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从热力学角度研究了酸度、湿度、水的存在状态不同时,单质铜在空气中生成碱式碳酸铜的电动势及其自由能变。通过计算发现:在酸性条件下,p H的大小对于反应的自发性没有影响;大气中二氧化碳溶解达到饱和时,空气湿度增加,反应的自发性略微增加;相同条件下,水由气态变为液态时,反应的自发性增幅较大。  相似文献   
2.
荧光光谱法研究橙皮甙与牛血清白蛋白的相互作用   总被引:1,自引:0,他引:1  
在pH7.40的Tris-HCl 缓冲体系中,采用荧光光谱技术研究了橙皮甙与牛血清白蛋白(BSA)的相互作用.随着温度升高,橙皮甙与BSA 的猝灭常数逐渐增加.实验表明:橙皮甙对BSA的荧光猝灭为动态猝灭过程.由热力学参数焓变(△H=70.71 kJ/mol)大于零和熵变[△S=316.29J/(mol·K)]大于零,...  相似文献   
3.
While spherical distributions have been used in many statistical models for high-dimensional data analysis, there are few easily implemented statistics for testing spherical symmetry for the underlying distribution of high-dimensional data. Many existing statistics for this purpose were constructed by the theory of empirical processes and turn out to converge slowly to their limiting distributions. Some existing statistics for the same purpose were given in the form of high-dimensional integrals that are not easily evaluated in numerical computation. In this paper, we develop some necessary tests for spherical symmetry based on both univariate and multivariate uniform statistics. These statistics are easily evaluated numerically and have simple limiting distributions. A Monte Carlo study is carried out to demonstrate the performance of the statistics on controlling type I error rates and power.  相似文献   
4.
A new dimension-reduction graphical method for testing high-dimensional normality is developed by using the theory of spherical distributions and the idea of principal component analysis. The dimension reduction is realized by projecting high-dimensional data onto some selected eigenvector directions. The asymptotic statistical independence of the plotting functions on the selected eigenvector directions provides the principle for the new plot. A departure from multivariate normality of the raw data could be captured by at least one plot on the selected eigenvector direction. Acceptance regions associated with the plots are provided to enhance interpretability of the plots. Monte Carlo studies and an illustrative example show that the proposed graphical method has competitive power performance and improves the existing graphical method significantly in testing high-dimensional normality.  相似文献   
5.
Organic chemistry is an important basic course for biology-majored students. Starting from the perspective of stimulating students' interest in learning, breaking through the key and difficult points, and realizing the course education, this paper proposes that teachers should combine the characteristics of biology discipline, strengthen the chemical cognition of biologically functional molecules or biomass components, and promote the cultivation of students' interdisciplinary integration consciousness. At the same time, this paper explores the teaching reform of organic chemistry for biology-majored students so as to lay a foundation for cultivating interdisciplinary talents with comprehensive innovation ability.  相似文献   
6.
在pH 2.4的Britton-Robinson(B-R)缓冲溶液中,5-(5-氯-2-吡啶偶氮)-2,4-二氨基甲苯(5-Cl-PADAT)与牛血清蛋白相互作用形成复合物而导致溶液吸收光谱发生变化,用分光光度法对光谱变化进行了研究.5-Cl-PADAT溶液在430 nm处有一个强的特征吸收峰,当在其溶液中加入牛血清蛋白后,溶液发生褪色现象,吸收峰强度降低,且没有新的吸收峰出现,吸光度降低值(ΔA)与牛血清蛋白的浓度(c)成正比.在选择的最佳试验条件下,牛血清蛋白浓度与ΔA的线性方程为ΔA=0.8141c+0.0041(r=0.9996),线性范围为1.071×10-9~5.902×10-9 mol/L,检出限为5.36×10-10 mol/L,该方法的回收率为96.9%~107.1%,测定结果的相对标准偏差为1.4%~2.3%(n=6).  相似文献   
7.
等离子体具有大量活性粒子和较高的温度,能够加快化学反应速率,彻底分解污染物。介绍了目前常用的处理氮氧化物、硫氧化物以及挥发性有机大气污染物的等离子体技术,并综述了该项技术在治理大气污染领域的应用前景。  相似文献   
8.

In this paper we employ the conditional probability integral transformation (CPIT) method to transform a d-dimensional sample from two classes of generalized multivariate distributions into a uniform sample in the unit interval \((0,\,1)\) or in the unit hypercube \([0,\,1]^{d-1}\) (\(d\ge 2\)). A class of existing uniform statistics are adopted to test the uniformity of the transformed sample. Monte Carlo studies are carried out to demonstrate the performance of the tests in controlling type I error rates and power against a selected group of alternative distributions. It is concluded that the proposed tests have satisfactory empirical performance and the CPIT method in this paper can serve as a general way to construct goodness-of-fit tests for many generalized multivariate distributions.

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9.
研究了对苯醌与克拉霉素之间的荷移反应。对苯醌与克拉霉素于39℃在甲醇–水(1∶2)中反应60 min,可生成稳定的荷移络合物,络合物在360 nm处的吸光度与克拉霉素的质量浓度在37.40~186.99 mg/L范围内呈良好的线性关系,线性方程为A=0.002 54ρ+0.597 79,相关系数r=0.998 6。该方法应用于样品中克拉霉素含量的测定,回收率为97%~104%,测定值的相对标准偏差为3.56%(n=5)。该反应可用于测定克拉霉素的含量。  相似文献   
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