6 research outputs found

    塔里木河中游天然植物群落结构与数量特征分析

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    运用典型样地法,对塔里木河中游30个天然植被样地的群落结构和数量特征做了调查分析。结果表明:(1)塔里木河中游沙吉力克、沙子河、乌斯满、阿其河、铁依孜五个断面的天然植物隶属11科,20属,22种。(2)塔里木河中游植物群落结构可分三层,即乔木层、灌木层与草本层,但这种乔、灌、草的三层现象不明显。生境条件差,植物对环境利用不充分。(3)荒漠植物群落物种多样性水平较低,群落结构简单,物种组成单一。从多样性指数的数量特征来看,Simpson多样性指数的变化范围为0.47~0.609,Shannon-Wiener指数变化范围0.849~1.302;Menhinick丰富度指数的变化范围为2.309~3.175,Margalef 2.731~5.461;JSW均匀度指数的变化范围为0.6~0.778,JSI指数的变化范围0.633~0.805。五个断面盖度的变化范围是0.259~0.563

    酚醛树脂热解的激波管实验

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    用激波管方法研究了酚醛树脂在温度范围1100K~1800K之间的热解过程。在激波管高温和短测量时间的实验条件下,分析了样品颗粒在高温气相中的传热过程,讨论了样品颗粒达到热平衡的条件。通过对反应扩散方程的分析,考察了扩散对热解过程的影响,结果表明实验中热解与扩散过程很快达到稳态,热解不受扩散过程影响。通过色谱、质谱方法检测激波管热解产物总量,获得了酚醛树脂热解速率常数</p

    硝基甲烷热解化学反应流的数值研究

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    本文对激波管硝基甲烷热解化学反应流进行了研究,给出了一个严格考虑到化学反应流中化学反应、体积和流动效应的一维Euler方程的全解析耦合算法。对硝基甲烷激波管热解进行了模拟,并把耦合算法得到的模拟结果和激波管实验数据进行了对比验证,两者符合较好。此外,本文还对耦合算法与等温、等压和等容三种简化模型的计算结果进行了对比分析,结果表明,当化学反应流热效应显著增强时,等温假设失效,等压和等容简化模型也偏离实际情形,而全解析耦合算法可以有效解决化学反应与流动相互耦合的问题。</p

    SHOCK TUBE STUDY OF PHENOLIC RESIN PYROLYSIS

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    采用激波管方法研究了酚醉树脂在温度1100K~1800K范围之间的热解过程.在激波管高温和短实验时间条件下,分析了实验样品颗粒在高温气相中的传热过程,讨论了样品颗粒达到热平衡的条件.通过色谱和质谱方法检测热解产物,获得了酚醛树脂高温热解产物分布和热解速率常数.酚醛树脂高温热解最主要的产物为水、一氧化碳、氢、乙炔和苯.温度1400 K将酚醛树脂热解分为高温和低温区,分别表现出不同的热解速率常数与温度的关系

    Aripiprazole versus other atypical antipsychotics for schizophrenia

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    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
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