利用拓扑和度量相结合的方法描述面目标间的空间关系

首先分析了9元组模型描述目标间空间关系的不足，提出了基于点集拓扑和度量特性相结合的方法来分析和描述GIS中面目标间的拓扑空间关系，并给出了合理的几何度量参数及计算方法，增强了空间关系的可区分性，进而提高了空间分析的准确性。该方法将空间关系描述过程概括为3步：①目标发现与定位；②空间拓扑关系的分类（粗略分类）；③在空间拓扑关系粗略分类的基础上，引进几何度量参数，实现空间关系的精化。     

国际区域友好关系和企业全球化的知识管道构建

经济地理学中的“本地蜂鸣-全球管道”模型解释了本地企业如何通过长期互动学习,逐步形成有利于企业全球化的重要知识俘获渠道。中小企业因自身能力和国际化经验的缺乏,往往会规避时间成本和风险,另辟蹊径地实施国际化战略。本文以浙江省和德国石荷州国际友好关系为例,通过田野调查和对利益相关人的深度访谈,对该关系框架下浙江中小企业“走出去”过程中的知识俘获机制进行分析。结果显示：①国际区域友好相关机构扮演着“知识守门员”角色,为双边中小型企业的全球化提供准确的、高效的和定制化的信息。②国际区域友好关系推动基于政府担保的、多方参与的“全球蜂鸣”空间形成,使得企业以较低成本获得社会、认知和组织临近,以此俘获“走出去”的关键知识;③国际区域友好关系为两地搭建一种新型的“全球管道”,有利于形成面向“精准全球化”的动态蜂鸣社群。本研究强调：地方政府主导的国际区域友好关系是中小企业“全球管道”构建的重要制度平台,这种“全球蜂鸣-全球管道”知识动态模式是对传统“本地蜂鸣-全球管道”概念的重要补充。     

Hydrology of part of the Oramiriukwa River basin,southeast of Owerri,Imo State,Nigeria

The Oramiriukwa River is within the sandy coastal plain strata of the Benin formation (Miocene–Recent). The base flow is very high ranging from 79.13–98.56%, which is caused by the excellent hydraulic interconnection between the river and the adjacent unconfined aquifer. Recharge rates are high, estimated to range from 1.8×10¹²–2.5×10¹² m³/year. Coastal sands are medium-to-coarse grained, moderately-to-poorly sorted, angular to subangular, with lenses of clay and clayey fine-grained sands. The coastal sands and clay lenses form aquifer and aquitard systems, which are unconfined to semi-confined. Groundwater recharge potential is high. Runoff from precipitation is low. Groundwater and surface water are fairly acidic; pH ranges from 5.5–6.1 (groundwater) and 5.8–6.5 (surface water), and hardness is generally low. Chemical analysis and percentage sodium show that groundwater and surface water are somewhat potable after some pH modification of the surface water. The waters are good for agricultural use, especially for irrigation and poultry water supply. However, pollution from landfill leachate is serious. Electronic Publication     

Phase equilibria in the hornblende-bearing basic gneisses of the Uvete area, central Kenya

Abstract The hornblende-bearing basic gneisses in the Uvete area, central Kenya, were metamorphosed under a narrow range of P and T (6.5 ± 0.5kbar and 530 ± 40°C) of the staurolitekyanite zone in the Mozambique metamorphic belt. They show a wide variety of divariant and trivariant mineral assemblages consisting of hornblende, cumminatonite, gedrite, anthophyllite, chlorite, garnet, epidote, clinopyroxene, plagio-clase and quartz. The bulk and mineral chemistries and the graphical representation of phase relations show that each mineral assemblage approaches chemical equilibrium and defines a unique composition volume in the A'(Al + Fe³⁺− (13/7)Na)-F(Fe²⁺)-M'(Mg)-C'(Ca-(3/7)Na) tetrahedron. The composition volumes are distributed quite regularly and do not overlap each other.
The phase relations in the Uvete area are in contrast with those in the staurolite-kyanite zone amphibolites in the Mt. Cube quadrangle, Vermont. The amphibolites there contain low-variance mineral assemblages formed under different values of μ_H2O and μ_CO2. These assemblages define overlapping composition volumes in the A'-F'-M'-C'tetrahedron.
The mineral assemblages in the Uvete area are interpreted as having formed in equilibrium with fluid at a high and nearly constant μH₂O value. Such a fluid composition was externally controlled by the supply of H₂O-rich fluid expelled from the surrounding pelitic and psammitic rocks. The body size of the basic gneisses in the Uvete area (less than 400m in thickness) was small enough for the fluid to migrate completely.     

人类命运共同体理念的理论分析及其在抗疫实践中的应用

中国是人类命运共同体理念的倡导者和建设者,其话语的国际传播需要坚实的理论支撑。新冠肺炎疫情给全球公共卫生安全带来了严峻挑战,也严重威胁着全球的政治、经济、社会等领域的安全。在全球抗击新冠肺炎疫情的关键时期,全社会亟需以人类命运共同体理念凝聚国际战疫共识,维护全球公共卫生安全。基于地缘政治学与共同体的视角,笔者从科学内涵、历史演进和时代价值方面,对人类命运共同体理念进行理论解析;采用案例分析法从国内抗疫实践、中国抗疫方案、西方抗疫实践方面,诠释人类命运共同体理念在抗疫中的应用,并论证其在传播与实践中的双重价值及困境问题;最后基于人类命运共同体理念的后疫情时代治理与担当,提出世界各国应当在诸如促进全球合作、维护世界公共卫生安全、防止全球衰退、消除疫情次生衍生灾害、变革全球治理以及重构国际关系等方面发挥巨大作用。     

1987年来台海关系变化对台湾入境大陆客流量的影响

两个国家(或地区)之间的政治关系是影响出入境旅游最重要的因素.1987年台湾当局解除居民来大陆探亲旅游限制.入境大陆旅游客流量急速增长:2008年开放大陆居民入岛旅游.拉开了两岸旅游流双向互动的新格局.1987-2007年的20年间,台海关系波动起伏.依据相关历史文献和统计数据.分析了两岸关系变化对台湾入境大陆旅游客流量的影响.结果发现.当台海关系恶化、危机事件爆发时,在入境客流量统计值、环比增长率和占出岛旅游比统计曲线上形成了明显的"凹形谷",采用三条理想曲线作为参照系.定量分析了7次危机事件对台湾游客入境大陆客流量的影响.其中,从1994年的千岛湖事件到1996年第四次台海危机,台海关系阴云密布.对入境大陆旅游影响最大、持续时间最长.累计损失客流量50万人次,相对损失率在11.4%.本研究为探索国际关系危机事件对出入境旅游的影响提供典型案例.     

Plant water relations of thornscrub shrub species, north-eastern Mexico

As an approach to understand how diurnal and seasonal plant water potentials (Ψ) are related to soil water-content and evaporative demand components, the responses of six thornscrub shrubs species (Havardia pallens, Acacia rigidula, Eysenhardtia texana, Diospyros texana, Randia rhagocarpa, and Bernardia myricaefolia) of the north-eastern region of Mexico to drought stress were investigated during the course of 1 year. All study species showed the typical diurnal pattern of variation in Ψ. That is, Ψ decreased gradually from predawn (Ψ_pd) maximal values to reach minima at midday (Ψ_md) and began to recover in the late afternoon. On a diurnal basis and with adequate soil water-content (>0.20 kg kg⁻¹), diurnal Ψ values differed among shrub species and were negatively and significantly (p<0.001) correlated with air temperature (r=−0.741 to −0.883) and vapor pressure deficit (r=−0.750 to −0.817); in contrast, a positive and significant (p<0.001) relationship was found to exist with relative humidity (r=0.758–0.842). On a seasonal basis, during the wettest period (soil water-content>0.20 kg kg⁻¹), higher Ψ_pd (−0.10 MPa) and Ψ_md (−1.16 MPa) values were observed in R. rhagocarpa, whereas lower figures (−0.26 and −2.73 MPa, respectively) were detected in A. rigidula. On the other hand, during the driest period (soil water-content<0.15 kg kg⁻¹), Ψ_pd and Ψ_md values were below −7.3 MPa; i.e. when shrubs species faced severe water deficit. Soil water-content at different soil layers, monthly mean relative humidity and monthly precipitation were significantly correlated with both Ψ_pd (r=0.538–0.953; p<0.01) and Ψ_md (r=0.431–0.906; p<0.05). Average soil water-content in the 0–50 cm soil depth profile explained between 70% and 87% of the variation in Ψ_pd. Results have shown that when gravimetric soil water-content values were above 0.15 kg kg⁻¹, Ψ_pd values were high and constant; below this threshold value, Ψ declined gradually. Among all shrub species, A. rigidula appeared to be the most drought tolerant of the six species since during dry periods it tends to sustain significantly higher Ψ_pd in relation to B. myricaefolia. The remaining species showed an intermediate pattern. It is concluded that the ability of shrub species to cope with drought stress depends on the pattern of water uptake and the extent to control water loss through the transpirational flux.     

一种建立公交网络的最短路径改进算法

目前,对最短路径问题的研究很多,基本都是关注算法的计算效率问题,而其应用到具体领域时会遇到一些算法本身无法解决的细节问题。如将邻接结点算法用于公交网络的最短路径计算时,会遇到诸如缺少网络拓扑信息、属性数据复杂等问题。本文针对这些问题给出了解决方法:在计算最短路径之前,利用算法将站点和线路数据进行自动匹配,建立公交网络的拓扑关系。同时在数据存储方式上进行了改进,运用数据库存储复杂的公交属性数据和中间过程中产生的公交网络数据,节约了运算时的内存占用率,提高了数据的利用率,使算法更具实际意义。     

空间关系推理方法分类体系

为对已有空间关系推理方法进行分析和评价,必须建立空间关系推理方法的分类体系.合理的分类体系不仅有利于正确理解和使用已有空间推理方法,更有助于提出新的空间关系推理方法.该文将空间关系种类、空间关系描述模型、推理参照系统、空间对象动态变化、空间对象类型、空间对象复杂程度、对象尺度特征、对象层次特征8个因素作为指标,建立了空间关系推理方法分类体系;以此体系为标准,分析和评述了已有空间关系推理方法.