Product Modeling in Virtual Manufacture

The competition among enterprises becomes more and more drastic. In order to win the market, so as to put itself in a stead station, the enterprise put forward many advanced manufacturing modes. Virtual manufacture is put forward by American as a wholly new concept under this situation. It is thought as advanced manufacturing technology of the 21st century. Based on the analysis to the prior, the author expatiated the concept of virtual manufacture and put forward the three demands which the product model suited for the virtual manufacture must satisfy. On the bases the author set up the product model which is composed by product function express and product definition and expatiated the product function and product definition at detail.     

Calculation of Capacity of Vertically Loaded RC Joint of Local Transf er from Square Column to Straight Wall

On the basis of experimental results on four specimens of vertically loaded RC joints of local transfer from square column to straight wall, interaction between the transfer beam and the straight wall above it is analyzed. In the test, the effect of height of armpit on the transfer beam upon the behavior of the joint is specially studied. As a result, determination of the design shear force and shear capacity of the transfer beam and calculation of capacity of the straight wall are suggested, taking into account the effect of shear span ratio of the beam.     

Application and Progress about Mechanics Technique Integrating with Botany

The survey and progress about the study applying mechanics to traditional botany are summarized. It gives brief analysis to the influence of plant growth and development under the mechanics factors, such as mechanical vibration, strong sound wave (or ultrasonic wave), electromagnetic field and microgravity, et al. In other word, the biological effects of plant caused by environmental stress stimulation are set out (They contain positive effects and negative effects). Furthermore, the profound biological effects and some possible mechanism of the plant tissue and cell are discussed. The paper put forward several main problems about botanical mechanics which must be researched at the beginning of 21st century, and the more significant thing about it is the operation of Ca 2+ which as a Second Messenger, will be probed into. At the end of the paper, the well development tendency and practical prospect of the newly compound subject _botanical mechanics is also presented.     

栗绛蚧形态生物指标与发生量关系研究

栗绛蚧是长江流域板栗主要害虫之一 ,常引起板栗大幅度减产。该害虫自然种群内雌虫个体间发育差异很大 ,并与其生殖力、死亡率及后代的发生量有密切关系。以雌虫体重、体积及虫体直径为形态指标 ,将雌虫发育分为 、 、 三个等级 ,各级体重 ( x1 )、体积 ( x2 )、虫体直径 ( x3 )分别为 级 ( 0 .1 0 1± 0 .0 0 4 )g,( 0 .1 6 3± 0 .0 1 2 ) m L,( 6 .6 2± 0 .1 7) mm; 级 ( 0 .0 6 52± 0 .0 0 6 ) g,( 0 .1 4 1± 0 .0 0 9) m L,( 6 .1 4± 0 .1 4 ) mm; 级 ( 0 .0 2 9± 0 .0 0 2 ) g,( 0 .0 6± 0 .0 0 4 ) m L,( 5.0 9± 0 .1 3) mm。发生量 ( Y)分别与体重 ( x1 )、体积 ( x2 )、虫体直径 ( x3 )成正相关关系 ,其线性回归方程分别为 :Y=-6 72 .7+ 381 78.7x1 ,Y=-1 1 4 1 .6 + 2 2 86 0 x2 ,Y=-8588+ 1 7359.3x3 ;相关系数 r1 =0 .9939,r2 =0 .8896 ,r3 =0 .96 39。其中体重与发生量相关关系最为密切     

Research progress of rumen hydrogen sulfide production in ruminants

Rumen fermentation can produce hydrogen sulfide (H₂S), and H₂S can be rapidly absorbed by the intestinal wall in nature. If excessive H₂S was produced in rumen, it might be toxic to ruminants. This article reviews the research progress of toxicity of H₂S, rumen H₂S production pathway and its influential factors to lay a foundation for further research and application of rumen H₂S‐producing regulation in ruminant.     

甘蓝型油菜FAD2基因cDNA片段的克隆和序列分析

为了提高油菜的油酸含量，继而培育高油酸油菜品种，从甘蓝型油菜成熟叶片中分离总RNA，经反转录合成cDAN第一条链，以此为模板进行多聚酶链式反应，产物为一长654bp的DNA片段，经克隆和序列测定表明，其核苷酸序列与GenBank中甘蓝型油菜FAD2基因在比较区的同源性达100％。     

我国二氧化硫污染状况及控制对策

根据有关资料 ,分析、论述了我国二氧化硫污染状况、形成原因 ,并提出了控制二氧化硫污染的对策     

β-酪啡肽7对早期断乳仔猪免疫器官及内分泌功能的影响

将12头体重相近的三元杂交仔公猪分为两组：对照组正常吃母乳到28日龄断乳；实验组于21日龄断乳后添喂β—酷酷啡肽7(β—CM7），进行饲喂实验至32日龄。结果表明，添喂β—CM7的仔猪，血清胃泌素水平比对照高31．76％(P＜0．01)，瘦素水平比对照组高7．0％(P＜0．01)，皮质醇低于对照组26．19％(P＞0．05)，IL—2、T3、T4和胰岛素水平均与对照组的接近。与对照组相比，胸腺、腹股沟淋巴结、脾脏的相对重分别增加31．48％，28．26％和2．7％，差异均不显；胸腺形态结构未见差别，脾脏的中央动脉周围淋巴鞘面积略小，回肠派伊尔氏结的总数增多，且总面积增加8．1％，但差异均不显。     

武夷山米槠林优势种群的竞争格局及动态模拟

用重要值百分数求取种间竞争系数 ,以优势种群在纯林中的优势度为其容纳量 ,采用Lotka- Volterra竞争方程探讨武夷山米槠林的 4种优势种群 (米槠、杨梅叶蚊母树、罗浮栲、黄瑞木 )的竞争格局 .结果表明 :平衡状态时 ,米槠、杨梅叶蚊母树、罗浮栲和黄瑞木相对优势度分别为 5 7.1 0 %、 5 .69%、 33.5 4 %、 3.67% ,即米槠和罗浮栲占据主林冠层 .同时模拟不同尺度的人为干扰 ,结果表明不同尺度的干扰对群落稳定性的影响都不显著 ,结果可为米槠林的保护和经营管理提供理论依据和信息     

杂交稻种子带菌及保活剂处理与生活力的关系

为了解杂交水稻种子带菌情况及保活剂处理后贮存2年对种子发芽的影响，收集了湖南长沙、沅江、常德、临澧等地的杂交水稻种子，保活剂处理前后通过组织分离了解种子带菌情况，同时测定了种子水分含量与发芽率。结果表明：不同来源杂交稻种子携带的真菌主要为曲霉、毛锥孢、链格孢与镰刀菌。不同地区不同组合携带的真菌种类有很大的差异。1999年收获的杂交稻种用保活剂处理后保存2年，携带真菌数量减少，发芽率比对照高1．8％－15．9％；2000年用保活剂处理的杂交稻种保存1年后，发芽率比对照高0．3％－11％。