高校要当好新时代农业科技推广体系中的"特种兵"

中国特色社会主义进入新时代以来,农业科技创新和应用推广愈发重要,农业科技推广体系中高校的作用日益凸显.文章阐述了我国农业科技推广体系的构成及特点,并分析了高校在该体系中的地位和作用,剖析了高校技术供给的局限性及主要原因,从加强学科建设、将自主创新与产学研相结合、探索和实践高校农技推广模式等方面提出了高校当好农业科技推广体系中的"特种兵"的对策建议.     

基于TOPSIS法的农机维修方案评估研究

科学地评估农机维修企业的维修方案,对提高客户服务质量及维修企业实现利润最大具有重要的现实意义。为此,基于效用函数及逼近理想点法(TOPSIS,Technique for Order Preference by Similarity to Ideal Solution)理论原理,建立了农机维修方案评估模型。该模型通过比较各方案与次理想解及次负理想解的距离,采用效用函数来求解距离的效用,从而筛选出更加符合实际的维修方案。实例结果验证表明,该算法是有效和可行的。     

Elevated expression of CAPON and neuronal nitric oxide synthase in the sciatic nerve of rats following constriction injury

Neuronal nitric oxide synthase (nNOS) has been implicated in peripheral nerve lesions and regeneration. The CAPON adaptor protein interacts with the PDZ domain of nNOS, helping to regulate nNOS activity at post-synaptic sites in neurones, but it is not known whether its expression is altered in sciatic nerves after chronic nerve constriction injury. In the present study, the spatiotemporal expression of CAPON was determined in chronically constricted rat sciatic nerves. Similar to the level of protein expression, CAPON mRNA was significantly up-regulated for almost 5 weeks following sciatic nerve injury. Immunohistochemistry demonstrated that increased CAPON was found mainly in S-100-positive Schwann cells. In addition, co-immunoprecipitation demonstrated an interaction between CAPON and nNOS in Schwann cells and the interaction was enhanced in injured sciatic nerves. CAPON may be involved in peripheral nerve regeneration through regulation of nNOS activity.     

Performance of different drought indices for agriculture drought in the North China Plain

The Palmer drought severity index(PDSI), standardized precipitation index(SPI), and standardized precipitation evapotranspiration index(SPEI) are used worldwide for drought assessment and monitoring. However, substantial differences exist in the performance for agricultural drought among these indices and among regions. Here, we performed statistical assessments to compare the strengths of different drought indices for agricultural drought in the North China Plain. Small differences were detected in the comparative performances of SPI and SPEI that were smaller at the long-term scale than those at the short-term scale. The correlation between SPI/SPEI and PDSI considerably increased from 1-to 12-month lags, and a slight decreasing trend was exhibited during 12-and 24-month lags, indicating a 12-month scale in the PDSI, whereas the SPI was strongly correlated with the SPEI at 1-to 24-month lags. Interestingly, the correlation between the trend of temperature and the mean absolute error and its correlation coefficient both suggested stronger relationships between SPI and the SPEI in areas of rapid climate warming. In addition, the yield–drought correlations tended to be higher for the SPI and SPEI than that for the PDSI at the station scale, whereas small differences were detected between the SPI and SPEI in the performance on agricultural systems. However, large differences in the influence of drought conditions on the yields of winter wheat and summer maize were evident among various indices during the crop-growing season. Our findings suggested that multi-indices in drought monitoring are needed in order to acquire robust conclusions.     

基于PDA的烟草信息采集系统设计与实现

结合云南烟草种植的实际，针对烟草生产的特点和要求，提出了一种基于PDA的烟草信息采集系统。在分析烟草生产管理模式及用户业务希求的基础上，构建了系统的集成框架，设计了系统功能，并采用c#面向对象编程、SQLServerCE数据库、合并复制等技术进行系统的实现。基于PDA的烟草信息采集系统的建立，为烟草生产管理提供了一种实用的解决方案。     

藏羊梭菌性疾病调查与防治

藏羊梭菌性疾病发病率较高,而且相应的死亡率并不低,使都兰县藏羊养殖的经济效益大受影响,不利于牧民收入增加,影响地方牧业和经济发展,必须采取合理措施加强防治。该文简单介绍都兰县藏羊养殖基本情况,并就藏羊梭菌性疾病的调查与防治进行探讨。     

Genetic variation and demographic history analysis of Pestalotiopsis,Pseudopestalotiopsis, and Neopestalotiopsis fungi associated with tea (Camellia sinensis) inferred from the internal transcribed spacer region of the nuclear ribosomal DNA

To elucidate the demographic history within and among the genera Pseudopestalotiopsis, Neopestalotiopsis, and Pestalotiopsis and their genetic diversity, we studied internal transcribed spacer (ITS) sequences of nuclear ribosomal DNA (nrDNA) with no saturation effects in 172 Pestalotiopsis-like fungal accessions isolated from Camellia sinensis planted in nine provinces in China (64 from Yunnan, 4 from Guangxi, 2 from Guizhou, 42 from Jiangxi, 3 from Sichuan, 3 from Zhejiang, 1 from Henan, 18 from Fujian, 12 from Chongqing, and 18 from other provinces) and in Japan (1), France (1), Turkey (1), and Thailand (2). Among these, 44 Pestalotiopsis-like isolates from Yunnan in this study formed a clade in phylogenetic trees with Pestalotiopsis accessions in GenBank, despite their cultural characteristics on potato dextrose agar displaying no genus specificity. Based on estimated sequence polymorphism parameters of average pairwise differences (K), haplotype diversity (H_d), nucleotide diversity (Pi), θ (per site) from η, and recombination event rate (R_m), we identified moderate genetic variation in these three genera. Molecular evolution analysis with neutrality tests and mismatch distribution demonstrated that Pseudopestalotiopsis and Pestalotiopsis ribosomal ITS sequences evolved under a neutral model. However, the recent demographic expansion of the three genera promoted geographical isolation but showed no clear geographical structure. Pairwise genetic divergences between haplotypes and a median-joining network revealed Yunnan or Jiangxi as a possible centre of origin, and that Pseudopestalotiopsis and Neopestalotiopsis may derive from Pestalotiopsis.     

菌草栽培杏鲍菇培养基配方筛选试验

以杏鲍菇P008菌种为研究对象,以巨菌草、象草、五节芒、类芦、芒萁等常见菌草为培养基筛选试材,采用三级系统筛选法,研究了菌草栽培杏鲍菇的最适培养基配方。结果表明:菌草栽培杏鲍菇最适培养基配方为五节芒48%、芒萁20%、麸皮25%、玉米粉5%、石膏1%、石灰1%,pH 8.6,含水量60%,五节芒与芒萁比较适宜作为栽培杏鲍菇培养基的主料原料。     

整流栅对管内流体流态影响的模拟研究

整流技术对泵站机组安全、稳定、高效运行起到了关键作用,因此研究整流技术是大时代背景下的必然趋势。本文运用Ansys-Fluent软件进行流场分析,模拟了弯头出口管段加装不同结构的整流栅对流体流态的影响。通过分析流线图得出如下结论:流体流经弯管后流态很不稳定,当通过整流栅后,流线分布明显均匀规律,且双层交错结构整流栅的整流效果要优于单层结构整流栅。