瑞昌山药茎段组织培养研究

用不同种类、浓度的植物生长调节剂对瑞昌山药茎段进行离体培养试验.试验结果表明,诱导瑞昌山药不定芽萌发最佳培养基为MS+6-BA 1.5 mg/L+NAA 1.0 mg/L,不定芽萌芽率为90%:继代培养用MS+6-BA 0.5 mg/L+NAA 0.5 mg/L,长势较理想;生根培养用1/2 MS+NAA 0.5 mg/L+0.2 g/L活性炭的培养基,瑞昌山药生根的效果最佳.     

烟叶编持机的设计与开发

为了解决人工编烟费时、费力,效率低下的问题,设计开发了摆动钩针式烟叶编持机,设计编烟速度为12～20s/m可调,铺叶厚度和编叶数量可自动调整,综合辅助用工实际应用效率达手工编烟的5倍以上.编烟测试表明,该型编烟机编制均匀牢固,线迹美观,明显减少了编烟用工,具有较好的应用前景.     

我国粮食综合生产能力效率评价及政策建议

为提高我国粮食综合生产能力、确保国家粮食安全,需要对当前粮食综合生产效率进行评价.通过分析粮食综合生产能力的影响因素,建立评价指标体系,并运用DEA分析方法,对1990-2006年我国粮食综合生产能力进行效率评价.研究结果表明,历年的粮食生产效率普遍较高,平均效率值为0.9985.DEA整体技术有效的年份有13年,而造成部分年份生产无效率的原因在于较低的规模效率.在效率优化的基础上,提出了相关政策建议.     

静电喷雾中的雾滴荷电特性分析

通过建立静电喷雾3种充电方式的电学模型,分析了雾滴在电场作用下的荷电机理及荷质比与荷电电压间的关系,其结果表明:充电方式决定电荷产生机理和雾滴的荷电效果.在稳定的工作状态下,接触充电电荷为正极性;感应充电和电晕充电显示负极性;同时,荷质比与充电电压成线性关系,随充电电压的升高而增大,充电电压升高引起介质介电状态的改变,会使充电方式和电荷特性产生质的变化;气体的自持放电使感应充电成为电晕充电,荷质比产生跳跃,形成倒Z形的荷质比-电压关系;当电晕进入电弧放电时,电晕充电成为接触充电,电荷极性产生突变.     

DFC技术在农业机械设计中的应用

描述了面向成本设计(Design for cost)的概念以及我国农机行业的现状;通过对农机全生命周期的分析,阐述了在我国农机企业中实施面向成本设计的必要性;介绍了在农机设计阶段所需要的成本估算方法, 并提出了基于CAD/CAPP模型的农机成本估算框架体系,从而有助于提高我国自主品牌农机的市场竞争力.     

提高特殊柱塞泵往复密封寿命的优化设计

针对输送含颗粒介质柱塞泵的柱塞、填料寿命问题,从接触型往复密封的摩擦学机理出发,通过优化匹配柱塞直径、行程及泵速各参数,合理控制柱塞的线速度,降低摩擦速度,对柱塞填料密封进行优化设计;通过求解间隙中的流体力学层流运动问题,合理控制冲洗液的压力,保证全压密封系统中接触区的液膜处在混合润滑状态下工作,使密封副有良好的润滑;提出了两种填料函方案,并和采用不同表面处理工艺的柱塞及多种填料搭配组合进行试验.试验结果表明,密封累计运行了4 455 h后,组合1和组合2柱塞的磨损仅为0.03 mm和0.05 mm;在生产实际中,改进后的密封设计,使柱塞及填料的使用寿命从原来的1 500 h提高到4 500 h以上.     

Effects of dietary highly unsaturated fatty acids and astaxanthin on the fecundity and lipid content of pond-reared Penaeus monodon (Fabricius) broodstock

Five diets that contained fresh squid meat as the basic constituent and were supplemented with different amounts of highly unsaturated fatty acids (HUFA) and astaxanthin were fed to pond‐reared Penaeus monodon broodstock. Diet A was sole squid meat. Diets B and C were supplemented with astaxanthin 50 and 100 mg kg^?1 respectively. Diets D and E were supplemented with HUFA 5 and 10 g kg^?1 and astaxanthin 50 mg kg^?1 respectively. The result showed that the group fed diet E had the best reproductive performance in all experimental groups. It had a higher proportion of spawns (71.5%), spawning rate (0.047), a shorter latency period (7.7±0.3 d), higher absolute fecundity (× 10³) (361.6±5.5) and egg production/female (× 10³) (597.0±18.0) than all the other experimental groups. The fatty acid composition in broodstock diets strongly affected the tissue and fecundity of broodstock. Good correlations between the content of 20:4n‐6 in eggs and the fecundity (r²=0.6109) and egg production (r²=0.9876) of broodstock were found. On the other hand, 22:6n‐3 and DHA/EPA ratio was negatively correlated with the fecundity of broodstock (r²=0.5362, 0.8702 respectively). The result also showed that the balance between n‐3 and n‐6 fatty acid families, total polyunsaturated fatty acids and total saturated fatty acid and 20:5n‐3 (EPA) and 22:6n‐3 (DHA) may play vital roles in maturation and reproductive performance of P. monodon broodstock.     

育珠期三角帆蚌的生长及其与珍珠增长的关系

通过对三角帆蚌壳长、壳宽、蚌总重（整体湿重）、内脏团湿重、壳重和珍珠重等指标在5-11月间的逐月连续测定,研究了常规养殖模式下育珠期2龄三角帆蚌在主要生长季节的生长规律及其与珍珠生长的相关性。结果表明：珍珠重(PW)与壳长(SL)、壳宽(SW)的关系分别为PW=0.0008SL3.3946 (R2=0.6948)和PW=0.7809SW1.0227 (R2=0.6888);而珍珠重(PW)与蚌重(TW)、内脏团重(BW)和壳重(W)的关系分别为PW=0.0021TW1.5434 (R2=0.7337),PW=0.107BW0.9125 (R2=0.7158)和PW=0.0324W1.1259 (R2=0.7101);三角帆蚌总重(TW)与壳长(SL)、 壳宽(SW)的关系最适合用指数函数进行拟合,其关系式分别为TW=16.003e0.1681SL,(R2=0.7961),和TW=64.311e0.1372SW (R2=0.6822);而内脏团重(BW)和壳重(W)与壳长(SL)、壳宽(SW)的关系则适合为幂函数曲线拟合,关系式分别为BW=0.0188SL3.1427,(R2=0.6927);W=0.0656SL2.7721, (R2=0.8271)和BW=12.446SW0.8974 (R2=0.617);W=19.876SW0.802 (R2=0.7563)。本研究结果发现,珍珠生长与蚌总重、壳长和壳宽等外部测量指标之间的相关性显著,从而无须通过杀蚌取珠而直接通过这些外部生长指标的测定就能较好地了解珍珠的生长,更好地为珍珠养殖生产和管理提供指导。     

CYP450 epoxygenase/EET pathway attenuates adipose inflammation of obese mice through HIF-1α

AIM To investigate the effects of cytochrome P450 （CYP450） epoxygenase/epoxyeicosatrienoic acid （EET） pathway on insulin resistance in obese mice, and to explore the possible mechanisms. METHODS High-fat diet-induced obesity model was established in C57BL/6Cnc mice, and the obese mice were randomly divided into 3 groups, including obesity group （treated with saline; n=10）, EET group （treated with 11,12-EET; n=10） and EET inhibitor 14,15-epoxyeicosa-5（Z）-enoic acid （EEZE） group （n=10）. Normal C57BL/6Cnc mice （n=10） treated with saline served as control. Protein expression of CYP2J2 （one of CYP450 epoxygenases） and hypoxia-inducible factor-1α （HIF-1α） was measured by Western blot. Vessel-like structure was detected by immunofluorescence staining. The serum levels of insulin, tumor necrosis factor-α （TNF-α）, interleukin （IL）-1β, IL-6 and monocyte chemoattractant protein-1 （MCP-1） were measured by ELISA. RESULTS In obese mice, homeostasis model assessment of insulin resistance （HOMA-IR） values were increased, the protein level of CYP2J2 was reduced, and the protein level of HIF-1α was increased in adipose tissues as compared with the controls （P<0.05）. The serum levels of MCP-1, IL-1β, IL-6 and TNF-α were also significantly increased in obese mice （P<0.05）. After treatment with 11, 12-EET, the HOMA-IR values were decreased compared with vehicle-treated obese mice, HIF-1α expression levels were decreased in the adipose tissue, and the serum levels of MCP-1, IL-1β, IL-6 and TNF-α were reduced （P<0.05）. Immunohistochemical results of adipose tissue from vehicle-treated obese mice showed a marked decrease in vessel-like structures （CD31-positive） compared with normal control mice （P<0.05）. EET treatment significantly increased the newly formed vessel-like structures in the visceral adipose tissues of obese mice as compared with vehicle-treated obese mice （P<0.05）. CONCLUSION High-fat diet-induced obesity and insulin resistance are closely related to the CYP450 pathway. Exogenous EETs effectively decrease obesity-induced insulin resistance possibly through pro-angiogenesis and attenuation of hypoxia and inflammation.     

陆地棉脱水素基因GhDHN1启动子序列分析

为了筛选棉花抗逆转基因育种的候选启动子,根据陆地棉脱水素基因GhDHN1的cDNA序列和陆地棉基因组序列,利用生物信息学分析方法,获得棉花陆地棉脱水素基因GhDHN1启动子序列。结果表明,该启动子上多个位点含有启动子的基本元件TATA-box和CAAT-box,并含有非生物逆境胁迫响应元件、响应植物激素顺式作用元件、多种光调控相关的顺式作用元件以及胚乳表达顺式调控元件等。推测GhDHN1基因的启动子受光诱导,同时受低温和干旱胁迫等非生物逆境的诱导,参与棉花的生长发育。