政府补贴和企业出口动态:营商环境的重要性

政府补贴与企业出口动态之间的关系依赖于企业所处地区的营商环境,在政府对辖区内经济活动干预程度较低的地区,补贴收入不仅能够提高企业的出口可能性,而且还能帮助企业维持其出口地位,而在政府行政干预程度较高的地区,补贴对企业出口的作用方向由正逆转为负。进一步的检验表明,地方政府干预程度越高,企业管理费用支出对其获得补贴具有越高的促进作用,同时,政府干预程度越高,补贴对企业研发创新活动的促进作用越低。改善营商环境、减少政府干预有利于中国对外贸易发展方式的转型升级。国家自然科学基金项目(71603221);;教育部人文社会科学青年基金项目(16YJC790125);;中央高校基本科研业务费专项资金资助项目(20720161071

蓝斑背肛海兔神经连索外表层超微量多肽组成的研究

蓝斑背肛海兔(NotarcusleachiicirrosusStimpson,NLCS)中枢神经系统缺少腹神经节.选用基质辅助激光解吸电离化飞行时间(Matrix assistedlaserdesorptionionization/timeofflight,MALDI TOF)质谱技术研究NLCS中枢神经系统连索外表层的超微量的多肽组成和分布时,发现该连索外表层含有丰富的酸性多肽(Aicdicpeptide,AP)的酶解片段和其他多肽组分.不同NLCS个体的中枢神经连索外表层多肽分布与组分有些差异,推测这些神经多肽可能参与中枢神经系统的信息传导和行为的可塑性.在不同的神经连索之间发现相同一级结构和聚合体的多肽组成,认为这些组份以不同的形式分泌到神经节或连索外表层参与信息传导活动,起到相似或相同的生理功能

XPS Analysis of the HgCdTe Surface Etched by ICP

文章将ICP刻蚀技术应用于刻蚀HgCdTe,使用微区X射线光电子光谱学(XPS)、扫描电子显微镜(SEM)等表面分析技术研究了ICP各工艺参数,包括ICP功率、气体成分与配比、腔体压力等对刻蚀表面形貌、刻蚀后表面成分、聚合物形成的影响。XPS分析结果发现,使用光刻胶作掩模时,刻蚀气体CH4会与光刻胶发生反应,生成物可能为C6H5(CH3)。如果腔体压力较高,生成物不能及时被带走,就会附着在样品表面上,使样品表面发黑;当腔体压力较低时,生成物被及时带走,则样品表面光亮,无聚合物残留。光刻胶也会与H2发生反应,生成多种含C有机物。SiO2作掩模时,在一定的条件下,CH4会与SiO2或者真空硅脂发生反应,生成聚脂薄膜。ICP(Inductively Coupled Plasma) etching technique has been applied to HgCdTe providing significant benefits such as high uniformity, low damage and anisotropic profile,etc.We have studied the dependence of surface profile,post-etch composition,formation of polymer on the effect of ICP parameters(ICP power,gas ratio,chamber pressure) by using micro regional XPS and SEM(scanning electron microscopy).We have found that methane can react with photoresist(PR) which is used as mask,the product may be C_6H_5(CH_3).The product can't be pumped out if the chamber pressure is high,then it will be left on the sample surface forming so-called polymer.Otherwise if the chamber pressure is low,the product is pumped away the chamber in time,and there is no polymer on the surface.H_2 can react with PR,and the products are several organic compounds with carbon.Under certain condition,methane can reacts with SiO_2 or high vacuum grease,generating Mylar Polyster

Local Protectionism, Ownership and Firms' Market Expansion Choices

本文基于世界银行2003年中国企业调研数据,考察了地方保护对企业市场扩张选择的影响。研究发现,地方保护主义对企业外部市场扩张的影响存在显著所有制差异,同样是进行区域间市场扩张,地方保护显著降低了本土企业进入跨区域市场的概率,而对外资企业却不显著。进一步研究发现,获得国内区域间市场规模的本土企业具有更高的研发投入和再投资比重,相反,出口比重越高的本土企业其研发投入越低,且更倾向于停留在简单再生产阶段。本文研究表明,在外部市场扩张带来规模经济效应这一点上,国际贸易并不能完全替代国内贸易。因此,消除地方保护不仅有利于本土企业获得国内统一大市场的规模效应,而且对中国经济增长模式的转型升级具有深远意义。This paper uses Chinese firms＇ survey data collected by the World Bank in 2003 to study the effect of local protectionism on firms＇ market expansion choices. In general, we find heterogeneous effects of local protectionism on firms＇ market expansion choices, implying the disparate consequences of local protectionism between the local enterprises and foreign firms. The results show that local protectionism significantly hinder local firms＇ cross-regional markets entry. Such a negative role of local protectionism, however, fails to exist for foreign firms. Further study shows that local firms with domestic market entry spend more on R＆D investment and reinvestment. In contrast, the larger the export proportion is, the lesser the local firms spend on R＆D investment. Our analysis indicates that international trade cannot completely replace domestic trade as to the scale of economy effect of external market expansion, and confirms the importance of eliminating local protectionism.国家自然科学基金(71603221)；教育部人文社会科学青年基金项目(16YJC790125)；中央高校基本科研业务费专项资金(20720161071)的资助

The Heterogeneity and Domestic Market Entry of Enterprises: Microcosmic Evidence from Chinese Export Enterprises

基于中国工业企业数据库,本文考察了企业异质性与完全出口企业国内市场进入之间的关系。研究发现,更高的生产率水平能够显著提高完全出口企业进入国内市场的可能性,使用IV-Probit模型纠正二者之间可能存在的内生性问题后,这一影响依然显著。使用Heckman选择模型的估计结果表明,企业生产率水平同企业在国内市场上的销售比重存在显著正相关关系。进一步的研究发现,随着制度环境的改善,生产率对企业国内市场进入的作用程度将增强。此外,企业融资能力对企业进入国内市场具有重要作用。本文结论表明:国内市场商业环境的不健全增加了企业在国内市场上的经营成本,不利于出口企业开拓国内市场,也不利于中国对外贸易增长方式的转型。国家自然科学基金项目(71603221)；教育部人文社会科学青年基金项目(16YJC790125)；中央高校基本科研业务费项目(20720161071)的资助

Foreign Competition,Industrial Linkage and Domestic Firms' Survival in China

大规模外资涌入不可避免地挤占了本土企业的生存空间。基于2000—2007年中国微观企业数据,本文首次采用生存模型考察了外资进入对中国本土企业的存活期限与退出行为的影响。研究表明,虽然外资企业加剧了行业内竞争,从而迫使同行业内资企业更快退出,但也通过与当地企业构建上、下游产业关联,为内资企业创造了新的存活机会与市场空间。这一作用也决定了外资进入对内资企业存活的竞争冲击并不如普遍预期的剧烈。与国有企业相比,民营企业更有可能与外资企业建立产业关联,从而较好地适应外资冲击。本研究不仅为客观评价外资进入的生存冲击提供了经验证据,也对东道国本土企业积极应对外资竞争、融入全球化分工网络具有借鉴意义。The influx of foreign investment inevitably forces China's domestic firms to exit,and hence decreases the survival probability of the latter.Using Chinese manufacturing firms' data during 2000—2007,we adopt the survival analysis to examine the effect of foreign entry on the survival of Chinese domestic firms.We find that although foreign firms do propel more domestic firms to exit among the same industry through the competition effect,they also help to promote the survival of the local firms through both backward and forward industrial linkages.As we estimate a significantly positive combined effect,it indicates the external shock due to foreign entry is not as big as we usually expect.Compared with SOEs,Chinese private firms are more likely to establish vertical industrial linkages with foreign-invested firms.Generally our findings provide evidence and policy suggestions on how local firms in developing economies adapt themselves to market competition due to foreign entry.教育部“新世纪优秀人才支持计划”(NCET-11-0248); 国家自然科学基金(71203107;71473136); 霍英东教育基金基础性研究课题(141083); 南开大学中央专项基金课题(NKZXB1226)的资

Salient Building Detection Based on SVM

提出了一种针对自然图像中显著性建筑物的检测方法.首先,采用自底向上的注意力机制,对图像进行Haar小波分解,对得到的HL,LH分量进行平方求和,得到增强图像,然后对该增强图像在垂直方向上进行侧投影,基于得到的投影曲线进行多层阈值分割,找到显著性建筑物候选区域.进而,利用Sobel算子进行水平边缘与垂直边缘的检测,并统计较长的水平边缘与垂直边缘的数目,组成特征矢量.最后利用线性支持向量机对特征进行分类.实验证明了所提算法的有效性.This paper focuses on detecting salient buildings in a scenery image. A method based on bottom-up attention mechanism is proposed to detect salient buildings. Firstly, Haar wavelet decomposition is used to obtain the enhanced image which is the sum of the square of LH sub-image and HL sub-image. Secondly, the enhanced image is projected in the vertical direction to obtain the projection profile, and building candidates are separated from the background based on multi-level thresholding. Thirdly, the structure statistic features of buildings are extracted based on Sobel operator. The feature vector is formed by the number of long horizontal edges and that of vertical edges. Finally, linear support vector machines are used to classify buildings and the others. The proposed approach has been experimented on many real-world images with promising results.国家自然科学基金项目(60635050,60405004);; 国家自然科学创新研究群体基金项目(60021302

共沸精馏分离烯丙醇-水的工艺模拟及优化

研究了一种以苯为共沸剂的烯丙醇-水的共沸精馏工艺,运用专业软件Aspen Plus7.2版的Rad Frac精馏模块,选择NRTL热力学模型对该体系进行了工艺模拟及计算。考察了理论板数、进料位置、回流进料比等参数对分离效果的影响,并进行了参数优化。结果表明:理论板数为20块,进料位置为10块,回流进料比为3.5,塔釜烯丙醇的纯度能达到99.88%,回收率能达到99.9%,验证了工艺的可行性,并对某企业1万吨/年烯丙醇脱水工艺进行了优化设计。</p

高铝AlxGa1-xAs氧化层对垂直腔面发射激光器的影响

针对可见光垂直腔面发射激光器的制备,通过湿氮氧化实验和测量微区光致发光谱分别研究了高铝组分AlxGa1-xAs的氧化特性及氧化产物的收缩应力对有源区的影响,结合器件结构设计确定了氧化限制层AlxGa1-x-As的铝组分和最佳位置,并制备出了低阈值电流的AlGaInP系垂直腔面发射激光器

80×40 Gbit/s DWDM系统及800km传输实验

介绍了烽火通信研制的国内首套、具有完全知识产权的80×40 Gb it/s密集波分复用（DWDM）系统,该系统采用了低成本的非归零（NRZ）码,开发了分布拉曼放大、超强前向纠错（FEC）、子速率复用等多项技术,并在G.652光纤上进行了10×80 km的无电再生中继传输实验。实验结果表明,经过800 km传输后,光通道代价&lt;2 dB,连续观察60 h无误码