At the Juncture of China's Entry to WTO, An Overall Development of Foreign Economic Relations andTrade Will Be Carried out in XPCC

The Xinjiang Production andConstruction Corps (XPCC) was foundedin October 1954. Since 1990, its plan hasbeen listed directly under the state councilof PRC.After 50 years of arduouspioneering and development, the XPCChas now developed to be a specialorganization with a solid economicstrength and enterprise group superiority,which is based on the large-scale andmodernized agriculture, and guided

A Successful Piggyback Microgravity Experiment Carried out by China for Japan

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Investigation on the Radial Micro-motion about Piston of Axial Piston Pump

The limit working parameters and service life of axial piston pump are determined by the carrying ability and lubrication characteristic of its key friction pairs. Therefore, the design and optimization of the key friction pairs are always a key and difficult problem in the research on axial piston pump. In the traditional research on piston/cylinder pair, the assembly relationship of piston and cylinder bore is simplified into ideal cylindrical pair, which can not be used to analyze the influences of radial micro-motion of piston on the distribution characteristics of oil-film thickness and pressure in details. In this paper, based on the lubrication theory of the oil film, a numerical simulation model is built, taking the influences of roughness, elastic deformation of piston and pressure-viscosity effect into consideration. With the simulation model, the dynamic characteristics of the radial micro-motion and pressure distribution are analyzed, and the relationships between radial micro-motion and carrying ability, lubrication condition, and abrasion are discussed. Furthermore, a model pump for pressure distribution measurement of oil film between piston and cylinder bore is designed. The comparison of simulation and experimental results of pressure distribution shows that the simulation model has high accuracy. The experiment and simulation results demonstrate that the pressure distribution has peak values that are much higher than the boundary pressure in the piston chamber due to the radial micro-motion, and the abrasion of piston takes place mainly on the hand close to piston ball. In addition, improvement of manufacturing roundness and straightness of piston and cylinder bore is helpful to improve the carrying ability of piston/cylinder pair. The proposed research provides references for designing piston/cylinder pair, and helps to prolong the service life of axial piston pump.

Dynamic model for internally carried air-launched rocket

For rigid-flexible coupling multi-body with variable topology,such as the system of internally carried air-launched or heavy cargo airdrop,in order to construct a dynamic model with unified form,avoid redundancy in the modeling process and make the solution independent,a method based on the equivalent rigidization model was proposed.It divides a system into independent subsystems by cutting off the joints,of which types are changed with the operation process of the system.And models of different subsystems can be constructed via selecting suitable modeling methods.Subsystem models with flexible bodies are on the basis of the equivalent rigidization model which replaces the flexible bodies with the virtual rigid bodies.And the solution for sanction,which is based on the constraints force algorithm(CFA)and vector mechanics,can be independent on the state equations.The internally carried air-launched system was taken as an example for verifying validity and feasibility of the method and theory.The dynamic model of aircraft-rocket-parachute system in the entire phase was constructed.Comparing the modeling method with the others,the modeling process was programmed;and form of the model is unified and simple.The model,method and theory can be used to analyze other similar systems such as heavy cargo airdrop system and capsule parachute recovery system.

A model to assess fundamental and realized carrying capacities of island ecosystem:A case study in the southern Miaodao Archipelago of China

Research on carrying capacity, aiming at maintaining the limited ability of the Earth＇s life supporting system to sustain human development, requires a comprehensive and ecosystem-based approach to monitor and assess the localized sustainability of coupled social and ecological systems. A definition termed the ecosystem-based carrying capacity of island（EBCCI） was developed in this paper of which the indices of fundamental and realized carrying capacities of island（FCCI and RCCI） were highlighted to emphasize the inter-dependencies between social systems and ecological systems. In order to avoid the difficulties and uncertainties of direct assessment, the related assessment model was established on the basis of synthetic evaluation of inherent and external factors affecting the EBCCI. The southern Miaodao Archipelago（SMA） located in the intersection of the Bohai Sea and the Yellow Sea, China, was taken as a typical example to acquire integrated recognition of the island ecosystem and its carrying capacity so as to discuss its sustainable development. The index scores of FCCI and RCCI in the SMA were 0.818 5 and 0.712 9 out of 1.0, respectively, with acceptable uncertainties. The results showed a relatively well capacity to sustain progress and relatively well realization of the carrying capacity of island ecosystem, owing to a well capacity of ecologically regulating, general performance of both ecologically supporting and resource provisioning, and a relatively high level of social supporting system. The study implied that it was critical to optimize the inter-dependencies and to sustain the relative balance between social systems and ecological systems so as to improve the RCCI and further facilitate the sustainability of SMA. The approach proposed in this paper provides a powerful tool which is well applicative to the regional level of an oceanic island or archipelago to study the sustainable development and can be further popularized to the coastal zone.

Exploration of the dynamic water resource carrying capacity of the Keriya River Basin on the southern margin of the Taklimakan Desert,China

The water resource carrying capacity(WRCC)in river basin changes dynamically under climate change,economic development,and technological advancement.Climate change affects hydrological processes and spatial/temporal distribution of water resources;while economic develo-ment and technological advancement can also affect the balance of water resources systems.Under climate change,economic development,and technological advancement,itis of great significance to explore the dynamic behavior of WRCC in river basins.This will help to alleviate water resources security issues and build a sustainable water resources system.This study was carried out to evaluate the dynamic WRCC using the"climate,economics,and technology-control objective inversion mode",which used total water consumption,water-use efficiency,and restrained total pollutant control in the water functional area as boundary conditions.This study was conducted on the Keriya River Basin,a sub-catchment located in southem margin of the Taklimakan Desert.The WRCC in the Keriya River Basin in 2015 was calculated,and the trends in the short term(2020),middle tem(2030),and long term(2050)were predicted.The results revealed that climate change factors have a positive effect on WRCC in the Keriya River Basin,which leads to an increase in total water resources.Economic and technological development exhibits an overall positive effect,while increasing in water consumption and sewage discharge exhibit a negative effect.

Borana rangeland of southern Ethiopia:Estimating biomass production and carrying capacity using field and remote sensing data

Assessing rangeland productivity is critical to reduce ecological degradation and promote sustainable livestock management.Here,we estimated biomass productivity and carrying capacity dynamics in the Borana rangeland of southern Ethiopia by using field-based data and remote sensing data(i.e.,normalized difference vegetation index(NDVI)).Data was collected from both rainy and dry seasons when biomass production was high and low respectively.Results of linear regression showed that both biomass production(R^(2)_(adj)=0.672)and NDVI value(R^(2)_(adj)=0.471)were significantly decreased from 1990 to 2019.Field data and NDVI values for mean annual biomass showed a significant linear relationship.The model accuracy in the annual relationship between the observed and predicted biomass values was strong(R^(2)_(adj)=0.986)but with high standard error,indicating that the observed biomass production in the rangeland area was not in good condition as compared with the predicted one.This study suggests that,using NDVI data and field-based data in combined way has high potential to estimate rangeland biomass and carrying capacity dynamics at extensively grazed arid and semi-arid rangelands.And to use for estimating stoking rates and predicting future management techniques for decision making.

Herbivory of sympatric elk and cattle on Lincoln National Forest,south-central New Mexico

Background： Wildlife and livestock grazing are important products of forest ecosystems, but can be controversial. Herbivory by North American elk and domestic cattle is a contentious management issue throughout western North America, often driving management proposals to decrease cattle and elk numbers based on perceived overutilization of forages. Such observations are often site level rather than landscape, and may confuse ecological sustainability with desired conditions. Methods： We used line transects to document vegetation composition, structure, and grazing and browsing utilization for 4 key habitat types： mountain meadows, aspen, thinned conifer, and burned conifer on Lincoln National Forest, New Mexico, USA. We documented relative habitat use of these types by elk, mule deer, and cattle and modeled relative use on residual grass biomass of mountain meadows and browse utilization of forested types. We determined diets and diet quality of elk and cattle to assess degree of competition. Results： Use of grasses in meadows was below management thresholds, and combined elk, cattle, and deer relative habitat use accounted for 〈 14 % of the variance in residual stubble height of Poa protensis, the most abundant grass. Palatable browse was limited in habitat types （〈 107 stems.ha^-1）, use was generally high, and elk presence was correlated with the majority of browsing. Elk and cattle diets did not significantly overlap （Schoener＇s index 0.54-0.57）; elk fed primarily on deciduous shrubs （34 %-55 % of annual diets） and cattle on grass （72 %-77 %）. Digestibility and crude protein levels of cattle diets and body condition of elk indicated high quality diets for cattle and marginal-good quality diets for elk. Conclusions： At observed stocking levels and densities, cattle and elk were not competing for forage based on diet similarity, nor were key habitat types being used beyond sustainable levels. Low browse availability indicates that opportunity exists to increase forage availability on Lincoln National Forest, and thus maintain or increase populations without increasing impacts to plant communities. Management actions that address increased stand densities and forest encroachment of meadows, a result of altered historical disturbance regimes, could increase distribution, quantity, and quality of forage.

Editor’s Note on “Frontier Outlook” Column

In this issue,we are pleased to carry on the theme of Frontier Outlook(https://doi.org/10.1002/eem^(2).12313)to publish the invited contribution“The Transference Number”from Prof.Balsara and colleagues.As one of the“triad properties”required to fully describe an electrolyte(i.e.,conductivity,diffusivity,and transference number),the last proved to be the most challenging quantity that can be accurately and reliably determined,as evidenced by the widely scattered data from different techniques。

Carry out an Independent Policy and Advance with the Times

The topic of "China’s foreign policy under new circumstances" for discussion raised by Experts Forum of Contemporary International Relations is very important, because situation determines tasks, tasks produce policies and foreign policy is the continuation of domestic policy.

Ecological Carrying Capacity of Cities in Southwest China Against the Background of Rapid Urbanization: A Case Study of Mianyang, Sichuan, China

As Mianyang has neglected the coordination relationship with the ecological environment in the course of rapid urbanization,its ecological environment is getting worse.To this end,this study used the ecological footprint method to explore the ecological carrying capacity of Mianyang from 2007 to 2014 under the background of rapid urbanization,which has important guiding significance for the future development of Mianyang.The results showed that in 2007–2014,the ecological footprint of Mianyang was greater than its ecological carrying capacity,indicating that Mianyang is in an ecological deficit.Specifically,the per capita ecological footprint showed a downtrend,and the per capita ecological carrying capacity showed a trend of smooth decline.In addition,the per capita ecological deficit was generally decreasing.In summary,Mianyang was generally in an ecological deficit in 2007–2014.Thus,the ecological environment of the region should be protected,in order to promote the sustainable development of the ecosystem in the region.

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.

Foreign-oriented Hengshui Carries out Opening Policy

Since ushering in the 1990s, Hengshui City has been taking advantage of its excellent geographical position to develop its foreign-oriented economy, with good results. Take last year for example, the city signed contracts for altogether 28 foreign-invested projects, with a total capital of US$19.37 million and contractual capital of US$ 5.73 million, 14 completed and constructing foreign-invested projects, of which six have been put into operation. The infrastructure is being further improved in the Hi-tech Industrial Park which includes 49 projects of a total investment of RMB 180 million. The Hengshui Lake Economic and Technology

VIGOROUSLY CARRYING OUT FOREIGN TRADE AGENCY SYSTEM

Voices are growing louder and louder,calling for vigorously carryingout the foreign trade agency system in China’s foreign economic andtrade field.Vice Premier Li Lanqing in charge of foreign trade andeconomic cooperation has pointed out many times recently that theoperational mode of foreign trade should be transferred from thetraditional purchase system to service-type agency system.This isimportant to deepening the reform of the foreign trade system.

Stories About the Qin Dynasty Terra-cotta Army

The terra-cotta army of the Qin Dynasty,called the eighth wonder of the world,is well known both inside and outside China,butstories about its discovery,excavation and publicity are known fem.Beginning with this issue,Cultural Exchange will carry aseries of interesting stories written by Ji Chen.

Achievements in Carrying out ISO 9000

The export enterprises of China have made outstanding achievements in carrying out the ISO 9000, according to the State Commodity Inspection Bureau. By the end of May 1995, 130 export enterprises had been issued with the certificate of appraised quality after passing the assessment of the CCQSEM of ISO 9000. These enterprises have shown great superiority in signing contracts with foreign undertakings in bidding, export expansion, the rise of sales prices and the reduction of the rate of sub-standard goods.

Silk Road Youth Admire China

Young music lovers from the BRI participating countries use music as a way to promote peopletopeople exchanges and carry forward the ancient spirit of the Silk Road in the modern era.

Integrated Coastal Management Dynamic Models:A Case Study of Development Seaweed Cultivation in the Waters Luwu and Palopo Regency Bone Bay,South Sulawesi

Waters carrying capacity in seaweed of Eucheuma cottonii cultures should be a concern for optimum seaweed culture.Carrying capacity can determine by Ecological Footprint(EF)analysis,which in this research use footprint production,and mas balance nitrate analysis.This research on Mei 2015(1st transitional season)and September 2015(2nd transitional season)in Luwu and Palopo,South Sulawesi.Map and land use analyzed with geographic information systems(GIS).The results showed that the Ecological Footprint production(EFP)in Luwu waters is 67,88 ton/capita/year,or equivalent to 235.823,93 tons/year.Based on the analysis of the availability of water for seaweed is 38.374,69 hectares,it can produce seaweed(biocapacity)for 922.928,96 tons/year and the number of farmers that allows for use the waters is 13.595 capita.The Ecological Footprint production(EFp)in Palopo waters is 3,08 ton/capita/year,or equivalent to 4.589,99 tons/year.Water availability analysis is 979,82 hectares are able to produce seaweed(biocapacity)for10.115,34 ton/year and the number of farmers that allows for use the waters is 3.276 capita.Based on the four scenario simulation management results of the development seaweed cultivation Eucheuma cottonii in Luwu and Luwu Regency is based on the present waste input,pressing inputs of waste into the waters of 10%,25%and 50%yield different waters biocapacity.The results comparison between biocapacity and Ecological Footprint,ecological status for Luwu and Palopo waters are still in sustainable use.Based on those simulation results showed that in second scenario by pressing the waste input by 10%from the existing waste input,as well as assuming the availability of water utilizing the entire area of 38.374,69 hectares continuously(on the years scale of 2008-2030),it will produce the highest biocapacity waters in the amount of 8.257.274,94 tons/year.So with the management of seaweed in Palopo with second scenario,assuming the availability of water utilizing the entire area of 979,82 hectares will produce the highest waters biocapacity of 14.306,92 tons/year.