基于产业链空间网络的京津冀城市群功能协同分析

京津冀协同发展虽已取得显著成效,但缓解区域差异的挑战依然十分严峻。本文基于城市间投入产出表,构建京津冀产业链空间网络,考察京津冀协同发展战略提出前城市间功能协同存在的问题,据此探讨京津冀协同发展政策设计对改善城市间功能协同的有效性。研究发现,京津冀协同发展战略提出前,京津冀城市群存在着有分工、缺协同的问题,主要表现为：① 交通运输设备制造业和机械设备制造业产业链中游部门相对薄弱;② 北京生产性服务业的辐射强度和辐射范围不足;③ 产业链空间网络不均衡,空间融合程度低。产业链空间网络分析表明,《京津冀协同发展规划纲要》针对京津冀城市间功能协同的存在问题提出了解决方向与对策,但在补强产业链中游的加工制造环节、增强首都圈增长极作用和强化石家庄南部支点作用等方面,应加以完善。     

考虑温度效应的岩石损伤内时本构关系

本文根据岩石类材料受载时的损伤破坏机理,首次引入两个损伤变量 D_1和 D_0用以反映外载荷体量和偏量的作用,在内时理论的基础上建立起考虑温度效应的岩石损伤本构方程,并导出具有明确物理意义的本构方程增量型关系式。在不同温度下用大理岩试样进行了压缩实验和声发射实验。根据实验所得结果,确定了本构方程中材料的所有参数,得到了大理岩材料受温度影响其性质发生变化的一些有意义的结论。     

脆性岩石的损伤与裂隙扩展

岩石内部各种微裂隙的产生及发展,导致岩石的物理力学性质的劣化,此即损伤对岩石作用的结果。本文根据大理岩破坏过程中裂隙扩展的作用,定义了视损伤变量D=ε_v~k/ε_v~m,并导出了岩石的应力-应变关系和损伤变量D与D的关系。通过损伤试验,得出与理论值相吻合的结果。     

Rubidium Isotope Ratios of International Geological Reference Materials

In this study we determined rubidium isotope ratios in twenty-one commonly used international geological reference materials, including igneous, sedimentary and metamorphic rocks, as well as an IAPSO seawater reference material. All δ⁸⁷Rb results were obtained relative to the NIST SRM 984 reference material. For most reference materials, Rb was purified using a single column loaded with Sr-spec resin. For reference materials containing low Rb but high mass fractions of matrix elements (such as basic rock and seawater), Rb was purified using two-column chromatography, with the first column packed with AGMP-50 resin and the second column packed with Sr-spec resin. Two methods for instrumental mass bias correction, sample-standard bracketing (SSB) mode, and the combined sample-standard bracketing and Zr internal normalisation (C-SSBIN) method, were compared for Rb isotopic measurements by multi-collector inductively coupled plasma-mass spectrometry (MC-ICP-MS). The long-term reproducibility of Rb isotopic measurements using both methods was similar, better than 0.06‰ (2s, standard deviation) for NIST SRM 984. Significant Rb isotopic fractionation was observed among the reference materials, with an overall variation in δ⁸⁷Rb values of approximately 0.5‰. The δ⁸⁷Rb values of igneous rocks ranged from -0.28‰ to +0.06‰, showing a trend from heavier isotopic compositions in mafic rocks to lighter δ⁸⁷Rb values in the more evolved felsic rocks. The sedimentary and metamorphic rocks had Rb isotope ratios similar to those of igneous rocks. The δ⁸⁷Rb values of the reference materials related to low-temperature geological processes showed a wider range than those of high-temperature processes. Notably, the IAPSO seawater reference material had a δ⁸⁷Rb value of +0.14‰, which deviated from that of igneous rocks, and represents the heaviest reservoir of Rb isotopes found thus far on Earth. The comprehensive dataset presented here has the potential to serve for quality assurance purposes, and provide a framework for interlaboratory comparisons of Rb isotope ratios.     

中国省区间产业内贸易与产业结构同构分析

基于2002 年中国省区间投入产出模型,从产业内贸易角度重新审视产业结构同构问题。研究表明,中国制造业存在着一定的产业结构同构现象,但空间上不均衡。华东沿海地区存在着大类层面的产业内贸易和中小分类的产业间贸易,使得江浙沪之间形成了密切的产业关联,因此不能仅以产业结构同构程度来判断产业地域分工和区域经济一体化进程。基于大类产业层次的产业结构同构分析可能会高估产业结构同构程度,在中小类产业层次判断区域间产业结构同构会得到更符合现实的结论。产业内贸易已成为中国省区间贸易联系的重要形式。各省区制造业在产业链中的分工不同、相似的需求偏好和产品差异化竞争是促进产业内贸易的重要因素。产业内贸易既可以在产业结构相似的省份之间发生,也存在于产业结构差异明显的省份之间。如果区域之间存在着活跃的产业内贸易,产业结构同构不一定阻碍区域经济一体化。     

多尺度人口增长的空间统计分析

以全国第5、6次人口普查的数据为基准,在GIS环境下采用空间统计的方法探讨我国近10年来人口增长的空间分布特征及规律。以Ripley's K的变体函数L(d)分析获得的不同空间尺度下人口增长的集聚/离散的空间分布模式为依据,选择合理的距离尺度进行全局自相关分析和局部自相关分析。     

武汉市钻孔灌注桩静载试验结果的研究与讨论

根据武汉市19个工程桩基静载试验的实测资料,论述了钻孔灌注桩静载试验结果所反映的一些特点;对桩沉降量较大的原因作了初步分析;针对桩顶沉降量超过4cm时,提出了以屈服极限荷载、容许下沉量、以及以7.5—8.0％的桩径沉降量作为控制标准以确定单桩极限承载力的方法。     

Fluid Property Discrimination in Dolostone Reservoirs Using Well Logs

The Ordovician Majiagou Formation is one of the main gas-producing strata in the Ordos Basin,China.The identification of hydrocarbon-bearing intervals via conventional well logs is a challenging task.This study describes the litholog of Ma 5(Member 5 of Majiagou Formation)dolostones,and then analyzes the responses of various conventional well logs to the presences of natural gas.The lithology of the gas bearing layers is dominantly of the dolomicrite to fine to medium crystalline dolomite.Natura...     

岩石在循环荷载作用下的强度及变形特征

本文着重研究了岩石在循环荷载作用下的强度及变形特征。实验结果表明,岩石在循环荷载作用下的强度低于其静力强度,而这个循环疲劳强度极限与振幅、频率有关;岩石在循环荷载作用下的变形特征类似于静力蠕变特征。