地下空间功能演变及历史研究脉络对当代城市发展的启示

地下空间形态从点、线、网状发展到空间的立体化与系统化利用,与城市发展聚集程度密切相关。地下空间利用在城市产生之初就具有系统性特征,柯布西耶等提出的"垂直的田园城市"规划思想对当代中国地下空间规划及利用具有奠基性意义。1790至今的研究表明,"地下空间"一词出现于1980年后地下空间的规模化开发,2000年之后中国成为地下空间开发及研究的主战场。中国由于城市发展状况多样、地理气候多样,地下空间开发模式兼具世界各国的特征,未来地下空间的开发将吸取国外地下空间的发展经验,建立多种地下空间开发模式。

浅谈自然设计在室内空间中的运用——“本色”咖啡书吧的自然设计

纵观建筑史,古人将自然元素作为室内设计中不可缺少的一部分,因为自然的纯粹、自然的强大、自然对人心灵产生的影响,"崇尚自然、师法自然"更被作为中国园林建筑所秉承的原则,因此自然设计在室内空间中的运用相当重要。文章阐述自然设计的内涵、其在室内空间的运用及其对室内空间的要求,并以作品"本色"咖啡书吧为案例分析自然设计在室内空间中的运用。

“八合一”理念下城市滨水空间营造的六个维度

上海自2002年启动黄浦江两岸综合开发后,于2014年底提出《黄浦江两岸地区公共空间建设三年行动计划》,作为其中杨浦滨江南段公共空间的总设计师团队,深度介入了上海城市滨水空间的复兴。依托实践提出“八合一”理念,即城市设计、建筑设计、景观设计、市政设计、水工设计、生态修复、智能设计和艺术设计协同合作;并在突破学科壁垒的基础之上,构建包含系统化空间营造、历史文脉延续、基础设施复合、场景节点构筑、生态环境修复和公共艺术植入的六维城市滨水空间再生体系。

Symmetries and Group-Invariant Solutions for Transonic Pressure-Gradient Equations

Lie symmetry group method is applied to study the transonic pressure-gradient equations in two-dimensionalspace.Its symmetry groups and corresponding optimal systems are determined,and several classes of irrotational groupinvariantsolutions associated to the symmetries are obtained and special case of one-dimensional rarefaction wave isfound.

Landscape Changes from 1974 to 1995 in the Upper Minjiang River Basin, China

Landscape changes were traced over the 20 years from 1974 to 1995 in the upper Minjiang River basin, one of the most important forest regions in China, based on satellite image interpretation to provide basic data for local decision-making as well as sustainable landscape use and management. Results revealed that landscape from 1974 to 1995 changed at the regional scale as the area of forestland decreased, while cropland, shrubland, economic forest, grassland, and built-up land increased. Landscape changes mainly occurred in forestland, shrubland, grassland, economic forest, and built-up land. Moreover, the changes among forestland, shrubland, and grassland were the largest, influencing the whole characteristics of the changes in the basin. Analysis of the changes between 1974 and 1995 in the study area indicated that landscape heterogeneity and fragmentation increased, whereas landscape connectivity decreased. There were multiple reasons for landscape changes. A principal component analysis (PCA) was used to quantitatively study driving forces of landscape changes. The PCA results showed that economic and population factors were the principal driving forces of landscape changes from 1974 to 1995 in the upper Minjiang River basin, and that PCA was a suitable method for investigating driving forces of landscape changes.

Nitrogen Deposition and Its Spatial Pattern in Main Forest Ecosystems along North-South Transect of Eastern China

A continuous three-year observation(from May 2008 to April 2011)was conducted to characterize the spatial variation of dissolved inorganic nitrogen(DIN)deposition at eight main forest ecosystems along the north-south transect of eastern China(NSTEC).The results show that both throughfall DIN deposition and bulk DIN deposition increase from north to south along the NSTEC.Throughfall DIN deposition varies greatly from 2.7 kg N/(ha·yr)to 33.0 kg N/(ha·yr),with an average of 10.6 kg N/(ha·yr),and bulk DIN deposition ranges from 4.1 kg N/(ha·yr)to 25.4 kg N/(ha·yr),with an average of 9.8 kg N/(ha·yr).NH4+-N is the dominant form of DIN deposition at most sampling sites.Additionally,the spatial variation of DIN deposition is controlled mainly by precipitation.Moreover,in the northern part of the NSTEC,bulk DIN deposition is 17%higher than throughfall DIN deposition,whereas the trend is opposite in the southern part of the NSTEC.The results demonstrate that DIN deposition would likely threaten the forest ecosystems along the NSTEC,compared with the critical loads(CL)of N deposition,and DIN deposition in this region is mostly controlled by agricultural activities rather than industrial activities or transportation.

Soil pH Management across Spatially Variable Soils

Knowledge and management of soil pH, particularly soil acidity across spatially variable soils is important, although this is greatly ignored by farmers. The objective of the study was to evaluate in-field spatial variability of soil pH, and compare the efficiency of managing soil pH through site-specific method vs. uniform lime application. The study was conducted on three sites with study sites I and II （23°50＇ S; 29°40＇ E）, and study sites IIl （23°59＇ S; 28°52＇ E） adjacent to each other in the semi-arid regions of the Limpopo Province, South Africa. Soil samples were taken in four replicates from geo-referenced locations on a regular grid of 30 m. Soils were analyzed for pH, and SMP buffer pH. Soil maps were produced with Geographic Information System （GIS） software, and soil pH datasets were interpolated using a geostatistical tool of inverse distance weighing （IDW）. Soil pH in the fields varied from 3.93 to 7.00. An excess amount of lime as high as 30 t/ha under uniform lime application were recorded. These recommendations were in excess on field areas that needed little or no lime applications. Again, there was an under applications of lime as much as 35 t/ha for uniform liming applications. This under- and over-recommendations of lime based on average soil pH values suggests that uniform soil acidity correction and soil pH management strategy is not an appropriate strategy to be adopted in these fields with spatially variable soils. The field can be divided into lime application zones of （1） high rates of lime, （2） low rates of lime and （3） areas that requires no lime at all so that lime rates are applied per zone. A key to site-specific soil acidity correction with lime is to reach ideal soil pH for the crop in all parts of the field.

Spatial evolution of coal transportation at coastal ports in China

Coal is a basic resource and its use guarantees the development of national economies and human society. Thus, coal transportation is an important part of China's overall transportation system. In this system, ports are the vital transit nodes. This study considered coastal ports in China and analysed the evolution of coal transportation from 1973 to 2013. We focused on the spatial pattern of coal loading and unloading, and summarized the main characteristics and development of the processes. Then, we examined the volumes of coal transported and regional changes in these amounts using mathematical models and indicators. Finally, we analysed the specialized function and spatial differentiation of the ports involved in coal transportation to reveal their spatial relationship and temporal evolution. We found that the spatial pattern of coal transportation changed from "south input and north output" to "all input and north output". However, the prominent ports used for coal unloading are still concentrated in areas south of the Yangtze River. Coal loading is concentrated on the west bank of Bohai Bay. In addition, some ports around Bohai Bay, such as Dandong, Dalian, Yantai, and Qingdao, changed from traditional coal loading ports to unloading ports. This study further developed the theory of transport geography, and improved our understanding of China's coal transportation system.

The Cauchy problem of generalized Landau-Lifshitz equation into S^n

In this paper,we study the Cauchy problem of an integrable evolution system,i.e.,the n-dimensional generalization of third-order symmetry of the well-known Landau-Lifshitz equation.By rewriting this equation in a geometric form and applying the geometric energy method with a forth-order perturbation,we show the global well-posedness of the Cauchy problem in suitable Sobolev spaces.

STABILIZATION OF COUPLED PDE-ODE SYSTEMS WITH SPATIALLY VARYING COEFFICIENT

The paper is concerned with the stabilization of a class of coupled PDE-ODE systems with spatially varying coefficient,via state-feedback or output-feedback.The system is more general than that of the related literature due to the presence of the spatially varying coefficient which makes the problem more difficult to solve.By infinite-dimensional backstepping method,both state-feedback and output-feedback stabilizing controllers are explicitly constructed,which guarantee that the closed-loop system is exponentially stable in the sense of certain norm.It is worthwhile pointing out that,in the case of output-feedback,by appropriately choosing the state observer gains,the severe restriction on the ODE sub-system in the existing results is completely removed.A simulation example is presented to illustrate the effectiveness of the proposed method.

Scale dependence in the phylogenetic relatedness of alien and native taxa

Aims Darwin’s naturalization hypothesis proposes that successfully established alien species are less closely related to native species due to differences in their ecological niches.Studies have provided support both for and against this hypothesis.One reason for this is the tendency for phylogenetic clustering between aliens and natives at broad spatial scales with overdispersion at fine scales.However,little is known about how the phylogenetic relatedness of alien species alters the phylogenetic structure of the communities they invade,and at which spatial scales effects may manifest.Here,we examine if invaded understorey plant communities,i.e.containing both native and alien taxa,are phylogenetically clustered or overdispersed,how relatedness changes with spatial scale and how aliens affect phylogenetic patterns in understorey communities.Methods Field surveys were conducted in dry forest understorey communities in south-east Australia at five spatial scales(1,20,500,1500 and 4500 m2).Standardized effect sizes of two metrics were used to quantify phylogenetic relatedness between communities and their alien and native subcommunities,and to examine how phylogenetic patterns change with spatial scale:(i)mean pairwise distance and(ii)mean nearest taxon distance(MNTD).Important Findings Aliens were closely related to each other,and this relatedness tended to increase with scale.Native species and the full community exhibited either no clear pattern of relatedness with increasing spatial scale or were no different from random.At intermediate spatial scales(20-500 m2),the whole community tended towards random whereas the natives were strongly overdispersed and the alien subcommunity strongly clustered.This suggests that invasion by closely related aliens shifts community phylogenetic structure from overdispersed towards random.Aliens and natives were distantly related across spatial scales,supporting Darwin’s naturalization hypothesis,but only when phylogenetic distance was quantified as MNTD.Phylogenetic dissimilarity between aliens and natives increased with spatial scale,counter to expected patterns.Our findings suggest that the strong phylogenetic clustering of aliens is driven by human-mediated introductions involving closely related taxa that can establish and spread successfully.Unexpected scale-dependent patterns of phylogenetic relatedness may result from stochastic processes such as fire and dispersal events and suggest that competition and habitat filtering do not exclusively dominate phylogenetic relationships at fine and coarse spatial scales,respectively.Distinguishing between metrics that focus on different evolutionary depths is important,as different metrics can exhibit different scale-dependent patterns.

Conceptual study of lunar-based SAR for global change monitoring

As an active microwave remote sensing imaging sensor, Synthetic Aperture Radar(SAR) plays an important role in earth observation. Here we establish a SAR system based on the platform of the moon. This will aid large-scale, constant, and long-term dynamic Earth observations to better meet the needs of global change research and to complement the space borne and airborne earth observations. Lunar-based SAR systems have the characteristics of high resolution and wide swath width. The swath width could be thousands of kilometers in the stripe mode and it could cover 40% of earth's surface with 10 meters or even higher spatial resolution in the scanning mode. Using the simplified observation model, here we quantitatively analyze the spatial resolution and coverage area of lunar-based SAR and simulate the observation on the Qinghai-Tibet plateau and the Amazon plain. The results show that this system could provide near 100% daily coverage of the Qinghai-Tibet plateau, whereas 40% to 70% daily coverage of the Amazon plain. Lunar-based SAR could provide large-scale, long-term and stable time series data in order to support future research of global change.

Existence and Gevrey regularity for a two-species chemotaxis system in homogeneous Besov spaces

We study the Cauchy problem of a two-species chemotactic model. Using the Fourier frequency localization and the Bony paraproduct decomposition, we establish a unique local solution and blow-up criterion of the solution, when the initial data（u0, v0, w0） belongs to homogeneous Besov spaces B^˙p,1^-2＋3/p（R^3） ×B^˙r,1^-2＋3/r（R^3） ×B^˙q,1^3/q（R^3） for p, q and r satisfying some technical assumptions. Furthermore, we prove that if the initial data is sufficiently small, then the solution is global. Meanwhile, based on the so-called Gevrey estimates, we particularly prove that the solution is analytic in the spatial variable. In addition, we analyze the long time behavior of the solution and obtain some decay estimates for higher derivatives in Besov and Lebesgue spaces.