黄土低山丘陵及坨甸草原区风蚀规律的研究

本文通过对黄土低山丘陵及坨甸草原区248个风蚀图斑资料的分析,运用线性模型理论,对此地区的风蚀规律进行了研究。获得了下垫面各因素与风蚀量关系的数学模型。找出了影响风蚀的主导因素,并系统阐述了植被覆盖度和土地利用类型对风蚀量大小的影响,且与水蚀规律进行了比较分析。     

柔性坐标测量机参数辨识方法

设计了一种六自由度关节式柔性坐标测量机,并对该测量机测量方程中的参数进行了辨识,提出了一种快速简易的单点锥窝标定方法。该方法基于单点锥窝提供的空间单点基准,利用非线性最小二乘中的高斯-牛顿法,求解测量机测量方程的参数值。实验结果表明,该方法能够有效提高测量机的整体精度,且操作简单、计算效率高。     

番茄品种耐弱光性的综合评价

研究了苗期弱光条件对幼苗素质，开花，果实大小及产量的影响，采用模糊数学的隶属法对品种的耐弱光性进行评价，并探讨了番茄耐弱光性状的鉴定方法，结果表明，苗期弱光对幼苗素质影响最大，其次影响开花，果实大小和产量，春雷２号和春雷１号属于耐弱光惭弱的品种，白果强丰属不耐弱光品种。     

Experimental studies with foot-and-mouth disease virus type Asia-1, responsible for the 2005 epidemic in China

This study was carried out to investigate the biological characteristics of the foot-and-mouth disease (FMD) virus strain Asia-1 China/2005, which is responsible for the 2005 epidemic in China. The result showed that this strain is not host restricted, and could not only cause FMD in cattle and sheep but also in pigs by either inoculation or direct contact.     

高效液相色谱法测定低聚壳聚糖含量

本实验建立高效液相色谱法测定原料和复合预混料中低聚壳聚糖含量。采用ODSC18柱(150mm×4.6mm,5μm),以磷酸盐缓冲液(pH=2.8～3.0)-乙腈(95+5,V+V)为流动相,流速为1.5mL/min,检测波长为195nm,柱温为35℃。在此色谱条件下,低聚壳聚糖在0.056～0.450mg/mL浓度范围内呈良好线性关系,r=0.9998,方法平均回收率为98.8%,相对标准偏差(RSD)为1.1%(n=9)。本法操作简便、快速、结果准确,可作为低聚壳聚糖含量测定的质控方法。     

成都地区草坪粘虫发生规律与测报

通过1992～2004年13年的观测结果表明,危害成都地区草坪的粘虫为外迁入的二代粘虫,其暴食期一般年份发生在7月中旬,最佳防治时期在7月上旬;诱蛾量和草把诱卵量与粘虫的发生程度密切相关,可作为草坪粘虫发生的测报因子,且方法简便、有效。     

特高多花黑麦草在贵州的适应性研究

通过对特高多花黑麦草在贵州不同生态条件下的试验研究,结果表明:特高多花黑麦草在三个不同地区均能完成正常的生育期,且生长良好、适应性强、产草量高、营养价值丰富,具有良好的推广应用前景。     

Effects of berberine on the growth performance,antioxidative capacity and immune response to lipopolysaccharide challenge in broilers

This study evaluated the effects of berberine on growth performance, immunity, haematological parameters, antioxidant capacity, and the expression of immune response‐related genes in lipopolysaccharide (LPS)‐challenged broilers. We assigned 120 one‐day‐old male broilers (Ross 308) to two treatment groups; each group included two subgroups, each of which included six replicates of five birds per replicate. The experiment used a 2 × 2 factorial arrangement with berberine treatment (0 or 60 mg/kg dietary) and challenge status [injection of saline (9 g/L w/v) or LPS (1.5 mg/kg body weight)] as the main factors. On days 14, 16, 18 and 20, broilers were intraperitoneally injected with LPS or physiological saline. Blood and liver samples were collected on day 21. Dietary berberine supplementation significantly alleviated the compromised average daily gain and average daily feed intake (p < 0.05) caused by LPS. The LPS challenge led to increased lymphocyte and white blood cell (WBC) counts, malondialdehyde (serum and liver) content, and immunoglobulin G and M, tumour necrosis factor‐α (TNF‐α) and interleukin‐1β (IL‐1β) expression (p < 0.05) and significantly reduced serum total superoxide dismutase (T‐SOD) activity (p < 0.05). Dietary berberine significantly mitigated the LPS‐induced decreases in the mRNA expression of nuclear factor‐kappa B (NF‐κB), TNF‐α, IL‐1β, inducible nitrite synthase and cyclooxygenase‐2 (p < 0.05) in the liver. In conclusion, berberine supplementation has a positive effect on LPS challenge, which may be related to the increase in antioxidant enzyme activity and inhibition of both NF‐κB signalling and the expression of inflammatory mediators.