Satellite-based estimation of biomass carbon stocks for northeast China''s forests between 1982 and 1999

Northeast China maintains large areas of primary forest resource and has been experiencing the largest increase in temperature over the past several decades in the country. Therefore, studying its forest biomass carbon (C) stock and the change is important to the sustainable use of forest resources and understanding of the forest C budget in China. In this study, we use forest inventory datasets for three inventory periods of 1984–1988, 1989–1993 and 1994–1998 and NOAA/AVHRR Normalized Difference Vegetation Index (NDVI) data from 1982 to 1999, to estimate forest biomass C stock and its changes in this region over the last two decades. The averaged forest biomass C stock and C density were estimated as 2.10 Pg C (1 Pg = 10¹⁵ g) and 44.65 Mg C ha⁻¹ over the study period. The forest biomass C stock has increased by 7% with an annual rate of 0.0082 Pg C. The largest increase in the C density occurred in two humid mountain areas, Changbai Mountains and northern Xiaoxing’anling Mountains. Climate warming is probably the key driving force for this increase, while anthropogenic activities such as afforestation and deforestation may contribute to variations in the C stocks.     

慈竹、西风竹、硬头黄竹整秆带蔸埋秆育苗试验

对慈竹、西风竹、硬头黄竹三个竹种分别采用不同年龄的竹秆进行整秆带蔸埋秆育苗试验。结果表明：三个竹种都可萌发、生根、成苗。但硬头黄竹、西风竹成苗率低、育苗成本高，不可在生产上推广应用。慈竹成苗率高，育苗成本低，经济上可行，可在生产上推广应用，但以采用2、3年生竹秆为宜。     

An Analysis of the Existing Problemsand Countermeasures in Chongqing Listed Companies

This paper makes a comprehensive analysis of such problems as industrial structure readjustment and corporate governance in Chongqing's 22 A-type listed companies from 1993 to 1994.Based on present realistic situation and future development need,a set of countermeasures including industrial structural readjustment,modern enterprise system promotion,capital market development and macro policy formulation has been put forward for consideration.     

红麻对短光钝感材料的发掘及其研究

为解决我国长江、淮河流域红麻主产区春播能留种，大面积夏播不早花且纤维相对高产问题，在我国拥有的红麻育种材料中发现了１５份现蕾开花期对光长变化钝感的材料。纯感材料在短光下第一朵花节位在１９￣３７节之间，播种至始花在８０￣１０５天之间，变异丰富。其中１份材料在正常生长季节表现早熟，其余晚熟。敏感材料在短光下的始花节位在８￣１１节之间，始花时间比钝感材料提前２８￣５８天。经遗传分析，钝感对敏感表现为隐性     

烟草高分子量核DNA提取方法比较

高分子量(HMW)核DNA的制备是构建BAC文库关键环节之一。为构建高质量的烟草BAC文库,作者研究了一次选择法和二次选择法提取烟草高分子量核DNA的效果。研究结果表明:虽然二次选择法得到的高分子量核DNA浓度较低,但此法省略了对细胞核连续3￣5次的漂洗,而且得到含DNA的凝胶块(plugs)数量是用一次选择法的3倍,因此得到高分子量DNA的总量更高;同时二次选择法得到的plugs纯度更高,排除了酶切时细胞杂质对HMWDNA的干扰,此外在节约材料等方面也优于一次选择法。     

RESEARCH ON THE MECHANISM OF GAS OUTBURST INITATION IN MINES

The mechanism of coal-gas outburst iniration is comprehensively analysed. The direct courses of initating coal-gas outburst are the sudden loss of confining stresses and the gas pressure gradient in coal seam. The effects of working face's advancing rate, geological conditions and gas pressure gradient as well as mechanical & physical characteristics of coal on outburst initation are expounded by means of mathematic analyses about gas seepage which takes place in coal seams. The results are of certain practical significance and reference value to further quantitive study of outburst and its predication.     

STUDY ABOUT FLOW THEORY AND GOVERNING EQUATION OF GAS SEEPAGE FLOW IN COAL BEDS

This paper analyzes comprehensively the present approaches about the flow theory and governing equation of the gas seepage in China from the equations of the gas flow continuity, motion, state ane content. The viewpoint is put forward in the paper that the gas amount taking part in seepage flow is only a part of the whole gas content. The governing equation, of gas seepage flow in coal seams is set up on condition that procedures of adsorption and desorption are convertible completely.     

Cleaner Production Information Database''s Building of Chongqing

Cleaner Production must be done to achieve sustainable development. One of the most important things to develop Cleaner Production in Chongqing is to build Cleaner Production Information Database. The database confirms its purpose and function accorded with the situation of Chongqing. Furthermore, this database is designed by Delphi5 in Windows 2000 and proved to run well after debug. It can give service of technological information to Chongqing Cleaner Production.     

THERMAL EFFICIENCY ANALYSIS AND PRACTIS ON CONDENSATION-TYPE GAS INSTANCAUS WATER HEATER

This paper carries on theoretic anatysis about the energy save effect and thethermal efficien cy of conde nsation-type gas instan eaus water heater.Listed test values prove that thethermal efficiency of condensation-type natural gas instaneaus water heater is high 14% than com-mon-type.