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111.
112.
本文总结了花卉命名中存在同名异物、同物异名以及种属不当和大小属的问题,并从历史、商业等方面分析了原因,同时针对不同的问题提出了一些建议。 相似文献
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114.
分析了应用较为普遍的农业机械工具—农业手钳的人机安全学设计因素,并通过实验计算得出以人机工程学为基础的手钳的参数设计。主要从人机工程学的角度出发,通过分析手钳在使用时的舒适度和把手尺寸,以评估设计的合理性。同时,分别针对男女群体正态分布的第5百分位、第5 0百分位和第9 5百分位的测量数据进行手柄设计和尺寸评估,得出农业机械手钳的科学合理性尺寸设计。 相似文献
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水稻品种苗期阶段对白叶枯病的抗性研究 总被引:1,自引:0,他引:1
根据水稻品种各叶期对白叶枯病的抗性表现和强弱程度可分为四类:(1)全期抗病型;(2)全期中抗型;(3)苗感成株抗病型;和(4)全期感病型。可以看出,水稻品种除少数苗感成抗型外,其余三种抗性类型苗期与成株期的抗性反应是一致的。由于中抗、成抗和感病品种各叶期的抗性有随着叶位的升高而抗性增强的趋势,不同抗性品种在苗期阶段抗感对比均较成株期明显。因此,水稻品种对白叶枯病的抗性鉴定采用苗期鉴定方法是可行的。影响水稻品种苗期抗性的因素是:苗龄(叶期)、观察时期、品种与菌株的组合等。 相似文献
117.
Malignant hyperthermia (MH) and the mycotoxin cyclopiazonic acid (CPA) are each associated with abnormal calcium homeostasis in skeletal muscle, a key underlying factor in the development of pale, soft, and exudative (PSE) pork. To determine whether the natural presence of CPA in livestock feed ingredients contributes to the varying incidence of PSE in the pork industry, various levels of CPA (.1 to 50 mg/kg of diet) were included in the diets of market weight hogs (n = 52) of defined malignant hyperthermia genotype (NN = normal, Nn = a MH carrier, and nn = MH-positive). Animals with two copies of the MH mutation (nn) displayed improved live animal performance compared with NN and Nn animals (increased feed intake, average daily gain, and feed efficiency) but yielded lower quality loin chops as indicated by lower 45-min pH (P<.01), higher Commission Internationale de l'Eclairage (CIE) L* color coordinate values (P<.05), and higher drip losses (P<.01). The effects of CPA varied. In the first feeding trial, conducted under normal outside temperatures (2 degrees C), CPA had no effect (P> .2) on either live animal performance or meat quality. During the second trial, conducted under extreme outside temperatures (-18 degrees C), CPA-dependent reductions (P<.05) in feed intake, average daily gain, and 45-min pH in nn hogs support the possibility of interactions between malignant hyperthermia and dietary CPA on skeletal muscle calcium homeostasis and the development of PSE pork. These results suggest that this interaction may require stressful environmental conditions or the ingestion of CPA doses much higher than occur under natural conditions. 相似文献
118.
北京栽培白蘑菇病害的研究 总被引:3,自引:0,他引:3
1979~1980年进行箱式栽培白蘑菇的试验,并同时调查对比病害发生情况,和采用各种措施的效果。 相似文献
119.
Canine transmissible venereal tumor (CTVT) can be allo-transplanted across major histocompatibility complex barriers. The expression of MHC molecules is usually low in the progression (P) stage and then greatly increases during tumor regression (R). We investigated the effects of tumor infiltrating lymphocytes (TIL) on the expression of MHC molecules of CTVT cells. Isolated, viable CTVT cells were inoculated at each of 12 sites (1 x 10(8) CTVT cells per site) on the back of six, mixed-breed dogs. Tumor masses were collected every 2-3 weeks and prepared for histopathologic, immunocytochemistry, flow cytometry and immunoblotting studies. The level of MHC expression on tumor cells from different stages of growth was measured. Initially, expression of MHC I and II molecules in P phase CTVT was low. Twelve weeks post-inoculation (PI), expression increased dramatically and it continued to increase during R phase. Tumor growth slowed after 12 weeks PI and tumors entered R phase around 17 weeks PI. We hypothesize that CTVT evades host immunosurveillance and grows progressively for 12 weeks, when it becomes vulnerable and subject to the host's anti-tumor immune responses. We further demonstrated that R phase, but not P phase, TIL were closely associated with the over-expression of MHC I and II molecules by CTVT cells. The number and proportion of TIL were higher in R phase tumors. Supernatants, from R phase co-cultures (CTVT+TIL) and TIL only, promoted MHC I and II expression on P phase CTVT cells. After culturing alone for 1 month, expression of MHC classes I and II molecules in R phase CTVT cells decreased to the level of P phase CTVT cells. However, the above-mentioned supernatants restored their expression of MHC I and II molecules. In contrast, supernatants from P phase TIL or CTVT cells increased expression slightly or had no effect. Therefore, TIL, not CTVT cells, produce the effective substance (s) to promote the expression of MHC molecules by the tumor cells. Heat treated supernatant was unable to promote the expression of MHC I and II molecules by CTVT cells. In conclusion, TIL isolated from R phase CTVT secreted a heat-sensitive, soluble substance(s) that triggered over-expression of MHC I and II after 12 weeks PI. This caused the tumor to enter R phase and helped stop CTVT growth. Our findings will facilitate the understanding and further investigation of the mechanisms that initiate host immune surveillance against tumors. 相似文献
120.
为研制并开发地产新饮品,以黑龙江地产稻米为原料,采取制酒的工艺流程,研制香气独特的龙江清酒。提出了龙江清酒的加工工艺及技术要点,并策划了该产品的营销策略。加工工艺关键是筛选优良的酒曲霉菌和特定酵母菌、优化制曲工艺和发酵工艺条件等;营销关键是打品牌、强宣传、重营销。 相似文献