环烷酸在水溶液中型体分布的研究

在本论文的实验中，利用强酸滴定混合碱法获得了环烷酸钾的滴定曲线，并据此确定环烷酸是一元弱酸；通过同环烷酸分子量测定结果比较得知，在水溶液中环烷酸是以单分子形式存在的；作者在对上述实验结果进行理论分析的基础上，推得了环烷酸的在水溶液中的离解常数和型体分布规律。

数形结合巧讲不同酸度下弱酸(碱)各型体分布

《普通化学》是高等农林院校各专业的基础必修课程之一,其教学内容经常会涉及数学知识和数学思维的运用,在教学过程中充分巧妙的运用数学知识和数学思维,可以使化学问题变得简单,从而会达到事半功倍的学习效果。文中通过“酸度对弱酸(碱)各型体分布的影响”——即“酸效应”的课堂教学具体实例,阐述了巧妙运用数形结合法解决化学问题的逻辑分析。通过教学反馈,发现巧妙运用数形结合法,可使困难的内容变得容易理解,更有助于培养学生的逻辑思维能力,激发学生的学习兴趣和创造力,从而提升学生的学习兴趣,提高学习效率。

手持技术探究酸碱滴定过程中缓冲容量的变化

针对韶关学院基础化学课程中酸碱滴定的学习内容,以酸碱滴定为基础,绘制滴定过程中溶液缓冲容量的变化图,并结合型体分布分数的知识联合讨论酸碱滴定过程中溶液缓冲容量变化,扩充了酸碱滴定和缓冲容量的知识,可以加深临床医学本科专业学生对酸碱滴定的理解.使用手持技术实验设备中的pH传感器和滴数传感器设计了酸碱滴定实验,使用NaOH溶液分别滴定HAc,H_(2)C_(2)O_(4),H_(3)PO_(4)溶液,绘制相应的pH-V曲线和β-pH曲线,基础借助δ-pH曲线解释缓冲容量变化,并联合分析其滴定过程中缓冲容量的变化,有利于加深学生对酸碱滴定和缓冲溶液的理解.

计算分布分数的新方法

基于代数法建立了一种计算溶液中型体分布分数的新方法。方法仅需对pL及相关lgK作加减和常用对数运算 ,复杂体系也仅需增加少量以 10为底的乘方运算 ,因而方法简便 。

酸碱分布分数及其应用的教学探讨

介绍了分布分数的意义和计算方法,将教材中的δ-pH图改进为型体分布优势图,给出了分布分数的应用实例,使复杂知识简单化,激发了学生的学习兴趣.

高考复习中值得关注的“弱酸弱碱的型体分布图”

＂酸度对平衡体系中各型体分布分数的影响＂是高等分析化学重要的一部分教学内容,近几年在各地高考试题中备受青睐,特别是在江苏、浙江等教育先进省份自2010以来几乎年年考查,2017年全国Ⅱ卷也开始考查此类题型.以近几年此类高考题为例就常见的考查方式和解题方法进行分析.

对竞赛、高考新热点——弱酸(碱)型体分布图的思考

对近几年浙江省和江苏省化学竞赛及高考试题中有关弱酸（碱）型体分布图试题进行深入的分析，并提出一些自己的见解，以供广大教师和学生参考。

对高考化学热点试题——酸碱型体分布图的思考

课题《基于微信公众平台的高中化学微课程设计与应用》简介:收集高中教学过程中不同层次学生遇到的化学问题,结合学生的学习需求,设计出特定主题的微课程资源,如论文、微专题、微课,利用微信公众平台的平台优势,进行推送和应用,打破地域与时间的限制,让更多孩子享受到更好的优质教育资源,为一线教师今后设计开发微课程提供参考,打造化学教育品牌。

Modeling of Rocks with Spatial Distributed Fractures by Random Medium Theory

By using the spectrum expanding theory of random processes and Hudson's crack model,we developed a random medium model for rocks with spatial random distributed number density of cracks. This model could connect the micro-parameters of the cracks with the macro- mechanical properties, and can be effectively applied to model the real inhomogeneous medium. Numerical example indicates that the random distribution characters could be different for different elastic constants under the same random distribution of number density of cracks. By changing the value of the autocorrelation length pair, it is possible to model the difference of the distribution in the two coordinate directions. Numerical modeling results for seismic wave propagating in rocks with random distributed fractures using a staggered high-order finite-difference (SHOFD) are also presented.

CFD Simulation and Experimental Validation of Fluid Flow in Pre-distributor

Liquid distributor is a very import intemal for distillation columns. Pre-distributor is usually set on the top of distributor for initial distribution. Fluid flow in pre-distributor is a complex system of variable mass flow with many orifices and sub-branches. Consequently, the two phase modeling of pre-distributors was carried out andthe homogeneous model with free surface model was applied. The numerical method was validated by comparing with experimental data. Using the simulated results for different pre-distributors, the impacts of inflow rate, location and orientation uoon the outflow distribution were investigated. Furthermore, influences of the outflow distribution for pre-distributor on liquid uniformity in trough were also analyzed, The conclusions can De aaoptea for me structural design of liquid distributor and pre-distributor of large scale.

The Resident Time Distribution of Injected Dispersed Drops in Stirred Extraction Columns

A resident time model is proposed to evaluate the performance of agitated extraction columns. In this model, the resident time of dispersed drops is simulated with the discrete phase modeling, where the continuous phase and the dispersed phase （drops） are described by the single-phase Navier-Stokes （turbulence） model and Lagrangian model, respectively. The interaction of dispersed phase and continuous phase is neglected for the low concentration of drop in the cases studied. The statistical parameters of drops （the average resident time and standard deviation） under different operation conditions are computed for four columns. The relation of the above statistical parameters with the performance of columns is discussed and the criterions for an optimal compartment are outlined. Our results indicate that the resident time model is useful to evaluate the performance and optimize the design of extraction columns.

An improved cross entropy algorithm for steelmaking-continuous casting production scheduling with complicated technological routes

In order to increase productivity and reduce energy consumption of steelmaking-continuous casting(SCC) production process, especially with complicated technological routes, the cross entropy(CE) method was adopted to optimize the SCC production scheduling(SCCPS) problem. Based on the CE method, a matrix encoding scheme was proposed and a backward decoding method was used to generate a reasonable schedule. To describe the distribution of the solution space, a probability distribution model was built and used to generate individuals. In addition, the probability updating mechanism of the probability distribution model was proposed which helps to find the optimal individual gradually. Because of the poor stability and premature convergence of the standard cross entropy(SCE) algorithm, the improved cross entropy(ICE) algorithm was proposed with the following improvements: individual generation mechanism combined with heuristic rules, retention mechanism of the optimal individual, local search mechanism and dynamic parameters of the algorithm. Simulation experiments validate that the CE method is effective in solving the SCCPS problem with complicated technological routes and the ICE algorithm proposed has superior performance to the SCE algorithm and the genetic algorithm(GA).

The Anti—tumor Effects of an Anti—CD71 Chimeric Antibody in Vitro and Its Distribution in a Tumor Xenograft Model

Objective To investigate the anti-tumor effects in vitro and in vivo distribution of the human/murine chimeric antibody (D2C). Methods The CD71 positive target cells (K562, GEM and SMMC7721) and the effector cells, freshly isolated human PBMC, with the ratio of target cells to effector cells 1:50, were incubated in various dilutions of D2C antibody ( Ab) . Antibody dependent cytotoxicity (AD-CC) was tested by using an LDH-release assay. Instead of effector cells, complement was added to the target cells (GEM, SMMC-7721) with various dilutions of D2C Ab. A method of counting death cells was used in complement dependent cytotoxicity (CDC) assay. Tumor localization and distribution of the chimeric antibody (D2C) were observed by labeling the chimeric Ab with radioiodine(131I) and injecting it into nude mice (Balb/c nu/nu) transplanted with human hepatocellular carcinoma cells (SMMC-7721).Results A significant ADCC was observed with the increased concentration of the D2C Ab. Cytolysis of CD71-positive target cells by the D2C Ab was found in the presence of fresh rabbit complement. Labeled D2C administered by intraperitoneal as well as tumor regional injection, was visualized by SPECT. The distribution of D2C Ab in murine organs and tissues showed that non-specific binding was lower following tumor regional administration than when the antibody was administered by an intraperitoneal injection. The human/murine chimeric antibody (D2C) has in vitro anti-tumor effects and can exert its effects in specific tumor localization. Its distribution and local effects in vivo can be detected by radioimmunoimaging.Conclusion CD71 human/murine chimeric antibody showed marked killing of tumor cells in vitro, and specific recognition and high affinity binding to tumor tissue in vivo

CFD modeling of methane distribution at a continuous miner face with various curtain setback distances

Knowledge of the airflow patterns and methane distributions at a continuous miner face under different ventilation conditions can minimize the risks of explosion and injury to miners by accurately forecasting potentially hazardous face methane levels. This study focused on validating a series of computational fluid dynamics(CFD) models using full-scale ventilation gallery data that assessed how curtain setback distance impacted airflow patterns and methane distributions at an empty mining face(no continuous miner present). Three CFD models of face ventilation with 4.6, 7.6 and 10.7 m(15, 25, and 35 ft) blowing curtain setback distances were constructed and validated with experimental data collected in a full-scale ventilation test facility. Good agreement was obtained between the CFD simulation results and this data.Detailed airflow and methane distribution information are provided. Elevated methane zones at the working faces were identified with the three curtain setback distances. Visualization of the setback distance impact on the face methane distribution was performed by utilizing the post-processing capability of the CFD software.

几组有着“亲缘”关系的图像题分析

对近几年各省高考试题中有关弱酸（碱）型体分布图、离子浓度关系图试题进行分析比较,揭示了此类试题的＂形似＂与＂神似＂,还原了命题者针对相同重复考点追求不同新颖情境的命题思路.

A Population Balance Model for Disperse Systems:Particle Size Distribution in Suspension Polymerization

On the basis of population balance a mathematical model is developed to describe the formation of polymer particle in styrene suspension polymerization. The characteristics of coalescence and breakage of droplets and the gel effect are analyzed in particular. Parameters of the models are estimated by experimental data on reaction conversion and particle size distribution. The results show that the model is suitable for predicting polymerization processes.

Subcellular distribution of nitric oxide synthase isoforms in the rat duodenum

AIM:To study the cell-type specific subcellular distribution of the three isoforms of nitric oxide synthase(NOS) in the rat duodenum.METHODS:Postembedding immunoelectronmicroscopy was performed,in which primary antibodies for neuronal NOS(nNOS),endothelial NOS(eNOS),and inducible NOS(iNOS),were visualized with protein A-gold-conjugated secondary antibodies.Stained ultrathin sections were examined and photographed with a Philips CM10 electron microscope equipped with a MEGAVIEW II camera.The specificity of the immunoreaction in all cases was assessed by omitting the primary antibodies in the labeling protocol and incubating the sections only in the protein A-gold conjugated secondary antibodies.RESULTS:Postembedding immunoelectronmicroscopy revealed the presence of nNOS,eNOS,and iNOS immunoreactivity in the myenteric neurons,the enteric smooth muscle cells,and the endothelium of capillariesrunning in the vicinity of the myenteric plexus of the rat duodenum.The cell type-specific distributions of the immunogold particles labeling the three different NOS isozymes were revealed.In the control experiments,in which the primary antiserum was omitted,virtually no postembedding gold particles were observed.CONCLUSION:This postembedding immunoelectronmicroscopic study provided the first evidence of celltype-specific differences in the subcellular distributions of NOS isoforms.

Picoplankton distribution in different water masses of the East China Sea in autumn and winter

Abstract Picoplankton distribution was investigated in different water masses of the East China Sea in November, 2006 and February, 2007. The autumn and winter cruises crossed three major water masses： the coastal water mass （CWM）, the mixed water mass （MWM）, which forms on the continental shelf, and the Kuroshio water mass （KWM）. Picoplankton composition was resolved into four main groups by flow cytometry, namely Synechococcus, Prochlorococcus, picoeukaryotes, and heterotrophic bacteria. The average abundances of Synechococcus, picoeukaryotes, and heterotrophic bacteria were （0.63＋ 10.88）~ 103, （1.61＋1.16）x103, （3.39~1.27）x105 cells/mL in autumn and （6.45~8.60）x103, （3.23~2.63）x103, （3.76~1.37）x 105 cells/mL in winter, respectively. Prochlorococcus was not found in the CWM and seldom observed in surface samples in either season. However, Prochlorococcus was observed in the MWM and KWM （approximately 103 cells/mL） in both auttman and winter. Synechococcus distribution varied considerably among water masses, with the highest levels in KWM and lowest levels in CWM. The depth-averaged integrated abundance of Synechococcus was approximately 5-fold higher in KWM than in CWM, which may be due primarily to water temperature. In the MWM, Synechococcus was resolved as two subgroups; the presence of both subgroups was more common in autumn. Picoeukaryote abundance varied less among water masses than Synechococcus, and heterotrophic bacteria depth-averaged integrated abundance exhibited the smallest seasonal variations with respect to water mass. Correlation analysis showed that relationships between picoplankton abundances and environmental factors （temperature, nutrients, and chlorophyll a） differed among the three water masses, suggesting that the three water masses have different effects on picoplankton distribution （particularly Synechococcus）.

Dverview and Main Advances in Permutation Tests for Linear Regression Models

When the population, from which the samples are extracted, is not normally distributed, or if the sample size is particularly reduced, become preferable the use of not parametric statistic test. An alternative to the normal model is the permutation or randomization model. The permutation model is nonparametric because no formal assumptions are made about the population parameters of the reference distribution, i.e., the distribution to which an obtained result is compared to determine its probability when the null hypothesis is true. Typically the reference distribution is a sampling distribution for parametric tests and a permutation distribution for many nonparametric tests. Within the regression models, it is possible to use the permutation tests, considering their ownerships of optimality, especially in the multivariate context and the normal distribution of the response variables is not guaranteed. In the literature there are numerous permutation tests applicable to the estimation of the regression models. The purpose of this study is to examine different kinds of permutation tests applied to linear models, focused our attention on the specific test statistic on which they are based. In this paper we focused our attention on permutation test of the independent variables, proposed by Oja, and other methods to effect the inference in non parametric way, in a regression model. Moreover, we show the recent advances in this context and try to compare them.

Spatial Probabilistic Model of Block Failure Capacity of Piles in Clay

A probability based model of block failure capacity of pile foundation in clay soil under axial load is developed. The model was based on the first order second moment method. Instead of using point variability, the soil inherent variability is modelled as random field model. Based on this model, a reliability based factor of safety for designing pile group foundation, taking into account bock failure mechanism, is proposed. Furthermore, using simplified lognormal model, the relationship between the factor of safety used in design practice and target reliability may be derived explicitly.