施用有机肥对生菜产量和品质影响的Meta分析

通过研究有机肥对生菜产量和品质的影响,为生菜的绿色生产及提质增效提供数据支撑。在中国知网(CNKI)、万方、维普、Web of Science等数据库中,分别以“生菜(lettuce)”或(or)“叶用莴苣(lettuce)”和(and)“有机肥(organic fertilizer)”为     

水稻植质钵育秧盘制备工艺及参数优化

为实现适合中国国情的钵育栽植技术,该文以水稻秸秆为主要原料,配以热固性胶粘剂、固化剂和增强剂经热压制备水稻植质钵育秧盘,采用正交试验设计分析成型配比(施胶量、固化剂量、增强剂量和混料量)和制备工艺(成型压力、模具温度和保压时间)对植质钵育秧盘性能影响。通过对试验结果分析得出制备植质钵育秧盘工艺优化参数为:施胶量0.9kg、固化剂量0.002kg、增强剂量0.09kg、混料量1.3kg、成型压力30MPa、模具温度120℃、保压时间300s,优化后的工艺参数可满足实验室试验研究要求(钵孔率99.46%,膨胀率1.12%),为进一步研究和植质钵育秧盘产业化生产提供技术借鉴与参考。     

日粮类型对细毛羊甲烷排放及代谢物碳残留的影响

为探索减少或控制反刍动物向大气中排放污染物的方法,该文就日粮类型对绵羊甲烷排放及代谢物中碳残留的影响进行探讨。试验选择60只4月龄、体重为25 kg左右的新疆细毛羊进行完全随机试验设计分成4组。Ⅰ组和Ⅱ组日粮精粗比为2：8,Ⅲ组和Ⅳ组日粮精粗比为4：6,Ⅰ组和Ⅲ组粗饲料为玉米秸秆,Ⅱ组和Ⅳ组粗饲料为玉米青贮。结果表明,用玉米青贮完全替代玉米秸秆饲喂绵羊时,甲烷产量Ⅱ组比Ⅰ组显著降低（P＜0.01）,Ⅳ组比Ⅲ组降低了12%（P＞0.05）。当粗饲料为玉米秸秆时,产甲烷效率随日粮精粗比的提高显著降低（P＜0.05）。当粗饲料为玉米青贮时,产甲烷效率组间差异不显著（P＞0.05）。代谢物中的碳残留量Ⅳ组比Ⅰ组显著降低（P＜0.05）,Ⅱ组和Ⅳ组分别比Ⅰ组和Ⅲ组降低16.67%和9.09%（P＞0.05）。研究结果表明,日粮类型对新疆细毛羊排放甲烷有显著影响,同时也影响其代谢物中碳的残留量。     

北京市气候变化对奶牛热冷应激的影响

气候变化对奶牛养殖的影响日益凸显,一些地区奶牛养殖的热应激或冷应激外部环境有所加剧。该文采用温湿度指数（temperature humidity index,THI）和风寒温度（wind chill temperature,WCT）2个指标,分析了北京地区1951－2012年逐日的THI和WCT的变化特征,重点分析了气候变化对奶牛养殖应激环境变化规律的影响。结果表明：近62 a来北京地区温度提升了1.93℃,气候变暖特征明显快于全国,气候变化加剧了北京地区热应激温度环境,降低了冷应激温度环境,综合考虑相对湿度和风速等气象因素,气候变化对北京地区热应激综合环境影响小,对冷应激综合环境影响大。但值得关注的是,2008年以来,北京地区热冷应激环境呈现"双升"态势,尤其冷应激环境明显增强,2012年冷应激天数为近10 a来最高,对北京地区的奶产量产生了不利影响。研究结论对以开放或半开放式牛舍养殖为主的北京地区的牛舍改造和应激设施设备改善提供了科学决策依据。     

白缘䱀的年龄结构与生长特征及生活史类型

为丰富白缘?(Liobagrus marginatus)的基础生物学资料,在金沙江支流黑水河采集白缘?244尾,分析其年龄结构、生长特性和生活史类型,并通过脊椎骨进行其年龄鉴定。结果显示,黑水河白缘?由5个年龄组构成,其中以2龄个体为主,占50.4%。全长与体重的关系式为W=3×10-5L2.78 （R2=0.947）,全长与体重的Von Bertalanffy生长方程分别为Lt =133. 13 [1 - e-0.24 (t+1.92)]和Wt = 24.02 [1- e-0.24 (t+1.92)]2.78。体重生长速度和加速度均具有拐点,拐点年龄为2.34龄,拐点体长85.19 mm,拐点体重6.30 g。通过模糊聚类法分析,确认白缘?属于r-选择鱼类。研究表明,白缘?的种群结构呈现低龄化,水电开发和过度捕捞是影响其种群结构的主要因素;白缘?的捕捞规格应该高于其拐点年龄,即体长大于85.19 mm,体重大于6.30 g。     

弱光对茄子光合系统Ⅱ（PSⅡ）的影响

根据快速叶绿素荧光诱导动力学原理,以遮光(光照强度相当于自然光照的40%)15 d 或30 d为处理,以同期生长不遮光(自然光照)为对照,用JIP-测定法分析了弱光对茄子光合系统Ⅱ(PSⅡ)结构和功能的影响.遮光使O-J的荧光上升速度明显加快.遮光导致反应中心捕获的激子中用来推动电子传递到电子传递链中超过QA的其它电子受体的激子占用来推动QA还原激子的比率(ψO)、单位叶面积上有活性的反应中心的比例(RC/CSO)、单位面积电子传递的量子产额(ET/CS)和单位叶面积热耗散(DI/CS)降低,但是反映单位反应中心活性的各项比活性参数如ABS/RC、TR/RC、ET/RC、DI/RC值却升高.最大光化学效率(φPo)受弱光影响不大,但以吸收光能为基础的性能指数PIABS和以单位面积为基础的性能指数PICS却分别减少22.76%和25.12%.通过以上结果我们得出如下推断:(1)遮光导致PSⅡ反应中心受体侧QA-往下的电子传递体减少,较多的光能被用来还原QA;(2)长期弱光条件不能满足叶片生长的需要,叶片中生成的PSⅡ反应中心数量减少,并产生了非QB还原反应中心(NQB);(3)在遮光胁迫下性能指数比最大光化学效率(φPo)更敏感,能更准确地反映遮光后PSⅡ光合结构的变化.     

基因型与环境对小麦粗脂肪含量的影响及其稳定性分析

针对生产上小麦粗脂肪含量变化很大的问题,选用参加2005~2006年山东省小麦高肥1组区域试验的11个材料,进行粗脂肪含量及其稳定性分析试验。结果表明:不同品种、不同地点间小麦籽粒粗脂肪含量变幅为1.6%~2.7%,变异系数为4.55~13.28;利用主效可加互作可乘模型(AMMI)对其进行稳定性分析,得知粗脂肪含量存在显著的品种和地点间的互作效应,其中品种的固定效应导致的变异最大,品种和地点互作次之,地点(含重复)效应较小;但不同品种与不同试点的交互作用不同,每个品种(系)对试点都有其特殊的适应性。因此,在小麦产业化种植时,要获得粗脂肪达到标准的商品粮食,既要选准适宜的品种又要注意适宜的种植区域。     

Fluorescence and NIR spectroscopic study on the water interaction in polycarbonate film

Water interactions in polycarbonate films have been studied using fluorescence and NIR Fourier transform spectroscopy. During water sorption process, the fluorescence emission spectra showed sensitive changes with the peak at 332 nm red shifted by 18 nm with water sorption. This red-shifted peak could be due to phenyl-2-phenoxybezoate, which is one of two major thermal degradation products in polycarbonate. In the spectra of phenyl-2-phenoxybenzoate in dimethyl formamide solution, a progressive red shift was also observed with the water addition. By using the NIR spectra, hydrogen-bonding interactions of the sorbed water with polycarbonate were investigated. It was found that water can be analyzed as free water S₀ or single hydrogen bonded water, S₁ while double hydrogen bonded water was negligible. During water immersion, most water species which are present as S₀ species decrease slightly, with a small increase in S₁ species. During desorption, S₀ species decrease sharply, while S1 species is reduced gradually. Two examples of S₁ structure in water-sorbed polycarbonate are proposed.     

Effect of glycerol cross-linking and PDI on the shape memory effect and mechanical properties of polyurethane

A series of shape memory polyurethane (PU) copolymers synthesized from 1,4-phenyldiisocyanate (PDI), poly(tetramethyleneglycol) (PTMG), 1,4-butanediol (BD) as a chain extender, and glycerol as a cross-linking agent were tested for the mechanical properties and the shape memory effect at the temperature 20 °C above melting temperature (T _m), and were compared with other PUs synthesized from 4,4′-methylene-bis-phenyldiisocyanate (MDI), PTMG, and BD. Mechanical properties and shape memory effect were improved substantially by adopting both PDI and glycerol. Interestingly, enthalpy of melting and T _m were not affected by the glycerol content. Vibration and shock absorption ability was investigated by measuring both loss tan δ and storage modulus with dynamic mechanical analyzer (DMA).     

Dual functions of ferrous sulfate as a pore-size controller and a carbon-yield enhancer in fabricating cellulose based porous carbons

This study reports the dual-functions of ferrous sulfate, i.e. as a carbon-yield-enhancer and as a pore-size-controller, in the preparation of porous carbons from rice straws. Through the impregnation of rice straws with 0.5 M aq. FeSO₄, the carbon yield of the resultant porous carbons increased by ca. 10% and the size of the newly created pores was precisely controlled at the diameter of 0.53 nm during carbonization process. The observed results were discussed from the view points of the thermal degradation mechanism of cellulose and the pillar effects by the in-situ formed crystallites of Fe₃O₄. The inherent magnetic property due to the presence of magnetite, Fe₃O₄, was an additional merit of the obtained porous carbons.