矿山测量生产实习改革的实践与思考

本文从矿山测量生产实习的目的出发，深入分析了在新的形势下传统矿山测量生产实习教学模式出现的新问题，提出了“现场实习与校内模拟实习有机结合”的具体内容和方法。几年的实践表明：充分利用学校和现场的实习条件，优势互补。

构建泛珠三角的区域生产-贸易链

'泛珠三角'的概念在2003年CEPA签署以后紧接着被提出来,目前早已被区域内各地广泛接受并进入了实质性的操作阶段,取得了一定的成效.区域内已然形成了相对明显的以香港地区为龙头的强大的贸易能力和以广东地区为龙头的强大的生产能力,其他各地亦显现出各具特色的生产贸易发展实力与潜力.

The Effect of Pulverization Equipment Types and Tractor Velocities on Some Technical Indicators for Machinery Unit

This experiment was conducted in silty clay loam soil and cultivated with previous season wheat. Tillage for experiment field was applied using moldboard plow with 0.22-0.24 m depth, the rate of tractor velocity was 2.45 km hf^-1, as a tillage velocity. Two rates of tractor velocities （first factor） were applied： 3.24 km hr^-1, for the first velocity, and 4.71 km hr^-1 for the second, Three types of tillers （second factor） were used： disk harrow, rotavator tiller, and spring spike tooth harrow. The first velocity rate was： 2.51 km hr-l（with disk harrow as a machinery unit）, 2.92 km hr^-1 （with rotivator）, and 3.06 km hrl（with spring spike tooth harrow）, while the second velocity rate was： 3.19 km hr-1 （with disk harrow as a machinery unit）, 4.05 km hrl（with rotivator）, and 4.26 km hrl（with spring spike tooth harrow）. Split plot design in RCBD with three replicates was used at the constant of soil moisture 11%-13%. Results were analyzed statistically and means were tested with LSD. The results showed the significant differences between both two experiment factors and their interaction for all study parameters which included： slippage percentage, practical productivity, numbers of masses 〉 5 cm m^-2, and the implement width. At the constant of pulverization equipment types, the higher percentage of slippage was 16.45%, the higher rate of practical productivity was 0.677 h hr1, and the higher rate of implement width was 2.05 m, while the rate of masses 〉 5 cm m-2 decreased to 13.8 mass m2. At the constant of velocity, disk harrow achieved higher slippage percentage 17.69%, spring spike tooth harrow tiller achieved higher practical productivity 0.858 h hr^-1 and higher rate of implement width 2.73 m, and the rotivator achieved the lower rate of masses 〉 5 cm m2 and 4.1 mass m2. The comparison among the three pulverization equipment typess was the purpose of this study to give the best studied indexes under two different velocities.

An experimental study of a yielding support for roadways constructed in deep broken soft rock under high stress

A rationally designed support for deep roadways excavated in broken soft rock under high stress was investigated. The deformation and failure characteristics and the mechanism of ''yielding support'' was studied for anchor bolts and cables. The rail roadway of the 2-501 working face in the Liyazhuang Mine of the Huozhou coal area located in Shanxi province was used for field trials. The geological conditions used there were used during the design phase. The new ''highly resistant, yielding'' support system has a core of high strength, yielding bolts and anchor cables. The field tests show that this support system adapts well to the deformation and pressure in the deep broken soft rock. The support system effectively controls damage to the roadway and ensures the long term stability of the wall rock and safe production in the coal mine. This provides a remarkable economic and social benefit and has broad prospects for fur- ther application.

Suggestions on Perfecting Index Systems of Building a Well-Off Society in an All-Round Way

The index systems are not only the tools to evaluate existing practice results, but also the guides to the future development direction and development way of practical activities. ＂Well-off society＂ is a relatively vague concept, and the contents of it ceaselessly change with the advancement of society and the development of productivity. Now the construction of a well-off society in an all-round way enters a critical stage, so the original evaluation standards must change with gradual advancement of the construction goal of a well-off society. So it is very necessary for us to build a comprehensive evaluation index system and make it better and better to provide effective statistical consultation and statistical supervision for constructing a well-off society in an all-round way. This paper attempts to analyze the current evaluation index system, then puts forward the general thinking and flame work of the index system of building a well-off society in an all-round way.

Responses of Grassland Net Primary Productivity to Environmental Variables in Northern China

Various environmental factors affect net primary productivity （NPP） of grassland ecosystem. Extensive reports on the effects of environmental variables on NPP can be found in literature. However, the agreement on the relative importance of various factors in shaping the spatial pattern of grassland NPP has not yet been reached. Here a grassland in situ NPP database comprising 602 samples in northern China for 1980-1999 was developed based on a literature review of published biomass and forage yield field measurements. Correlation analyses and dominance analysis were used to quantify the separate and combined effects of environmental variables （climate topography and soil） on spatial variation in NPP separately. Grassland NPP ranged from 4.76 g C m-2a-1 to 975.94gCm-2a-1, showing significant variations in space. NPP increased with annual precipitation and declined with annual mean temperature significantly. Specifically, precipitation had the greatest impact on deserts, followed by steppes and meadows. Grassland NPP decreased with increasing altitude because of water limitation, and positively correlated with slope, but weakly correlated with aspect. Soil quality showed positive effects on NPP. Annual precipitation was the dominant factor affecting the spatial variability of net primary productivity, followed by elevation.

Functional attributes： Compacting vs decompacting earth- worms and influence on soil structure

A short term field mesocosm experiment was performed in semi-deciduous forest areas of Ivory Coast to assess the impact of a decompacting （Hyperiodrilus africanus, Eudrilidae） and two compacting （Millsonia omodeoi and Dichogaster terrae nigrae, Acanthodrilidae） earthworm species on soil properties. These species have been selected for their predominance in the re- gion and their contrasting impact on soil structure. The experimental design consisted of a treatment without worms （control）, and treatments with one, two or three species of earthworms. Both compacting and decompacting earthworms increased water infil- tration rate in all treatments, with marked impact in H. africanus and M. omodeoi＋D, terraenigrae treatments. Interactions be- tween compacting and decompacting species resulted in more large aggregates in comparison to when the compacting species D. terraenigrae was alone. This may be accounted for by their compacting attribute as compacting earthworms are responsible for producing the highest number of large aggregates. The low values of mean weight diameter in treatments combining decompact-ing and compacting earthworms compared with compacting ＂M. omodeoi＂ one also confirmed the trend of decline in soil com-paction in the presence of the decompacting species. These results showed positive impact of species richness on soil structure regulation, which is crucial in ecosystem productivity and support consequently the insurance hypothesis. In fact, this study showed that the preservation of earthworm species belonging to these two contrasting functional groups is essential for the main-tenance of stable soil structure regulation in agro-tropical ecosystems.