Hardening of St. 3 Steel by Shock‐Wave Action

A method for studying the strength characteristics of multiphase media based on construction of microhardness histograms is developed. It is shown that for St. 3 steel, the microhardness histograms are divided into two groups based on the type of high explosive used: histograms with one maximum and those with two maxima. Using the method proposed, we determined the contribution of zones consisting mainly of ferrite and pearlite grains and zones of multiple distortions to hardening of St. 3 steel. The behavior of these zones under annealing, various pulse actions, and longterm storage is studied. It is shown that under shockwave action, zones with predominant pearlite and ferrite grains are hardened synchronously.     

Synthesis of magnetic mesoporous silica composites via a modified Stöber approach

In this work, magnetic Fe₃O₄@mesoporous silica composites were synthesized by a microemulsion (oil-in-water/ethanol) approach which was applied with a modified Stöber reaction. Cetyl trimethyl ammonium bromide was employed as the surfactant, nano-Fe₃O₄ particles were dispersed in microemulsion. Tetraethyl orthosilicate (TEOS) formed oil drops, and ammonia solution facilitated the hydrolysis polymerization of TEOS. The diameters of the magnetic Fe₃O₄@mesoporous silica composites can be tuned within the range 120–380 nm by varying the ratio of ethanol/water and the amount of nano-Fe₃O₄ particles. Brunauer–Emmett–Teller surface areas of magnetic Fe₃O₄@mesoporous silica composites were determined to be within the range 490–759 m²/g and their pore sizes were around 2.3 nm as it was determined by Barrett–Joyner–Halenda method. Furthermore, the encapsulation of poorly water-soluble drugs within magnetic Fe₃O₄@mesoporous silica composites was investigated using protoporphyrin IX. Magnetic Fe₃O₄@mesoporous silica composites showed a drug loading within 22–68 mg/g, which can be an excellent drug delivery platform for photodynamic therapy.     

MMA、St及MMA/St聚合温度和极限转化率的关系

在60～90℃温度范围内进行甲基丙烯酸甲酯(MMA)、苯乙烯(St)本体聚合和MMA/St本体共聚,研宄聚合温度与极限转化率的关系,进一步证实了限极转化率是聚合温度和聚合物分子量的函数。发现分子量大于10万时,在特定温度范围内,极限转化率与聚合温度有近似线性关系。     

Bd／St乳液共聚合反应数学模型

以Ｓｍｉｔｈ－Ｅｗａｒｔ乳聚理论为基础，建立了Ｂｄ／Ｓｔ浮液共聚合生产Ｅ－ＳＢＲ的动力学数学模型。并根据过程的稳态和动态特性，分别建立 态和动态动力学数学模型。模型中全面与查了由于化学反流入、注等对体系中各组份的深度乳胶料总数和粒径分布、转化率等过程状态的影响     

MMA—St高转化率共聚动力学

在60～90℃范围内,以AIBN、BPO为引发剂进行甲基丙烯酸甲酯(MMA)～苯乙烯(St)本体共聚,研究了高转化率下聚合温度、引发剂浓度及单体配比对共聚速度的影响。结果表明,聚合温度升高、引发剂浓度增大及单体配比中MMA含量增加,均使MMA～St共聚速率增大。但当聚合反应进行到转化率达70%左右时,聚合速率开始显著降低?当转化率达到90%以上时,聚合反应几乎停止。推导并关联了高转化率下共聚动力学模型,在转化率70%以下,模型计算值与实验结果符合很好,该模型为MMA～St共聚生产控制提供了理论依据。     

Isolation and Characterization of Microsatellite Markers in Brown Planthopper (Nilaparvata lugens Stål)

Brown planthopper (Nilaparvata lugens Stål) (Homoptera: Delphacidae) is an economically important pest on rice. In this study, 30 polymorphic microsatellite markers were developed from N. lugens genomic libraries using the method of Fast Isolation by AFLP of Sequence Containing Repeats (FIASCO). Polymorphism of each locus was detected in 48 individuals from two natural populations. These microsatellite loci revealed 2 to 18 alleles, and the expected and observed heterozygosities ranged from 0.042 to 0.937 and from 0.042 to 0.958, respectively. These markers will be useful for the future study of this agricultural pest in population genetics and molecular genetics.     

Bd／St乳液共聚合反应数学模型

建立了Ｂｄ／Ｓｔ乳液共聚合反应过程的聚合物微观质量数学模型，在模型中全面考查了聚合物的微观质量参数，如平均组成，、平均分子量、分子量分布和支化度等与聚合过程状态的关系。     

石墨烯在MMA和St中的分散性研究

本文通过第二单体甲基丙烯酸二甲氨基乙酯(DMAEMA)将石墨烯分散到甲基丙烯酸甲酯(MMA)中制成石墨烯/MMA分散液,分别以第二单体甲基丙烯酸二甲氨基乙酯(DMAEMA)、乙烯基三甲氧基硅烷偶联剂(KH-171)、单烷氧基类钛酸酯偶联剂(JTW-101)为分散助剂将石墨烯分散到苯乙烯(St)中制成石墨烯/St分散液。通过沉降实验、离心实验、偏光显微镜、X射线衍射(XRD)、傅里叶变换红外光谱(FTIR)和拉曼光谱等对石墨烯/MMA和石墨烯/St分散液的分散情况进行分析和研究。实验结果表明:石墨烯已被均匀、稳定地分散于MMA或St中;以第二单体甲基丙烯酸二甲氨基乙酯(DMAEMA)为分散助剂制备的石墨烯/MMA分散液分散效果最好。     

St/FR-2共聚体系竞聚率

通过对苯乙烯/双(2,3-二溴丙基)反丁烯二酸酯(St/FR-2)共聚体系的研究,用核磁共振氢谱方法分析了共聚物组成,运用Fineman-Ross的理论进行数据处理,得到了90℃下,FR-2与St的竞聚率分别为0.026 9±0.000 3和0.120 0±0.057 7.     

VAc、St不同乳液聚合方式的研究

对水溶性引发剂、有乳化剂存在的常规乳液聚合,水溶性引发剂无皂乳液聚合及有乳化剂存在的油溶性引发剂乳液聚合三种聚合方式,选择了水溶性相差较大的醋酸乙烯酯(VAc)和苯乙烯(St)两种单体,对其聚合动力学进行了比较,讨论了其不同的成核机理及单体水溶性对聚合速率的影响,考察了乳液的反应稳定性。结果表明聚合方式的不同、单体水溶性的不同对聚合动力学具有显著的影响。     

钯络合物催化CO/St共聚合动力学

采用以醋酸钯为催化剂母体组成的催化体系 ,催化CO/St(苯乙烯 )的共聚合 .动力学研究表明 ,共聚合经历了短暂的过渡期 ,其间形成了真正的活性中心 .配体结构和用量的变化将影响过渡期内所生成的活性中心的结构及其在催化循环中的活性和寿命     

Bd—St低温乳液共聚物动力学数学模型

对丁二烯－苯乙烯乳液生产乳聚丁苯橡胶的动力学数学模型进行了较系统的评述，讨论了生产过程的动力学数学模型的基本结构及模型的求解，验证和应用。     

P(St/MAH)和P(St/MAH/BA)施胶剂的改性及应用

以苯乙烯(St)和马来酸酐(MAH)为主要原料、单链脂肪醇(脂肪醇中碳原子数n=4、5、6、8)为改性剂,通过在主链中引入软单体丙烯酸丁酯(BA),成功制备出改性P(St/MAH/BA)和P(St/MAH)系列施胶剂。结果表明:在相同条件下,经改性P(St/MAH)或P(St/MAH/BA)施胶剂施胶后,不同施胶纸具有不同的施胶效果;对文化书写纸而言,前者的油墨吸收率高于后者、平滑度小于后者,但两者的拉伸强度和施胶度差别不大;对瓦楞纸而言,前者的施胶度和环压强度均高于后者。随着单链脂肪醇中碳原子数的不断增加,文化书写纸的油墨吸收率增大、平滑度和拉伸强度下降,而瓦楞纸的环压强度增大、拉伸强度略有下降,但两种施胶纸的施胶度均呈先升后降态势。     

Olin公司St．Gabriel氯碱装置依然关闭

该套19．7万池汞法氯碱装置去年底定期检修关闭以来,经济形势一直不好,但该公司继续实施以前宣布的改扩建项目。这一投资1．42亿美元的项目,将建设1套离子膜法氯碱装置替代汞法装置．生产能力将增加25％,达到24．6万t／a、能耗将降低29％,预计2009年二季度投产。     

St／BA／AN水性防腐涂料的研制

合成了St/BA/AN水性乳液,并以该乳液为基料,配制了性能稳定、适应性好、无环境污染的水性防腐涂料,适用于各种金属构件的表面涂装。