不同配比的赤霉素和激动素与营养液配施对平菇产量与品质的影响

不同配比的ＧＡ３和ＫＴ与营养液配合，通过拌料和喷洒菇蕾两种方法施在平菇上，发现ＧＡ３和ＫＴ对平菇菌丝伸长均有抑制作用，但只要ＧＡ３和ＫＴ配比恰当，就能促进菌丝分枝生长，也能显著提高平菇产量和品质，但使维生素Ｃ等的含量下降，ＧＡ３和ＫＴ若与营养液配合施用，则更能发挥其增产作用。     

Hemolytic assay for goat (caprine) and swine (porcine) complement

Optimal conditions for assaying hemolytic complement of goat (caprine) and swine (porcine) sera were determined. Effects of the following were tested: pH, ionic strength, calcium and magnesium ion concentrations, time and temperature of incubation, and ethylenediamine tetracetate concentration. Guinea pig erythrocytes sensitized with goat or cattle antibodies were the most sensitive target cells for goat complement. Sheep and cattle erythrocytes sensitized with rabbit hemolysin were the best target cells for swine complement. Barbital buffer, pH 7.3, ionic strength of 90 nmM relative salt concentration, containing 0.5 mM CaCl2 and 1 mM MgCl2 was the best for swine complement assay. Goat complement lysed best in a barbital buffer, pH 8, ionic strength of 90 to 120 mM of relative salt concentration, in presence of 0.5 mM CaCl2 and 1 mM MgCl2. The optimal incubation temperature was 37 degrees C for both complements. The complement dependent lysis required 75 minutes to reach its maximum. Ethylenediamine tetracetate in 4 mM concentration completely inhibited lysis by both species complements. The CH50 for goat sera varied between 18 and 75 per ml, in swine sera between 75 and 210 per ml.     

耕牛“闪膊”的病因分析和治疗

绝大多数伴有肩胛骨向下方移位这一症状的耕牛前肢疾病,称"闪膊".它是由于臂神经丛(包括肩胛上神经)受损后使肌肉失去控制,或因肌肉撕裂而造成的. 近年来,有人认为它是前肢疾病的必然症状(或前肢某一部位病痛的反映),笔者对此不敢苟同. "闪膊"的治疗原则必须是病因治疗,即以治本为主.笔者采用0.25%的低浓度普鲁卡因溶液静脉滴注法,不仅能阻断病灶传向中枢神经的恶性刺激,保护大脑皮层的调节机能;还对恢复神经的营养作用,改善组织的新陈代谢,增强机体的抵抗能力等方面产生积极作用,因而能促使病肢很快痊愈.     

高效液相色谱法测定伊维菌素缔合胶体溶液的含量

建立了0.3%伊维菌素缔合胶体溶液中伊维菌素含量的HPLC测定方法。采用的流动相为乙腈-甲醇-水（60∶32∶8）,检测波长为254 nm。结果表明,伊维菌素H2B1a在6.795-217.4μg/mL浓度范围内线性关系良好（r=0.999 8）,平均回收率为99.7%。该方法准确可行,伊维菌素H2B1a与相邻峰分离完全,能排除溶剂和表面活性剂的干扰。     

不同营养液对蝴蝶兰生长的影响

研究了不同营养液配方对蝴蝶兰(Phlaenopsis amabilis)生长的影响.结果表明:配方B处理植株的各项形态指标均明显优于其它配方,叶绿素和全氮、全磷含量也高于其它配方.     

不同氮素浓度对水培韭菜生长发育与品质的影响

为确定韭菜水培营养液的氮素水平,试验设置4、6、8、10、12(CK)、14、16mmol·L-1共7个氮素浓度梯度处理,采用北京市农林科学院蔬菜研究中心研发的新型水培系统进行水培试验,通过对水培韭菜的生长指标、单株干质量及鲜质量、产量、生理指标以及营养品质等测定分析表明:适合用于水培韭菜的营养液氮素水平为8~12mmol·L-1,其中以10mmol·L-1氮素浓度的营养液水培韭菜其生长状况及产量最佳;12mmol·L-1氮素浓度的营养液水培韭菜品质最优。     

搭建培训平台,探究搬迁农民培训内容和方式——以北京市大兴区采育镇搬迁农民培训为例

随着北京市"城南行动计划"的实施,大兴区与北京经济技术开发区行政资源的整合,航空新城的筹建,加速了大兴区城乡一体化的进程,全区10万农民已经搬迁。采育镇经济开发区因北汽零部件产业基地和新能源汽车产业基地的进入、小城镇建设的提速,2010年13个村近2 794户农民进行了搬迁,后续还要有更多的农民进行搬迁。在搬迁的过程中,由于农业发展空间的减少,农民在生产生活等方面出现了巨大变化,而大部分搬迁农民沿袭着传统守旧的思想观念和生活习惯,文化素质偏低,出现了各种各样的矛盾,带来了诸多的社会问题。帮助农民转变观念,正确面对搬迁,培养新型市民已成为了地方发展的重要课题。     

Large deflection of beams of thermorheologically simple material

The large deflection of thermorheologically simple material beam under various temperature fields was studied. The derived governing equation is complicated integro-differential equation that in general requires numerical solution to determine the large deflection of the beam. The governing equation can be used for not only the general loading condition but also any temperature fields. Numerical solutions of large deflection of thermorheologically simple material under a combined load were obtained by using numerical method.     

保鲜液中蔗糖浓度与瓶插深度对切花月季保鲜效果的影响

采用不同蔗糖浓度(0%,2%,3%,5%的保鲜液)与不同瓶插深度(5、8.5、12.5 cm),测定月季的瓶插寿命和花径增大量,研究2因素对瓶插月季保鲜效果的影响。结果表明:保鲜液中蔗糖浓度对月季瓶插寿命和花径有极显著影响(P<0.01);保鲜液中瓶插深度对月季瓶插寿命没有影响(P>0.05),但对其花径有极显著影响(P<0.01)。蔗糖浓度为2%,瓶插深度为5 cm时月季瓶插寿命最长,可达8.75 d;蔗糖浓度为5%,瓶插深度为12.5 cm时对瓶插月季花朵增大效果最好,达29.3 mm。     

Soil Fertility and Plant Nutrition Research Under Controlled Conditions: Basic Principles and Methodology

In modern agriculture, use of essential plant nutrients in adequate amounts and proper balance is one of the key components in increasing crop yields. Further, in developing crop production technologies, research work under field and controlled conditions is necessary to generate basic and applied information. In addition, research is very dynamic and complex due to variation in climatic, soil, and plant factors and their interactions. This demands that basic research information can only be obtained under controlled conditions to avoid or reduce effects of environmental factors on treatments. Hence, the objective of this article is to discuss basic principles and methodologies of research in soil fertility and mineral nutrition under controlled conditions. Topics discussed are soil and solution culture experimental techniques including, fertilizer application and planting, liming acid soils, experimental duration and observations, composition of nutrient solutions, preparation and sources of iron (Fe) in nutrient solutions, pH of nutrient solutions, and stable supply of nutrients in the solution culture.