南通台核旋观测干扰的排除

针对南通地震台核旋观测的干扰 ,通过多种试验最终加以排除。这项工作表明 ,地震台站环境改造中要注意监测环境的保护 ,特别是铠装电缆的铺设要考虑到对磁、电观测的影响 ,并就如何进一步提高核旋的观测质量提出建议。     

岩体开挖卸荷过程力学特性分析

基于岩体开挖卸荷过程中力学参数变化理论的分析研究,建立卸荷岩体有限元分析模型,运用ADINA有限元分析软件对岩体进行一维卸荷数值仿真研究。根据有限元数值分析计算成果得到岩体力学参数与主卸荷方向累计开挖卸荷量间的变化关系曲线。结果表明:岩体开挖卸荷过程中,岩体力学参数变形模量、泊松比、粘聚力和内摩擦角等呈现出随开挖卸荷量的变化而发生变化的特征,随卸荷量的增大有减小的趋势,但它们不是从初始值一直减小到零,而是随卸荷量的增大减小到一定的量值后,岩体的裂隙张开、结构面的扩展到一定的程度,岩体的力学参数保持一定的量级不再减小。     

An application of a modified theory of planned behavior model to investigate adolescents’ job safety knowledge,norms, attitude and intention to enact workplace safety and health skills

Introduction: For many reasons, including a lack of adequate safety training and education, U.S. adolescents experience a higher rate of job-related injury compared to adult workers. Widely used social-psychological theories in public health research and practice, such as the theory of planned behavior, may provide guidance for developing and evaluating school-based interventions to prepare adolescents for workplace hazards and risks. Method: Using a structural equation modeling approach, the current study explores whether a modified theory of planned behavior model provides insight on 1,748 eighth graders’ occupational safety and health (OSH) attitude, subjective norm, self-efficacy and behavioral intention, before and after receiving instruction on a free, national young worker safety and health curriculum. Reliability estimates for the measures were produced and direct and indirect associations between knowledge and other model constructs assessed. Results: Overall, the findings align with the theory of planned behavior. The structural equation model adequately fit the data; most path coefficients are statistically significant and knowledge has indirect effects on behavioral intention. Confirmatory factor analyses suggest that the knowledge, attitude, self-efficacy, and behavioral intention measures each reflect a unique dimension (reliability estimates ≥0.86), while the subjective norm measure did not perform adequately. Conclusion: The findings presented provide support for using behavioral theory (specifically a modified theory of planned behavior) to investigate adolescents’ knowledge, perceptions, and behavioral intention to engage in safe and healthful activities at work, an understanding of which may contribute to reducing the downstream burden of injury on this vulnerable population—the future workforce. Practical application: Health behavior theories, commonly used in the social and behavioral sciences, have utility and provide guidance for developing and evaluating OSH interventions, including those aimed at preventing injuries and promoting the health and safety of adolescent workers in the U.S., who are injured at higher rates than are adults.     

Experiment and simulation research of evolution process for LNG leakage and diffusion

The frequent occurrence of LNG leakage accidents has caused serious economic loss and environmental damage. Experiments and simulations can be combined to obtain the transient process of LNG leakage and diffusion. This paper analyzed LNG leakage diffusion rules with experiment results obtained by depleting 1.4t LNG. The vapor clouds and LNG concentration are measured, which can be a comparison with the simulation results. Computational fluid dynamics and gas diffusion theory were chosen as the theoretical basis, simulating the transient process of LNG gasification to obtain the diffusion concentration rules. The simulation of LNG diffusion is divided into two parts: LNG leakage at the source and atmospheric diffusion. The maximum concentration of methane in the experiment was 4.1%, and the maximum concentration in the simulation was 4.6%. The results show good agreement of the deviation statistics, which fall in the standard recommendation value range. Then we make a prediction of the dangerous concentration area and the flammability hazard zone of LNG leakage accident. The simulation results show that the range of the lower wind direction danger area firstly increases and then decreases, and the maximum distance of IDLH increases firstly and arrived at the peak of 52  m at 300s.     

新垦赤红壤不同轮作的养分变化

五年的研究结果是:赤红壤耕垦之后只要采取合理的轮作和结合适当的秸秆返回措施,它的肥力就可以得到保持,而且还可以获得显著提高。在四种轮作形式中,效果最明显的为1:1,它的土壤有机质、全量N、P、K含量比轮作前分别提高了L 22、1.84、2.27和0.06倍1:2和2:1的效果较差,分别提高了0.57、0.83、2.08、0.39倍和1.02、0.91、1.46、-0.07倍,0:1的由于没有轮作,加上每年把长好的草皮铲走,导致了土壤有机质、全氮量反而比轮作前下降了6.5％和25.0％。随着轮作土壤养分的提高,土壤物理和微生物状况也获得了改善。     

南京河西地区岩土体剪切波速与土层深度的关系

南京河西地区是南京市重点开发的新市区,该区域工程地质条件相似,主要为长江高河漫滩地质地貌单元。本文选取该地区47个典型钻孔的岩土体剪切波速资料,采用三种数学模型进行统计回归分析,运用相关系数R(或测定系数R2)检验Vs—H之间的线性相关关系,并根据计算的SD值选择较优的数学模型。统计结果表明,该地区各类岩土体的Vs—H线性相关关系显著,说明采用上述数学模型进行Vs—H回归是可行的。对两个工程场地进行剪切波速预测,并对场地类别作出划分,检验结果表明,该地区各类岩土体的Vs—H经验关系是可靠的,符合当地岩土特征,在样本深度范围内有足够的工程应用精度,可以应用。     

《安全与环境学报》2007-2017年文献计量分析

运用文献计量学方法,对《安全与环境学报》(下称《学报》)2007-2017年刊载的4147篇论文进行了文献计量分析。从《学报》论文的时序产出与影响、分类产出与影响、期刊层面的知识流动及主题热点4个方面讨论了《学报》的文献计量学特征。结果表明,《学报》经过多年的发展,产出、影响力及知识密度不断提升,产生了一大批有影响的地区、机构、作者等。《学报》保持期刊内外的知识流动、交换和更新,使得期刊充满知识活力。经过长期的积累,《学报》已经形成了安全工程与管理、环境科学、环境工程,以及特色专题--安全与环境事故和事件统计快报4个方面的主题方向。《学报》的这些文献计量指标,为全面认识《学报》及未来发展提供了详实的科技情报。     

秸秆还田配施化肥及微生物菌剂对水田土壤酶活性和微生物数量的影响

土壤微生物学特性是表征土壤质量的重要生物学指标。通过田间试验研究了秸秆还田配施不同配比化肥及微生物菌剂对水田土壤酶活性和微生物数量的影响。结果表明,与单施秸秆相比,秸秆还田配施N、P、K及微生物菌剂后,土壤过氧化氢酶、转化酶和尿酶活性分别提高了37.5%~68.8%、32.3%~61.5%和48.8%~102%,细菌和真菌数量分别提高了95.3%~174%、286%~351%,放线菌数量减少了34.5%~39.4%,差异显著。统计分析显示,土壤过氧化氢酶与尿酶活性之间及其酶活性与微生物数量之间关系密切。氨化细菌和硝化细菌数量主要控制土壤过氧化氢酶活性,真菌数量是转化酶活性的主要影响因素,而尿酶活性主要受细菌数量影响。秸秆还田配施微生物菌剂及平衡施肥可以促进酶活性的增强,使土壤微生物群落物种个体数增加更多,分布更为均匀。过量施用氮肥会抑制土壤酶活性和微生物的生长和繁殖。     

陕西省1990年自然灾害和救灾工作回顾：兼谈1991年减灾对策

本文在回顾1990年陕西省灾情及救灾工作基础上,提出了强化政府在减灾中的职能,搞好灾情预测预报、及早制定防灾预案及灾前准备工作的减灾对策。     

长江上游沿江产业带产业结构演进研究

长江上游沿江产业带是一个资源富集,开发潜力巨大的区域,既是长江产业带的重要组成部分,也是西南地区经济发展的重心地带。区域经济的快速发展有赖于区域产业结构的有序演进。本文在分析长江上游沿江产业带产业结构演进背景－产业基础,经济基础,资源基础和宏观环境的基础上,根据国外产业结构演进手一般经验,对本区产业结构演进的历史进程和目前所处阶段进行了分析和判定。