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1.
腐植酸胶体稳定性及其对悬浮液稳定性的作用   总被引:2,自引:0,他引:2  
郭晓峰 《腐植酸》2001,(2):18-21
本课题研究的是腐植酸胶体溶液自身的稳定性及腐植酸加入到固体悬浮液后对悬浮液稳定性的影响,本研究在理论上属于胶体及界面化学和高分子化学领域,有一定的交叉性,本研究的应用范围属煤化工。  相似文献   

2.
城市规划建设是一个多因素、多层次的复杂过程,在城市规划中如何择优利用、适应改造工程地质环境条件,防治可能出现的环境工程地质问题,减少地质灾害的发生,无疑是十分重要的.本文以GIS作为工具,从三个方面对工程地质环境质量进行评价.  相似文献   

3.
通过PP加工稳定性试验,热烘箱老化试验和户外曝露试验,评价了抗氧剂3114在聚丙烯中的热氧稳定性和耐候性。  相似文献   

4.
陈林  徐保明 《四川化工》2003,6(2):10-13
介绍了 4 5 %高效氯氰菊酯微乳剂的配方 ,讨论了乳化剂、助乳化剂、防冻剂、水质、原料等因素对制剂物理和化学稳定性的影响  相似文献   

5.
稳定性二氧化氯的生产与应用   总被引:1,自引:0,他引:1  
汪家铭 《化工科技动态》1995,11(6):12-13,11
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6.
7.
在石油化工工程设计领域,钢结构因其强度高、工业化程度好、自重轻等优势,被大量采用,但是由稳定性设计不合理或概念不清而导致事故发生或材料大量浪费现象时有发生。因此,合理完成结构稳定性设计对石化行业钢结构工程起到关键性作用。首先基于ANSYS有限元软件对轴心受压柱进行特征值屈曲分析;其次就钢结构稳定性设计中涉及到的相关问题进行总结、分析,并针对该问题作了总结,提出了一些提高、改善结构稳定性的相应措施,希望对合理完成钢结构稳定设计起到一定的借鉴作用。  相似文献   

8.
人们早就知道,PVC的降解反应是由于主链上发生脱氯化氢(随之产生多烯和变色)及在氧参与下发生分子断链或分子间交联,进而发焦等各种反应所组成。为了PVC树脂的稳定化,一般使用金属皂、无机酸盐类(铅盐)、有机锡化合物及各种辅助稳定剂等。近年来,人们不断进行PVC稳定化的研究,确实是基于技术上的迫切要求。这种要  相似文献   

9.
10.
导热油稳定性的研究   总被引:2,自引:0,他引:2  
导热油经过一段时间的工业和实验室运行后,油品的主要性能指标如酸值、闪点、运动粘度、残炭及各组成含量等,随运行温度、运行时间及运行时氮气保护状况而变化。我们研究了 YD-300导热油的运行稳定性,并提出延长导热油使用寿命的措施。  相似文献   

11.
2004~2005年国外塑料工业进展   总被引:1,自引:0,他引:1  
收集了2004年7月-2005年6月国外塑料工业的相关资料,介绍了2004年~2005年国外塑料工业的发展情况。提供了世界几大区域塑料的产量、增长率及所占份额;美国、德国、日本、韩国、法国、比利时、印度、西班牙、中国台湾、加拿大、巴西、英国等国家和地区的不同树脂的产量及消费量;各国、各地区塑料原料的产量、进出口量、国内消费量和人均消费量;日本塑料原料的生产情况。按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、通用热固性树脂(酚醛、聚氨酯、不饱和树脂、环氧树脂)、特种工程塑料(聚苯硫醚、液晶聚合物、聚醚醚酮、聚砜)的品种顺序,对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。  相似文献   

12.
沥青质引发的蜡油体系结蜡层分层现象及分层规律   总被引:1,自引:1,他引:0       下载免费PDF全文
李传宪  蔡金洋  程梁  杨飞  张皓若  张莹 《化工学报》2016,67(6):2426-2432
利用自主研发的Couette结蜡装置,对蜡含量相同的油样1(不含沥青质)和油样2[含0.75%(质量分数)沥青质]进行结蜡实验,并研究其结蜡层的分层现象和分层规律。通过对油样1和油样2结蜡表层和底层的宏观形貌、DSC放热、析蜡量、蜡晶微观形貌的分析发现:油样1结蜡层无明显分层现象,而油样2结蜡层分层现象明显,沥青质的加入导致了结蜡层的分层。与结蜡表层相比,油样2结蜡底层的析蜡点、蜡含量与沥青质含量显著升高,蜡晶形貌发展为致密的类球状大蜡晶。油样2结蜡表层沉积量随壁温的升高、油壁温差和转速的增大而减小;结蜡底层沉积量随壁温升高而减小,随油壁温差和转速的增大而增大;总的蜡沉积量随壁温的升高和转速的增大而减小,随油壁温差的增大先增大后减小。  相似文献   

13.
Protein solubility is based on the compatibility of the specific protein surface with the polar aquatic environment. The exposure of polar residues to the protein surface promotes the protein’s solubility in the polar environment. The aquatic environment also influences the folding process by favoring the centralization of hydrophobic residues with the simultaneous exposure to polar residues. The degree of compatibility of the residue distribution, with the model of the concentration of hydrophobic residues in the center of the molecule, with the simultaneous exposure of polar residues is determined by the sequence of amino acids in the chain. The fuzzy oil drop model enables the quantification of the degree of compatibility of the hydrophobicity distribution observed in the protein to a form fully consistent with the Gaussian 3D function, which expresses an idealized distribution that meets the preferences of the polar water environment. The varied degrees of compatibility of the distribution observed with the idealized one allow the prediction of preferences to interactions with molecules of different polarity, including water molecules in particular. This paper analyzes a set of proteins with different levels of hydrophobicity distribution in the context of the solubility of a given protein and the possibility of complex formation.  相似文献   

14.
姚翰林  辛忠 《化工学报》2022,73(8):3518-3528
以碳酸钙水相合成为模型反应,借助对流动反应过程的放大观测,从沉淀悬浮液的流变特性分析了液相沉淀反应在毫米级管式微通道中的流动行为特征以及通道堵塞的过程机理。结果表明,碳酸钙-水悬浮体系的黏度在低剪切速率下随固含率的增加而飙升,而反应通道堵塞的本质可归因于在壁面和流动主体区形成了固含率较高的局部高黏区,使流动性严重恶化。提高反应的流速加快了壁面沉积层和沉淀颗粒团聚体的形成,反而加快了堵塞;其中团聚体的形成远快于沉积层的积累,使团聚体的“架桥”虽晚于沉积层出现,却成为管路堵塞的主要因素。基于破坏流动壁面和主体的局部高黏区,设计了两种新型的微通道反应器模型,有可能为解决反应通道堵塞这一难题提供新的思路。  相似文献   

15.
Processing of concentrated lignocellulosic biomass suspensions typically involves the conversion of the cellulose into sugars and sugars into ethanol. Biomass is usually pretreated via methods like comminution or steam explosion to form fine cellulosic fibers to be dispersed into an aqueous phase for further treatment. The resulting cellulose suspensions need to be pressurized and pumped into and out of various processing vessels without allowing the development of flow instabilities that are typically associated with “demixing”, that is, the segregation of the cellulosic biomass from the aqueous phase via the formation of mats of cellulosic fibers and the filtration of the aqueous phase. Such demixing can prevent continuous processing at high rates. Here, the development of flow instabilities via the demixing effect for cellulose suspensions is demonstrated using capillary and compressive squeeze flows. It is shown that the use of a gelation agent, hydroxypropyl guar gum, at the critical concentration of 0.5 wt% or higher significantly affects the viscoelastic material functions of cellulosic suspensions, improves the dispersive mixing of the fibers within the aqueous phase, and results in the elimination of the flow instabilities and associated demixing effects that are ubiquitously observed during the pressurization and processing of cellulosic suspensions.  相似文献   

16.
One of the fundamental questions discussed in the course of the development towards Industry 4.0 is that of responsibility for machines. The inner-juridical discussion of this issue suffers from the unclear concept of artificial intelligence and the fascination about the creation of very high technical performance while lightning-fast access to a huge amount of information or the determination of previously undiscovered correlations between individual phenomena is no indication of the appearance of the superhuman. Technicians, on the other hand, are confused about the differentiations by which lawyers approach the question of responsibility. This article aims at bridging the gap in order to strengthen the interdisciplinary dialogue.  相似文献   

17.
ACR对PVC加工性能的影响   总被引:1,自引:0,他引:1  
详细研究了丙烯酸酯类PVC加工助剂———ACR的特性黏度、组成对PVC共混物加工性能的影响。结果表明,随着甲基丙烯酸甲酯用量的下降和丙烯酸丁酯用量的提高,其塑化速度增大,但熔体强度降低,在组成相同的情况下,特性黏度越大,塑化越慢,熔体强度越大;丙烯酸酯类加工助剂对PVC制品的拉伸强度和维卡软化点无明显影响,高黏度的加工助剂有提高PVC制品拉伸强度和维卡软化点的趋势。  相似文献   

18.
牟新竹  陈振乾 《化工学报》2020,71(z2):241-252
由于在超声波声场中污泥微粒会发生分层现象,声互作用力使得微粒于超声传播方向相垂直的平面上发生凝聚,因此污泥厚度大小对超声波辅助热风干燥污泥特性有着重要的影响。通过实验的方法,对不同厚度污泥在超声波声场中的分层凝聚现象进行观察,发现污泥内部结构的分层现象随其厚度的增加而明显。研究了超声波对不同厚度污泥干燥过程中各时期干燥时长、干燥速率的影响效果,以及分析了湿分有效扩散系数(Deff)随污泥厚度变化的情况。从实验结果中可以发现,在超声波功率小于135 W范围内,污泥厚度越大,干燥过程中第一降速期时间越长,干燥速率提升效果越差,而对恒速干燥期内干燥速率提升效果更明显;在5、10以及15 mm厚度的污泥中,10 mm厚度的污泥在超声波功率小于90 W的条件下总干燥时长降低幅度最大,干燥速率在各阶段提速也较快;污泥厚度越小,超声波功率对污泥湿分有效扩散系数影响越小,反之影响越大。  相似文献   

19.
电解质溶液非理想性行为的解释和预测   总被引:2,自引:0,他引:2       下载免费PDF全文
王仁远  时钧 《化工学报》1997,48(2):143-151
提出一个新的电解质溶液理论,从粒子相互作用的能量效应和溶液微观结构的熵效应两个方面解释电解质溶液的非理想性行为,并建立一个新的电解质溶液原始模型。新模型考虑了溶液微观结构的熵效应,显著提高了对各种电解质溶液的非理想性行为的预测。  相似文献   

20.
Molecular mechanics modelling is used to calculate the energies of interaction, hence the molecular level energy of adhesion at the interface with crystalline cellulose I of three different photopolymerizable primers and of a polyester varnish at the interface with the primer/cellulose assembly. The energy of interactions for just one of the primers with the statistically most common conformation of amorphous cellulose has also been obtained for comparison. Experimental results of adhesion by a standard peel test and by thermomechanical analysis, in which the effect of viscoelastic energy dissipation by crack tip propagation has been respectively minimized or is not present, hence in which the energy of interfacial interaction is nothing else but the work of adhesion, correlated well with the energies of interaction calculated by molecular mechanics. An equation correlating the energy of interaction at each finish/cellulose interface with the deflection derived by thermomechanical analysis, and with the number of internal bond rotational degrees of freedom as well as the degree of networking of the finish, has been derived and is presented. A relationship between the intrinsic fracture energy Go and the molecular mechanics-derived energy of interaction at the interface equating this to the square of the work of adhesion is obtained and is presented.  相似文献   

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