土地利用现状调查资料在耕地地力评价中的应用

以1∶10 000土地利用现状图为空间数据框架基础,结合农业部门现有的土壤普查和样点调查分析资料进行耕地地力评价,相比目前我国测土配方施肥工作方案中以1∶50 000为基础进行的耕地地力评价结果,本研究方法的评价结果耕地分布的空间定位更正确、更切合现状,评价单元的划分更合理、耕地地力等级划分更加精细,能大幅度提高耕地地力评价的精度。本研究方法在耕地地力评价上的应用,有利于为建立测土配方施肥信息管理系统提供详细的基础信息和科学管理耕地,更好地满足精准农业和农业生产中施肥管理对耕地信息的需要。     

轿车冲击高路阶的安全性动态仿真研究

应用计算机模拟仿真的方法,对轿车冲击高路阶的安全性进行研究,可以改善实车试验的成本高、周期长、重复性差以及检测数据量有限等缺点。根据实车试验的条件和要求,建立轿车-高路阶系统的有限元模型,进行动态仿真,并与试验数据对比。对比表明仿真结果与试验吻合良好,能量变化也符合实际的情况,在此基础上可以进一步研究车辆在冲击载荷作用下的非线性动态响应,为深入研究车辆的可靠性、安全性提供依据。     

The banding patterns of normal canine chromosomes

The chromosomal banding patterns of canine normal chromosome were analyzed by G-, Q-, C- and N-banding techniques. The chromosomes of canine normal lymphocytes consisted of 38 acrocentric autosome pairs and X-, Y-metacentric sex chromosomes. Their G- and Q-banding patterns corresponded to the those reported by Manolache et al. in 1976. C-bands of chromosomes were found on the centromeric regions of the 7th, 26th, 34th, 35th, 37th and 38th pairs of chromosomes. In addition, N-bands whose location had not been confirmed until now were recognized on the telomitic regions of the 7th, 9th and 22nd pairs of chromosomes.     

马斯京根法洪水演算公式参数确定方法的商榷

针对近年来最小二乘法用于马斯京根法出现的一种趋势,从流量演算法的水力学理论出发,剖析了马斯京根法进行洪水演算的原理,指出了马斯京根法中参数的物理意义.同时通过马斯京根法的理论解释,从理论上论证了康吉演算法推算具有衰减特性的洪水波运动必须满足的条件,指出了最小二乘法用于马斯京根法公式参数确定时造成的参数物理意义的模糊,并且该做法并不能从理论上保证该条件的成立以及可能出现的问题,所得结论愿与读者商榷.     

Effects of zinc on intact and castrated cockerels

1. Fourteen‐week‐old intact and castrated cockerels (White Leghorn) were injected intramuscularly with zinc (100 μg/kg body weight) as zinc ammonium sulphate solution once daily for 4 weeks and the effects on testes, pituitary and adrenal glands investigated histologically.

2. In intact cocks zinc decreased testes weight significantly, inhibited spermatogenesis and disturbed testicular hormone production. There was an increase in pituitary gonadotrophic cell activity, perhaps an indication of feed‐back response to low concentration of testicular hormone. Cortical and medullary cells of the adrenal glands showed signs of activation.

3. No discernible effects of zinc injection on pituitary and adrenal cells of castrates were observed. This may reflect a decrease in pituitary and adrenal responsiveness to repeated stimulation with zinc.

4. The results indicate that the effectiveness of a given dose of zinc was dependent on the physiological condition of the cockerels and the effective site of zinc action was centred in the testes.     

家蚕BmN细胞S期同步化体系建立

细胞S期为DNA复制期,探索细胞S期的同步化将为研究各种调控因子对DNA复制、细胞分裂和增殖的影响奠定基础。本研究以家蚕BmN细胞为研究对象,采用脱氧胸苷(TdR)双阻断、脱氧胸苷-诺考达唑(TdR-Nocodazole)双阻断及羟基脲(HU)法,探索BmN细胞S期同步化的最佳体系。结果发现,TdR双阻断法处理对BmN细胞S期的同步化效率为67.2%,TdR-Nocodazole双阻断法处理为69.7%,HU处理对S期同步化效果最好,达90%以上。进一步对HU处理后不同释放时间点的细胞进行研究发现,1 mmol/mL HU处理后释放7 h时BmN细胞S期同步化效率最高,达94.9%。通过不同处理方法研究家蚕BmN细胞的S期同步化效果,发现1 mmol/mL的HU处理16 h,然后于正常培养基中释放7 h,可有效的将BmN细胞同步化在S期,且该处理方法简单,易于操作。     

残膜机械化回收技术

地膜具有保墒、提高地温、抑制杂草生长和增产增收等作用,得到了广泛应用,并极大地促进了我国农业经济的发展。但是残留在土壤中的地膜极难降解,给农业生产和生态环境造成了巨大危害,残膜回收对于保护耕地、改善农田生态环境具有重要的意义。总结了国内外残膜回收技术的研究现状及研究方法,指出我国残膜回收机具存在的主要问题,提出了实施机械化残膜回收技术的建议,为机械化回收残膜的研究提供理论依据。      

基于数据挖掘的熊继柏教授诊疗失眠模型构建研究

目的 构建熊继柏教授关于失眠的辨证论治模型。方法 通过对熊继柏教授治疗失眠的162人、254例次病案进行整理,运用Weka 3.7.12软件,采用FP-Growth算法,对就诊患者中不同性别与年龄段的证候特点、方剂间配伍、证候与用方进行关联规则分析,使用SPSS 17.0软件对常用药物进行R型系统聚类分析。结果 就诊的失眠患者证候特征随年龄变化由单纯虚证或实证逐渐演变为虚实夹杂证,男性与女性的失眠证候特点各异;熊继柏教授治疗失眠的4个常用方剂组合中,黄连温胆汤与痰热内扰证相关联,黄连温胆汤合酸枣仁汤与痰热兼肝郁化火证相关联,酸枣仁汤合孔圣枕中丹与肝肾阴虚相关联,黄连温胆汤、酸枣仁汤、孔圣枕中丹3方合用与肝肾阴虚合并痰热证相关联。常用治疗失眠的药物为酸枣仁、龙齿、甘草、茯神、黄连、半夏、陈皮、竹茹、枳实、知母等,大致可分为清热化痰、重镇安神、育阴潜阳3类。结论 熊继柏教授辨治失眠,多责之于痰热内扰、肝郁化火、肝肾阴虚,辨证注重辨舌脉,因证选方,经方与时方灵活搭配应用。     

Oxidative stress and antioxidant responses in juvenile Brazilian flounder <Emphasis Type="Italic">Paralichthys orbignyanus</Emphasis> exposed to sublethal levels of nitrite

This study evaluated the effects of short-term exposure to sublethal levels of nitrite on oxidative stress parameters and histology of juvenile Brazilian flounder Paralichthys orbignyanus. An assessment of fish recovery was also performed. Fish were exposed to 0.08 (control), 5.72, 10.43, and 15.27 NO₂-N mg L^?1 for 10 days followed by the same recovery time. Gill, liver, and muscle samples were collected after 1, 5, and 10 days of exposure and after recovery for the measurement of antioxidant capacity against peroxyl radicals (ACAP), glutathione-S-transferase (GST) activity, content of non-protein (NPSH) and protein thiols (PSH), and lipid peroxidation levels by thiobarbituric acid-reactive substances (TBARS) content. Nitrite exposure induced alterations which compromised the overall antioxidant system (reduced ACAP and GST activity) and enhanced oxidative damage in lipids and proteins. Increases in GST activity and NPSH and PSH contents were also demonstrated. The recovery period allowed for resumption of basal levels for all (treatment 5.72 NO₂-N mg L^?1) or some of the evaluated parameters (other treatments). In conclusion, exposure to nitrite concentrations from 5.72 to 15.27 NO₂-N mg L^?1 induced oxidative stress and antioxidant responses in juvenile Brazilian flounder. The 10-day recovery period was sufficient for a complete resumption of basal physiological condition of fish exposed to concentrations of up to 5.72 NO₂-N mg L^?1.