茂金属催化剂体系及其丙烯聚合性能调控

国内聚丙烯的生产基本上使用传统的Ziegler-Natta催化剂,国外已经使用茂金属催化剂.茂金属催化剂生产的聚丙烯提升了产品性能,市场需求份额逐年增加,国内需要开发茂金属催化剂并拓展工业应用.茂金属催化剂与传统的Ziegler-Natta催化剂相比,结构类型丰富,反应调控能力强,可以催化生成结构多样的聚丙烯.以茂金属催化剂的发展为主线,探讨催化剂结构对反应性能的影响;分析体系中多种因素如温度、压力、催化剂浓度、助剂等对反应活性的调控;讨论催化反应机理.中国石化茂名石化公司基金;;聚烯烃催化技术与高性能材料国家重点实验室基金;;上海市聚烯烃催化技术重点实验室基金(Nos.201501-PT-C01-005,沪CXY-2015-003,16DZ2270800,16DZ2290700);;国家自然科学基金(Nos.21473142,20673191);;教育部创新团队基金(No.IRT_14R31)资助项目~

关键参数对滚子包络内啮合蜗杆传动接触与润滑性能的影响

为了分析关键参数对滚子包络内啮合蜗杆传动接触与润滑性能的影响，构建了该新型蜗杆传动的数学模型，通过啮合方程构建了该传动的润滑角与诱导法曲率方程，利用数值计算方法分析了中心距、传动比、蜗轮偏转角、滚子半径等关键参数对蜗杆传动润滑与接触性能的影响。分析研究得知，在这些关键参数中，蜗轮偏转角对滚子包络内啮合蜗杆传动的接触性能与润滑性能有较大的影响，建议蜗轮偏转角取值在0°～40°为最佳。选取了相应参数进行三维建模，验证了分析参数的有效性。该研究为滚子包络内啮合蜗杆传动的进一步研究提供了参考

Synergistic Functions of Trimethl Phosphate and Vinylene Carbonate as Additives for the Li-ion Batteries

应用循环伏安、交流阻抗、扫描电子显微镜和锂离子电池性能检测装置研究了阻燃添加剂磷酸三甲酯(TMP)和成膜添加剂碳酸亚乙烯酯(VC)对锂离子电池的复合作用.结果表明,复合使用TMP和VC不仅能提高电池的安全性而且能改善电池的循环性能,原因可能是在电池首次充放电过程中VC优先还原,还原产物在负极表面聚合形成良好的SEI膜,有效地制约了因TMP在石墨负极表面的分解而造成负极石墨的脱落,同时提高了SEI膜的稳定性.The cooperative effects of trimethl phosphate and vinylene carbonate as additives for Li-ion batteries are investigated by using the cyclic voltammetry,electrochemical impedance spectroscopy and scanning electronic micro-photographs.The results show that the combination application of TMP and VC as additives for Li-ion batteries not only enhances safety of the batteries,but also improves their cycling performance.The reason may be ascribed to firstly VC being reduced and the reduction product polymerized to form excellent solid electrolyte interface(SEI) layer on the surface of graphite electrode during the first charge and discharge process,which prevents effectively the decomposition of TMP on the surface of the graphite electrode that leads to exfoliation of graphite electrode,at same time,improves the stability of SEI.作者联系地址：天津大学化工学院应用化学系,天津大学化工学院应用化学系,天津大学化工学院应用化学系,天津大学化工学院应用化学系,天津大学化工学院应用化学系,天津大学化工学院应用化学系 天津300072,天津300072,天津300072,天津300072,天津300072,天津300072Author's Address: Applied Chemistry Department,College of Chemical Engineering,Tianjin University,Tianjin 300072,Chin

辣木籽油的提取及其中神经酸的纯化工艺研究Extraction of Moringa oleifera seed oil and purification technology of nervonic acid

为促进辣木籽油中神经酸的开发利用，以辣木籽为原料，采用低温压榨法、超临界CO2萃取法、索氏抽提法提取辣木籽油，筛选合适的提油方法，再以辣木籽油为原料制备混合脂肪酸，通过低温结晶法纯化辣木籽油中的神经酸，通过单因素实验和响应面实验优化神经酸的纯化工艺。结果表明：低温压榨法提取的辣木籽原油中神经酸含量较高，达到0.88%；低温结晶法纯化辣木籽油中神经酸的最优工艺条件为料液比（混合脂肪酸与结晶溶剂质量体积比）1∶ 4.2、结晶温度-21 ℃、结晶时间2.3 h，该条件下所得产品中神经酸含量为(5.36±0.01)%，相比辣木籽原油中神经酸含量提升了5.1倍。通过低温压榨法提取辣木籽油，再采用低温结晶法纯化神经酸，能够获得神经酸含量较高的产品。 In order to promote the development and utilization of nervonic acid in Moringa oleifera seed oil, with Moringa oleifera seed as raw material, Moringa oleifera seed oil was extracted by low temperature pressing, supercritical CO2 extraction and Soxhlet extraction to select suitable oil extraction method. Then, mixed fatty acids were prepared using Moringa oleifera seed oil as raw material, and the nervonic acid in Moringa oleifera seed oil was purified by low temperature crystallization method. The purification process of nervonic acid was optimized by single factor experiment combined with response surface methodology. The results showed that the content of nervonic acid in crude Moringa oleifera seed oil extracted by low temperature pressing method was higher, reaching 0.88%.The optimal purification process of nervonic acid from Moringa oleifera seed oil by low temperature crystallization method was obtained as follows: solid-liquid ratio(ratio of mixed fatty acid mass to crystallization solvent volume) 1∶ 4.2, crystallization temperature -21 ℃ and crystallization time 2.3 h. Under these conditions, the nervonic acid content in the product was (5.36±0.01)%, which was 5.1 times higher than that in crude Moringa oleifera seed oil. By extracting Moringa oleifera seed oil through low temperature pressing method and purifying nervonic acid through low temperature crystallization method, products with high levels of nervonic acid can be obtained

Aripiprazole versus other atypical antipsychotics for schizophrenia

BACKGROUND: In most western industrialised countries, second generation (atypical) antipsychotics are recommended as first line drug treatments for people with schizophrenia. In this review we specifically examine how the efficacy and tolerability of one such agent - aripiprazole - differs from that of other comparable second generation antipsychotics. OBJECTIVES: To evaluate the effects of aripiprazole compared with other atypical antipsychotics for people with schizophrenia and schizophrenia-like psychoses. SEARCH METHODS: We searched the Cochrane Schizophrenia Group Trials Register (November 2011), inspected references of all identified studies for further trials, and contacted relevant pharmaceutical companies, drug approval agencies and authors of trials for additional information. SELECTION CRITERIA: We included all randomised clinical trials (RCTs) comparing aripiprazole (oral) with oral and parenteral forms of amisulpride, clozapine, olanzapine, quetiapine, risperidone, sertindole, ziprasidone or zotepine for people with schizophrenia or schizophrenia-like psychoses. DATA COLLECTION AND ANALYSIS: We extracted data independently. For dichotomous data we calculated risk ratios (RR) and their 95% confidence intervals (CI) on an intention-to-treat basis based on a random-effects model. Where possible, we calculated illustrative comparative risks for primary outcomes. For continuous data, we calculated mean differences (MD), again based on a random-effects model. We assessed risk of bias for each included study. MAIN RESULTS: We included 12 trials involving 6389 patients. Aripiprazole was compared to olanzapine, risperidone and ziprasidone. All trials were sponsored by an interested drug manufacturer. The overall number of participants leaving studies early was 30% to 40%, limiting validity (no differences between groups).When compared with olanzapine no differences were apparent for global state (no clinically important change: n = 703, 1 RCT, RR short-term 1.00 95% CI 0.81 to 1.22; n = 317, 1 RCT, RR medium-term 1.08 95% CI 0.95 to 1.22) but mental state tended to favour olanzapine (n = 1360, 3 RCTs, MD total Positive and Negative Syndrome Scale (PANSS) 4.68 95% CI 2.21 to 7.16). There was no significant difference in extrapyramidal symptoms (n = 529, 2 RCTs, RR 0.99 95% CI 0.62 to 1.59) but fewer in the aripiprazole group had increased cholesterol levels (n = 223, 1 RCT, RR 0.32 95% CI 0.19 to 0.54) or weight gain of 7% or more of total body weight (n = 1095, 3 RCTs, RR 0.39 95% CI 0.28 to 0.54).When compared with risperidone, aripiprazole showed no advantage in terms of global state (n = 384, 2 RCTs, RR no important improvement 1.14 95% CI 0.81 to 1.60) or mental state (n = 372, 2 RCTs, MD total PANSS 1.50 95% CI -2.96 to 5.96).One study compared aripiprazole with ziprasidone (n = 247) and both the groups reported similar change in the global state (n = 247, 1 RCT, MD average change in Clinical Global Impression-Severity (CGI-S) score -0.03 95% CI -0.28 to 0.22) and mental state (n = 247, 1 RCT, MD change PANSS -3.00 95% CI -7.29 to 1.29).When compared with any one of several new generation antipsychotic drugs the aripiprazole group showed improvement in global state in energy (n = 523, 1 RCT, RR 0.69 95% CI 0.56 to 0.84), mood (n = 523, 1 RCT, RR 0.77 95% CI 0.65 to 0.92), negative symptoms (n = 523, 1 RCT, RR 0.82 95% CI 0.68 to 0.99), somnolence (n = 523, 1 RCT, RR 0.80 95% CI 0.69 to 0.93) and weight gain (n = 523, 1 RCT, RR 0.84 95% CI 0.76 to 0.94). Significantly more people given aripiprazole reported symptoms of nausea (n = 2881, 3 RCTs, RR 3.13 95% CI 2.12 to 4.61) but weight gain (7% or more of total body weight) was less common in people allocated aripiprazole (n = 330, 1 RCT, RR 0.35 95% CI 0.19 to 0.64). Aripiprazole may have value in aggression but data are limited. This will be the focus of another review. AUTHORS' CONCLUSIONS: Information on all comparisons are of limited quality, are incomplete and problematic to apply clinically. Aripiprazole is an antipsychotic drug with a variant but not absent adverse effect profile. Long-term data are sparse and there is considerable scope for another update of this review as new data emerges from the many Chinese studies as well as from ongoing larger, independent pragmatic trials