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941.
世界贸易组织(简称WTO),作为处理世界自由贸易机制的国际组织,允许为可持续发展和保护自由贸易和环境选择利用世界自然资源。中国作为世界贸易组织成员国,签定入世议定书,入世后中国在林业的可持续发展方面受到世界贸易组织的条约和原则的制约和挑战。中国的林业资源应当作为基础资源加以保护,政府的行政管理职能在世界贸易组织的原则下加以改革。因此,中国林业的可持续发展的目.标是优先处理环境保护和经济发展的关系。在入世条件下,按照世界惯例,中国林业资源可持续发展问题瞄准中国林业体制改革,以便适用中国天然林业战略,依靠科技进步依法保护中国环境,特别是在中国林业保护和处理环境和自然资源等关系方面。依据世界贸易组织的协议和规则,建立林业的生态化体系,尤其是GATT20条的规定,保护中国林业可持续发展,为中国林业创建国际环境。表1参21。  相似文献   
942.
The optimal formula of Beta-Cypermethrin aqueous capsule suspension was screened out through the experiment,preparation and manufacture of basic formulas, which has no sedimentation, suspended drops of oil, peels and agglomerating and the diameter of capsule is in range of 10-30μm, conformed to the technical requirement. The aftereffect of the 3.3% Beta-Cypermethrin aqueous capsule suspension which was manufactured according to the optimal formula was up more than 25 days. The experiments on controlling the larvae of Dendrolinmus superans Butler and the adults of Xylotrechus rusticus L were carried out with different concentrations of this chemical. The death rate reached 80% when 250 times solution of the chemical was sprayed on stem to control the larvae of D. superans. For control of the adults of X. rusticus, 200, 400 and 600 times solution of the chemical were applied and their control effects (death rate) reached 85.23%, 74.21% and 66.59% respectively. Two kinds of solution (200 times and 300 times) of the chemical were used to control the larvae of D. superans in large area, and the control effect for both concentrations was over 90%.  相似文献   
943.
This review details the Korean species of the Eilema group in the subfamily Arctiinae of Erebidae: 19 species in five genera (Manulea, Collita, Katha, Dolgoma, and Wittia), a new species (Collita hwacheonensis Bayarsaikhan & Bae, sp. nov.), and an unrecorded species [C. vetusta aegrota (Butler 1877)]. All species are diagnosed, and figures of the adults and genitalia and a key to species based on male genital structure of Eilema group in South Korea are included.  相似文献   
944.
以乙酸乙酯为溶剂 ,无水AlCl3作催化剂 ,由大茴香油在室温下反应 4h ,合成了聚合物大茴香油聚合树脂 (简称PAOR) ,凝固点降低法测定了树脂的分子质量 ,对树脂进行IR、UV测试分析 ,并考察了树脂对桔皮色素的柱层析吸附分离性能。结果表明 ,合成树脂的分子质量约 1.0 2× 10 3,PAOR在 965cm- 1吸收峰减弱 ,在 70 0~ 80 0cm- 1之间出现 3个新峰 ;PAOR紫外最大吸收峰蓝移 11nm ,表明大茴香油中的双键参与了聚合反应 ,产物中存在芳环三取代物。讨论了反应机理 ,PAOR对桔皮色素有良好的吸附作用 ,树脂的重复使用性较好。  相似文献   
945.
油橄榄是一种重要的木本油料植物。营养价值很高。油橄榄的果实除榨油外,还可以制盐渍或糖渍果实除榨油外,还可以制盐渍或糖渍果品和罐头食品。对几种油橄榄制品的加工技术作了介绍。  相似文献   
946.
木聚糖酶解反应与膜分离技术研究   总被引:2,自引:1,他引:2  
过程耦合是应用技术领域研究的热点之一 ,膜及膜分离技术的开发促进了过程耦合技术的发展。如膜超滤、膜萃取、膜蒸馏、渗透蒸发。在超滤膜反应器中木聚糖酶解制备低聚木糖的条件 :酶体积用量1 0 % ,木聚糖质量浓度 3 0 .0 g/L ,稀释率 1h-1,pH值 5 .0 ,反应温度 48℃ ,酶解时间 1 3 5min。在该条件下 ,低聚木糖得率、木糖得率、低聚木糖生产能力及低聚木糖与总糖之比分别为 2 8.5 % ,4.1 % ,3 .80g/ (L·h)和0 .87,并比较了分批加料、浓缩酶、常规反应器中酶解反应效果 ,浓缩木聚糖酶酶解结果表明 :木糖得率很低(0 .2 % ) ,低聚木糖得率为 3 5 .9%。  相似文献   
947.
保护与建设好大兴安岭生态环境产业 ,不仅是东北经济、社会发展的最基本需要 ,而且是改善中华民族的生存环境、实现可持续发展的战略需要。  相似文献   
948.
Little is known about the extent of work-related accidents occurring during the performance of forestry work by the non-industrial private forest owner or their assistant (hereafter called self-employed NIPF). The absence of an effective accident registration system largely excludes this group from accurate representation in official statistics. In this study, data from 1996 to 2001 were collected from hospital injury records managed by the Umeå Accident Analysis Group at the University Hospital in Umeå. During that period, it was found that 485 persons in the Umeå region were given medical attention due to injuries possibly acquired during self-employed forestry work. Questionnaires about the accidents were sent to each of the 485 injured persons and 80% were returned. Responses revealed that 225 of the respondents were injured during self-employed forestry work. Out of these, 81% performed fewer than 31 days of forestry work annually. Due to the injury, 29% had been on sick leave for some period of time and 42% had persistent symptoms. On average, each injury led to 13 days of sick leave and 24 hours of institutional care. Firewood production was shown to be a key factor behind the large number of accidents for self-employed NIPF. Further studies on the lack of knowledge about how the work should be done and conscious risk taking should be considered as an important link to the development of effective accident prevention strategies.  相似文献   
949.
The amount of photosynthetic radiation intercepted by a crop is a function of the incident solar radiation on the plants, the leaf area index (L AI), and the light extinction coefficient (k). We quantified L AI and k in stands of black wattle (Acacia mearnsii De Wild.) over a 7-year growth cycle at two locations in the state of Rio Grande do Sul, Brazil. Our study was conducted in commercial stands in agroecological regions with high densities of black wattle plantations. L AI was calculated as the ratio between the leaf area of a tree and its planting space, and k was derived from Beer’s law. L AI depends on the planting site and stand age. Between the two sites, the L AI was similar over time, the amount of variation differed. Values of k depended only on stand age, with the highest average observed for stands up to 5 years old. The trend of k during the plantation cycle was inversely proportional to L AI and was correlated with L AI, leaf area, leaf dry mass, canopy volume, height, branches dry mass, total dry mass, and crown diameter.  相似文献   
950.
Tea tree oil is extracted from the leaves and twigs of Melaleuca alternifolia (Maiden & Betche) Cheel, and it is widely used in medicines, food preservatives, cosmetics and health care products. Traditional propagation of M. alternifolia from seeds does not necessarily transfer the desired characteristics from their mother trees, the seedlings are not uniform, and the multiplication rate from cuttings is relatively low. For these reasons, it is necessary to develop tissue culture techniques for this species. This study showed that an efficient explant initiation medium for M. alternifolia was MS 1/2 + BA 0.6 mg L?1 + NAA 0.1 mg L?1 + sucrose 30 g L?1, which yielded a 75.9 % initiation rate. An efficient multiplication medium was MS + BA 0.3 mg L?1 + NAA 0.15 mg L?1 + sucrose 30 g L?1, which yielded a 4.3 multiplication rate and 3.2 cm shoot length. The rooting medium was MS 1/2 + IBA 0.1–0.25 mg L?1 + sucrose 15 g L?1, which yielded a 100 % rooting rate, 2.94–3.32 roots per individual and 1.36–1.44 cm root length. Local red-core soil was suitable as a transplant medium, and yielded 98 % survival. This study improved the tissue culture technique for mass-propagation of M. alternifolia, enabling the production of high quality plants for market.  相似文献   
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