Hatching phenology,life history and population dynamics of the Oriental clam shrimp Eulimnadia indocylindrova Durga Prasad and Simhachalam with notes on phenology patterns in the Spinicaudata

We studied the natural history, hatching phenology and egg bank composition of the Oriental spinicaudatan clam shrimp Eulimnadia indocylindrova Durga Prasad and Simhachalam using both field studies and ex situ sediment rehydration. Field observations revealed that hatching began very early (1–2 days) after inundation, and continued for about 5 days. Mature adults could be observed by 10 days, and they survived up to 16 days. The population showed a largely hermaphrodite-biased sex ratio (male:hermaphrodite 1:3) observed over three years, with a decrease in number of males throughout the hydroperiod. Both amphigenic and monogenic hermaphrodites were observed. The total lifetime fecundity recorded was about 300 eggs laid in multiple clutches. The egg bank composition showed a high proportion of intact eggs, indicative of predictable hydrations and low sediment adversity. Hatching began on the first day post-inundation for all successive cyclical hydration treatments, with peak hatching on days 2 and 3. Hatching rate was highest (57% of total hatching in successive cycles) for the first hydration, decreasing subsequently for the further hydrations. Hatching duration decreased with successive hydrations and was the longest (around 7 days) for the first hydration. Maximum hatching (93%) occurred in the first 10 days for the continuous hydration treatment. Overall, the total emergence of nauplii in successive hydrations was larger than that observed for the continuous hydration treatment, indicative of a risk-spreading strategy across hydroperiods. Early and concentrated naupliar emergence, along with decreased hatching durations for successive cycles, was observed for all the hydrations. A survey of literature revealed a general lack of data on hatching phenology of clam shrimps, particularly from tropical and sub-tropical regions. Based on the available data, it appears that hatching patterns, particularly high, early hatching fractions, are commonly observed in Spinicaudata species, and do not seem to differ much across biogeographical regions.     

沙葱总RNA的提取与质量分析

以沙葱种子和沙葱幼叶为材料,分别用RNAiso Plus试剂法、RNAiso Plus醋酸钠改进法、CTAB-异丙醇法、CTAB-LiCl法4种不同的方法提取沙葱总RNA,经琼脂糖凝胶电泳,采用紫外分光光度法测定总RNA纯度并进行RT-PCR检测.结果表明,沙葱不同组织总RNA提取的最优方法有所不同.采用CTAB-LiCl法能有效地提取出沙葱种子高质量、完整性好而且无胶状不溶物的RNA,没有明显的蛋白和基因组DNA的污染.采用RNAiso Plus醋酸钠改进法能有效地去除沙葱幼叶中多糖的干扰,所提取的RNA条带清晰,完整性好,是沙葱幼叶总RNA提取的有效方法.     

黑节铁皮石斛原球茎诱导、再分化以及腋芽萌发和生根的初步研究

对黑节铁皮石斛的原球茎诱导、再分化以及腋芽萌发和生根进行了初步的研究,以期为黑节铁皮石斛的人工繁殖提供理论指导。采用植物组织培养和单因子试验的方法,获得了黑节铁皮石斛带芽茎段最佳的消毒方式为70%酒精处理30s后再用0.1%HgCl2处理20min。黑节铁皮石斛带芽茎段原球茎诱导的最佳培养基为MS＋KT1mg/L＋NAA0.1mg/L。黑节铁皮石斛带芽茎段原球茎再分化的最佳培养基为MS＋KT2mg/L＋NAA0.5mg/L。黑节铁皮石斛带芽茎段腋芽萌发的最佳培养基为MS＋KT2mg/L＋NAA0.5mg/L。黑节铁皮石斛带芽茎段生根的最佳培养基为1/2MS＋NAA0.5mg/L。这些实验结果为黑节铁皮石斛试管苗的工厂化生产奠定了技术基础。     

栽培大黄叶片色素的含量比较

该实验以栽培于同一生境下的4年生唐古特大黄与药用大黄为研究对象,对两种大黄同一部位叶片中的色素含量进行比较研究,从光合色素水平比较高原强紫外线辐射下两种大黄的生理适应性.结果表明唐古特大黄叶片中的叶绿素a、叶绿素b、叶绿素总量、类胡萝卜素含量均高于药用大黄.     

混杂纤维树脂基复合材料梁试验

为研究碳纤维含量对混杂纤维树脂基复合材料梁性能的影响,进行了4组14根3种不同碳纤维含量的混杂纤维树脂基复合材料HFRP(hybrid fiber reinforced plastic)梁的对比试验,分析了梁的制备工艺稳定性、抗弯刚度提高程度、腹板剪切极限承栽力和受弯构件的可能破坏形式.试验结果表明:成型工艺制备的HFRP梁密度具有良好的均匀性,但抗弯刚度离散性较大;与单一纤维复合材料梁相比,HFRP梁可以有效地提高抗弯刚度,但构件的腹板剪切承载力基本不变;构件会出现翼缘局部破坏、腹板剪切破坏和层间剪切破坏3种破坏形式.     

火灾工况下城市隧道自然通风模型实验

南京城东隧道采用自然通风方式,为判定其在火灾工况下能否满足安全性要求,开展了火灾工况下隧道自然通风模型实验,考察了最不利工况下烟气排除效果.从理论上探讨了模型与原型的相似规律,并以此为指导搭建模型实验台.结合实验现象和数据,分析了烟气温度、CO2浓度分布变化规律和烟气运动规律,与隧道原型实验进行了对比,验证了实验结果的可信性.并对火灾时逃生人员的安全性进行了分析,得到了烟气温度最高达77.2°C,烟气大部分时间维持在2 m以上高度的结论,此时逃生人员的安全能够得到保证.     

爆破地震波的分形机制

为深入研究爆破地震波的分形特性,采用分形理论中的盒维数方法,针对爆破地震信号的传播规律和特征,建立了其分形盒维数模型,结合在岩石场地进行深孔爆破的试验数据,计算了爆破震动信号的分形盒维数值D.通过分析D的数理意义及其与场地介质特性的关系,探讨了爆破地震波分形的物理力学机制.研究表明,爆破地震信号D能够反映爆破地震波传递介质岩石性质的特征信息,可作为描述爆破地震信号一个新的重要参量,为建立更加有效的爆破震动响应预测模型奠定了基础.     

平菇菌种S_(17)、F_6生长发育条件的研究

该实验对平菇的两个种S-17、F_6菌丝生长及子实体发育条件进行了试验研究,为生产提供一些依据,具有一定实践意义。     

新疆5种蒿属植物的脂肪酸成分研究

采用气相色谱法首次对新疆5种蒿属植物脂肪酸成分进行了分析．结果表明，湿地蒿含21种脂肪酸(鉴定了其中18种)；黄花蒿含21种脂肪酸(鉴定了其中19种)；龙蒿含19种脂肪酸(鉴定了其中17种)；白叶蒿含22种脂肪酸(鉴定了其中19种)；北艾蒿含19种脂肪酸(鉴定了其中17种)．多不饱和脂肪酸(PUFA)与饱和脂肪酸(SFA)相对含量比值显示，5种蒿的油脂都具有降血脂的功能．5种蒿所含脂肪酸中，人体必需亚油酸亚麻酸含量较高．探讨了5种蒿属植物脂肪酸成分的异同及可利用性．