Penetration and Post-infection Development of Meloidogyne Incognita on Tobacco as Treated by Rhizobacteria Pseudomonas Fluorescens Strain P-72-10

The bio-control potential of rhizospere bacteria Pseudomonas fluorescens against plant-parasite nematode had been demonstrated. P. fluorescens had shown the effect to enhance tobacco resistance to root-knot nematode Meloidogyne incognita. Inoculation with P. fluoreseens in tobacco could lead to significant reductions in the number of juveniles that penetrated tobacco root and further life stage development of the juveniles. The number of juveniles penetrated into tobac- co root in treatment with P. fluorescens is significantly different from CK at 2DAI, 6DAI, 8DAI and 10DAI. Significant reduction and delayed development of juveniles that penetrated into tobacco root and treated were observed in treatment at 14DAI, 21DAI, 28DAI and 35DAI. In addition, P. fluoreseens treatment leads to a significant reduction in the number of eggs per egg-mass at 35 DAI. The results show P. fluorescens induced a continuously suppression on root-knot nema- tode M. incognita throughout their entire early infection phase of root penetration, subsequent life stage development and reproduction.     

工业机器人应用对制造业就业的影响--基于中国地级市数据的实证研究

利用2013-2017年中国286个地级市的面板数据实证研究发现,工业机器人应用对中国制造业就业总量存在显著的负影响,工业机器人渗透度提升1单位将导致制造业就业总量下降3.35个百分点。针对影响制造业就业结构的实证研究发现,工业机器人应用对东部、西部地区有显著的负影响,对中部和东北地区的影响不显著,对制造业细分行业、低技能劳动者和男、女劳动者就业均存在普遍的负影响,对高技能劳动者就业存在正向影响,但不显著。深入研究后发现,工业机器人替代不是导致制造业就业下降的根本原因,而是对制造业就业岗位的补充与延伸。政府在制定针对智能制造的产业政策时,应根据地方制造业劳动供给与企业生产需求进行灵活安排。     

Quantile functions for multivariate analysis: approaches and applications

Despite the absence of a natural ordering of Euclidean space for dimensions greater than one, the effort to define vector-valued quantile functions for multivariate distributions has generated several approaches. To support greater discrimination in comparing, selecting and using such functions, we introduce relevant criteria, including a notion of "medianoriented quantile function". On this basis we compare recent quantile approaches and several multivariate versions of trimmed mean and interquartile range. We also discuss a univariate "generalized quantile" approach that enables particular features of multivariate distributions, for example scale and kurtosis, to be studied by two-dimensional plots. Methods based on statistical depth functions are found to be especially attractive for quantile-based multivariate inference.     

关于SY/T5128-1997标准中穿孔深度判定方法所存在的系统误差

在SY/T5128-1997油气井聚能射孔器通用技术条件的执行过程中，发现对不带扶正装置的射孔器混凝土靶穿孔深度指标的评价存在系统误差。通过对标准中的评价方法和试验结果的分析。指出了该问题存在的原因。并给出了修正方法。希望有助于标准的修订。     

On the statistical identification of technology disruption

This study suggests a statistical procedure to identify technology disruption. In particular, a threshold autoregressive model enables the identification of threshold penetration for disruptive technology that affects the dynamic adjustment of an established technology. Both the magnitude and direction of the impact is identified by country World Bank income category in the context of the impact of (disruptive) mobile telephone diffusion on (primary) fixed-line markets. Importantly, as the procedure only requires a short time-series for the introduced technology and can readily be conducted on an ongoing basis.     

金融渗透、民营经济发展与金融体系内生化--民营经济发展模式与金融渗透差异的比较分析

本文对我国民营经济发展最为活跃的几个省区--浙江、江苏及广东的金融渗透差异进行比较和分析,并与全国的情况进行对比.分析表明,之前我国正规的金融体系对民营经济的"所有制歧视"导致了内源式发展与内生性金融渗透之间的极为密切的联系,但是近年来的政策转变和民营经济自身资质的提高使得这种现象有了很大的改变,正规金融机构的内生化趋势日益明显.     

中国高科技企业价值创造的中介效应研究

以高科技企业为样本,研究其在研发投入实现价值创造过程中由创新深度和创新广度两个因素所产生的中介效应.结果表明:我国高科技企业研发费用率与企业的 ROA 和 ROE 呈显著正向关系,研发费用率与企业价值不相关.研发费用率与研发广度之间的相关性不显著,研发费用率与创新深度之间在1%的显著性水平下呈现显著的正相关关系,研发费用率越高,创新深度越强,创新广度与创新深度是企业研发费用率与企业绩效之间的显著中介变量,但创新广度与创新深度不是企业研发费用率与企业市场价值之间的显著中介变量.     

The Dynamics of Security Trades,Quote Revisions,and Market Depths for Actively Traded Stocks

We examine the dynamics of return volatility, trading volume, and depth—in an intraday setting for a sample of actively traded NYSE and NASDAQ stocks. We show that depth is a useful intervening variable and mitigates the impact of trading activity on price volatility. Furthermore, depth is affected by the perception of prevailing information asymmetry between informed and uninformed traders. We demonstrate empirically that the NYSE supplies greater depth under conditions of high, perceived information asymmetry as compared to NASDAQ. NASDAQ makes up for this deficiency by its capability of managing large volume shocks without a major decline in depth.JEL Classification: C32, D82, G10     

垂直地震勘探深度测量的可靠性分析

介绍了在垂直地震勘探中主要的深度测量方法，对比了各种方法的精度，分析了不同方法的可靠性，归纳了增强深度测量可靠性的措施，指出了计数器检验工作中存在的不足，得出了垂直地震深度测量方法综合应用的结论。