3 research outputs found

    A Self-assembly Route to Porous Polyaniline/Reduced Graphene Oxide Composite Materials with Molecular-level Uniformity for High-performance Supercapacitors

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    PANI具有赝电容高、稳定性好和掺杂/去掺杂反应可逆等优点,而RGO则能提供高导电和大比表面积。PANI与RGO的复合能将两种材料的优势进行互补产生协同作用。而传统的PANI/RGO电极材料的制备通常聚焦于苯胺在还原RGO上的原位聚合,其不足之处在于难以精确控制PANI组分的形貌和分布来优化材料电子转移和电解质的扩散。白华课题组巧妙利用了PANI的溶解性,设计了溶液中的自组装方法以制备PANI/RGO复合材料。白华课题组在聚苯胺/还原氧化石墨烯(PANI/RGO)电极材料研究方面取得新进展。该课题组提出了一种简便可控的自组装方法,成功制备了分子水平均匀的PANI/RGO复合凝胶(PGG)。该方法大幅度提高了电极材料的比电容和倍率性能。此外,本工作还证实了GO是一种有效的二维表面活性剂,可与其他分子形成复合物,并使它们进入复杂的自组装过程。该方法还可以指导我们设计具有各种组成,结构和其他功能的基于RGO的复合材料。 该论文的第一作者为我院已毕业2016届硕士生巫继锋,我院张勤娥(2015级硕士生)、王菁菁(2014级博士生)、黄晓萍(2016级硕士生)参与了论文的部分工作。【Abstract】Polyaniline/graphene composites constitute an important class of electrode materials for supercapacitors. In this paper, we designed a new self-assembly method for preparing polyaniline/reduced graphene oxide three-dimensional porous composite gels with molecular-level uniformity even at a very high PANI content (>80%). The method involves two successive self-assembly processes, namely, two-dimensional assembly of polyaniline on graphene oxide sheets in a water/N-methyl-2-pyrrolidone blend solvent, and three-dimensional reduction-assembly of the obtained polyaniline/graphene oxide composite sheets. The prepared polyaniline/reduced graphene oxide composite gels possess a three-dimensional porous network composed of reduced graphene oxide sheets, which are covered by polyaniline molecules with controlled content. Because of this favorable microstructure, the composite shows a high specific capacitance of 808 F g−1 (5717 mF cm−2) at a current density of 53.33 A g−1 (377.4 mA cm−2), as well as excellent rate performance. These results demonstrate that two-step self-assembly is a promising method for precisely controlling the microstructure of reduced graphene oxide based composite electrode materials.This work was supported by Natural Science Foundation of China (21774104). 该工作得到国家自然科学基金和福建省青年拔尖人才项目的大力资助

    Review of Research on Regional Land Use Change and Its environmental Impacts

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    以黄土高原为重点 ,对植被变化及其引起的土地利用变化的环境影响的有关研究进行了比较系统的阐述。对植被研究态势 ,土地利用变化对水文生态过程、土壤环境及生物多样性影响做了简要的述评 ,对该领域的目前存在的问题进行了分析 ,并提出了有关进一步研究的建

    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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