西安蓝田S_4古土壤剖面中针铁矿富集层与土壤古水分研究

利用野外调查与观察、电镜观察和X-射线衍射法,对西安市蓝田县白鹿塬东端安村北约1km的第四纪黄土-古土壤剖面(34&deg;17&#39;N, 109&deg;32&#39;E)中第4层古土壤(S_4)的铁锰结核样品进行了实验分析。整个S_4古土壤风化剖面厚度为5.6m,粘化层的厚度为1.5m,在S_4古土壤层下部5.0?5.6m深度范围发现了具有指示当时土壤水分含量、地下水富集、水分循环等作用的针铁矿(a-FeO(OH))与铁锰结核富集层。针铁矿呈褐黄色薄膜分布于土体表面。含针铁矿的铁锰结核呈黑褐色球形,电镜下主要呈颗粒状、球形和呈菊花形等形态。针铁矿和铁锰结核呈层分布在同一层位,形成于当时的地下水位附近。在铁锰结核样品中,针铁矿含量为0.9%~3.3%,粘土矿物伊利石含量为6.0% ~ 15.5%,高岭石含量为2% -5%,石英含量为61.1%~66.6%, 斜长石含量10% ~ 16.4%, 钾长石含量3.8%-6.0%。针铁矿与铁锰结核的发育和迁移深度指示,在西安蓝田安村附近S_4古土壤发育时期,年降水量至少为900mm,且重力水分布深度达到了5.6m,5.6m深度范围内的含水量大于25%,在针铁矿和铁锰结核发育层位,含水量接近饱和。当时土壤水分含量很充足,土壤水分平衡为正,有较多水分补给地下水,适于茂盛森林植被发育。研究显示,组成铁锰结核的物质成分来自S_4古土壤粘化层中高价铁锰氧化物迁移,并随着地下水位的升降而发生还原和氧化聚集形成。</p

A UNIVERSAL AUTOMATIC FILM MEASURING SYSTEM

自动通用胶片判读仪是一种高智能化的精密光学测试设备,采用了计算机控制飞点扫描技术、精密光学测量技术、图象跟踪测量与信息处理技术。飞点管分辨率达4096&times;4096象元,通过光学系统胶片上获得6.55&mu;m高分辨率,飞点扫描方式灵活多样且可随意控制,通用于目前我国靶场所有的电影经纬仪和高速摄影机35mm胶片的数据判读。具有自动判读和半自动判读两种工作模式,自动判读的速度为5帧/秒,自动判读的精度为&sigma;=&plusmn;0.011mm,半自动判读的精度为&sigma;=&plusmn;0.009mm,测量数据可以记录、打印和显示

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