近 30 年西北地区耕地生产力动态演变及能力评价

为了明确西北地区耕地生产力及其动态演变过程，掌握该区在全国粮食生产中的整体水平，利用 1982&mdash;2012 年西北地区耕地生产力数据，结合 GIS 分析描述了该区近 30 年耕地生产力和耕地压力指数动态演变 过程，及该区在全国粮食生产中的整体水平，结果表明:近 30 年来，西北地区耕地生产力呈现出小范围波动、连续 上涨的发展趋势，从 1982 年的 2078． 28 kg&middot;hm －2 上升至2012 年的5 643． 75 kg&middot;hm －2 ，翻了近3 番，但其年均增长 率不稳定，年际间变化幅度相对较大，在 1996 年到达历史最高水平 23%;西北地区耕地生产力在全国的比重明显 上升(由 1982 年的 0． 455 上升到 2012 年的 0． 749)，但又始终低于全国平均水平(耕地粮食生产力指数始终小于 1)，随着时间的推移，该区粮食生产中心主要向粮食生产能力较高的新疆和陕西地区集中;西北地区耕地压力指数 在阶段性波动变化中呈现出略微减小趋势，耕地压力有所缓解，但其缓解幅度并不大，耕地压力级别始终处在Ⅱ级 预警值(0． 91 ～1． 10)范围内。</p

离子液体法再生纤维素纤维制造技术及发展趋势

首先概述了再生纤维素纤维制造技术的发展历史,总结了以天然纤维素为原料的黏胶纤维、Lyocell纤维和离子液体纤维(Ioncell)及其技术发展现状。重点介绍了这三种再生纤维素纤维的性能、应用领域及市场前景,并比较了其生产工艺,包括纺丝原液的制备、纺丝工艺、溶剂回收等。与黏胶纤维相比,Lyocell纤维和Ioncell纤维在溶解纤维素及干喷湿纺纺丝方面具有独特的优势。进一步对该类技术的重点和难点,如纺丝原液的连续制备和溶剂的高效回收进行了分析。与Lyocell纤维使用的NMMO溶剂相比,Ioncell纤维使用的离子液体具有离子液体可设计等优点,可根据纤维素原料的不同来源,设计合成对纤维素具有更好的溶解能力而无降解特征且环境友好的离子液体溶剂,同时对温度、金属离子具有很好的稳定性,为发展新一代纤维素绿色制造技术提供了新途径。另外,对Ioncell纤维存在的问题也进行了详细的分析,提出了未来拟开展的重点研究方向和拟解决的关键难题

离子液体法再生纤维素纤维制造技术及发展趋势

首先概述了再生纤维素纤维制造技术的发展历史,总结了以天然纤维素为原料的黏胶纤维、Lyocell纤维和离子液体纤维(Ioncell)及其技术发展现状。重点介绍了这三种再生纤维素纤维的性能、应用领域及市场前景,并比较了其生产工艺,包括纺丝原液的制备、纺丝工艺、溶剂回收等。与黏胶纤维相比,Lyocell纤维和Ioncell纤维在溶解纤维素及干喷湿纺纺丝方面具有独特的优势。进一步对该类技术的重点和难点,如纺丝原液的连续制备和溶剂的高效回收进行了分析。与Lyocell纤维使用的NMMO溶剂相比,Ioncell纤维使用的离子液体具有离子液体可设计等优点,可根据纤维素原料的不同来源,设计合成对纤维素具有更好的溶解能力而无降解特征且环境友好的离子液体溶剂,同时对温度、金属离子具有很好的稳定性,为发展新一代纤维素绿色制造技术提供了新途径。另外,对Ioncell纤维存在的问题也进行了详细的分析,提出了未来拟开展的重点研究方向和拟解决的关键难题

京津冀蒙共建环北京首都生态圈的若干基本措施

环北京首都生态圈的建设已经引起北京及其周边地区的关注,其能够促进京津区域协同发展。而要完成预期目标,下列各项工作是关键,一是建立联合领导协调机构,并推动各省市区也建立相应的下属机构来进行统一规划,二是完善自然保护领域的立法体系,三是充分发挥保护区的活力,四是大力利用本地优良树种绿化造林,五是加强生态城镇的建设,六是大力发展生态农业,七是确定相关的生态旅游路线,以及加强生态教育培训,大力造就人才

谈保护区建设和有效管理的迫切性

指出了保护区是生态文明建设的基本单元,但是,一直未能引起有关方面足够的重视。应该抓住当前这个机遇,加速其发展,以适应生态发展文明时代的要求。简要地探讨了两者之间的密切关系,并提出了相应的建设供有关方面参考

保护区规范化管理的基本要求和实施途径

指出了保护区的规范化管理是保护生态文明建设落到实处、促进生态发展文明时代不断前进的关键。从保护区的性质、目的、任务、类型划分、管理体系和实施途径等方面进行了深化和发展探讨,对如何才能实现其规范化管理的要求,提出了相应的建议

基于“国有林场改革方案”和“国有林区改革指导意见”的保护区建设和发展对策

分析了保护区的基本含义和总体要求,探讨了保护区建设的主要内容,提出了完善保护区管理体制、加强领导、落实各项任务,以期促进保护区建设工作

L-半胱氨酸作为化妆品美白添加剂的作用机理

酪氨酸酶(EC 1.14.18.1)是黑色素形成的关键酶,其抑制剂的研究是当前美白添加剂研究的热点.研究了L-半胱氨酸(L-Cys)对蘑菇酪氨酸酶和小鼠B16黑色素瘤细胞粗提的酪氨酸酶的抑制效应,实验结果表明,L-Cys对2种来源的酪氨酸酶有较强的抑制作用,其半效抑制浓度分别为1.75,15μmol/L.对小鼠B16黑色素瘤细胞粗提的酪氨酸酶的抑制主要表现为显著延长酶促反应的迟滞时间,同时显著降低酶的活力.进一步对L-Cys在细胞毒性方面进行了研究,结果表明,在200μmol/L浓度下,L-Cys对小鼠黑素瘤细胞B16的生长未显示出明显影响,对细胞状态、代谢MTT的能力、细胞增殖率等均无影响,无明显细胞毒性,是一种有潜力的增白剂,为L-Cys作为美白添加剂提供了依据

Mediating effect of self-control between mindfulness experience and sleep disorder

目的 探讨正念经验与睡眠障碍的作用机制。方法 采用匹兹堡睡眠量表(PSQI)、自我控制问卷(SCS)对860名被试进行线上测量。结果 无正念经验组中睡眠障碍的检出率明显高于有正念经验组。自控力在正念经验与睡眠障碍中起部分中介作用。结论 正念经验与较高睡眠质量相关，正念练习可部分通过提高自控力水平发挥作用。</p

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