陕北黄土区小檗属植物资源调查与播种育苗试验

经调查,陕北黄土区小哭属(Berberis)植物资源有6种,蕴藏量3000担左右。可分为抗旱、中生和湿生3种生态类型。播种育苗试验,种子沙藏处理比热水浸种和干播,平均出苗率分别提高9%和15%,平均提前5天、10天。     

PKS-NRPS数据库的研究进展

非核糖体多肽合成酶(NRPS)和聚酮合成酶(PKS)是调控次级代谢物聚酮类物质和非核糖体多肽合成的关键酶。随着生物息学的快速发展,国外的NRPS-PKS数据库和预测软件不断推出。本文对几个重要NRPS和PKS领域的数据库与预测软件的研究做一综述     

白背飞虱危害对水稻产量结构的影响

白背飞虱［Ｓｏｇａｔｅｌｌａｆｕｒｃｉｆｅｒａ（Ｈｏｒｖａｔｈ）］是太湖稻区的主要害虫之一,近年来,随着耕作制度的变化及水稻品种的变更,白背飞虱跃升为太湖稻区水稻生长前期的优势种群。目前国内的研究多侧重于褐飞虱的危害及其防治,关于白背飞虱危害对水稻产量的影响,国内鲜见报道［１,２］。为了探明白背飞虱在水稻不同生育期危害时,不同虫口密度与产量的关系,作者于１９９７年进行了白背飞虱危害对水稻产量结构影响的研究。１　材料与方法供试水稻品种为Ｓ０１５。试验田共分２８小区,小区面积２０ｍ２。选取均匀饱满的…     

浅谈钢铁生产与环境保护

随着我国经济的高速发展,钢铁产能大幅度增长,随之带来是环境保护及生产成本问题.一个好的企业既要有拳头产品又要不断进行企业的升级改造,降低企业生产对环境的污染,加大企业循环再利用的投入,使钢铁生产日趋完善,达到企业生产健康发展的良性循环轨道上.     

不同来源微粒子孢子间血清学关系的比较研究

应用玻片凝集法和酶标抗体法比较了几种不同来源微粒子孢子间的血清学关系，包括本所保存的家蚕微粒子孢子（ＢｍＮ．ｂ），从安徽绩溪和江苏东台的饲养蚕中收集到的微粒子孢子和从四川收集到的蓝叶虫（ｐｈｙｌｌｏｂｒｏｔｉａｃａｒｍａｔａＢａｌｙ）微粒子孢子。结果表明，绩溪、东台微粒子孢子与ＢｍＮ．ｂ之间具有相同的血清学关系，而蓝叶虫微粒子孢子与ＢｍＮ．ｂ之间无血清学关系。     

森林生态系统土壤碳库对氮沉降的响应研究进展

大气氮沉降的不断加剧,改变了土壤理化性质,直接影响植物的生长与发育,间接影响了陆地生态系统碳库,进而可能改变全球气候变化进程。森林是陆地生态系统的主体,因此,弄清氮沉降如何影响森林生态系统碳库,对预测全球气候变化具有重要意义。笔者旨在详细分析氮沉降对森林生态系统土壤碳库输入和输出的影响,阐述氮沉降对森林生态系统凋落物分解、细根周转和土壤呼吸的影响研究进展和作用机制。截至目前,关于氮沉降对于陆地生态系统的影响研究报道较多,且国内外诸多学者也在森林生态系统土壤碳库对氮沉降的响应领域开展了较多试验研究,但多集中于碳输入和输出的总量分析,而对输入和输出各个组分的研究相对较少。笔者综述了国内外有关森林生态系统碳库输入和输出各组分对氮沉降响应的相关研究,为进一步揭示其响应机制和途径提供参考依据。     

科尔沁草地的畜草平衡与草业发展途径的研究

根据实地调查和历年的统计资料，系统分析研究了科尔沁草地多年来草业发展速度落后于牲畜增长速度、畜草供需严重失衡的现状。结果表明，草地退化４５．９％，超载率达３６．１％。该地区发展草业的自然和社会经济条件优越，但必须采取以下措施才能达到畜草平衡的目的：加强合理利用和改良天然草地；发展人工饲草料基地，迅速增加种植畜牧业比例；大力发展秸秆及农副产品饲草料加工业     

Topography of ganglion cells in the retina of the horse

Topography of ganglion cells in the retina of the horse (Thoroughbred) was analyzed in the wholemount retina stained with cresyl violet, and a total number of ganglion cells were estimated. Sizes of ganglion cells were also measured and size spectra were analysed. The main results showed that: (1) a common point in 4 wholemount retinae, based on cell densities and retinal locations, was that a retina could be divided into 5 regions, namely visual streak, nasal, temporal, dorsal and ventral region to the visual streak. A maximum cell density of 4,000 cells/mm2 was found in the visual streak. And a total number of ganglion cells was estimated in a range of 398 x 10(3) - 469 x 10(3), with a mean of 441 x 10(3) +/- 31 x 10(3) (n=4). (2) cell sizes were measured as the mean lengths of the major and minor axes of the somas, and were in a range of 5-53.8 microm. The lowest mean diameter was 14.0 microm (+/- 3.7) in the visual streak and the highest was 25.9 microm (+/- 7.6) in the ventral region. Cell size spectra were unimodal and positively skewed. It is expected that these analyses will provide an anatomical and physiological background for further study of the visual system in the horse.     

Effect of Fermentation Bed with Spent Mushroom Substrate of Pleurotus eryngii on Weaning Piglets

[Objective] The paper was to investigate effects on fermentation bed temperature,growth performance,diarrhea rate and digestive en-zyme activity of weaning piglets by using spent mushroom substrate of Pleurotus eryngii as padding.[Method] A total of 120 weaning piglets(Duroc × Landrace ×Yorkshire) with average initial body weight of(8.0 ±0.5)kg were allocated to five dietary treatments in a randomized complete block design for 42 d,each of which was replicated three times with eight piglets per replicate(half male,half female).The padding for control group was(50% sawdust +50% rice husk);experimental group Ⅰ 100% spent mushroom substrate;experimental group Ⅱ(15% sawdust +15% rice husk +70% spent mushroom substrate);experimental group Ⅲ(25% sawdust +25% rice husk +50% spent mushroom substrate);experimental group Ⅳ(35% sawdust +35% rice husk +30% spent substrate).[Result] There was no significant difference in surface temperature of fermentation bed between experimental groups and control group(P0.05).Compared with the control group,the temperature under 20 cm of fermentation bed in ex-perimental groups I,Ⅱ and Ⅲ increased significantly(P0.05).Except for experimental group Ⅳ,other three experimental groups had higher aver-age daily gain(P0.05) and experimental group Ⅰ had higher average daily feed intake(P0.05) compared to the control group.The diarrhea rate and mortality of weaning piglets in experimental groups Ⅱ,Ⅲ and Ⅳ were significantly decreased compared with the control group(P0.05).Compared with the control group,other three experimental groups had higher digestive enzyme activity in duodenal contents except for experimental group Ⅳ(P0.05).[Conclusion] Spent mushroom substrate of P.eryngii can be used as fermentation bed padding,and the optimal proportion was experimental group Ⅲ.