Comparing the soil quality changes of different land uses determined by two quantitative methods

Soil quality is one of the most important environmental factors in sustaining the global biosphere and developing sustainable agricultural practices.A study was initiated in Wolong Nature Reserve,Sichuan Province,China to elucidate the soil quality changes of natural secondary succession,forest planting and agricultural practices after deforestatin in the humid mountainous region.The soil qualities of six land use types(natural forestland ,grassland,shrub land,secondary index(QI) and soil deterioration index(DI).The QI values of natural forestland ,grassland,shrub land,secondary forestland,cultivated land ,reforested land were 0.8039,0.3277,0.9127,0.6881,0.0285 and 0.3183,respectively.The DI values were 0%,-14%,12%,1%,-26% and -18% respectively.Both indexes suggested that shrub land can restore soil properties.To compare the two methods more directly,a deduced index QI‘based on QI value was developed,.The results showed that DI and AI‘ had a very high linear correlation coefficient(r=0.9775) despite the values were different .Both methods were efficient in evaluating the soil quality levels and DI was a more simple way in soil quality assessment,while QI could show more ecological meanings.     

人工神经网络模拟芳基脲土壤吸附系数研究

对38种芳基脲类化合物的土壤吸附系数进行了定量结构－活性相关研究。利用量子化学的AM1方法提取化合物的结构参数，运用多元回归分析和人工神经网络对该化合物进行比较研究。研究结果表明，神经网络法所得结果优于多元回归分析结果，并对分析结果进行了吸附机理讨论。     

利用鱼外周血红细胞微核技术监测长江江苏段水质污染

应用鱼类外周血红细胞微核技术对长江江苏段水质进行监测,测定江苏7个点位水中的鱼类外周血微核千分率(MCN‰),并进行统计分析.结果表明,7个采样点中有2个采样点的微核千分率达到0.20‰左右,与实验室阴性对照的检测结果相比有极显著性差异(P＜0.01),表明这2个点位的水质受到污染.     

水土流失的定量遥感及其应用研究进展

简要介绍了水土流失定量遥感的概念，阐述了它的四项基本要求，报道了它的应用研究进展，并为尽快实现中国水土流失定量遥感提出了若干建议。     

植物生物技术在黑麦草遗传改良中的应用

黑麦草是重要的牧草和草坪草,是畜牧业和草坪业重要的产业支柱.由于高度自交不亲和,传统遗传改良困难而复杂.生物技术尤其是转基因技术为其遗传改良带来希望.本文概述了组织培养技术、基因遗传转化技术、分子标记及数量性状基因定位、分子标记辅助育种等技术在黑麦草遗传改良中的应用及获得的成果;评述了遗传改良的重要意义,以及黑麦草遗传改良的主要目标,如品质改良、提高病害抗性、降低毒性生物碱浓度、控制花粉致敏性、抗除草剂品种的培育、提高抗逆性及其作为生物反应器的潜在应用价值等;并分析了功能基因组学的研究及RNA干扰技术在黑麦草研究中可能的应用前景.     

Social and geographical inequalities in prenatal care in Italy

The purpose of this study was to find out possible differences in prenatal diagnosis (PD) by amniocentesis or chorionic villus sampling and ultrasound examination before 16 weeks' gestation (early ultrasound examination, EUE), according to area of residence and level of education of the mothers. Data come from a multicentre study in Italy involving 43 maternity hospitals (Mercurio project) and were collected through structured interviews a few days after delivery. Study subjects were 1541 mothers of single non-malformed infants born between April 1992 and March 1994. Overall, the incidence of PD and EUE was 5.8 and 80 per cent, respectively. After adjustment for maternal age and other possible confounders, the odds ratios for PD were 2.19 (95 per cent confidence interval (CI)=1.26–3.81) when women residing in the northern regions were compared with those residing in the southern regions, and 2.06 (95 per cent CI=1.12–3.79) and 4.08 (95 per cent CI=1.97–8.42) when women with medium and high levels of education were compared with those with low level. For EUE, the odds ratios were 1.77 (95 per cent CI=1.32–2.36) and 2.88 (95 per cent CI=1.56–5.29) when comparing women with medium and high levels of education with those with low level. No relationship was found between area of residence and EUE. These geographical and social inequalities in prenatal care in Italy should be taken into account for the organization, delivery, and evaluation of pregnancy services in the coming years.     

勋西小寨山31万方硐室大爆破的安全措施

中国地质大学爆破开发研究中心实施的郧西小寨山硐室大爆破，经过周密设计，专家组审查通过，广大师生的辛勤施工，400吨炸药控爆一次成功，该工程采用了切实可行的安全措施，值得了总结推广。     

ICP-MS半定量分析及其应用

ICP-MS具有等离子发射光谱检测能力高、测量速度快、测量元素多等特点,能对样品中存在元素进行定性及半定量分析,半定量分析准确度为±30%.同时还能快速确定样品中存在的元素及浓度范围.     

HAPSITE便携式气相色谱／质谱仪对苯系物定量检测方法的探讨与应用

利用HAPSITE便携式气相色影质谱仪对挥发性有机化合物的检测具有很高的灵敏度。采用不同浓度的苯系物标气做一条标准曲线，可编辑出一个自动鉴别和定量所选化合物库文件，进行准确的定量分析。     

南通市PM_(10)浓度的综合预报方法探索

应用历史监测数据 ,结合南通市气候特征 ,分析了PM1 0 浓度值与天气系统的关系 ,研究了PM1 0 的变化趋势 ,介绍了一种关于南通市PM1 0 浓度的综合预报方法。该方法准确、实用、经济