冬季猪舍粪便贮存过程中CH4排放特征试验

利用丹麦猪舍和液态猪粪便进行了CH4气体排放测试,比较了3种粪坑内粪便高度（0.15、0.40、0.65m）、4种通风量（211、650、1852、3088m3/h）、粪坑内有无挡板情况下冬季猪舍粪便贮存过程中CH4排放通量。测试结果表明：粪便高度、粪便温度和通风量可以用来解释大部分的CH4排放通量变化差异;对于使用渗透性天花板进气和负压通风排气系统,4种通风量之间CH4排放通量差异不显著,但由于通风量的增加同时会降低舍内与粪坑内空气温度和粪便温度,因此要综合考虑通风量和温度对气体排放通量的影响;液态猪粪便中CH4排放通量随着粪坑内粪便高度的降低而减少;设置粪坑挡板对粪坑内CH4排放没有影响;敏感性分析表明CH4排放通量相对于粪便温度、粪便高度和通风量的敏感性依次减小（敏感度依次减小）。在较低的通风量和粪便高度变化区间,CH4排放通量变化的敏感性要高于较高的通风量和粪便高度变化区间,但对于粪便温度变化趋势正好相反。     

饲料收获机矮秆割台拨禾轮导轨运动轨迹研究

对矮秆割台核心喂入部件拨禾轮的结构和运动轨迹进行了分析研究,利用计算机辅助软件对拨禾轮导轨曲线进行了优化设计,并对拨禾弹齿运动轨迹进行了模拟,找出了保证矮秆割台能够正常工作的弹齿运动轨迹形状,确定其正常工作的拨禾轮速比区间为（0.78,∞）。     

水果采摘机器人通用夹持机构设计

为提高采摘机器人的实用性和利用率,提出了一种通用型夹持机构,并构建了虚拟样机。为使机械夹持不损伤水果,研究了水果受力对夹持构型的影响,以柑橘为例进行变形、应力分析,为机构提出设计依据,进而对结构进行优化,确定了机构外壳及杆件的合理参数和对果实损伤最小的夹持量,单类型水果夹持量为直径方向小于2mm。     

马波沙星在罗非鱼体内的药物代谢动力学研究

【目的】研究马波沙星在罗非鱼Oreochromis niloticus体内的药物代谢动力学(简称药动学)特征,为临床合理用药提供参考。【方法】将罗非鱼随机分成2组,水温维持在30℃,以10 mg·kg-1分别单剂量肌内注射和口服给药,高效液相色谱(HPLC)-荧光检测法测定血浆中马波沙星的质量浓度,用Win Nonlin 6.1药动学软件的"非房室模型"分析药动学参数。【结果】肌内注射马波沙星后,药物吸收和消除均较口服快,体内分布广泛。达峰时间(tmax)为0.25 h,峰质量浓度(ρmax)为4.31μg·mL~(-1),消除半衰期(t1/2λz)为19.21 h,表观分布容积为3.94L·kg-1,药-时曲线下面积(AUC)为70.36μg·mL~(-1)·h-1。口服马波沙星后,药物吸收和消除均较慢,体内分布广泛。tmax为4.00 h,ρmax为2.45μg·mL~(-1),t1/2λz为22.67 h,表观分布容积为4.27 L·kg-1,AUC为76.66μg·mL~(-1)·h-1。【结论】10 mg·kg-1马波沙星能够有效治疗大多数敏感菌引起的罗非鱼感染。     

福建省将乐县金溪建电站前后雨水情变化分析

本文通过对将乐县金溪建电站前的1953～1978年、建电站后的1990～2009年雨水情进行分析,结果表明:自然状态下的将乐县(1953～1978年)无论雨水大小,每年都有洪水超过警戒水位,年最大洪水发生时间在4～7月;1953～1978年有16年的当年最大洪峰水位发生在当年最大日降雨量当日至第16日内,频率为61.5...     

鲟鱼气泡病病例简报

本文首次对鲟鱼气泡病作了报道,文章对该病病症进行了描述。初步分析了鲟鱼气泡病病因,并提出了防治鲟鱼气泡病的几点意见。     

微卫星DNA标记在番茄亲子鉴定中的应用

采用242对微卫星DNA标记引物分析了29份番茄自交系的遗传多态性,从中筛选出扩增带型清晰、稳定的34对引物,34对引物的平均等位基因数为4.53,平均多态信息量(PIC)为0.514 1,累积鉴别力(CDP)达0.999 999.利用其中的11对SSR引物对杂交种‘浙杂210’、母本‘01-199-1-1-0’及7个...     

对小型茶树开沟和施肥一体机的有限元分析

目前,在广西等地区的茶树开沟和施肥主要依靠纯人工的方法进行,虽然目前有用于茶树的开沟与施肥的机械,但限于成本以及广西丘陵地带等地理条件的制约,市场上茶树的开沟机械无法适于广西地区的使用,而人工的方法劳动强度大,不利于大规模地进行茶树的种植。为了解决农民在对小型茶树开沟和施肥过程中劳动强度大等问题,提出了一种小型茶树开沟和施肥一体机的机械,并在此之前申请了国家发明专利。运用UG对该机械进行有限元分析,以此来验证茶树开沟和施肥一体机的机械化强度满足生产要求,旨在提高茶树种植业的经济效益和产品化水平,满足茶叶的增长需求。     

HBV/HAV复合抗原基因在CHO细胞中的表达

为探讨HBV／HAV复合疫苗的可行性，利用DNA重组技术将HBsAg与HAW复合多表位抗原基因VPX进行融合，插入到真核表达质粒pVAX1多克隆位点，构建成核酸表达疫苗pVAX1／SVPX，将其转染CHO细胞。转染细胞培养48h后，进行RTPCR、Western-blot、ELISA分析，结果表明HBV／HAV复合抗原基因SVPX能够在CHO细胞内转录、表达，融合蛋白具有HBV和HAV抗原的特性。     

Determinants of the biodiversity patterns of ammonia-oxidizing archaea community in two contrasting forest stands

Purpose

The variation in soil microbial community patterns is primarily influenced by ecological processes associated with spatial distance and environmental heterogeneities. However, the relative importance of these processes in determining the patterns of soil microbial biodiversity in different successional forests remains unclear.

Materials and methods

Based on the species data from denaturing gradient gel electrophoresis (DGGE) analysis, we described the composition and beta diversity of ammonia-oxidizing archaea (AOA) community, an important functional microbial group in regulating nitrogen cycle, in a middle-succeed stand (60 years of secondary succession) and an undisturbed native stand in a subtropical forest in southern China. The composition pattern was examined using a multi-response permutation procedure (MRPP), and the beta diversity was described using the Sørensen index. The relative influence of edaphic, vegetational, spatial, and topographical factors on AOA composition and beta diversity was assessed by variation partitioning and multiple regression on distance matrices (MRM), respectively.

Results and discussion

We did not find any stand-specific patterns in AOA community composition in the two stands; however, the influential variables were different between the two stands; 7.3 and 4.5 % of the total variation in AOA community composition could be explained by edaphic (i.e., available potassium and total phosphorus) and spatial variables, respectively, in the middle-succeed stand, while 3.7 and 2.8 % of the variation were explained by spatial variable and available phosphorus, respectively, in the native stand. Soil total phosphorus influenced the beta diversity of AOA community most in the middle-succeed stand, while genetic distance of tree species was found to be the most important factor in driving the beta diversity pattern in the native stand.

Conclusions

Soil nutrients influenced the beta diversity of AOA community in the middle-succeed stand more than that in the native stand, while vegetation is more important in the native stand. The substantial unexplained variations were possibly due to the effects of other unmeasured variables. Nevertheless, dispersal process is more important in controlling AOA community composition in the native stand, while processes associated with environmental heterogeneities are more important in the middle-succeed stand in this subtropical forest.