) controlling the degree of PAA ionization by changing pH, and (3) increasing the polymer content in the PAA network. Young's moduli and the maximum stress-at-break of the swollen hydrogels were normalized on the basis of their polymer content. Strain hardening in the IPNs exhibited a strong dependence on the molecular weight of the first network macromonomer, the pH of the swelling buffer, as well as the polymer content of the second network. The results indicate that the mechanical enhancement of these IPNs is mediated by the strain-induced intensity of physical entanglements between the two networks. The strain can be applied either by mechanical deformation or by changing the pH to modulate the swelling of the PAA network. At pHs below the pK_a of PAA (4.7), entanglements between PEG and PAA are reinforced by interpolymer hydrogen bonds, yielding IPNs with high fracture strength. At pHs above 4.7, a “pre-stressed” IPN with dramatically enhanced modulus is formed due to ionization-induced swelling of the PAA network within a static PEG network. The modulus enhancement ranged from two-fold to over 10-fold depending on the synthesis conditions used. Variation of the network parameters and swelling conditions enabled “tuning” of the hydrogels' physical properties, yielding materials with water content between 58% and 90% water, tensile strength between 2.0 MPa and 12.0 MPa, and initial Young's modulus between 1.0 MPa and 19.0 MPa. Under physiologic pH and salt concentration, these materials attain “biomimetic” values for initial Young's modulus in addition to high tensile strength and water content. As such, they are promising new candidates for artificial replacement of natural tissues such as the cornea, cartilage, and other load-bearing structures.     

基于MCGS的液化气梭式窑操作的计算机仿真

通过全面分析梭式窑操作系统运行的规律,就整个系统的燃气流量、压力以及炉膛内的温度等参数进行研究,选择ADMA为数据采集模块,根据操作流程以及现场控制设备的要求,提出了用计算机仿真操作设计的方案,并基于MCGS工控组态软件技术,设计了“液化气梭式窑操作仿真系统”.     

Studies on the semirigid chain polyamide—poly(1,4-phenyleneterephthalamide)

In this article, the polycondensation of terephthaloyl chloride and p-phenylenediamine was systematically studied, including the liquid–crystalline state of the solution and the spinning of poly(1,4-phenyleneterephthalamide) (PPTA). High-molecular-weight PPTA with ε_inh = 5–7 was prepared and the main factors influencing the solution polycondensation of 1,4-phenylenediamine with terephthaloyl chloride were studied in detail. Experimental results showed that the water content of the reaction system, reactant concentration, and volume ratio of mix solvents have a great influence on the inherent viscosity of the poly(1,4-phenyleneterephthalamide) obtained. The highest ε_inh was obtained at 0.3M/liter reactant concentration in a mixed solvent ratio HMPA/DMAC of 4/1 (by volume), at 0.35M/liter reactant concentration in a mixed solvent of HMPA/NMP = 7/3, and at 0.5M/liter of reactant concentration in a mixed solvent of HMPA/THF = 9/1. The water content must be controlled to less than 100 ppm in the polymerization system. In the early stage of the polycondensation process, the ε_inh of the polymer obtained increased rapidly with time. The system gelled within 2 or 3 min, while the monomer conversion reached about 100%. However, the reaction of polycondensation continued after gelation and the ε_inh of the polymer increased appreciably. We have studied the viscosity behavior at 20–155°C for the anisotropic solution of PPTA in 100% sulfuric acid (ε_inh of PPTA 2.5–4.9). Experimental results showed that, at low concentrations the viscosity of isotropic solution increases with the increase of polymer concentration to reach a maxium near the critical polymer concentration, beyond which the solution changes to an anisotropic liquid–crystalline solution. The appropriate spinning region was obtained as shown in the phase diagram determined by viscosity, degree of depolarization anisotropy, and region of thermal depolymerization. Fibers of PPTA with high modulus and high tenacity were obtained by dry-jet wet spinning. The fibers obtained have a tenacity of ～22 g/denier, a modulus of ～600 g/denier, and elongation at break ～3.5%.     

一种检测单晶炉热场温度的新方法

为去除单晶炉热场温度测量信号中的低频干扰、提高温度信号的估计精度,本文提出了一种基于跨维模拟退火(trans dimensional simulated annealing,TDSA)的单晶炉热场温度检测方法.该方法首先将AIC(Akaike information criterion)信号个数判断准则纳入采样机制中以便对干扰个数采样估计,进而利用所设计的基于信号频谱和轮盘赌思想的Metropolis Hastings机制对相应个数的干扰频率进行采样,最后设计了混合均匀和高斯采样机制对单晶炉热场温度进行采样估计.仿真和单晶炉工程实验结果表明,该方法在干扰个数未知的情况下,能够有效地抑制低频干扰、准确检测单晶炉热场的温度.     

稀土基汽车尾气催化剂的研究Ⅰ:催化剂老化和SO_2添加对催化活性的影响

制备了低Pt、Rh担载量的稀土基催化剂体系 ,研究了贵金属担载量、催化剂高温老化、抗硫水热老化和SO2 对催化活性的影响。结果表明 :随着贵金属质量分数从 0 2 5 %降低到0 1% ,CO、碳氢化合物 (HC)和NO的起燃温度分别平均提高 2 0℃ ;随着m(Pt)∶m(Rh)从 5∶1提高到 9∶1,CO、HC和NO的起燃温度分别提高 17、2 0和 5 3℃ ;当在反应体系中添加SO2 ,随SO2 体积分数从 0 0 0 2 %增加到 0 0 1% ,CO和NO的起燃温度和完全转化温度分别平均提高2 0℃ ,而对于HC ,催化活性几乎保持不变 ;催化剂在水热含硫条件下连续老化 4 0 0h ,CO、NO和HC的起燃温度分别为 2 5 2、2 6 7和 30 3℃ ,仍具有良好的反应活性。表明该稀土基催化剂在一定条件下 ,能满足汽车实际工况的要求     

现代核磁共振技术及其在新药创制中的应用

简述了核磁共振技术的基本原理和最新进展 ,讨论了现代NMR技术在新药创制中的应用     

用烧结刚玉研制再结合刚玉砖

介绍了以烧结刚玉和板状刚玉为原料试制再结合刚玉砖的生产工艺。同时，研究了不同原料、氧化铝微粉、外加物及工艺条件对制品性能的影响。     

基于“二叉决策树”模型的嵌入式软件调试

在嵌入式软件开发过程中,软件不可避免地会出现各种错误,因此调试是软件生命周期中一个非常重要的环节。针对嵌入式软件开发的流程和特点,对其调试部分进行较为深入具体的研究和探索,提出基于调试器的"二叉决策树"调试模型。该模型描述了嵌入式软件调试的一般过程、调试对象和常用方法。实践表明"二叉决策树"调试模型具有较好的实用性和扩展性。     

Effects of Additive on the Microwave Synthesis of AlN Powder

In this paper, a series of aluminum nitride powders were synthesized using a microwave synthesis method with various additives. The effects of additives on the nitridation of aluminum powder by microwave processing were studied. The results showed that the pure AlN powder with regular and fine grains could be obtained at a temperature of 1050°C for 30 min by the mixed additive under atmospheric pressure of nitrogen. The mixed additive composed by ammonium fluoride and zinc granules played a vital role in the microwave synthesis process.