不同经度天山云杉林分因子随海拔梯度的变化

选择新疆天山山脉从西到东处于不同经度的昭苏、巩留、乌苏、乌鲁木齐和哈密的天山云杉林进行垂直样带调查:将各地点划分为低、中和高3个海拔范围,比较不同范围内主要林分因子的差异;分析主要林分因子随海拔梯度(50 m间隔)的变化.结果表明:各地点3个海拔范围内主要林分因子呈现出不同的变化规律;天山云杉林分平均胸径和最大胸径随海拔梯度的变化差异不显著,而平均树高、最大树高、林分密度、胸高断面积和蓄积量随海拔的增加总体上呈现单峰型的变化趋势;尽管不同经度位置天山云杉林分布的海拔上下限范围不同,但各个位置天山云杉林分的平均树高、最大树高、林分密度、胸高断面积和蓄积量随海拔梯度的变化都可以用二次曲线方程进行描述.     

He-Ne激光辐射对糯玉米种子的生物学效应

种子活力是检验种子质量高低的一项最重要的指标。采用苏糯一号玉米种子为材料,研究了He-Ne激光不同剂量以及不同照射时间对糯玉米种子发芽率、发芽指数、活力指数、电导率、可溶性蛋白含量以及淀粉含量的影响。结果表明,采用13mA剂量的激光照射糯玉米种子50s能够明显的提高其种子活力,增加幼苗可溶性蛋白和淀粉的含量。     

漏磁腐蚀检测器新型探头机构的设计

为了解决漏磁腐蚀检测器在管道内检测过程中因探头机构姿态不稳、偏磨及支撑弹簧易折断、易震颤带来的一系列问题,对检测器所用探头机构进行研究,设计制造了一种全新的探头机构.该机构增加了辅助支撑弹簧和柔性连接铰链,很好地解决了传统探头机构存在的不足.该机构的检测探头将以往探头加耐磨层结构变为整体灌装探头壳形式,改善了检测探头的提离值,提高了检测信号的可靠性.与传统探头机构相比,该机构的使用能够有效提高检测数据的可靠性和稳定性.     

Performance of four Chinese Trichogramma species as biocontrol agents of the rice striped stem borer, Chilo suppressalis, under various temperature and humidity regimes

The striped stem borer, Chilo suppressalis (Walker), is one of the most economically important rice pests worldwide. However, biological control of this pest using natural enemies has rarely been documented. Indigenous natural populations of four Trichogramma species (i.e., T. japonicum, T. chilonis, T. dendrolimi, and T. ostriniae) were collected from the eggs of C. suppressalis in paddy fields. With the objective of screening suitable candidate species for controlling the striped stem borer, parasitism by these four Trichogramma species of the eggs of their native host, C. suppressalis, was evaluated at five temperatures (18, 22, 26, 30, and 34?°C) and four relative humidity (RH) regimes (30, 50, 70, and 90?%). The temperature and the humidity significantly affected the ability of all of the Trichogramma species to parasitize the eggs of their host. T. chilonis parasitized more eggs at 26?°C than at the other temperatures. By contrast, T. dendrolimi, T. ostriniae, and T. japonicum performed best within a wider temperature range. The host number parasitized was highest at 70?% RH and differed significantly among the Trichogramma species at all of the temperatures and humidities tested, except at 30?°C and 50?% RH. Generally, T. dendrolimi and T. japonicum performed better than the other species at 18–26 and 30–34?°C, respectively, whereas T. ostriniae parasitized the fewest host eggs at 30–70?% RH. Both T. dendrolimi and T. japonicum appear to be promising candidates for augmentative release against C. suppressalis in northeastern China.     

小麦秆锈菌鉴别寄主品种Orofen对小种21C3和34C2抗病基因的单体分析

 用中国春单体系列和二体中国春作为母本与Orofen杂交。选择出所有类型的单体杂种F1植株,令其自交结实。在温室内(10-25℃)用秆锈菌小种21C3和34C2的单孢菌系分别接种鉴定各杂交组合的F₂代苗期的抗性分离表现。对小种21C3,除2D和6D之外,其它单体类型和二体对照的F₂代都符合抗病15:1感病的分离比例;对小种34C2,除2D之外,其它单体类型和二体对照的F₂代都符合抗病3:1感病的分离比例。用Orofen与含有国际上已定位于2D和6D染色体上的已知Sr基因的品系(或品种)杂交。对小种21C3,Orofen与含有Sr5和Sr6的单基因系的杂交F₂未分离出感病的植株;对小种34C2,只有与含有Sr6的单基因系的杂交F₂代未分离出感病的植株。这表明,Orofen在2D染色体上含有Sr6,它兼抗小种21C3和34C2,分别提供0-1;1⁺⁺x^-和;1-;1⁺⁺x^-的抗性效应;而在6D染色体上携带抗病基因Sr5,它只抗小种21C3.控制0-;1^-的侵染型。对无毒性的小种,Sr5对Sr6的抗病效应是上位的。     

单纯形—正反步长优化方法（SSPSS）及其在农业上的应用

本文提出了一种新的多变量有约束非线性函数的寻优方法——单纯形一正反步长法(SSPSS)。文中详细阐述了该方法的搜索策略和具体步骤。同时,通过实例比较了相对步长模拟法的优点。     

The influence of level of feeding on growth and serum insulin-like growth factor I and insulin-like growth factor-binding proteins in growing beef cattle supplemented with somatotropin

The objective of this study was to determine the effects of level of feeding on growth, feed efficiency (gain:feed; G:F), body composition (BC), and serum concentrations of somatotropin (ST), IGF-I, and IGF-binding proteins (BP) in growing beef cattle supplemented with bovine (b) ST. In each of two consecutive years, 40 growing beef cattle were blocked by weight (average BW: yr 1 = 316 kg, yr 2 = 305 kg) and used in a 2 x 2 factorial arrangement with main effects of bST (0 or 33 microg x kg BW(-1) x d(-1)) and level of feed intake (ad libitum [AL] or 0.75 AL). Relative to uninjected cattle, treatment with bST increased ADG 9.6% (1.14 vs 1.25 kg/d; P < 0.05) and increased G:F 8.1% (12.3 vs 13.3 gain [g]:feed [kg]; P < 0.05), whereas ADG in AL animals was 39% greater than that in 0.75 AL animals (1.39 vs 1.00 kg/d; P < 0.05). There was a tendency (P = 0.10) for a bST x level of feeding interaction, such that the increase in ADG with bST was greater in AL cattle than in 0.75 AL cattle (10.6 vs 7.8%; P = 0.10). Serum concentrations of ST were greater in 0.75 AL cattle than in AL cattle (13.0 vs 8.6 ng/mL; P < 0.05) and in bST-treated cattle than in uninjected cattle (16.3 vs 5.2 ng/mL; P < 0.05). Due to a bST x level of feeding interaction (P < 0.01), the magnitude of the increase in serum ST to exogenous bST was greater (P < 0.01) in 0.75 AL cattle than in AL cattle. Relative to uninjected cattle, treatment with bST increased (P < 0.05) serum concentrations of IGF-I and IGFBP-3 and reduced (P < 0.05) concentrations of IGFBP-2. Similarly, AL cattle had greater (P < 0.05) serum concentrations of IGF-I and IGFBP-3 and reduced (P < 0.05) IGFBP-2 compared with 0.75 AL cattle. In summary, treatment with bST increased growth rate and G:F and stimulated serum IGF-I and IGFBP-3 while reducing IGFBP-2. Feeding at 0.75 ad libitum intake reduced the magnitude of response for each of these variables. Thus, limit-feeding may reduce the effect of exogenous bST on growth rate by blunting bST-induced increases in IGF-I and IGFBP-3 and bST-induced decreases in IGFBP-2.     

维生素C对快大型黄羽肉鸡肺动脉高压综合征的影响

采取分组对比的方法(对照组,肺动脉高压综合征(PHS)发病组,维生素C治疗组)分别检测试验鸡只肝组织、肠黏膜、心肌线粒体中的NO含量和NOS的活性。结果显示,对于发生PHS的快大型黄羽肉鸡,其肝脏、心肌和肠黏膜线粒体NO含量呈现先显著上升后显著下降的变化趋势(P<0.05)。线粒体NOS活力的变化趋势则与NO一致。与对照组相比,维生素C治疗组各指标则呈现相反的变化,说明其能有效地阻止快大型黄羽肉鸡发生PHS这一过程。     

日本对虾的实验室养殖研究

我们曾将发病残存的日本对虾继续养殖作为亲虾，进行夏季高温育苗，所得到的虾苗在实验室里桶养，证明在人工饲养条件下它们是可成活和生长的，本实验还提示，若能解决水质净化问题，日本对虾甚至有可能移至内陆养殖。     

龙牙楤木、长白楤木种子繁育技术

楤木有较好的经济价值,可供食用、药用、园林绿化、工业原料等。野生资源在人们长期的过度超采下已濒临枯竭,因此,探索人工繁育方式以保证资源的可持续利用势在必行。经过几年的试验总结,采用种子繁育楤木较比其它繁殖方式,具有繁殖倍数高,操作简便易行,农民便于掌握,成本低、投资少,便于产业化生产。人工栽培楤木,特别对于黑龙江省东部及东南部山区、半山区,是一项很有发展前景的新兴产业。