科技型创新区人本化构建的国际实践及启示     

林静  蔡建明  Douglas WEBSTER  Larissa MULLER 《地理研究》2018,37(4):834-846

创新和创新区已日益成为城市经济发展和城市竞争力的重要元素,在科技和人才日渐成为激发城市创新型经济,及促进城市活力的主导甚至决定性因素的当今时代,尤为如此。通过对欧洲、北美和亚洲三个不同类型的科技型创新区国际最佳实践的系统梳理,甄别出用以打造一个科技型创新区的共通性要素、标准和原则。国际最佳实践证明,科技型创新区的人本化构建正在成为一种主流趋势,即综合考虑人在各阶段、各层次等多样化需求的基础上,通过对文化要素的有效鉴别和这些要素之间的作用机理,使它们有机融合并系统嵌入到创新区的空间打造中。结论表明：要成功打造一个科技型创新区,必须考虑并重视七大要素,即创意人才、企业集群、能动设施、资金保障、运营管理、空间结构和文化氛围。基于此,提出对中国科技型创新区建设与发展的五大启示,即愿景导向下的持续培育、前瞻性定位、人本化空间布局、创新激发型活动安排和多利益群体参与。最后,还提出要从四个方面进行互动关联研究,以构建空间/地方人本化打造的完整理论体系。  相似文献   

Successive mixing and mingling of magmas in a plutonic complex of Northeast Brazil   总被引：19，自引：0，他引：19  

S. P. Neves  A. Vauchez 《Lithos》1995,34(4):275-299

Field and petrographic evidence together with major element geochemistry suggest that mixing and mingling of magmas of contrasting compositions were important petrogenetic processes in the Fazenda Nova/Serra da Japeganga plutonic complex of Northeast Brazil. The complex was emplaced at pressures of 300–500 MPa in amphibolite facies metamorphic rocks of Neoproterozoic age and consists of three main rock types: (1) coarse-grained granite; (2) porphyritic granite and (3) diorite to quartz-monzodiorite. The latter two make up the Fazenda Nova batholith which is located on the northwestern side of the sinistral, NE-trending, Fazenda Nova strike-slip shear zone. NE-plunging stretching lineations in the shear zone suggest that this batholith represents an uplifted, and therefore deeper, portion of the complex. The structure of the complex reflects the stratigraphy in a magma chamber, with the porphyritic granite above the diorite and below the coarse-grained granite.

The porphyritic granite has a uniform composition, intermediate in mafic mineral content, quartz, and majorelements between the coarse-grained granite and the diorite. It is free of disequilibrium mineral assemblages, and locally displays gradational contacts with the overlain coarse-grained granite. Most elements display linear correlation with SiO₂ in Harker diagrams. These features are interpreted as resulting from mixing of almost crystal-free felsic and intermediate magmas. Fluid dynamic calculations using the coarse-grained granite and the silica-poorest diorite as end-members in the mixing process show that mechanical mixing was possible, and thermal modelling suggests that the formation of an homogeneous hybrid may have been achieved in less than 50,000 yr.

The diorites contain corroded K-feldspar megacrysts, and range in composition from low to relatively high silica contents, partly overlapping with the porphyritic granite. This suggests that a new mixing event occurred during the crystallisation of the porphyritic granite, this time producing a heterogeneous, xenocryst-bearing, dioritic hybrid. Abundant enclaves of diorite in the porphyritic granite, despite their textural diversity, are typically devoid of chilled margins, and were therefore formed relatively early in the crystallisation history of the granite. They are interpreted as liquid droplets separated from the heterogeneous hybrid magma through convection currents and incorporated in the, crystallising granitic magma.

Subsequently, during the crystallisation of the porphyritic granite, mafic magma supply to the batholith continued at a declining rate, probably assisted by the development of the Fazenda Nova shear zone. This leads to the production of stromatitic-like structures, with alternating bands of mutually contaminated granite and diorite, then to the intrusion of contorted synplutonic dykes, and, finally, of late-stage dykes, some of which with chilled finer-grained margins.  相似文献   

Well productivity controlling factors in crystalline terrains of southeastern Brazil   总被引：1，自引：0，他引：1  

Mirna A. Neves  Norberto Morales 《Hydrogeology Journal》2007,15(3):471-482

Over the last decades, increasing water demands have fostered research to obtain high well yields in crystalline terrains where, besides the intrinsic properties of rocks, the groundwater flow depends on several factors. The depth of the wells, the lithotypes, the presence and thickness of sedimentary coverings and weathered layers, the landforms, the geological structures, and the effects of tectonic stresses are among the most investigated factors considered as determinant of well productivity. The influence of these factors on productivity of wells that exploit the Crystalline Aquifer System in the Jundiaí River Catchment, southeastern Brazil, is investigated in this work. The largest region of the studied area is located on the Precambrian Basement, partially covered by sedimentary deposits. The results show that the sedimentary deposits and the weathered layer are important for high well yield, but it also depends on the existence of a net of open fractures, in order to maintain high productivity. The sites that have more possibility of occurrence of such structures are the regional shear and fault zones and other minor structures with NW–SE and E–W directions, which characterize areas subjected to transtensional stress related to the neotectonics.  相似文献   

Heat-producing Elements-enriched Continental Mantle Lithosphere and Proterozoic Intracontinental Orogens: Insights from Brasiliano/Pan-African Belts     

Srgio Pacheco Neves  Gorki Mariano 《Gondwana Research》2004,7(2):427-436

Collisional and accretionary processes have been recognized in several Precambrian orogens, but the formation of intracontinental (ensialic) orogens has remained elusive. The recognition that modern orogenic belts (as, for example, the mountain belts of central Asia) may form in response to far-field stresses transmitted to the interior of continental plates removed much of the objection against Proterozoic intracontinental deformation. However, the causes responsible for the localization of contractional deformation are still uncertain. Due to the strong dependence of lithosphere rheology on temperature, lithospheric thermal weakening prior to contraction must be a required condition. Studies of dioritic rocks from Borborema Province, northeastern Brazil, and Damara belt, southern Africa, indicate that they are derived from ancient, incompatible elements-enriched subcontinental lithosphere. The concentrations of the heat-producing elements K (0.6 wt %), U (0.02–0.2 ppm) and Th (0.15–1.5 ppm) estimated for this source allow calculations of heat production between 0.09 and 0.25 mW m⁻³. These high values of heat generation may cause increases in temperature of several tens to three hundred degrees Celsius with respect to cratonic mantle lithosphere, leading to great reductions in lithosphere strength. Consequently, continental domains underlain by hot and weak continental mantle may thicken under the action of relatively feeble tectonic forces. High rheological contrasts between these domains and adjacent stiff and cold blocks provide an explanation for formation of intracontinental orogens.  相似文献   

土地资源约束下的北京食物供给潜力与优化(英文)   总被引：1，自引：1，他引：0  

蔡建明  郭华  Larissa MULLER  Margaret ZHOU 《资源与生态学报(英文版)》2012,3(3):269-277

全球气候变化所带来的极端天气的频繁发生,水资源短缺情况下的农业用水的不断减少和伴随着人口增长与社会经济发展所引起的耕地面积下降,正在严重影响着世界范围内的食物安全。近年来由于食品价格的迅猛增长而导致的食品危机正在引起人们对增加地方食物供应的普遍关注。城市作为对食品安全更为敏感的地区,更是首当其冲受到食品危机的影响,城市一方面由于城市化快速发展,带来城市人口膨胀和消费多样性要求,从而形成需求的大幅增加,另一方面有由于城市周边耕地面积的不断减少,农业生产空间受到压缩,农业生产能力减弱,降低了城市的自我食品供给,引起自给率明显下降。如何保持供需之间的平衡,保障城市食品安全,成为亟需研究的问题。本文提出以食物足迹的概念,来衡量城市所间接消耗的土地资源,并以此为工具,以自给率为条件,来求得满足一定自给率条件下食物供给的空间对应格局。通过分析30年来北京食物足迹以及食物自给率的年际变化,得出结论:北京食物足迹从1981年的1.18万km2增加到2010年的2.94万km2,而自给率整体下降较多,蔬菜、水果、谷物及油脂类的自给率从1981年的59.3%、35.8%、37.3% 和 13.1% 下降到2010年的39.0%、27.0%、6.7% 和2.2%,可以看出蔬菜仍能保持相当的自给率,因此提高蔬菜自给率是增强城市自给能力的最佳选择。最后,以60%的蔬菜自给率为目标,提出了两种情景,包括完全以耕地为来源的空间应对格局,以及屋顶农业参与下的空间应对格局。  相似文献   

Updating Mining Resources with Uncertain Data     

Neves  João  Pereira  Maria João  Pacheco  Nelson  Soares  Amilcar 《Mathematical Geosciences》2019,51(7):905-924

Mathematical Geosciences - In mining operations, the time delay between grade estimations and decision-making based on those estimations can be substantial. This may lead to the scheduling of...  相似文献   

Modeling flood dynamics in a temporary river draining to an eutrophic reservoir in southeast Portugal     

David Brito  Ramiro Neves  Maria A. Branco  Maria C. Gonçalves  Tiago B. Ramos 《Environmental Earth Sciences》2017,76(10):377

Enxoé is a small temporary river with a flushy regime, which flash floods carry significant loads to the reservoir. As a result, the reservoir, which supplies 25,000 inhabitants, exhibits a high trophic state and cyanobacteria blooms since its construction in 1998, with water abstractions requiring extensive treatment. This study aimed to understand the contribution of flash floods to the Enxoé’s reservoir high trophic state using a modeling approach. This was the first time the river was monitored and that a modeling study was carried out. The MOHID-Land model was implemented to assess the water path in the catchment, and was integrated with field data to compute river loads. Results confirmed the importance of flash events. During flash floods, water properties were determined by soil surface and river bottom wash out, and depended mostly on the flush sequence and intensity. Model simulations showed that soil surface permeability reduction was an important factor regulating surface runoff while soil moisture was low. The first flood after the dry period contributed to 2% of the yearly discharge, 3% of yearly N load, and 7% of the yearly P loads. Winter floods contribution differed, producing 10% of both yearly discharge and loads. However, concentration of particulate matter and organic compounds in the first flood were one order of magnitude higher than in winter floods. This was due to river bottom resuspension and erosion of riparian areas, representative dynamics of a flushy regime. During subsequent winter floods, nutrient concentrations tended to remain constant as the watershed surface and respective soils were washed. Further work should link a watershed model to a reservoir model to depict the flood impact in the reservoir, and test management strategies to reduce the reservoir trophic state.  相似文献   

Inter-annual changes in fish communities of a tropical bay in southeastern Brazil: What can be inferred from anthropogenic activities?     

Francisco Gerson Araújo  Samara Macedo Pinto  Leonardo Mitrano Neves  Márcia Cristina Costa de Azevedo 《Marine pollution bulletin》2017,114(1):102-113

We assessed inter-annual changes in fish assemblages of a tropical bay which experienced a heavily industrialized process in the last decades. A highly significant difference in community structure among the bay zones, and a decrease in fish richness and abundance over time were found. Changes in fish richness and abundance between the two first (1987–1988 and 1993–1995) and the two latter time periods (1998–2001 and 2012–2013) were sharpest in the inner bay zone, the most impacted bay area, and in the middle zone, whereas the outer zone remained comparatively stable over time. These changes coincided with increased metal pollution (mainly, Zn and Cd) in the bay and with the enlargement of the Sepetiba Port. Spatial changes in the fish community structure among the bay zones were related to differences in salinity, transparency and depth with this latter variable acting as a buffer stabilizing temporal community changes.  相似文献   

The role of Bells in the continuous accretion between the CM and CR chondrite reservoirs     

Elishevah van Kooten  Larissa Cavalcante  Daniel Wielandt  Martin Bizzarro 《Meteoritics & planetary science》2020,55(3):575-590

CM meteorites are dominant members of carbonaceous chondrites (CCs), which evidently accreted in a region separated from the terrestrial planets. These chondrites are key in determining the accretion regions of solar system materials, since in Mg and Cr isotope space, they intersect between what are identified as inner and outer solar system reservoirs. In this model, the outer reservoir is represented by metal‐rich carbonaceous chondrites (MRCCs), including CR chondrites. An important question remains whether the barrier between MRCCs and CCs was a temporal or spatial one. CM chondrites and chondrules are used here to identify the nature of the barrier as well as the timescale of chondrite parent body accretion. We find based on high precision Mg and Cr isotope data of seven CM chondrites and 12 chondrules, that accretion in the CM chondrite reservoir was continuous lasting <3 Myr and showing late accretion of MRCC‐like material reflected by the anomalous CM chondrite Bells. We further argue that although MRCCs likely accreted later than CM chondrites, CR chondrules must have initially formed from a reservoir spatially separated from CM chondrules. Finally, we hypothesize on the nature of the spatial barrier separating these reservoirs.  相似文献   

A Chart for Judging Optimal Sample Spacing for Ore Grade Estimation: Part II     

Drumond  David Alvarenga  Amarante  Flávio Azevedo Neves  Koppe  Vanessa Cerqueira  Costa  João Felipe Coimbra Leite 《Natural Resources Research》2020,29(1):551-560

Natural Resources Research - Resources of mineral deposits are commonly estimated using data extracted from rock cores obtained by drilling. Information of good quality and quantity is essential to...  相似文献