基于LaTeX渲染的微积分在线测试小程序设计与实现

为解决传统微积分在线考试系统中数学公式显示不清、存储空间占用大的问题,文章提出了一种基于LaTeX渲染的微信小程序解决方案。相较于传统的图片存储方式,LaTeX渲染可以显著提高公式显示质量,并减少存储空间。该系统可用于微积分课程的过程性考核,实现个性化学习跟踪,提高教学效率。

Natural rubber latex as a potential additive for water-based drilling fluids

The environmental hazards and"carbon footprint"of oil and gas drilling can be significantly reduced by replacing traditional petroleum-based chemical additives with natural materials derived from plants and animals.This paper explored for the first time the interaction mechanism between natural rubber latex(NRL)and bentonite suspensions(BTs)through a series of characterization experiments,as well as the potential applications in water-based drilling fluids(WBDF).The gel viscoelasticity experiments showed that NRL could decrease the consistency coefficient(k)and flow index(n)of BTs,and enhance the shear thinning performance of BTs as pseudo-plastic fluids.In addition,0.5 w/v%NRL not only increased the critical yield stress and strengthened the structural strength between the bentonite particles,but also facilitated the compatibility of pressure loss and flow efficiency.The evaluation of colloidal stability and WBDF performance indicated that NRL particles could promote the hydration and charge stability on the surface of BTs particles,and optimize the particle size distribution and flow resistance of WBDF under the"intercalation-exfoliation-encapsulation"synergistic interaction.Moreover,NRL can improve the rheological properties of WBDF at high temperatures(<150.C),and form a dense blocking layer by bridging and sealing the pores and cracks of the filter cake,which ultimately reduces the permeability of the cake and the filtration loss of WBDF.

Physical and Chemical Characterizations of Rubber Latex Cup Bottom Oil

Rubber latex is an important economic resource. However, the residues from its harvesting are thrown away, even though they contain lipids that can be recycled. This recovery of the residues from the bottom of the cup requires first and foremost their characterization. The aim of this study is therefore to determine the main physical and chemical characteristics of rubber latex cup bottom oil. Oil’s physical parameters determination shows that it has a density of 951 kg∙m−3, a kinematic viscosity of 48.57 cSt and a water content of 0.0845%. Chemical parameters, meanwhile, indicate that this cup bottom residue has a fat content of 95.96%, an acid number of 2.805 mg KOH/g and an iodine number of 92.42 g I2/100g. Therefore, rubber latex cup bottom oil can be used in the formulation of biofuels, biolubricants, paints, varnishes, alkyd resins, polishing oils, soaps, and insecticides.

Formulation of Motor Oil from Blends of Rubber Latex Cup Bottom Oil (RLBO) and Used Frying Oil (UFO)

Most motor oils are made from mineral oils derived from petroleum, the reserves of which are limited and exhaustible. The aim of this study is to produce and characterize motor oil formulations based on mixtures of rubber latex cup bottom oil (RLCBO) and used frying oil (UFO). The results show that these formulations have a density between 0.91 and 0.92. These densities evolve linearly with the proportion of cup bottom oil and temperature. Similarly, the kinematic viscosity of the blends follows an exponential relationship with temperature. By plotting the logarithm of these kinematic viscosities against the inverse of the temperature, we were able to determine the activation energy of the various blends and deduce that the formulations behave Newtonian.

Properties of Polyacrylate Latex Prepared Under Different Emulsified Systems

The polyacrylate latexes were synthesized via pre-emulsified and semi-continuous seeded emulsion polymerization technology when conventional surfactant or polymerizable surfactant was used as emulsifiers. The resultant latexes and their films were characterized with the contact angle determinator and rheometer. Effect of the polymerizable surfactant on water resistance, stability and rheology of the latex was studied. Results show that the water resistance of film is increased first then decreased with the increase of the amount of the polymerizable surfactant. There exists the optimum value of the amount of the polymerizable surfactant for the water resistance of the film. In comparison with the latex prepared with the conventional surfactant, both the mechanical stability and the freezing-thaw stability of the latex are improved when the polymerizable surfactant is used during the course of the emulsion polymerization. The resultant latex has rheological properties of pseudo-plastic fluid and belongs to non-Newtonian fluid.

Comprehensive treatment of latex wastewater and resource utilization of concentrated liquid

Latex wastewater is a kind of refractory organic wastewater containing high concentrations of organics and ammonia nitrogen.In this work,the combined process of forward osmosis(FO)and reverse osmosis(RO)was designed to treat the latex wastewater in the whole process,achieving the water recovery rate of 99%and basically no waste discharge after the catalytic oxidation process.The turbidity of the latex wastewater was decreased to below 1 NTU by microfiltration pretreatment,and then using MgCl_2 worked as the draw solution for FO process to treat the latex wastewater.Different operation conditions including adding acid or scale inhibitor as the pretreatment methods were conducted to improve the treatment performance of the combined process.After the treatment of the whole process,the concentration of COD was less than 20 mg·L^(-1),the concentration of NH_3-N was less than 10 mg·L^(-1),and the concentration of TP was less than 0.5 mg·L^(-1)for the treated latex wastewater.The water quality met standards of industrial water reuse after the complete analysis of the treated latex wastewater,meanwhile,useful substances of L-Quebrachitol(L-Q)were successfully extracted from the concentrated solution.Therefore,the combined process of FO and RO could realize the efficient treatment and reuse of latex wastewater,which provided with some important guidance on the industrial application.

Toxic Effects of Ficus benghalensis Latex Based Combinatorial Formulations on Various Enzymatic Parameters in Indian White Termite Odontotermes obesus

In the present investigation, various bioassays were conducted to evaluate the alteration in levels of various enzymes i.e. alkaline phosphatase, acid phosphatase, glutamate oxaloacetate transaminase, glutamate pyruvate transaminase and acetylcholinesterase. For this purpose worker termites were treated with sub-lethal doses of 40% and 80% of 24 hrs LD50 of latex-based combinatorial formulations and observations were taken at 4 hours intervals up to 24 hours. Ficus benghalensis crude latex and its combinatorial mixtures, like C-MLT-A, CU-MLT-A, AQ-MLT, P-MLT and EA-MLT significantly altered the level of enzymes in Odontotermes obesus and this effect found time and dose-dependent. Reduction or increase in enzymes was calculated by using the corresponding control. The maximum decrease in acid phosphatase level was observed at 16 h when termites were treated with 80% of LD50 of B-MLT-B and P-MLT i.e. 82.84% at 16 h of treatment. A similar dose caused a very slight decrease in glutamate pyruvate transaminase at 4 h of treatment but with the increase in time. Further decrease was noted in other successive treatments that were significant at p > 0.05. Similarly, 40% and 80% of LD50 of the C-MLT-B mixture caused significant (p > 0.05) decrease in alkaline phosphatase and acid phosphatase level at 16 h treatment i.e. 93.42%, 89.46% and 95.89%, 88.17% respectively. The level of acetylcholinesterase was also found to be decreased when termites were treated with 40% and 80% of LD50 of C-MLT-B mixture i.e. 92.72% and 97.27% respectively. All the above alterations noted in levels of various enzymes confirm the action of latex ingredients on worker termites that were anti-feedant or deterrent types. These ingredients can be used to control not only termites but also other phytophagous insects.

Defensive Role of Plant Latex on Insect Pests’ Suppression: A Critical Review

Over 350 million years have passed since the documentation of the first interaction between plants and insects. Numerous plant defense qualities and associated counter-adaptive features have developed as a result of these interactions between insects and plants. These characteristics might be either morphological or biological in nature. One of the most significant and useful biochemical characteristics in plants is latex. Latex has a sticky property due to presence of secondary metabolites in it, which aids in entangling or sealing the mouthparts of small insects. These metabolites also chemically interact with the insects interfering with crucial bodily processes. Plant latex has amazing properties that help protect plants from insects and inhibit them in general. It may be possible to control insect pests in a natural, secure, and long-lasting manner by correctly identifying plant latex with strong insecticidal properties and developing formulations of plant latex.

Effect of Ficus benghalensis Latex Based Combinatorial Formulations on Various Bio-Molecules in Indian White Termite Odontotermes obesus

In present investigation, various bioassays were conducted to evaluate the alteration in levels of certain biomolecules, such as glycogen, protein, amino acid, DNA, RNA and lipids. For this purpose, worker termites were treated with sub-lethal dose 40% and 80% of 24 hrs LD50 values and observations were taken at 4 hrs interval up to 24 hrs. Crude latex and its combinatorial mixtures, like S-MLT-A, B-MLT-A, C-MLT-A, CU-MLT-A, AQ-MLT significantly altered level of bio-molecules in Odontotermes obesus. This effect was found time and dose dependent. Reduction or increase in biomolecules was calculated by using corresponding control. Maximum decrease in glycogen level was observed at 16 h when termites were treated with 80% of LD50 of Ficus benghalensis aqueous extract i.e. 56.88% at 16 h of treatment. A similar dose caused very slight decrease in lipid contents at 4 h of treatment but it was found further significantly (p > 0.05) decreased in other successive treatments. 40% and 80% of LD50 of C-MLT-B mixture caused significant (p > 0.05) decrease in DNA and RNA level at 16 h treatment. The level of DNA and RNA level was recorded 83.90%, 90.18% and 85.42% and 74.05% respectively. Similarly, total proteins were also found to be decreased with 40% and 80% of LD50 of C-MLT-B mixture i.e. 71.47% and 66.45% respectively. All these alterations found in levels of various bio-molecules confirm the action of latex ingredients on worker termites that was antifeedant or deterrent types. These ingredients can be used to control not only termites but also other phytophagous insects in a sustainable and eco-friendly way.

基于LaTeX的高等数学题库建设与试卷生成

题库管理与出试卷是高校老师工作中的重要组成部分.传统的管理与操作方法费时费力,同时在试题重复率、格式化与标准化等方面相对难以控制.针对中文理工科组卷,利用Te X系统实现题库管理与组卷,能大大减轻老师工作量.在分析高校题库与试卷管理现状及高校理工科试卷特点等基础上,利用LaTeX排版系统和Exam文档类制作与生成题库,利用LaTeX实现自动编号、一键生成试卷和参考答案,以及数学公式、图表等格式化处理,从而形成一整套题库管理与出卷系统.

Mechanical Characterization of Rubber Latex-Based Carpets (Hevea bresiliensis): Influence of Rubber Latex Content and Fiber Fabrics (Cotton and Mosquito Nets) on Wear Resistance of Rubber Latex-Based Carpets

This work focuses on the development of carpets from sand, fabrics of cotton fiber and mosquito nets and rubber latex. Following a study on the choice of the best formulations, the quantity of rubber latex used for shaping varies between 14% and 18% (latex/sand + latex ratio) for the carpet with the fabric of mosquito nets and between 16% and 18% for the one made with the fabric of cotton fiber. Thus, with a mixture of sand, fiber fabrics (cotton and mosquito nets) and rubber latex, carpets were developed. In addition, the wear test carried out on these samples indicates that it is possible to produce carpets with the new material made of rubber sand and latex: SABLATEX At room temperature. Following the characterization test, it resorts to only 16% latex with cotton fiber fabric, allowing to have carpets with good mechanical characteristics.

基于LaTeX的题库管理与组卷系统设计

题库管理与试卷组织是高校老师工作中的重要组成部分.传统的管理与操作方法往往费时费力,同时在试题重复率、格式化与标准化等方面相对难以控制.针对中文理工科组卷,利用计算辅助系统实现题库管理与组卷,能大大减轻老师工作量.在分析高校题库与试卷管理现状及高校理工科试卷特点等基础上,利用Excel及VBA工具制作与生成题库,利用LaTeX实现随机组卷、自动编号、试卷及参考答案控制,以及公式、图表、化学式等的格式化处理,从而形成一整套题库管理与组卷系统.

基于ASP.NET的在线LATEX编译环境的构建

以Microsoft Visual Studio 2010作为开发环境,Visual C#作为编程语言,以.NET Remoting分布式应用程序为原理,构建一个基于ASP.NET的在线LATEX编译环境,从而使得使用LATEX进行编辑文档更为方便快捷。为开发存储LATEX格式文本的在线试题库管理系统提供了一条思路,既解决了自动生成试卷中处理数学公式的一个难点,也搭建了一个使用LATEX语言进行学术交流的网络平台。

LATEX中选择题模板设计及其应用

要把选择题排版的美观大方,录入人员通常得花费较多的时间。LATEX是一种可编程的科技排版软件,本文主要使用"ifthen"宏包中的"\ifthenelse"选择分枝语句设计了LATEX环境中的一个选择题模板,本模板有以下主要特点:依据四个选项的最大长度来自动确定四个选项排一行、两行或四行;当一行中有两个或四个选项时能使选项按指定宽度均匀排列;可以排版单项选择和多项选择;自动生成选项序号ABCD等;自动生成小题编号;可以自动生成参考答案。使用本模板时试题录入人员能把注意力集中在试题的内容上,完全无需考虑选项排版问题。

Latex法测定血浆D二聚体的临床应用研究

血浆D二聚体(D—DIMER)是交联纤维蛋白在纤溶酶作用下产生的一种特异性的降解产物,正常人血浆中此降解产物甚微(【200ng/ml),仅当纤溶作用增加时,血浆中才会出现大量的D—DIMER。本文应用Latex法测定正常人群和心脑疾病患者血浆中的D—DIMER的含量。

应用LaTeX系统排版自然科学类期刊的优势分析

编辑手段现代化是科技期刊发展的一个十分重要的前提条件。如何改革传统编校过程,实现科技期刊编、排、校一体化,是科技期刊迫切需要解决的问题,而排版软件的选择是其关键。LaTeX是一种格式化的排版系统,将它应用于自然科学类期刊的排版,便于编辑真正做到编、排、校一体化,在较高层次上实现科技论文排版的美感,便于作者从网上校对,便于实现全文上网,形成一条龙出版模式。

LaTex系统在新疆大学学报排版的应用与实践

编辑手段的现代化是科技期刊发展的一个重要方面,将LaTex应用于科技期刊的排版,便于编辑实现编、排、校一体化.作者结合科技期刊使用LaTex排版系统的一点经验,给出了新疆大学学报(自然科学版)LaTex排版系统的简易模板,希望能对使用LaTex排版系统的作者有所帮助.

MATLAB高级绘图功能介绍──2.利用LaTeX语言对图形进行标注

介绍在应用ＭＡＴＬＪＡＢ进行绘图时；利用ＬａＴｅＸ语言对图形进行标注的一个很有用的功能，该功能使ＭＡＴＬＡＢ所绘制的图形满足国内外各种期刊杂志的出版要求。

函数图形描绘用LaTeX编辑高等数学幻灯片的实现

本文在对LaTeX的plot操作的使用作深入研究的基础上,解决一元函数图形较精确描绘中的常见问题,得到绘制二元函数图形的示意图的简易方法。

“微积分”教与学评价系统的小程序设计与实现

利用微信小程序、SpringMVC、MyBatis和Vue等技术,设计和实现一个实用、高效且功能丰富的“微积分”教与学双向评价平台。一方面,通过对学生进行章节在线测验强化微积分课程的过程性考核与评价。另一方面,设定合理的评价指标,学生对老师完成教学指标的情况进行评价,并可通过师生信箱双向交流。在线测试系统题库采用LaTeX代码存储和渲染数学公式,比传统的采用截图方式存储数学公式的方式可节省大量存储空间。