运载火箭动力系统试验承力环的静力试验

建立了某型号运载火箭动力系统试验用承力环的非破坏性静力试验方案,以评估该承力环的强度和刚度。为模拟发动机关机时的载荷冲击,将静力试验最大载荷设定为发动机额定总推力的2倍,包含水平和垂直两个分量,均分为8个载荷步加载。在承力环上设置了27个三向应变测点和12个轴向位移测点,以监测一些关键点的应力和位移。测量结果显示,在最大载荷下,当量应力达到303 MPa,低于材料屈服强度;轴向变形达到3.16 mm,低于设计许用变形;应力最大点位于支腿销孔处。对销孔孔距的变化进行了测量,并对附近的钢板表面进行了MT探伤。数据结果表明,该承力环在两倍的动力系统试验额定载荷下有足够的强度和刚度,可用于该试验。

Reviews on Soil Environmental Capacity and Carrying Capacity

The research introduced the current development of carrying capacity of environment and population size. Based on analysis of atmosphere environment bearing capacity and water environment carrying capacity, it further studied and summarized the soil environmental capacity on pollutants and social activities. The soil environmental capacity on pollutants is the maximum pollutants contained in a unit of soil within a limited time. Current research mainly focuses on background values, limit and migration coefficient of soil and the relevant modeling. The soil environmental capacity on social activities refers to the limit values of soil on the size,density and pace of development of social activities, while maintaining the normal structure and function of the bio-and eco-system of the soil. In other words, it not only refers to the capacity on pollutants, but also refers to the capacity on social and economic activities. Based on the research ＂Criteria on the standards of soil system＂, this report is mainly focused on the capacity of soil system on heavy metals. Further studies are still needed to come up with a universal definition of the soil environmental capacity and its theory system, as well as the standard and complete evaluating system.

Relation between Economic Development Level and Resource and Environment Carrying Capacity of Central Area of Yunnan Province Based on Decoupling Analysis

Based on the decoupiing theory and method, an indicator system was built for the relation between economic development level and resource and environment carrying capacity. And the study was carried out on decoupling degree and temporal changes of economic development level and resource and environment carrying ca- pacity in the central area of Yunnan Province. Results indicated that （i） the economic development level and resource and environment carrying capacity in the central area of Yunnan Province mainly experienced strong decoupling, weak decoupling, and ex- pansive negative coupling, and in general it was strong decoupling, and it took on re- verse ＂N＂ in temporal changes. （ii） Change rate of economic development level in the central area of Yunnan Province was greater than zero, but the amplitude of change was not large, while the change rate of resource and environment carrying capacity was negative in 2007-2008, and it was positive in the rest years; from 2007, it took on gradual expansion trend, and scissors difference gradually increased after experi- encing reverse ＂V＂ change. （iii） The strong decoupling was the main situation and it reached the peak value in T5 period and T6 pedod.

Assessment of Land Comprehensive Carrying Capacity in Lin'an City

According to regional characteristics and the actual situation in Lin ’an City, an evaluation index system of land comprehensive carrying capacity composed of three support subsystems （eco-environment, social and economic carrying capaci-ties） containing 22 evaluation indexes was established to evaluate the comprehen-sive carrying capacity of land resource in Lin’an City during 2005-2012. Meanwhile, based on the target data of overal land use plan, the level of land comprehensive carrying capacity was predicted at the end of the plan period （2020） .The results showed that land comprehensive carrying capacity had a significant growth in Lin ’an from 2005 to 2012, and the development trend was basical y sustainable. The sub-systems also had been greatly improved, in which the constant improvement of ec-ological environment carrying capacity made the largest contribution to the constant raising of land comprehensive carrying capacity. The degree of coordination between the systems was poor, in which eco-environment carrying capacity had the maxi-mum growth, far more than the social and economic carrying capacities. According to the land comprehensive carrying capacity in 2020, utilization of land resources in Lin＆#39;an city can achieve sustainable development in general. Final y, proposals of im-proving comprehensive carrying capacity were put forward in terms of the enhance-ment of eco-environment protection, accelerating economic development and policy guidance.

Research on Resources and Environmental Carrying Capacity

This paper, in the context of resources and environmental carrying capaci-ty, systematic reviewed resources and environmental carrying capacity in monitoring, evaluation and early warning, and then putted forward the development direction for promoting the sustainable development of China’s social and economic environment.

Comprehensive Measurement for Carrying Capacity of Resources and Environment of City Clusters in Central China

Studying the carrying capacity of resources and environment of city clusters in the central China has important practical guidance significance for promoting the healthy, sustainable and stable development of this region. According to their influencing factors and reciprocity mechanism, using system dynamics approaches, this paper built a SD model for measuring the carrying capacity of resources and environment of the city clusters in the central China, and through setting different development models, the comprehensive measurement analysis on the carrying capacity was carried out. The results show that the model of promoting socio-economic development under the protection of resources and environment is the optimal model for promoting the harmony development of resources, environment, society and economy in the city clusters. According to this model, the optimum population scale of the city clusters in 2020 is 42.80×106 persons, and the moderate economic development scale is 22.055×1012 yuan (RMB). In 1996-2020, the carrying capacity of resources and environment in the city clusters took on obvious phase-change characteristics. During the studied period, it is basically at the initial development stage, and will come through the development process from slow development to speedup development.

Evaluation and Analysis of Provincial Differences in Resources and Environment Carrying Capacity in China

Resources and environment carrying capacity is central to not only regional sustainable development but also major function-oriented zoning. This paper presents an evaluation index system for resources and environment carrying capacity based on four aspects of carrying capacity(i.e., water resources, land resources, the environment, and ecosystems) by using a square deviation decision-making method, and on the basis of above effort evaluates the resources and environment carrying capacity across 31 provincial regions in China(not including Hong Kong, Macao and Taiwan regions of China). In addition, this paper evaluates the current state of socio-economic development, and analyzes the spatial distribution of resources and environment pressure. The results showed that distinct spatial differences in resources and environment carrying capacity and pressure across provincial regions. Resources and environment pressure is affected by both comprehensive resources and environment carrying capacity and socio-economic development. Regions subjected to lower degrees of resources and environment pressure will be restricted by resources and environmental problems through future courses of development owing to excessively low carrying capacities. By contrast, regions with higher comprehensive resources and environment carrying capacity will be subjected to excessively high levels of resources and environment pressure because of rapid socio-economic development. Both of resources and environment carrying capacity and pressure must therefore be considered in the allocation of country-binding targets to provincial regions.

The concept, connotation and method of representation of watershed water environment carrying capacity （WWECC）

Based on the relationship between water environment system and human society, water environment carrying capacity （WECC） probes into supporting ability of complex water environment system to the human society. Recent years, due to the shortage of water resources and serious water pollution in several watersheds in China, the research of watershed water environment carrying capacity （WWECC） becomes very important. The conception, connotation and method of representation of WWECC are discussed deeply in this paper. It shows that WWECC is a kind of index that instructs whether the water environment system in watershed can continue to support the development of social economy and ecology, it is dimensionless number.

Evaluation of Tourism Environmental Carrying Capacity of Pai Town-Medog County Hiking Route

Based on the actual situation of Pai-Medog hiking route, the tourism environmental carrying capacity of this route was calculated in this study. According to the analysis and calculation results and referring to the common control measures of tourism environmental carrying capacity, corresponding control measures were put forward for the Pai-Medog hiking route.

THE STATIC PERFORMANOE AND PARAMETER STUDY OF FLOATING-RING HYDRODYNAMIC THRUST BEARINGS

In this paper, floating--ring thrust bearings are investigated. A mathematical model is established to analyze the static performance of this kind of bearings, such as the load capacity, frictional power loss, temperature rise as well as the angular speed ratio between the floating ring and runner.Meanwhile, a parameter study is also conducted on the characteristics of floating-ring thrust bearings.Finally, the theoretical calculation results are verified by experiments.

Sustainable development of Shandong Peninsula urban agglomeration:a scenario analysis based on water shortage and water environment changes

China has experienced a rapid urbanization since late 1970s. The great increase of urban population has resulted in various environmental changes, of which urban water shortage and water environment problems have occurred in most cities, especially in the rapidly developing urban agglomerations in the eastern coastal region. This research, taking Shandong Peninsula Urban Agglomeration （SPUA） as a case study area analyzes the urbanization expansion in the last decades, discusses the water shortage and water environment changes following the rapid economic development and urbanization sueh as groundwater sinking in the urban and plain area, sea water and saltwater intrusion in the coastal cities, water pollution overspreading and water ecosystem degradation, and puts forwards some strategies for sustainabilitv in populous regions with severe water shortage. Some countermeasures for sustainable development of SPUA are put forward, such as constructing modern water resources inter-city networks to regulate water resouree between cities, adjnsting urbanization policy and urban scale planning to promote the development of small towns and medium sized cities, optimizing urban industry structure by restricting high water consumption enterprises and stimulating the growth of tertiary industry. improving water use efficiency to rednce fresh water consumption and wastewater discharge, introducing economic means to water pricing and water management system, and restoring ecological conditions to strengthen the natural water-making capacity.

Measuring coordination of economy-society and resource-environment based on major function oriented zoning: a case study of Pearl River Delta

A reasonable coordination degree assessment of the social-economic development level and the resource-environment quality level are essential to ident the key factory of the development, and vital to determine the appropriate development strategy and achieve sustainable development. The major function oriented zoning plays a role in spatial coordination mainly＇ by spatial guidance and restriction, so. the proposal of major function oriented zoning gives a new train of thought to generate a coordination evaluation of economy-society and the resource-environment system, From the view of major function oriented zoning that considers resource environmental bearing capacity, existing development density and development potential, this paper constructs an index system and model of coordination evahtation with a case study on Pearl River Delta. The results have shown： （I） It can reveal the conflicts of economic-social development and resource-environment quality to ac- curately consider resource environmental bearing capacity, existing development densio~ and development po- tential; （2） The coordination degree between social-economy system and resource-environment system in Pearl River Delta continued to decline in the past 10 years. The spatial extent of coordination evoh,es.from coordina- tion in the whole Pearl River Delta to imbalance in the core areas, and at present, the uncoordinated areas have already diffused from core areas to the outlying regions： （3） Most regions of the Pearl River Delta are in uncoordinated condition When considering the coordination degree of economic-social development and resollrceenvironment quality, not as coordinated as some scholars considered.

Conceptualizing Discourses on Ecological City and Its Planning

Ecological city(eco-city) and its planning approach are emerging concepts in urban study,urban planning,ecological economics,environmental policy and corporate environmental management.However,opinions remain divided over the connotation and denotation of the term"ecological city",what key issues ecocity planning can solve,and its specific contents.In this study,we present 10 basic propositions that define the eco-city and clarify its key parameters,thereby providing the basis for discussing the assumptions and principles underlying different approaches to sustainable urban development.We then summarize the concept and principles of an eco-city,and define the main requirements for ecocity planning.We conclude that an eco-city is a city in which the urban population,scale of land use and intensity of human activities are limited to the regional resource and environmental carrying capacity,which does not cause increasing or irreversible damage to the regional ecosystem's structure,functions and processes.

Research on the Knowledge System Framework of Eco-industrial Engineering

With intensified contradiction between the rapid devel- opment of modem industry and the carrying capacity of natural environment, coordinating the relationship between economic benefits and ecological benefits is a significant issue to be solved for modem industrial engineering. This paper firstly conducts the comparative analysis between traditional and ecological industry as well as traditional and modem industrial engineering, and in- dicates that eco-industrial engineering is an inevitable choice for sustainable development of modem industrial engineering; Then, based on industrial ecology, environmental economics and sustain- able development theory, the connotation and definition of eco- industrial engineering are proposed, and the theoretical and practi- cal development of the concepts of eco-industrial engineering are further investigated. Furthermore, the research subject, research content, academic system architecture and evaluation methods of eco-industrial engineering are discussed. Finally, combining the current scientific and technological development, we put forward the important scientific value and practical significance of con- structing eco-industrial engineering for the utilization of these concepts.

The Progress of Resources and Environment Carrying Capacity: from Single-factor Carrying Capacity Research to Comprehensive Research

As a concept to describe development restrictions,resources and environment carrying capacity（RECC）research has developed over more than 100 years since it was first proposed at the beginning of the 20th century.It is now regarded as a significant factor in evaluating the level of cooperation between regional population,resources,and environment;and it is currently used as an effective and operational tool to guide regional sustainable development.This article first reviews the origin of RECC and its early headway.It then reviews the historical development of RECC from single factors,such as land resources carrying capacity,water resources carrying capacity and environmental carrying capacity（environmental capacity）,to more comprehensive research,such as comprehensive evaluation,emergy analysis,and ecological footprint analysis.In general,it appears that comprehensive research will become increasingly important in RECC research.However,there are several deficiencies in the current state of comprehensive research.Firstly,comprehensive RECC research lacks a common measurement standard,though some scholars have attempted to create one.Secondly,the RECC evaluation of open systems and dynamic studies should be strengthened.Thirdly,more attention should be paid to standardization,digitalization,and systematization to promote the applicability of RECC research to national practical demands.

Subsurface crack propagation under rolling contact fatigue in bearing ring

The influences of subsurface cracks,distributing along the axial direction,on the rolling contact fatigue(RCF)faliure in a bearing ring are investigated.A realistic three-dimensional model of the bearing ring containing three subsurface cracks is used to evaluate the fatigue crack propagation based on stress intensity factor(SIF)calculations.Moreover,the distributions of the subsurface cracks along the axial direction are varied to study their effects on RCF.The results provide valuable guidelines for enhanced understanding of RCF in bearings.

The Effects of Tourism Industry Agglomeration on Tourism Environmental Carrying Capacity: Evidence from a Panel Threshold Model

By utilizing the panel data of 26 cities in the Yangtze River Delta urban agglomeration of China from 2000 to 2018, this study constructs a panel threshold model to examine the nonlinear relationship between Tourism Environmental Carrying Capacity(TECC) and Tourism Industry Agglomeration(TIA). TECC is evaluated based on the Driver-Pressure-State-Impact-Response(DPSIR) model, and TIA is estimated by the location quotient index.The analysis reveals that TIA and TECC both show growth trends and significant regional differences among the 26cities, but the latter fluctuates at certain stages. Moreover, TIA has a significant double threshold effect on TECC,which shows that the positive impact of TIA is enhanced initially but then weakens afterwards. Theoretically, this study contributes to enriching the current literature on TECC from the perspective of TIA. Practically, it could help local governments effectively arrange agglomerations to promote the sustainable development of the tourism industry in China.

Land Resource Carrying Capacity in Xilin Gol Grassland Transects: A Perspective on Food Nutritional Demand

Food safety is an important issue for the development of the national economy and society.Studying regional food supply and demand from the perspective of land resource carrying capacity can provide new references for regional resource sustainability.This study uses the data from farmer and herdsmen household questionnaires,statistical data,land use data,and other sources to construct a land resource carrying capacity(LCC)assessment framework,targeting the food supply and demand of residents in representative areas,specifically the typical grassland pastoral areas,sandy pastoral areas and agro-pastoral areas on the Xilin Gol grassland transects.The three food nutritional indicators of calories,protein and fat were selected for analyzing the balance of land resource carrying capacity.We found that:1)Along the Xilin Gol grassland,the main local food supply showed a shift from meat and milk to grains,vegetables and fruits.2)From north to south along the grassland transects,the calorie intake increased gradually,while the intake of protein and fat was highest in pastoral areas and lowest in agricultural areas.3)The overall land resource carrying capacity of the Xilin Gol grassland transects was in a surplus state,but the land carrying capacity of typical grassland pastoral area was higher than the two other types of areas.This study provides an empirical reference for the sustainable development of regional food nutrition.

A Study of China’s Air Pollution Prevention and Control Policy Framework from a Policy Instrument Perspective

Environmental pollution caused by rapid economic development like that seen in China over the past twenty years poses various threats to human health. People have started to place much more of an emphasis on environmental security, working to find a balance between sustainability and economic growth. In recent years, air pollution has emerged as a highly discussed topic of social and environmental relevance in China, due in part to persistent smog that affects everyday life and causes serious harm to human health. Although air pollution is normally associated with human activity, is can be caused by natural processes such as eruptions and forest fires, but is always characterized by the release of certain substances into the atmosphere which, when present in certain concentrations or for given durations, can harm human health, daily life, productivity, and other aspects. In humans, it mainly affects the respiratory system, notably the lungs, as well as the immune system. A series of studies both in China and overseas have shown, in certain cases, even low concentrations of air pollution can pose a great threat to human health. In this study, we conducted an analysis of air quality policies, focusing on the 2018 revision of the People’s Republic of China’s Law on the Prevention and Control of Air Pollution(LPCAP). We utilized the content analysis method and Strauss and Corbin’s grounded theory to construct a policy framework, demarcate analysis units, code and classify policy texts, determine descriptive statistics, and analyze dimensional interactions. We used two dimensions(basic policy instruments classified as demand-, supply-, and environment-side;and air carrying capacity) to quantify and analyze the LPCAP, which enabled us to analyze the deficiencies and conflicts within policy instruments. The results show a higher utilization frequency of environment-side policy instruments, particularly regulation management and strategic measures. This reflects efforts by the government to create a favorable environment for improving air quality. Additionally, supply-side policy instruments are used far less frequently than environment-side policy instruments. Air quality legal policies and pollution control measures mainly consist of environment-side policy instruments;ecological thinking and air quality policies that are based mainly on supply-side and environment-side policy instruments;and social coordination policies that mainly use environment-side policy instruments. Based on the results of this study, we recommend an increase in the number of supply-and demand-side policy instruments, particularly the latter which includes promoting ecological thinking amongst citizens, to optimize and improve air pollution prevention and control policies.

Measuring the Effect of Foreign Direct Investment on CO2 Emissions in Laos

This paper aims to explore the determinants of C〇2 emissions in Laos by accounting for the significant role played by foreign direct investment(FDI)in influencing C 02 emissions during the period 1990-2017.We apply a Johansen co-integration testing approach to investigate the presence of co-integration,and the empirical findings underscore the presence of a long-run co-integration relationship between CO2 emissions,FDI,per capita GDP,and industrial structure.We also employ an error-correcting model to examine the short-term dynamic effect of FDI on CO2 emissions.The empirical results show that FDI has a significant short-term dynamic effect on changes in CO2 emissions,indicating that the relationship between FDI and CO2 emissions is an inverted U-shaped curve.This is a validation of the EKC.Changes of FDI,per capita GDP,and industrial structure increase CO2 emissions.Based on the analysis results,this paper puts forward policy suggestions emphasizing the need for both Laotian policymakers and Chinese investors to improve eco-environmental quality.