2019年中国合成橡胶行业重大新闻

1 主要合成橡胶生产能力突破6 000 kt/a,产品结构逐步优化据中国合成橡胶工业协会统计,2019年我国主要合成橡胶装置生产能力再创历史新高,突破6 000 kt/a大关。苯乙烯类热塑性弹性体系列产品产能增长势头明显,2019年新增超过100 kt。我国合成橡胶行业产品结构逐步优化,但是行业整体供需矛盾依然十分突出。2 丁二烯产能快速扩张,合成橡胶行业喜忧参半2019年,2套丁烯氧化脱氢丁二烯装置投产     

配位链转移共聚合制备丁二烯和异戊二烯共聚物（英文）

采用 Nd(vers)_3/Al(i-Bu)_2H/Me_2SiCl_2三元催化体系实现了丁二烯与异戊二烯的配位链转移共聚合,得到结构与组成精确可控的丁异戊共聚产物。结果表明,体系中存在快速可逆链转移进程,此聚合反应具有与经典活性聚合反应相似的特点,即能够精确控制分子量,保持窄分子量分布,聚合产率高达100%;此外,稀土原子利用率大幅提高,每个钕金属中心可产生4～6条聚合物链;微观结构分析表明产物为无规共聚物。     

大柳塔煤矿五盘区5-2煤层DDF2断层特征

大柳塔煤矿五盘区5-2煤层在三维地震资料解释中发现存在一条影响较大、伸展较远的断层（DDF2断层）横切5-2煤层。综合研究表明，DDF2断层为走向为东南—西北方向（111°～291°）、倾向为西南方向（201°）的高角度正断层。该断层为坳陷盆地形成后控制部分煤层沉积:在D306钻孔和D307钻孔所在区域形成时间较早，形成于5-2煤层沉积之后，结束于4-3煤层形成之后，控制5-2煤与4-3煤之间的地层沉积，为同沉积断层；该断层在D304钻孔和D305钻孔所在区域形成时间较晚，形成于4-2煤层沉积之后，结束于3-1煤层形成之后，局部控制4-2煤层与3-1煤层之间沉积，为准同生沉积断层。DDF2断层形成于东南方向，逐渐向西北方向迁移、加剧到最后尖灭。     

Towards Efficient Nonenzymatic DNA Ligation: Comparing Key Parameters for Maximizing Ligation Rates and Yields with Carbodiimide Activation**

Chemical ligation is an important tool for the generation of synthetic DNA structures, which are used for a wide range of applications. Surprisingly, reported chemical ligation yields can range from 30 to 95 % for the same chemical activating agent and comparable DNA structures. We report a systematic study of DNA ligation by using a well-defined bimolecular test system and a water-soluble carbodiimide (EDC) as a phosphate-activating agent. Our results emphasize the interplay between template-substrate complex stability and the rates of the chemical steps of ligation, with 3′ phosphate substrates providing yields near 100 % after 24 hours for particularly favorable reaction conditions. Ligation rates are also shown to be sensitive to the identity of the base pairs flanking a nick site, with as much as threefold variation. Finally, the observation that DNA substrates are modified by EDC at rates that can be comparable with ligation rates emphasizes the importance of considering side reactions when designing protocols to maximize ligation yields.     

Effect of microRNA-143-3p-mediated CTNND1 on the biological function of lung cancer cells

Lung cancer poses a serious threat to human life with high incidence and miRNA is an important biomarker in tumors. This study aimed to explore the effect of miR-143-3p on the biological function of lung cancer cells and the underlying mechanism. Eighty-seven samples of lung cancer tissues and 81 samples of tumor-adjacent tissues from patients undergoing radical lung cancer surgery in our hospital were collected. The lung cancer cells and lung fibroblast cells (HFL-1) were purchased, and then miR-143-3p-mimics, miR-NC, si-CTNND1, and NC were transfected into A549 and PC-9 cells to establish cell models. MiR-143-3p and CTNND1 expression levels were measured by the qRTPCR, Bax, Bcl-2, and CTNND1 expression levels by the Western Blot (WB), and cell proliferation, invasion, and apoptosis by the MTT assay, Transwell assay, and flow cytometry. Dual luciferase report assay was used to determine the relationship between miR-143-3p and CTNND1. In this study, miR-143-3p was lowly expressed in lung cancer and CTNND1 was highly expressed in lung cancer. The overexpression of miR-143-3p inhibited cell proliferation and invasion, promoted cell apoptosis, significantly increased Bax protein expression, and decreased Bcl-2 protein expression. The inhibition of CTNND1 led to opposite biological characteristic in cells. The dual luciferase reporter assay demonstrated that miR-143-3p was a target region of CTNND1. Such results suggest that miR-143-3p can inhibit the proliferation and invasion of lung cancer cells by regulating the expression of CTNND1 and promote the apoptosis of lung cancer cells, sott is expected to be a potential target for lung cancer.     

含聚环氧乙烷链段梳形结构聚(异戊二烯-g-苯乙烯)的合成与表征

以聚苯乙烯(PS)大分子单体和异戊二烯为共聚单体,四氢呋喃为调节剂,正丁基锂为引发剂,三异丁基铝为助引发剂,脂肪族缩水甘油醚为官能化改性剂,采用一锅法经活性负离子共聚合制得以聚异戊二烯为主链、PS为规整侧链,且末端含星形聚环氧乙烷链段的极性化梳形聚(异戊二烯-g-苯乙烯-s-环氧乙烷)(PI-g-PS-s-PEO),利用凝胶渗透色谱仪、傅里叶变换红外光谱仪、差示扫描量热仪等对所制备的PI-g-PS-s-PEO进行了表征,并考察了PI-g-PS-s-PEO中聚环氧乙烷链段(PEO)质量分数(w_(PEO))的影响因素。结果表明,产物具有分子结构可设计、分子量分布窄等优点。此外,PS大分子单体分子量对w_(PEO)无影响,减小缩水甘油醚分子量、增加其用量及延长封端反应时间均可提高w_(PEO),且w_(PEO)在0.1%～1.8%可调。     

铣削加工每齿进给量的决定因素研究及验证

研究了面铣刀的主偏角对切屑厚度和每齿进给量的影响,铣削中每齿进给量的决定因素,切削宽度与刀具直径的比值对切屑厚度的影响等问题进行理论分析,同时结合变速箱壳体铣削加工过程进行验证,解决了合理选择铣刀及切削参数以提升加工效率的问题。     

新型斩切式稻杆粉碎机的设计与试验研究

针对目前秸秆粉碎装置存在缠轴铰刀、出料过长、无法有效处理湿度较大的稻秆等问题,论文提出了一种适于田间作业的新型斩切式稻杆粉碎机。通过Solidworks进行整体建模,基于TRIZ理论对曲轴同步输送斩切装置进行创新设计,并对圆弧形齿轮啮合调隙机构、二次粉碎装置进行了设计,对斩刀滑切角度参数进行计算,利用COMSOL软件对曲轴连杆强度进行有限元分析。制作了实物样机并进行粉碎试验,样机尺寸1.62 m×0.75 m×1.2 m、重量250 kg、试验结果表明生产效率达3.64 m^3/h、出料长度5 mm^10 mm、粉碎合格率90%左右,可大大提高稻杆利用价值,具有广阔的市场前景。     

Exploring the biomechanics of walking and crowd “flow”

Crowd movement simulation models are generally based on aggregated speed and flow data collected more than 50 years ago. There appears to be no validated modelling capability to include the impact of recent and future changes in population demographics, resulting from an ageing population and increasing obesity rates. New analytical approaches and data gathering are required to successfully model crowd movement and safety for current and future generations. This study carried out (a) a review of the primary components of crowd movement, demographics and analytical techniques, (b) prototype experiments to investigate age-related aspects of space and potential points of contact and (c) a new predictive model for crowd flow analysis based on pedestrian biomechanics and anthropometric data. The model uses the physical space taken up by the biomechanical walking process and the spatial buffer between points of potential contact with other pedestrians to predict the speed of movement at different levels of congestion. The new analytical model was used to predict single file speeds (for people with different demographics in congested space), which compared well with published experimental data. The next steps for model development for wider “flows” and additional experiments to provide data sets for wider demographics are also proposed.     

环保促进剂用量对丙烯酸酯橡胶/乙烯丙烯酸酯橡胶共混胶性能的影响

采用环保促进剂Vulcofac ACT 55与硫化剂Diak No 1组成硫化体系,研究了Vulcofac ACT 55用量对丙烯酸酯橡胶/乙烯丙烯酸酯橡胶共混胶性能的影响。结果表明,随着Vulcofac ACT 55用量的增加,共混胶的交联密度先增大后减小,焦烧时间逐渐缩短,硫化反应速率则逐渐增大;共混硫化胶的物理机械性能、耐热老化性能、耐ASTM No 1标准油性能和热稳定性先得到改善后又变差。差示扫描量热研究结果显示,Vulcofac ACT 55用量为2份(质量,下同)时共混硫化胶的耐IRM 903标准油性能最差、玻璃化转变温度最高。动态热机械分析结果显示,Vulcofac ACT 55用量超过2份后共混硫化胶的玻璃化转变温度逐渐降低,而用量不同共混硫化胶处于高弹态时的储能模量相近。