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导出了6N维和6维相空间的熵产生率,即熵增加定律的一个统计公式:P=kD(Δqθ)2,即熵产生率P等于扩散系数D、离开平衡率θ的空间梯度平方的平均值与Boltzm ann常数k 三者之乘积.指明非平衡系统的宏观熵产生是由其微观状态数密度在空间随机地不均匀离开 平衡引起的.作为公式的应用,研究了气体自由膨胀、布朗运动及固体变形和断裂三个非平衡 态课题,给出了它们的熵产生及其一次和二次时间变化率,得到了不可逆过程的系统内对应 的微观结构变化是不均匀的推论.进而导
关键词:
熵产生率
微观状态数密度
离开平衡率
随机扩散 相似文献
34.
Muhammad Arshad Khosa S. Sakhawat Shah Muhammad Faizan Nazar 《Journal of Dispersion Science and Technology》2013,34(11):1634-1640
Ultraviolet spectrometric study of alizarin red S (ARS) showed the substantial change in dye spectra by cationic CTAB as compared to anionic SDS and nonionic TX-100 surfactant. High spectral change by CTAB confirms the anionic nature of ARS dye and thus ARS-CTAB complex formation takes place due to electrostatic force of attraction. A little spectral change by SDS is the result of similarly charged repulsive forces that overcome weak hydrophobic-hydrophobic interaction between dye and surfactant micelles. TX-100 exhibited moderate spectral effect responsive to weak hydrophobic-hydrophobic interaction alone. MEUF study of ARS dye justified the spectral changes and dye rejection percentage (R) decreases in the following order: cationic > nonionic > anionic surfactant. Permeate flux (J) slightly decreases in presence of CTAB and it remains virtually constant for both SDS and TX-100. Addition of copper salt (i.e., CuCl2) in dye-CTAB complex solution, favors rejection (%) removing dye and copper simultaneously via micellar enhanced ultrafiltration. 相似文献
35.
The reactions of Cu(ClO4)2·6H2O with 6-(benzylamino)purine derivatives in a stoichiometric 1:2 metal-to-ligand ratio led to the formation of penta-coordinated dinuclear complexes of the formula [Cu2(μ-L1–8)4(ClO4)2](ClO4)2·nsolv, where L1 = 6-(2-fluorobenzylamino)purine (complex 1), L2 = 6-(3-fluorobenzylamino)purine (2), L3 = 6-(4-fluorobenzylamino)purine (3), L4 = 6-(2-chlorobenzylamino)purine (4), L5 = 6-(3-chlorobenzylamino)purine (5), L6 = 6-(4-chlorobenzylamino)purine (6), L7 = 6-(3-methoxybenzylamino)purine (7) and L8 = 6-(4-methoxybenzylamino)purine (8); n = 0–4 and solv = H2O, EtOH or MeOH. All the complexes have been fully characterized by elemental analysis, FTIR, UV–Vis and EPR spectroscopy, and by magnetic and conductivity measurements. Variable temperature (80–300 K) magnetic susceptibility data of 1–8 showed the presence of a strong antiferromagnetic exchange interaction between two Cu(II) (S = 1/2) atoms with J ranging from −150.0(1) to −160.3(2) cm−1. The compound 6·4EtOH·H2O was structurally characterized by single crystal X-ray analysis. The Cu?Cu separation has been found to be 2.9092(8) Å. The antiradical activity of the prepared compounds was tested by in vitro SOD-mimic assay with IC50 in the range 8.67–41.45 μM. The results of an in vivo antidiabetic activity assay were inconclusive and the glycaemia in pre-treated animals did not differ significantly from the positive control. 相似文献
36.
To use a newly developed wavelength modulation surface plasmon resonance (SPR) biosensor, an experimental protocol was developed to investigate the interaction of ginsenosides with serum albumin. With a known concentration of the ginsenosides, bound percentages of the ginsenosides with human serum albumin (HSA) or bovine serum albumin (BSA) were obtained. SPR technique could require no labeling and this method provided the detailed information on association and disassociation of molecules in real time. The results indicate that the sensitivity of wavelength modulation SPR biosensor is sufficient for detection and characterization of binding events involving low-molecular weight compounds and their immobilized protein targets. 相似文献
37.
Monoclonal antibodies against the hop-derived prenylated chalcone xanthohumol (X) and the prenylated flavonoids isoxanthohumol (IX) and 8-prenylnaringenin (8-PN) were developed. Carboxylic acid haptens of X, IX and 8-PN were synthesized by linking a spacer to their C4′-OH group followed by subsequent coupling to bovine serum albumin (BSA) to form conjugates that were employed as immunogens in BALB/c mice to raise antibodies. The monoclonal antibodies that were secreted from the established hybridoma cell lines proved, in cross-reactivity studies, to possess highly specific binding capacities in an optimized competitive indirect ELISA. The immunoassays make use of immunogen-coated microtiterplates and a peroxidase-labeled anti-mouse IgG1 secondary antibody with ABTS as a chromogenic substrate. For X the IC50 value derived from the standard curve was 62.91 ng mL−1, and for both IX and 8-PN 37.15 ng mL−1. The assay was validated for the quantitative analysis of X, IX and 8-PN in urine and serum. A simple sample pretreatment procedure using a diethyl ether extraction was optimized and the recoveries and matrix effects were assessed. The validity of the established assay was tested and mean inter- and intra-assay variations in urine were 2.32% and 1.91%, respectively for X, 6.24% and 2.39%, respectively for IX and 7.18% and 0.74%, respectively for 8-PN. In serum, the mean inter- and intra-assay variations were 8.90% and 1.37%, respectively for X, 6.13% and 1.57%, respectively for IX and 6.13% and 2.43%, respectively for 8-PN. Furthermore, the method demonstrated excellent accuracy and significant correlation with measurements by an established and validated HPLC-MS method. 相似文献
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从上海市某区386家中小企业申报的15项税收指标数据中筛选出对判定企业纳税情况具有重要影响的10个评价指标,并将全部386个样本分成性质相似的建模样本和测试样本(其中测试样本个数占45%),建立了基于投影寻踪分类(PPC)技术的税务稽查评价模型.与多元线性回归(MLR)、判别分析(MDA)、Logistic和支持向量机(SVM)模型相比,PPC模型的识别错误率最低,建模样本和测试样本的平均分类错误率低于6%,改进型PPC模型包含的评价指标少,两类错误率很接近,非常适用于实际企业的税务稽查评估研究和实践.对339家待判断企业纳税情况的判定结果研究表明,建立的改进型PPC模型具有很好的泛化能力和鲁棒性. 相似文献
40.
多功能无线光电鼠标运用2个图像摄影芯片,通过轨迹球滚动和鼠标座身移动两种方式实现光标移动。通过比较原始鼠标光路中2个图像摄影芯片能够接收到的最小光通量百分比,选择ADNS7530作为鼠标中唯一保留的图像摄影芯片。保持轨迹球光路不变,鼠标座光路中增加一个与轨迹球光路相同的LED光源。比较鼠标座的桌面反射光分别通过轨迹球反射、棱镜反射和平面镜反射后,最终到达图像摄影芯片的光通量百分比。确定并验证了鼠标座光路采用平面反射镜的设计方案,实现了无线空中操作鼠标轨迹球光路和鼠标座光路共用1个图像摄影芯片的目的。 相似文献