赤红壤坡地果园间种不同牧草的适应性及其持续利用研究

通过果园间作6种不同牧草对比试验，筛选出4种适宜于赤红壤坡地种植的牧草。同时开展了利用刈割后的牧草覆盖野生蔬菜地和覆盖、填埋果树周围（树冠滴水线以外）土壤的试验，结果表明，利用刈割牧草覆盖填埋处理来改良土壤，可明显增加土壤水分，提高土壤肥力，进而促进果树生长。这种方式是解决牧草持续利用的一种好的途径。     

益生素预防畜禽腹泻机理的研究

用革兰氏阳性的嗜酸乳杆菌和枯草杆菌的活菌和死菌喂饲了８０只雏鸡，用嗜酸乳杆菌的活菌和死菌喂饲了３７头仔猪和２４头犊牛，观察这些细菌防畜禽腹泻的效果。结果证明这两种细菌的活菌与死菌都有预防腹泻的功能，嗜酸乳杆菌的效果好于枯草杆菌。两种菌的活菌和死菌都有预防作用说明是菌体成分或代谢产物可能是预防腹泻的主要有效成分。     

桃需冷量遗传特性的研究

对桃的９个杂交组合４６３株杂种实生苗需冷量进行测定,统计结果表明：桃需冷量是由多基因控制的,Ｆ＿１需冷量平均值较亲中值短,不同组合偏离程度不同,南山甜桃、红日、玛丽维拉、白凤、大久保需冷量育种值分别为１５９、２１６、３１９、８３１、８３４ｈ,遗传传递力分别为７９%、５４%、９２%、８３%、９３%。需冷量的遗传力为８９．６９%。萌芽开花与需冷量密切相关。     

Factors influencing decline in soil pH in Hawaiian Eucalyptus and Albizia plantations

Soil pH declined from 5.9 to 5.0 in 8 years beneath plantations of Eucalyptus saligna (Sm.) in Hawaii. In stands of Albizia falcataria, (L.) Fosberg, the soil pH change was more dramatic, declining from 5.9 to 4.6. We measured several components of soil acidity beneath four mixtures of the two tree species to gain insight on the processes responsible for the decline in soil pH. These components were studied using an empirical method of comparing acid quantity, degree of neutralization (depletion of base cations), and acid strength. The decline in soil pH differed between species as a result of differences in the degree of neutralization of the soil exchange complex; the larger decrease in soil pH under Albizia was produced by greater acidification of the exchange complex. Empirical titration curves suggested that differences in acid strength moderated the divergence in soil pH beneath the species. Had the acids accumulating in the soil under Albizia been as strong as those in the Eucalyptus soil, the difference in soil pH would have been greater. Though the two species had contrasting effects on soil pH, the differences in degree of neutralization, responsible for the pH decline, were small compared with differences in the amount of cations stored in tree biomass. Continued supply of nutrient cations (from weathering or fertilization) will ultimately control both the extent of soil pH decline and the level of productivity sustained by the forest.     

Monoclonal antibodies to bovine viral diarrhea virus: cross-reactivities to field isolates and hog cholera virus strains.

Monoclonal antibodies to bovine viral diarrhea virus (BVDV) were examined for binding with a large number of North American BVDV isolates and eight strains of the serologically related pestivirus, hog cholera virus (HCV). No single BVDV monoclonal antibody reacted with all BVDV isolates. The most cross-reactive monoclonal antibody was an anti-p80/p125 antibody which showed a positive reaction with 173 of 180 (96%) North American isolates. From a fewer number of isolates tested, one anti-gp53 monoclonal antibody also showed a high cross-reactivity (94%). All BVDV isolates showed a positive reaction with at least one of the seven monoclonal antibodies in the panel. Thus, the results indicated that a pool of these monoclonal antibodies may be used in place of polyclonal antisera for the detection of BVDV contamination of cell lines or for virus isolation. For HCV, all three anti-p80/p125 monoclonal antibodies reacted positively with all eight virus strains. In contrast, none of the anti-gp53 monoclonal antibodies were reactive to HCV strains. Thus, the anti-gp53 monoclonal antibodies may be useful for distinguishing between usually innocuous BVDV infections and the highly significant HCV infections in swine for foreign animal disease surveillance.     

Comparative effects of mu and kappa opiate agonists on the cecocolic motility in the pony.

The electrical and mechanical activity of the large intestine and its response to administration of opiate mu and kappa agonists were assessed from electrodes and inductograph coils chronically implanted on the cecocolic segment in six ponies given a diet of hay and concentrates. Before the drugs were given, migrating complexes propagating from the cecum into the colon occurred at the rate of 1.5 to 16/hour. During this propulsive activity, the cecocolic sphincter opened and closed allowing the outflow of cecal contents and preventing the backflow of colic contents. Each pony was used as its own control and was given fentanyl (0.01 and 0.05 mg/kg of body weight, IV) and U50488H (0.1 and 0.5 mg/kg, IV) at weekly intervals. The mu agonist fentanyl elicited a marked phase of inhibition of the propulsive activity and a closure of the cecocolic sphincter that lasted one to two hours depending on the dose. The kappa agonist U50488H induced an inhibition of the short spiking activity, i.e. of the resting muscle tone. It did not disturb the occurrence of migrating complexes nor that of the openings of the cecocolic sphincter. These kappa compounds may be drugs of choice to alleviate visceral pain in colic stases without inducing delay of transit unlike mu compounds.     

高层建筑和低层裙房基础设计方案选择

针对高层建筑和低层裙房基础设计中常遇到的方案选择、高层主楼与低层裙房基础沉降差异处理等问题，提出了设计要求和实施的技术措施。     

波尔山羊胚胎数量、质量与受体移植妊娠率的关系

本文就波尔山羊胚胎数量，质量与受体移植妊娠率的关系进行了探讨。结果表明：胚胎质量优劣是直接影响胚胎移植成功率的关键因素。移植胚胎数量因品种不同有差异。移植双胚，奶山羊受体胚胎成羔率53．4％，明显高于成都麻羊胚胎成羔率36．3％，成都麻羊单胚成羔率为66．7％。     

单诺沙星对鸡败血支原体与大肠杆菌合并感染的药效学研究

采用试管二倍稀释法测得单诺沙星及其对照药物恩诺沙星、泰乐菌素对鸡败血支原体（MG）的最低抑菌浓度分别为0．0625、0.125、0.5mg/L。试验鸡每只左右气囊分别接种MG S6株菌液0.75ml、滴鼻约0.3ml，同时腹腔注射大肠杆菌菌液0.3ml,人工诱发鸡败血支原体与大肠杆菌合并感染的疾病模型。25、50、100mg/L的单诺沙星、500mg／L的恩诺沙星和500mg/L的泰乐菌素连续饮水5d给药，对人工合并感染鸡败血支原体与大肠杆菌病的治愈率分别为93.3%、96.6%、96.6%、93.3%、86.6%，而感染对照组的死亡率为23.3％。单诺沙星及其对照药物组的增重率显著高于感染对照组，并能极显著的降低感染鸡的死亡率、抗体反应阳性率、气囊损伤率及病原再分离率。     

哺乳动物性别决定机理及性别鉴定方法研究进展

哺乳动物的性别决定是由SRY基因为调控中心、多基因参与的级联调控过程。本文综述了性别决定基因及其功能、性别决定的分子模型及性别鉴定的方法等方面的研究进展。