Spatial and Sectoral Patterns of Firm Entry in China

This article provides new empirical evidence on the patterns of firm entry across sectors and space. Based on Pavitt’s four manufacturing industry categories—supplier-dominated, scale-intensive, specialized suppliers, and knowledge-based—we use China’s firm-level database, covering all manufacturing firms with sales above 5 million RMB from 1998 to 2008, to investigate the relation between spatial patterns of new entry firms and industrial structure change and firm heterogeneity. Based on our analysis, there are three key findings. First, industrial structure change plays an important role in influencing the sectoral pattern of new firm entry. Second, the transformation from a supplier-dominated industry to a scale-intensive industry from 1998 to 2008 in China has largely influenced spatial patterns of new entry firms (mainly spatial agglomeration and entry similarity between regions). Third, the heterogeneity of firms (mainly firm ownership, firm size, and technological relatedness) affected the location choice of new entry firms. Based on our findings, we conclude that the importance of industrial structure change and the heterogeneity of firms in revealing the spatial pattern of new entry firms should receive more attention. Key Words: China, firm entry, firm heterogeneity, industrial structure change, sectoral and spatial pattern.     

青州市农村土地整治工作的实践与思考

农村土地整治已成为当前国土资源管理工作的热点,它综合了统筹城乡发展、城市反哺农村、工业反哺农业等工作,将多年的土地开发整理和复垦工作推到了一个新的高度,同时该项工作在开展过程中也存在一些不容忽视的问题。该文以青州市农村土地整治开展情况为例,进行了一些有益探索与思考。     

泰安市城区地下空间开发与环境地质影响关系分析

通过对泰安市城区地质环境条件的深入分析,系统阐述了泰安市城市地下空间开发与地质环境因素之间的相互影响关系,一方面城市地下空间开发受到地表水、地下水水位、水质及岩溶塌陷地质灾害等地质环境因素的制约,而地下空间开发建设又反过来影响和改变着城区地下水环境、土壤环境,并有可能提高城区岩溶塌陷发生的机率,因此建议有关部门在规划建设城市地下空间的同时要加强地质环境保护。     

基于综合评价的日照市农用地整理时序研究

通过探讨农用地整理的时序,为规范土地整治管理提供技术支撑。运用综合评价法、实证分析法,选取自然经济社会条件、耕地利用现状和农用地整理3个因素、6个评价因子,构建农用地整理评价指标体系。以山东省日照市为例,进行实证分析,确定49个乡镇农用地整理时序。得出通过综合评价确定农用地整理时序,能够使农用地整理管理更加科学化和规范化。     

知识社会的城市生态系统复杂性探讨

以信息技术广泛应用、知识经济诞生为标志的第三次城市革命的来临，正对城市发展和人类社会产生重大的影响。本文用生态学、复杂性科学的研究思想、方法，围绕具有生命特征的城市及城市生态系统进行相关问题研究，着重分析了知识社会的城市生态系统复杂性，并进一步探讨了知识社会城市生态环境下的城市管理变革。     

A modulus‐multiplier approach for non‐linear analysis of laterally loaded pile groups

A modulus‐multiplier approach, which applies a reduction factor to the modulus of single pile p–y curves to account for the group effect, is presented for analysing the response of each individual pile in a laterally loaded pile group with any geometric arrangement based on non‐linear pile–soil–pile interaction. The pile–soil–pile interaction is conducted using a 3D non‐linear finite element approach. The interaction effect between piles under various loading directions is investigated in this paper. Group effects can be neglected at a pile spacing of 9 times the pile diameter for piles along the direction of the lateral load and at a pile spacing of 6 times the pile diameter for piles normal to the direction of loading. The modulus multipliers for a pair of piles are developed as a function of pile spacing for departure angle of 0, 90, and 180sup>/sup> with respect to the loading direction. The procedure proposed for computing the response of any individual pile within a pile group is verified using two well‐documented full‐scale pile load tests. Copyright © 2006 John Wiley & Sons, Ltd.     

Simplified procedure for laterally loaded drilled shafts in spatially random clays

Abstract

In this article, a simplified approach for the reliability-based design of laterally loaded drilled shafts considering the spatial variability of soil property is presented. This simplified approach utilizes a conventional reliability method implemented using the variance reduction technique. An algorithm for back-calculating the reduction factor and characteristic length for various shaft slenderness ratios is proposed. This simplified approach can yield responses for drilled shafts that are equivalent to those obtained using random field modeling (RFM), which is a far more complex process. The simplified approach does not require the knowledge of random field theory and can be an efficient design tool in geotechnical engineering practice.     

天山乌鲁木齐河源1号冰川融水可培养细菌生理生化特性及其系统发育

对天山乌鲁木齐河源1号冰川末端融水细菌进行分离,检测了分离菌株的生理生化表型特征,通过16S rRNA基因序列分析确定分离菌株的系统进化地位.结果表明:天山乌鲁木齐河源1号冰川融水中分离的36株代表菌株分属于5个系统发育类群、8个属,其中,Bacteroidetes和γ-Proteobacteria为优势类群,分别占41.7%和38.9%;在属水平上,假单胞菌属(Pseudomonas)菌株占39%.依据菌株最适生长温度,36株分离菌株80%以上属于耐冷菌;产酶实验显示,大多数菌株同时产蛋白酶和脂肪酶,仅3株菌不产酶,6株菌同时产脂肪酶、淀粉酶、蛋白酶.耐药性试验表明,36株分离菌株对各种抗生素有不同程度的耐药,其中,7株菌对测试的10种抗生素均具有耐药性.研究结果将有助于了解天山乌鲁木齐河源1号冰川微生物物种多样性、生理多样性,同时为评估气候变化、人类活动对冰川微生物生理特性潜在的影响提供依据.     

渤海海域旅大油田储层展布特征新认识

渤海海域旅大油田油水井注采实践表明,北东—北北东方向注采井网为优势受效方向,这与储层砂体呈北西—南东向展布的以往认识相矛盾。具右旋走滑性质的辽西一号断层由分段的弧形断层相接而成,构造转换带控制了油田储层展布,这一认识获得了地震属性、重矿物分析的支持。重新编制了主要油组的沉积体系图。旅大油田的储层展布方向为北东—北北东向,这一新认识对储层精细描述、水淹规律分析及剩余油挖潜等具有一定指导意义。     

Mineralogical and petrological features of the Cemilköy ignimbrite,Cappadocia, Turkey

The Cemilköy ignimbrite is one of the voluminous ignimbrite deposits in Cappadocia. The Cemilköy ignimbrite contains pumice and lithic clasts of volcanic and ophiolitic origin in an ash matrix. The unwelded Cemilköy ignimbrite is distinguished from other deposits in Cappadocia by flattened pumices, elongate vesicles and a slaty fabric. The mineral assemblage of the Cemilköy ignimbrite is plagioclase, biotite, quartz and oxides (magnetite and Ti-magnetite) and the matrix is glassy. Eutaxitic texture is dominant and all pumice clasts have a vitrophyric-porphyritic texture. The same textural properties were observed throughout the spatial distribution of Cemilköy ignimbrite. Microprobe studies reveal that plagioclase compositions range from albite through oligoclase-andesine. Estimated plagioclase-liquid temperatures (T) and pressures (P) are varying between 806 and 847?°C and 4.2–7.1 (kbar), and the H₂O content of the melt is estimated to have been 5?wt.% from the pumice clasts. Based on geochemical data, the Cemilköy ignimbrite is rhyolitic and calc-alkaline in character, and all pumice clasts are enriched in LIL and LRE elements relative to HFS elements. Negative Nb, Ta and Ti anomalies, ratios of Ba/Nb >28 (56–77), Ba/Ta ?450 (590–700) and Th/Yb vs. Ta/Yb are consistent with a subduction-related origin. According to the geochemical and mineralogical-petrographical data, the Cemilköy ignimbrite originated from partial melting of a mantle source which was enriched during previous subduction processes with variable degrees of assimilation fractional crystallization (AFC) through time and Cemilköy ignimbrite erupted from a crustal magma chamber at shallow to intermediate depth.