海藻多糖对小鼠骨髓放射性急性损伤的保护作用

目的：观察中药海藻多糖对小鼠骨髓放射性急性损伤的保护作用。方法：检测小鼠骨髓有核细胞总数、DNA含量及嗜多色性红细胞微核率。结果：小鼠接受2Gy γ射线照射后，小鼠骨髓有核细胞总数、DNA含量明显降低(P＜0．01)，骨髓嗜多色性红细胞微核率明显升高(P＜0．01)；20、40mg/kg剂量的海藻多糖能有效防止照射小鼠骨髓有核细胞总数、DNA含量降低(P＜0．05)；10、20、40mg/kg剂量的海藻多糖能防止照射小鼠骨髓嗜多色性红细胞微核率升高(P＜0．05)。结论：中药海藻多糖预防性给药对小鼠骨髓放射性急性损伤有一定的保护作用。     

西部大开发中的耕地问题探讨

西部开发是协调我国地区经济发展的重大战略，西部的开发和建设将带来耕地数量的减少和耕地质量的退化，针对这些问题，提出了应该如何保护耕地的对策。     

论环境伦理对资源环境保护的支撑

人类对环境问题的重视源于2个相互联系缺一不可的原因：一是经济发展过程中由于资源环境过度消费所导致的恶化，二是经济发展到一定阶段人们环境消费需求的提高。针对环境恶化和环境消费需求提高的尖锐矛盾，运用哲学的思辨方法，揭示环境伦理对第三关系（即人与自然的关系）的规范、设计和发展模式的理性选择，得出了环境伦理可以有力支撑资源环境保护的结论。参7     

Weed Detection Using Canopy Reflection

For site-specific application of herbicides, automatic detection and evaluation of weeds is desirable. Since reflectance of crop, weeds and soil differs in the visual and near infrared wavelengths, there is potential for using reflection measurements at different wavelengths to distinguish between them. Reflectance spectra of crop and weed canopies were used to evaluate the possibilities of weed detection with reflection measurements in laboratory circumstances. Sugarbeet and maize and 7 weed species were included in the measurements. Classification into crop and weeds was possible in laboratory tests, using a limited number of wavelength band ratios. Crop and weed spectra could be separated with more than 97% correct classification. Field measurements of crop and weed reflection were conducted for testing spectral weed detection. Canopy reflection was measured with a line spectrograph in the wavelength range from 480 to 820 nm (visual to near infrared) with ambient light. The discriminant model uses a limited number of narrow wavelength bands. Over 90% of crop and weed spectra can be identified correctly, when the discriminant model is specific to the prevailing light conditions.     

创新林业经营体制与森林资源保护的关系探索

在过去,林业经营的发展与森林资源保护似乎是一对水火不容的矛盾,发展林业经济必然损害森林资源的保护。但如今,以科学发展观的角度探索林业经营体制与森林资源保护的关系,可以发现创新林业经营体制,利用社会主义市场经济的杠杆,可以有效地将林业经济的发展与森林资源保护结合起来,使二者相互促进、共同发展、达到共赢。我国要平衡林业经济与森林资源保护之间的取舍关系,促进森林资源的可持续发展,从而达到“既要金山银山,也要绿水青山”的目标。     

以生境保护优先的北京市第二道绿化隔离地区郊野公园选址方法

[目的]在中国快速城镇化背景下,北京市边缘地区的生态环境不断恶化,绿化隔离带成为控制北京市建成区无序扩张、改善城市生态环境的手段,在绿化隔离带范围内建设郊野公园是落实规划的有效途径.郊野公园的核心目标是在生态保育的同时提供少量的游憩活动,因此对于绿化隔离带范围内生境质量高的区域进行保护应作为郊野公园选址的基础原则.[方...     

杂交水稻三交种的优势表现及其配合力

采用5×5不完全双列杂交观察杂交水稻三交种的产量优势表现,并对株高等13个农艺性状进行配合力方差分析。部分三交种产量极显著高于对应的单交种。三交种单株产量与特殊配合力相对效应值和配合力总效应值均呈极显著相关。剑叶长以基因非加性效应的作用为主;千粒重、有效穗数和单株产量虽然基因加性效应大于非加性效应,但后者仍占相当的比重;株高、抽穗期、主穗长、结实率、剑叶宽、粒长、粒宽和粒形以基因加性效应的作用为主。     

第9届国际储藏物保护工作大会技术交流概况

介绍了第9届国际储藏物保护工作大会中交流的主要技术概况,包括储粮损失研究;微生物、真菌毒素和其它生物污染;新化学药剂和食品中的残留;杀虫剂抗性及治理;储粮害虫的生物学、行为学及其检测;熏蒸与气调;化学防治的替代方法;粮食干燥与品质;书虱、螨类和其它污染物;储粮保护中的综合性问题等.     

A gamete abortion locus detected by segregation distortion of isozyme locus Est-9 in wide crosses of rice (Oryza sativa L.)

Summary A locus for male gamete abortion in hybrids for Japonica and Indica rice was identified with the aid of marker genes Rc and Est-9 on chromosome 7. In an Indica-Japonica cross, AKAMAI 1/IR50, the Indica allele Est-9 ² was transmitted via the male gamete with a ratio of 0.29 instead of the normal 0.5, whereas no segregation distortion was observed for the Rc locus. The recombination value (p) for Est-9 and Rc was estimated to be 0.38 by a least square method after adjusting Mendelian segregation ratios with the male transmission ratios of 0.29 (Tr) for Est-9 ² and 0.71 (1-Tr) for Est-9 ¹. The recombination value (q) for the new locus for male gamete abortion, ga-11, and Est-9 was estimated to be 0.23 by using 56 F₃ lines from F₂ plants which were heterozygous for the Est-9 locus. No linkage for Rc and ga-11 was found. Therefore, the two markers and ga-11 were located in the order of ga-11-Est-9-Rc. Using the estimated recombination value (q), the male transmission rate (k) of ga-11 ^a was estimated to be 0.11 with the F₂ data and-0.07 with the F₃ line data. Thus, it was apparent that male gametes possessing ga-11 ^a were frequently aborted in the Indica-Japonica hybrid.     

应用叶片保护率评价阿维菌素对小菜蛾的毒力

研究目的】尝试采用叶片保护率评价阿维菌素对小菜蛾（Plutella xylostella (Linnaeus)）2龄、3龄幼虫的毒力,以期为该药毒力的准确评价提供资料。【研究方法】浸叶法测定阿维菌素对小菜蛾2龄、3龄幼虫室内毒力的同时,观察记录24h、48h、72h校正死亡率、叶片保护率【结果】对小菜蛾2龄幼虫,24h、48h、72h的LC50分别为>10.00mg/L、2.87mg/L、0.56mg/L;相同时间内PC50分别为0.25 mg/L、0.82mg/L、1.43mg/L。对3龄幼虫,24h、48h、72h的LC50分别为>10.00mg/L、6.20mg/L、3.00mg/L;相同时间内PC50分别为<0.16mg/L、0.04mg/L、4.25mg/L。【结论】根据叶片保护率,可以发现阿维菌素对小菜蛾影响快,但是当阿维菌素毒力达到稳定时,必须有较高的校正死亡率,否则达不到理想的叶面保护效果。