量化管控 安全质变——国网湖南电力实施安全生产承载力量化管控探析

3月,湖南已然春意盎然。国网湖南省电力公司3月工作例会安排了一项春季重头戏——春季安全生产大检查。有关这次春检的安全管理,＂量化＂成为关键词。安全风险量化管控是国家电网公司安质部提升安全风险防控能力的重点工作之一。

提供安全承载力评价服务 促进电力施工企业安全管理

一、背景伴随国家电网建设的快速发展,电力施工类企业生产任务与人员、装备等资源的矛盾与日俱增,工作量猛增、人员相对不足、生产班组超负荷工作时有发生,而原有管理手段的滞后,无法满足当前对安全生产风险进行有效管控的需要,致使安全运营能力成为制约企业进一步扩大产能、做大做强的瓶颈。因此,在电力施工类企业生产全过程中,以企业安全承载力量化分析为基础。

碳素人工骨关节在骨科重建术中的应用

骨关节因外伤、疾病或退化性改变而失去功能时,用人工骨关节置换,便可恢复其功能,改善其外形。从1981年起我们与兰州碳素厂协作,将研制成的碳素人工骨关节用于难治骨折及骨肿瘤切除后的功能重建治疗,取得满意的效果,现报道如下,

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.

地基基础工程检测中常见易混概念解析

地基工程涉及一些易混淆的概念,需要引起注意。

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.

Using Remote Sensing and GIS Technologies to Estimate Grass Yield and Livestock Carrying Capacity of Alpine Grasslands in Golog Prefecture,China

Remote sensing data from the Terra Moderate-Resolution Imaging Spectroradiometer (MODIS) and geospatial data were used to estimate grass yield and livestock carrying capacity in the Tibetan Autonomous Prefecture of Golog, Qing-hai, China. The MODIS-derived normalized difference vegetation index (MODIS-NDVI) data were correlated with the aboveground green biomass (AGGB) data from the aboveground harvest method. Regional regression model between the MODIS-NDVI and the common logarithm (LOG10) of the AGGB was significant (r2 = 0.51, P < 0.001), it was, there-fore, used to calculate the maximum carrying capacity in sheep-unit year per hectare. The maximum livestock carrying capacity was then adjusted to the theoretical livestock carrying capacity by the reduction factors (slope, distance to water, and soil erosion). Results indicated that the grassland conditions became worse, with lower aboveground palatable grass yield, plant height, and cover compared with the results obtained in 1981. At the same time, although the actual livestock numbers decreased, they still exceeded the proper theoretical livestock carrying capacity, and overgrazing rates ranged from 27.27% in Darlag County to 293.99% in Baima County. Integrating remote sensing and geographical information system technologies, the spatial and temporal conditions of the alpine grassland, trend, and projected stocking rates could be forecasted for decision making.

Low cyclic fatigue performance of concrete-filled steel tube columns

Eight concrete-filled steel tubular(CFT) columns were tested subjected to cyclic loading under constant axial load. Experimental parameters included axial compression ratio, loading sequences, and strength of concrete and steel. The seismic performance of CFT columns and failure modes were analyzed. The test results show that different axial load ratios and loading sequences have effects on the load carrying capacity, ductility and energy dissipation capacity of CFT columns, as well as the failure modes of the CFT columns. The failure pattern can be categorized into two types: local buckling failure of steel tube in compression zone, and low cycle fatigue tearing rupture failure of steel tube. The seismic behavior was evaluated through the energy index obtained from each cycle.

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.

Conceptual Framework of Tourism Carrying Capacity for a Tourism City:Experiences from National Parks in the United States

There is no universally-accepted definition of tourism carrying capacity(TCC) .Numerical TCC focuses on use level and is considered as"a magic number"of the saturation point for tourism.There are several reasons why numerical tourism capacity is inadequate.Alternatively,tourism capacity can be defined in terms of limits of acceptable change,which shifts the focus from"how much use is too much"to"how much change is acceptable".This article proposes an improved conceptual framework for evaluating carrying capacity for the tourism city based on approaches used in US national parks,which consider the impact of human use on a city's economic,environmental/resource,and socio-cultural conditions.Based on the basic data of indicator values and relevant standards,the framework monitors the current indicators and predicts future indicator values;it can also be used to assess and predict TCC.

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.

Parametric analysis of thermal effect on hydrostatic slipper bearing capacity of axial piston pump

Hydrostatic slipper was often used in friction bearing design, allowing improvement of the latter's dynamic behavior. The influence of thermal effect on hydrostatic slipper bearing capacity of axial piston pump was investigated. A set of lumped parameter mathematical models were developed based on energy conservation law of slipper/ swash plate pair. The results show that thermal equilibrium clearance due to solid thermal deformation periodically changes with shaft rotational angle. The slipper bearing capacity increases dramatically with decreasing thermal equilibrium clearance. In order to improve the slipper bearing capacity, length-to-diameter ratio of fixed damper varies from 3.5 to 8.75 and radius ratio of slipper varies from 1.5 to 2.0. In addition, the higher slipper thermal conductivity is useful to improve slipper bearing capability, but the thermal equilibrium clearance is not compromised.

Vertical variation of trace elements and its relation to the water-bearing capacity of Ordovician strata,in Datun coal field

We tested for fourteen trace elements in samples collected from the Ordovician strata in Datun coal field. The vertical concentration variation of these trace dements is reported. The relationship of the variation to the water-bearing capacity of the Ordovician strata is discussed. The minimum concentration of eleven （of 14 total） trace elements appears in the lower Majiagou formation. The maximum concentrations mainly appear in the Badou and Jiawang formations： eight maxima are located in Badou and four more are in Jiawang. The study of karst development and the water-bearing capacity of Ordovician strata shows that karst is well developed in the Majiagou formation and there is a consequent high water-bearing capacity in this formation： Badou and Jiawang formations are contrary to this situation. The results illustrate that the minimum concentrations of most trace elements within certain Ordovician formations can be taken as strong evidence for the existence of a well developed karst and a high water-bearing capacity.

A Theoretical Analysis of the Bearing Performance of Vertically Loaded Large-Diameter Pipe Pile Groups

This paper aims to present a theoretical method to study the bearing performance of vertically loaded large-diameter pipe pile groups.The interactions between group piles result in different bearing performance of both a single pile and pile groups.Considering the pile group effect and the skin friction from both outer and inner soils,an analytical solution is developed to calculate the settlement and axial force in large-diameter pipe pile groups.The analytical solution was verified by centrifuge and field testing results.An extensive parametric analysis was performed to study the bearing performance of the pipe pile groups.The results reveal that the axial forces in group piles are not the same.The larger the distance from central pile,the larger the axial force.The axial force in the central pile is the smallest,while that in corner piles is the largest.The axial force on the top of the corner piles decreases while that in the central pile increases with increasing of pile spacing and decreasing of pile length.The axial force in side piles varies little with the variations of pile spacing,pile length,and shear modulus of the soil and is approximately equal to the average load shared by one pile.For a pile group,the larger the pile length is,the larger the influence radius is.As a result,the pile group effect is more apparent for a larger pile length.The settlement of pile groups decreases with increasing of the pile number in the group and the shear modulus of the underlying soil.

Mathematical Modelling of Cutting Force as the Most Reliable Information Bearer on Cutting Tools Wearing Phenomenon

Being one of their prominent exploitative characteristics, cutting tools durability depends on the character, intensity and the speed of wearing. Identification of tool wearing is of great significance for the purpose of avoiding sooner or later replacement of tools. The parameters of tool wearing can be measured by out-process and in-process-measuring systems. Given the extremely limiting role of the former in modern production lines, development of the latter （the indirect measuring systems） has gained prominence, The basis of indirect measuring systems comprises a set of various signals originating from the units of the system under treatment which stand in certain correlations with the wearing parameters. The paper presents mathematical models of axial force designed on the basis of experimental research in drilling tempered steel by twist drills made of high-speed steel manufactured by powder metallurgy.

Quantitative Assessment of Climate Carrying Capacity for Cities: A Case Study of Shanghai City

The concept of climate carrying capacity has been proposed recently for climate risk management. Based on identification of the concept of climate carrying capacity and analysis of the relationship among its influencing factors, this study established a comprehensive assessment indicator system of climate carrying capacity from aspects of the climate situation, the level of climate usage, and the development potential of cities. Taking Shanghai City as a case study, we developed a quantitative assessment model of climate carrying capacity. The climate carrying capacity and its influencing factors were analyzed and discussed in relation to the period 2004–2013. The results were as follows.（1） Current climate natural capacity indicator showed that the climatic situation of Shanghai City was inferior to its base climatic value and it had been in a state of fluctuation.（2） The climate stress and urban coordinated development capacity indicators increased steadily, but the growth rate of the urban coordinated development indicator was less than the growth rate of urban climate stress.（3） The climate carrying capacity was far lower than the benchmark value and it had been in a state of fluctuation mainly due to the effect of current climate situation.（4） According to a principal component analysis, seven factors of urban population density, per capita GDP, energy consumption per unit GDP, total industrial output value, investment in environment protection, spending on science and technology, and green area per capita were main influential factor of climate carrying capacity. It was proved that the proposed system for assessment of climate carrying capacity of a city was feasible. It can be used to describe the spatiotemporal changes of cities, and identify problems of regional climate carrying capacity associated with their development and function. This assessment system can provide a reference for the construction of an early warning system of climate carrying capacity for cities.

Alpine Grassland Aboveground Biomass and Theoretical Livestock Carrying Capacity on the Tibetan Plateau

The accurate simulation and prediction of grassland aboveground biomass (AGB) and theoretical livestock carrying capacity are key steps for maintaining ecosystem balance and sustainable grassland management.The AGB in fenced grassland is not affected by grazing and its variability is only driven by climate change,which can be regarded as the grassland potential AGB (AGB_(p)).In this study,we compiled the data for 345 AGB field observations in fenced grasslands and their corresponding climate data,soil data,and topographical data on the Qinghai-Tibetan Plateau (TP).We further simulated and predicted grassland AGB_(p)and theoretical livestock carrying capacity under the climate conditions of the past (2000-2018) and future two decades (2021-2040) based on a random forest (RF) algorithm.The results showed that simulated AGB_(p)matched well with observed values in the field (R^(2)=0.76,P<0.001) in the past two decades.The average grassland AGB_(p)on the Tibetan Plateau was 102.4g m^(-2),and the inter-annual changes in AGB_(p)during this period showed a non-significant increasing trend.AGB_(p)fluctuation was positively correlated with growing season precipitation (R^(2)=0.57,P<0.001),and negatively correlated with the growing season diurnal temperature range (R^(2)=0.51,P<0.001).The average theoretical livestock carrying capacity was 0.94 standardized sheep units (SSU) ha^(-1)on the TP,in which about 54.1%of the areas showed an increasing trend during the past two decades.Compared with the past two decades,the theoretical livestock carrying capacity showed a decreasing trend in the future,which was mainly distributed in the central and northern TP.This study suggested that targeted planning and management should be carried out to alleviate the forage-livestock contradiction in grazing systems on the Tibetan Plateau.

Carbon carry capacity and carbon sequestration potential in China based on an integrated analysis of mature forest biomass

Forests play an important role in acting as a carbon sink of terrestrial ecosystem.Although global forests have huge carbon carrying capacity(CCC)and carbon sequestration potential(CSP),there were few quantification reports on Chinese forests.We collected and compiled a forest biomass dataset of China,a total of 5841 sites,based on forest inventory and literature search results.From the dataset we extracted 338 sites with forests aged over 80 years,a threshold for defining mature forest,to establish the mature forest biomass dataset.After analyzing the spatial pattern of the carbon density of Chinese mature forests and its controlling factors,we used carbon density of mature forests as the reference level,and conservatively estimated the CCC of the forests in China by interpolation methods of Regression Kriging,Inverse Distance Weighted and Partial Thin Plate Smoothing Spline.Combining with the sixth National Forest Resources Inventory,we also estimated the forest CSP.The results revealed positive relationships between carbon density of mature forests and temperature,precipitation and stand age,and the horizontal and elevational patterns of carbon density of mature forests can be well predicted by temperature and precipitation.The total CCC and CSP of the existing forests are 19.87 and 13.86 Pg C,respectively.Subtropical forests would have more CCC and CSP than other biomes.Consequently,relying on forests to uptake carbon by decreasing disturbance on forests would be an alternative approach for mitigating greenhouse gas concentration effects besides afforestation and reforestation.