Regional Study on Economical Supporting Capacity of Land Resources in Shandong Province

Taking the land resources of 17 cities in Shandong Province as the basic data, the article studied on the economical supporting capacity of land resources in terms of the effect of land on economy. The author classified 17 cities of Shandong Province into four types according to the economical supporting capacity of land resources by quantitatively estimating the evaluation indices of the total amount of land resources, the potential of urban and other nonagricultural land, and the integrated economical sup- porting capacity of land resources, etc. The author proposes the questions requiring further study at the end of this article.

Study on urban water environmental support capacity

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A review of investigations on ground support requirements in coal burst‑prone mines

Ground support is widely implemented to mitigate dynamic rock failures in underground mines.This paper investigated the ground support requirements in burst-prone mines to mitigate the catastrophic dynamic rock failures of rock and/or coal bursts.First,the ground support principles and considerations in burst-prone conditions are identified.The objective of a ground support system is to increase the capacity to accommodate rock fracturing in a rockburst and,in turn,to minimize the kinetic energy of the ejected material.The support capacities of various yielding rockbolts and integrated support systems are then investigated using the test results in the laboratory.Apart from the energy absorption and yielding deformation capacity,the initial stiffness and energy absorption rate are also critical factors when applying yielding rockbolts in practice.Adding rope lacing and mesh strap to surface support elements can substantially enhance the support performance of the system.In practice,semi-analytical and empirical approaches are often used to determine the ground support elements in burst-prone areas.Semi-analytical methods first evaluate the support demand in burst risk zones and then select support elements according to their laboratory test results.Alternatively,empirical methods determine the ground support elements according to the locally established empirical rating scheme,which usually ranks the support capacities of various support systems based on ground support conditions and damage conditions.The outcomes of this study can provide insights into ground support strategies and assist the mining industry to develop effective coal burst control technologies.

Conventional approaches for assessment of caving behaviour and support requirement with regard to strata control experiences in longwall workings

Effective control of roof strata is very important for trouble free operation and regular face advance in mechanised longwall workings. It is now technically possible to exploit coal seams in difficult geomining conditions with the help of newer innovations in longwall face machineries. A reliable assessment of caving behaviour and support capacity requirement helps in selecting supports of adequate capacity and making operational preparedness for timely and confident solution of impending problems.This paper reviews the mechanism of roof caving and the conventional approaches of caving behaviour and support requirement in the context of major strata control experiences gained worldwide. The review shows that a number of approaches are being used for advance prediction of caving behaviour and support capacity requirement in a variety of geo-mining conditions. The theoretical explanation of the mechanism of roof caving and the design function of roof supports have been worked out through staged development of approaches, their evaluation followed by their gradual modification and enrichment of synthesized findings. This process is still continuing with consistently improved understanding through growing field experiences in the larger domain of geo-mining conditions and state-of-art strata analysis and monitoring techniques. These attempts have contributed significantly to improving the level of understanding and reducing the gap of uncertainty in planning and design of longwall operation in a given geo-mining condition.

Quantifying Contribution of DER-Integrated EV Parking Lots to Reliability of Power Distribution Systems

In the future smart cities,parking lots(PLs)can accommodate hundreds of electric vehicles(EVs)at the same time.This trend creates an opportunity for PLs to serve as a potential flexibility resource,considering growing penetration of EVs and integration of distributed energy resources DER(such as photovoltaic and energy storages).Given this background,this paper proposes a comprehensive evaluation framework to investigate the potential role of DER-integrated PLs(DPL)with the capability of vehicle-to-grid(V2G)in improving the reliability of the distribution network.For this aim,first,an overview for the distribution system with DPLs is provided.Then,a generic model for the available generation capacity(AGC)of DPLs with consideration of EV scheduling strategy is developed.On the above basis,an iterative-based algorithm leveraging sequential Monte Carlo simulation is presented to quantify the contribution of DPLs to the reliability of the system.In order to verify the effectiveness of the proposed method,a series of numerical studies are carried out.The simulation results show that the integration of DPLs with the V2G capability could help to improve the reliability performance of distribution grid to a great extent and reduce the adverse impact incurred by EV accommodation,if utilized properly.

Zoning assessment of water environmental supporting capacity for socioeconomic development in the Huaihe River Basin, China

There have been substantial conflicts in the human-water relationship in the Huaihe River Basin （HRB）. To achieve sustainable economic development without degrading the water environment in the HRB, we develop a three-dimensional water environmental sup- porting capacity （WESC） model based on water environmental carrying capacity （WECC）, water environmental pressure （WEP）, and water pollution prevention and control capacity （WPPC）. Geographic information systems spatial analysis with the analytical hierarchy process method and dynamic weighted summation is applied. Several proposals for suitable locations for industry and environmental protection strategies for water were presented. The following results were obtained. （1） The spatial differences in WECC are substantial; areas with high-value WECC zones are mainly located along the main stream of the Huaihe River on the south side. WEP is generally high, with an overall low level of pollution prevention and control in the whole HRB. WPPC and WEP show high spatial overlapping due to the fact that areas with higher environmental pollution usually have high level of economic development, and thus have a strong capacity for pollution control. （2） Overall, WESC is moderate in the HRB. In particular, areas with a high WESC value only account for 56.24% of the HRB in 2010 Distinct differences in WESC also exist between areas located in the south compared with in the north of the basin, and areas alongside the downstream region compared with alongside the upstream and midstream regions. （3） Consequently, according to the guidance for indus- try zoning in the HRB, the areas in the south and alongside the downstream and sub-streams with a low WEP value and high WECC and WPPC, traditional industries should be developed based on strict environmental access and pollution emission standards. While for the areas along the midstream of the HRB and along the whole Yishusi River Basin, which have a high WEP value, industrial restructuring and technological upgrading are suggested. Action should be taken to limit development and protect the environment in the upstream region of the basin which is a key source of drinking water, in the eastern route along the line of the South-toNorth Water Diversion Project, and in the ecologically fragile region alongside the basin. This will ensure good environmental functionality including subsistent provision of clean water, while at the same time satisfying the urgent need to adjust, transform, and upgrade the industrial structure.

Water environmental planning for new zone of economic-technological development in China

This paper analyzes the characteristics of water environmental planning in New Zone for EconomicTechnological Development (NZETD) in China and presents the task, procedure and method of the planning study Based on these analyses, the concept of Water Environmental Support Capacity (WESC) is put forward and the corresponding quantitative method is proposed to achieve the objective of coordinating the relationship between water environment and economic development As a case study, a comprehensive analysis and integrated water pollution control planning are made for the New Zone of EconomicTechnological Development in Benxi City in China Based on the costbenefit analysis and feasibility study of the planning alternatives, the comprehensive indexes of WESC are calculated and applied to evaluate the water pollution control planning alternatives

Analysis of relationship between economic growth and environment in Benxi Shiqiaozi Development Zone

How to express and assess the coordination between environmental system and economic system is one crucial problem for the studies on regional sustainable development.The present study applies environmental supporting capacity (ESC) to evaluate the comparative coordination of economic development plans in a case study in Shiqiaozi Development Zone.The analysis conclusion showed the method is practicable.A new method for judging the efficiency of utilization of environmental system is also discussed in this paper.

Vertical load capacities of roof truss cross members

Trusses used for roof support in coal mines are constructed of two grouted bolts installed at opposing forty-five degree angles into the roof and a cross member that ties the angled bolts together. The load on the cross member is vertical, which is transverse to the longitudinal axis, and therefore the cross member is loaded in the weakest direction. Laboratory tests were conducted to determine the vertical load capacity and deflection of three different types of cross members. Single-point load tests, with the load applied in the center of the specimen and double-point load tests, with a span of 2.4 m, were conducted. For the single-point load configuration, the yield of the 25 mm solid bar cross member was nominally 98 kN of vertical load, achieved at 42 cm of deflection. For cable cross members, yield was not achieved even after 45 cm of deflection. Peak vertical loads were about 89 kN for 17 mm cables and67 kN for the 15 mm cables. For the double-point load configurations, the 25 mm solid bar cross members yielded at 150 kN of vertical load and 25 cm of deflection. At 25 cm of deflection individual cable strands started breaking at 133 and 111 kN of vertical load for the 17 and 15 mm cable cross members respectively.