适应农业农村发展新变化 加强农业继续教育

我国农业农村发展变化迅速,对各类从业人员的能力与素质提出了新的要求,因此要把握新形势下农业继续教育重点,主动适应这种新的变化,大力加强农业继续教育,为农业增产、农民增收、农村社会和谐稳定提供人才保障。     

数字参考咨询服务的实践--NSTL网上专家咨询服务

数字参考咨询服务是网络环境下参考咨询服务发展的一种新形式。本文首先阐述了数字参考咨询服务的概念和主要形式 ,然后重点介绍了国家科技图书文献中心 (NSTL)网上专家咨询服务系统 ,对进一步提高NSTL网上咨询服务的水平提出了建议     

阿拉尔垦区常规棉与F2杂交棉产量纤维品质性状比较研究

为探究棉花是否具有较强的杂种优势,明确F2杂交棉纤维品质性状和分离特征,筛选出适宜于该区域的优质F2组合。以4个F2杂交组合(瑞杂1号、瑞杂2号、瑞杂4号、J杂708)和2个常规棉品种(J206-5、新陆中38号)为研究材料,通过大田试验比较了F2杂交棉与常规棉棉纤维品质性状的差异,并对F2杂交棉纤维品质性状分离程度进行分析。结果表明:1)4个F2组合材料的纤维品质性状分离都小于常规棉品种,相比常规棉,F2杂交棉的棉纤维品质出现优势衰退的真正原因是28~29mm纤维长度植株比例增加,而>32mm以上纤维长度植株比例减少;2)存在断裂比强度向减弱方向的分离,但是棉花纤维长度和整齐度与常规棉无明显差异,以上品质指标表明F2杂交棉性状分离程度不大。3)杂交棉纤维品质各项指标无显著差异,可以筛选出优良的F2杂交棉组合并在生产上进行推广种植。     

不同玉米基因型磷效率的因子分析

以33个不同玉米基因型为材料,在低磷和高磷两个供磷水平下,对玉米基因型的多个相对生物性状进行因子分析,结果表明：相对地下部干重、相对须根数和相对主根长是易于协同改良的性状,相对叶面积和相对地上部干重也是易于协同改良的性状,改良相对株高也不会对其他性状的改良产生负面影响。选育具有优良的相对地下部干重、相对须根数、相对主根长、相对叶面积、相对地上部干重和相对株高,是培育高磷效率玉米基因型的重要途径。结合相对根系性状因子、相对地上部生物量因子和相对株高因子的系统聚类分析,筛选出高磷效率玉米基因型178和5311。     

Performance analysis of transcritical organic rankine cycle

The performance analysis of a transcritical organic Rankine cycle system driven by exhaust heat is presented by using 24 organic working fluids. Four parameters, such as the net power output, thermal efficiency, exergy efficiency, and mass flow rate of working fluid, are used to evaluate the performance of this recovery cycle. The results reveal that the maximum net power can be obtained for the saturated ORC, when T1/TC is about 0.98～0.99,and the working fluid with higher critical temperature has more net power output. For the supercritical ORC, the higher expander inlet temperature will benefit the net power output, thermal efficiency, and exergy efficiency, as long as the expander inlet pressure isnnot too low. However, the influences of expander inlet pressure on these performance parameters are linked with the expander inlet temperature and working fluids. The capability of doing power output of supercritical ORC is not always better than that of subcritical ORC. Parameters, such as net power, thermal efficiency, and exergy efficiency, and mass flow rate are discontinuous in the process from subcritical conditions to supercritical conditions.     

Sodium nitrite reduces lipopolysaccharide-induced acute lung injury in mice

AIM: To investigate the effect of sodium nitrite (SN) on lipopolysaccharide (LPS)-induced acute lung injury (ALI) and its underlying mechanism in mice. METHODS: All male Institute of Cancer Research (ICR) mice were randomly divided into five groups: Control group; LPS group; and SN 4.8 nmol/L, SN 48 nmol/L, SN 480 nmol/L (ip) groups. Lung wet weight/dry weight (W/D) ratio and permeability were detected. Neutrophil infiltration in bronchoalveolar lavage fluid (BALF) was measured by cel1 counting and morphological changes in lung tissues were assayed by hematoxylin-eosin staining. The 1evels of interleukin-10 (IL-10) and tumor necrosis factor-α (TNF-α) in lung were detected. Nitric oxide (NO) level and nitric oxide synthase (NOS) activity in lung were measured according to the specification. RESULTS: Compared to lung in LPS-induced ALI mice, at doses of 4.8 nmol/L and 48 nmol/L, not 480 nmol/L, SN markedly decreased the lung W/D ratio, total leukocyte number and neutrophil percentage in the BALF, lung permeability, and TNF-α/IL-10 ratio, in lung. SN at dose of 480 nmol/L markedly increased the lung NO level compared to control group. In addition, SN decreased the total NOS and inducible NOS (iNOS) activities compared to LPS-induced ALI mice. CONCLUSION: These results indicate that the protective effect of SN against LPS-induced ALI in mice is associated with the low dose SN-induced NO, as well as the subsequent decrease in iNOS activity and TNF-α/IL-10 ratio.     

近50 a中国降水变化的准周期性特征及未来的变化趋势

通过分区分析了1961-2006年近50 a中国降水周期分量的年际变化特征,并对未来20 a（2006-2026年）降水的可能变化趋势做了预测。结果表明：就年际变化而言,大部分气候区的降水年际变化存在着显著的周期变化,并以高频（准3～4 a）变化为主,且具有相对的稳定性。过去的50 a,各气候区的降水呈现出下降趋势。周期叠加外推的结果表明,未来20 a,除西部干旱（半干旱）区的降水会出现少许的增多外,其余各气候区的降水量会出现弱的减少趋势。     

新西兰防潮型中密度纤维板及其应用

介绍了新西兰生产的高防潮中密度纤维板的性能，特点，产品的一般使用技术要点，以及在家具及室内装修方面的应用技术。     

农两优3135作菜后稻种植表现及高产栽培技术

2012年、2013年农两优3135连续两年参加福建省中稻区试,两年平均产量比对照品种II优明86增产10%左右;2014年、2015年引进在建瓯市水源乡大源村作菜后稻种植,表现高产、抗病。高产栽培技术要点包括适时稀播早播、合理密植、肥水管理、病虫害防治等内容。     

日粮磷和钙磷比例对小型猪(香猪)血清、肠、骨碱性磷酸酶及血清钙磷的影响

36头生长阶段香猪去势公猪 ,通过3×3析因安排分组 ,完全随机区组设计 ,随机分配到9个处理中 ,每个处理4个重复 ,每个重复1头猪。试验两个因子中日粮磷的3个水平分别为0.3 %、0.6 %和0.9 % ;日粮钙磷比例的3个水平为1 :1、1.25 :1和1.5 :1。试验基础日粮由玉米、豆粕、血粉和苜蓿粉组成 ,各处理日粮磷水平和钙磷比例用CaCO3、Na2HPO4 和CaHPO4 调配。从试验开始到结束 ,每隔两周颈静脉采血一次测血清AKP活性和钙、磷 ,并于试验结束时屠宰全部试验猪取小肠和肋骨样测AKP活性。试验结果表明 ,血清AKP活性和第六肋骨AKP活性随日粮磷从0.3 %增加至0.9 %显著下降(P<0.05) ,但十二指肠AKP活性不受日粮磷水平影响。日粮钙磷比例不影响血清、第六肋骨和十二指肠AKP活性(P>0.05)。血清磷随日粮磷增加而增加 ,随日粮钙磷比例增加而下降。血清钙不受日粮磷水平影响 ,但在日粮钙磷比例为1.25 :1时最高