刨花板的厚度膨胀率平行性现象

本文利用落叶松刨花和自制的异氰酸酯胶粘剂 ,通过正交重复实验研究了刨花板制造工艺参数中的密度、热压温度、热压时间、刨花含水率、施胶量和施蜡量对“2 4h吸水厚度膨胀率”与“不可逆厚度膨胀率”差的影响 ,同时通过单因素重复实验对刨花板制造常用的胶种和刨花种类对厚度膨胀率差也进行了研究。结果表明 ,在上述热压参数中 ,只有板的密度和刨花种类是影响刨花板“厚度膨胀率平行性”规律的显著性因素 ;结合和分析部分学者的实验结果发现 ,刨花形态和刨花预处理也是影响刨花板“厚度膨胀率平行性”规律的显著因素。研究表明前者对刨花板“厚度膨胀率平行性”规律影响的实质是不同密度刨花板在 2 4h的吸湿膨胀的速率与程度差异所致 ,后者则是由于这些因素影响了木材的吸湿膨胀特性所致     

突尼斯三个油橄榄品种开花生物学的研究

对３个油橄榄品种（Ｃｈｅｔｏｕｉ，Ｐｉｃｈｏｌｉｎｅｍａｒｏｃａｉｎｅ和Ｏｌｉｖｉｅｒａ）开花生物学的研究表明：在盛花期后的第二至第六周间有一幼果脱落高峰，该高峰与幼果从初生长高峰相吻合．这证实的果的大量脱落与果实间的竞争有关．统计结果显示：盛花期各个品种单位花序之结果数相差很大，但收获时这一参数却趋于同一；相反，收获时各品种结实花序的留存率却相差甚大，这说明品种间结实能力差异极大．控制授粉试验表现：品种Ｃｈｅｔｏｕｉ具有一定程度的自花不孕性．     

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。     

利用phi116和umc1044标记选育抗纹枯病玉米品系

玉米纹枯病已成为我国玉米产区的主要病害之一,为解决玉米纹枯病抗病育种工作中人工接种鉴定困难、选择效率低等问题,利用第7和第1染色体上与抗病QTL紧密连锁的两个标记phi116和umc1044对(CML270×478)×CML270回交后代13份BCF6:7选系进行了抗性分子标记辅助选择。结果发现,2份选系与478具有1条相同带型,1份与478具有2条相同的带新型;另10份选系与CML270具有相同带型。人工接种鉴定结果表明,依据标记推断为不抗病的3份材料表现为感到高感纹枯病,而其余10份表现从感到高抗,带谱与病性指数相关系数达极显著水平,相关系数r=0.6625>r0.01=0.64,从中获得高抗玉米纹枯病选系478C4-2-2、478C4-2-3、478C4-2-4。配合力分析表明,478C4-2-2具有较高的一般配合力和特殊配合力,所配组合渝单24在2006年已通过重庆市审定。研究表明,标记鉴定和表型鉴定相结合,选择玉米纹枯病抗病自交系是完全有效的。     

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.