Driving Analysis on Ecological Security in Vulnerable Transition Areas of Mountain and Plain

[Objective] This study aimed to investigate the driving mechanism of eco- logical security in vulnerable areas in mountain and plain. [Method] The ecological security evaluation index system of Lincheng County was established using PSR model. Driving mechanism was analyzed in total system and subsystems respectively by the principal components. The ecological safety driving factor was calculated through the total system and subsystem respectively. And the intersection was adopt- ed as dominant driving factor. [Result] A total of 10 indices including density index of rivers, land degradation index, farmland drought and flood insurance yield, human in- terference index, population density, the natural population growth rate, per capita GDP, the R＆D funds spending accounts for the proportion of GDP, laborer by edu- cation degree and three industry accounted for the proportion of GDP, are the domi- nant driving factors of the regional ecological security. [Conclusion] This study will pro- vide reasonable and feasible advice for the benign development of the area.

Application of a New Qeneration of Geophonesto Improve Seismic Acquisitionin Onshore-offshore Transition Areas

In this paper, we review the differences between velocity geophones （VG） and acceleration geophones （AG） and their effect on seismic signals acquired in onshore-offshore transition areas. We present a new generation of Land Piezoelectric Geophone （LPG） and analyze its performance. Our field experiments demonstrate that our new LPG can be used to substitute for VGs in order to eliminate phase, frequency and energy differences between different geophone systems commonlv used in transition areas.

Study on Sustainable Development in Vulnerable Eco-areas

The vulnerable eco-area is one of the important research targets in the field of sustainable development. It is the requirement of building a well-off society in an all-round way that we should study more on the vulnerable eco-areas, deal with the relationship between environmental protection and economic development, speed up the economic development in these areas and increase the living standard of the local people. This paper puts forward the countermeasures of environment---economy coordination, on the basis of the recognition of eco-environment features and social economic conditions in the vulnerable eco-areas of China, in view of the progress in sustainable development studies of the vulnerable ones, taking the transitional areas of farming and pasturing in northeast China as an example to study the regional environment vulnerability.

Research on spraying and fusing of non-self-fluxing copper powdered alloy on cast iron surface

A new type additive was added to the non-self-fluxing copper powdered alloy, and the powder showed satisfactory performance of spraying and fusing, self-protecting, and self-fluxing in the oxygen-acetylene flame spraying and fusing process. The additive was melted and could absorb copper oxide when spraying, then it created a layer of film to cover the copper liquid, which protected the copper liquid from oxidizing efficiently and promoted it wetting on iron surface. Thus it lead to real diffusion between Cu and Fe, which resolved the diffwulty of combining Cu with Fe and reduced the limitation of the powder, and it promoted the usage value of general powder. Through analysis of microstructures, it was found that the fastness and compactness of the combining interface was excellent as well as the diffusing of transition area, and the hardness was suitable, which meant that the performance could meet the needs of high quality valves completely.

JOINING MECHANISM OF FIELD-ASSISTED BONDING OF ELECTROLYTE GLASS TO METALS

Investigations of technological characteristics and bonding mechanism of field-assisted bonding are done, which are for bonding of electrolytes (Pyrex glass) to monocrystal silicon and aluminum. The features of microstructure and the distribution of the diffused elements in the bonding interface area are studied by means of SEM, EDX and XRD, and the influence of the technological factors on the bonding process is also studied. The model of 'metal-oxides-glass' of bonding structure and ions diffusion and bonding in the condition of electrical field-assisted are indicated.

Evaluating changes in business distribution within urban rail transit hubs in Beijing via Point of Interest (POI) data analysis (2008-2020)

This paper,set against the backdrop of expanding urban rail networks and dynamic urban development,focuses on the distribution and evolution of commercial Points of Interests(POIs)within the central urban rail transit areas of Beijing.The study examines data from four different years-2008,2013,2017,and 2020-to observe the temporal evolution of commercial entities.It identifies stable explanatory variables affecting the distribution and evolution of commercial POIs,which include rail transit accessibility,characteristics of the working and residential population distribution around stations,and the construction intensity in the vicinity of station areas.Through statistical analysis and model building,relatively stable linear regression equations were established,with R2 values generally maintained above 0.5(except for 2017).The study advances our understanding of the influence of rail transit on urban commercial spaces and how this influence shifts with temporal and urban developmental changes.It elucidates the correlation between changes in the number of businesses and spatial configuration,offering insights and information for urban planners and policy makers.This research also serves as a model for exploring the interplay between urban rail transit and commercial spaces in other major cities.

山区过渡性地理空间识别及分类研究——基于人文自然耦合分异视角

The coupling of humans and nature differs in terms of distribution and intensity, thus producing a gradient of synthetic geographical environments. Within this variety of gradients, the transitional zone represents a complex space where dynamic processes and unstable conditions are observed. Based on the concepts of ecotone and transitional zone, we propose a conceptual framework for the transitional geospace of coupled human and natural systems and a quantitative identification method for the zone. Taking the Sichuan Basin as an example, this study defined the strength and direction of the coupling of the natural ecosystem and socioeconomic system and divided different types of transitional geospace. The transitional geospace of the strong coupling type accounted for approximately 16.7% of the study area. Nine of the ten counties with the largest proportion of the type were formerly nationally poor counties in the study area. In the strong coupling type, human and nature jointly explained a high proportion of the variance in transitional stability(e.g., in Shifang city, with an unexplained proportion of 1.7%). The discovery and characterization of the transitional geospace types is crucial for facilitating more effective land use planning and sustainable balance among the population, resources, and environment.

评估全球自然对人类的贡献

自然对人类的贡献(nature’s contributions to people,NCP)是指大自然对人类生活质量的一切积极贡献和消极影响,分为10个调节型NCP、4个物质型NCP和4个非物质型NCP.但目前这些NCP的全球时空分布及其相互作用规律尚不清楚,直接制约了加强自然界多种有益贡献的生态系统管理实践.本研究构建基于指标体系的评价方法,结合生态系统演变、气候变化与人类活动全球尺度多源空间数据集,在全球范围内对1990~2018年所有18个NCPs进行空间制图,在15,204个流域单元上识别主导了NCP组合,并基于NCPs时空特征识别了全球景观变化的功能权衡关系和景观多功能性.结果表明,全球大部分NCPs的高值仅在局地出现.1992~2018年,6个调节型NCP、3个物质型NCP和2个非物质型NCP下降.29种调节型和物质型NCP组合(总共有54种组合)的主导流域占全球76%的陆地面积,而无NCP主导的流域占全球陆地面积的22%.NCPs变化的协同关系比权衡关系更为常见,但调节型和物质型NCP之间的关系普遍处于权衡状态.过渡气候地区的NCP相对少,并具有强烈的权衡关系;而低纬度地区NCPs之间的高度协同关系可能受到未来气候变化的影响.研究结果提供了对全球NCP空间变化规律的总体认知,可用于科学支撑区域景观功能的关系调控和景观多功能性提升,以增强全球人类福祉.

Sound propagation from the shelfbreak to deep water

Motivated by a phenomenon in an experiment conducted in the Northwestern Pacific indicating that the energy of the received signal around the sound channel axis is much greater than that at shallower depths,we study sound propagation from the transitional area(shelfbreak)to deep water.Numerical simulations with different source depths are first performed,from which we reach the following conclusions.When the source is located near the sea surface,sound will be strongly attenuated by bottom losses in a range-independent oceanic environment,whereas it can propagate to a very long range because of the continental slope.When the source is mounted on the bottom in shallow water,acoustic energy will be trapped near the sound channel axis,and it converges more evidently than the case where the source is located near the sea surface.Then,numerical simulations with different source ranges are performed.By comparing the relative energy level in the vertical direction between the numerical simulations and the experimental data,the range of the air-gun source can be approximated.