靖远滩羊体脂脂肪酸与肉品质关系的研究

肉羊体脂脂肪酸是影响肉品风味和膻味的重要因素之一。研究利用HP6890型气相色谱仪 ,选择了 5 0日龄、2 0 0日龄和 5岁3个年龄阶段的靖远滩羊 ,比较了不同年龄阶段肉羊体脂肪中短链脂肪酸和硬脂酸的变化趋势。结果显示 :短链脂肪酸和硬脂酸从5 0日龄、2 0 0日龄到 5岁有显著的增加。肾脏脂肪中 (公 /母 )短链脂肪酸的相对含量 (% ) 5 0日龄时为 0 5 2 /0 3 4,而在 2 0 0日龄时已达到 0 79/0 5 4,5岁时其含量为 0 91/0 75。 3个年龄组之间表现出显著性的差异 (P <0 0 5 ) ,增加的趋势非常明显。C18脂肪酸也显示同样的变化特性 ,在 5 0日龄的羔羊 (公 /母 )中含量仅为 17 2 /3 6 2 5 ,2 0 0日龄增加到 2 7 3 4/4 5 3 5 ,5岁时达到 3 6 0 3 /5 4 65 ,3个年龄组之间表现出显著性的差异 (P <0 0 5 ) ,增加的幅度也很显著。背膘脂肪中短链脂肪酸和C18(公 /母 )随年龄增大分别为 0 2 3 /0 11、0 62 /0 42、0 71/0 63 ,16 0 7/18 17、2 4 45 /2 6 66、3 3 5 2 /3 6 13。尾部脂肪中短链脂肪酸和C18(公 /母 )随年龄增大分别为 0 13 /0 10、0 2 3 /0 19、0 3 5 /0 3 3 ,11 76/13 79、19 78/2 0 89、2 0 89/2 2 65。     

Preliminary study of patients with chronic mountain sickness by GC-TOF-MS based serum metabolomics analysis

AIM: To evaluate specific metabolomics profiles in the serum of patients with chronic mountain sickness (CMS) and to explore the potential metabolic biomarkers in the native Tibetans living on the Qinghai-Tibet Pla-teau.METHODS: A gas chromatography time-of-flight mass spectrometry (GC-TOF-MS) approach as a metabolomics technique was used to evaluate metabolic differences. The native Tibetan CMS patients (n=10) and healthy Tibetan controls (n=10) were enrolled from YuShu in Qinghai province in this study. The serum samples were collected and analyzed by GC-TOF-MS coupled with a series of multivariate statistical analyses such as principal component analysis (PCA), partial least squares discriminant analysis (PLS-DA) and orthogonal partial least squares discriminant analysis (OPLS-DA).RESULTS: The intergroup differences between CMS patients and control subjects have been observed. A list of differential metabolites and several top altered metabolic pathways have been identified. The levels of fumaric acid, an intermediate in the tricarboxylic acid (TCA) cycle, and inosine were highly upregulated in the CMS patients, suggesting a greater effort to hypoxic adaptation in high elevation area. Other differential metabolites, such as methyl phosphate, 2-ketoadipate, lyxose and phytanic acid were also identified. Importantly, the differential metabolites possessed higher area under the ROC curve (AUC) values, indicating an excellent clinical ability for the prediction of CMS. Increased levels of amino acids (isoleucine, glycine, serine, L-cysteine, citrulline and trimethyllysine) were detected in CMS group, yet significantly decreased levels of sulfuric acid, oxamic acid, lyxose and glutamine were also detected in CMS group than those in control group. At the same time, the levels of ribose and glucose-1-phosphate were markedly elevated in CMS group (P<0.05).CONCLUSION: The metabolic activities are significantly altered in the serum of CMS patients. High altitude hypoxia may act on the disturbed glucose metabolism and amino acid metabolism in part of the Tibetan triggered by CMS.     

木材和人造板中五氯苯酚含量测定不确定度的评价

为测定人造板中的五氯苯酚含量,通过对LY/T 1985-2011《防腐木材和人造板中五氯苯酚含量的测定方法》的研究,得出了不确定度来源及其数学模型,对各不确定度分量进行计算,结果发现样品处理及设备重复性对不确定度贡献最大,因此应尽量提高试验结果平行性,以提高结果的准确度。     

Influence of Aguamiel (Agave atrovirens) as a Natural Feed Additive on Cecal Fermentation Kinetics of Some Forage Species in Horse Feeding

This study aimed to evaluate the effect of different dose levels of aguamiel (Agave atrovirens) on in vitro cecal gas, methane (CH₄), and carbon dioxide (CO₂) productions of five forage species (Avena sativa [hay]), Moringa oleifera, Caesalpinia coriacea, Salix babylonica, and Eichhornia crassipes using inocula from the horse. The forage samples were incubated with three doses of aguamiel: 0, 34, and 68 μg of aguamiel/g dry matter (DM) of substrate. Cecal inocula were collected from four adult female Criolla horses (3–4 years of age and weighing 300 ± 15.0 kg) grazed on native grasses for about 8 hours without supplementation. Forage type affected (P < .001) cecal asymptotic, rate and lag time of gas, CH₄ and CO₂ productions (mL/g DM), pH and DM degradability. Aguamiel dose had linear and quadratic effects (P < .05) on the asymptotic and rate of CH₄ productions and rate and lag time of CO₂ productions (mL/g DM). Forage type × aguamiel dose interactions were significant (P < .05) for asymptotic, rate and lag time of gas, and CH₄ and CO₂ productions (mL/g DM). Forage species effects were pronounced (P < .05) on CH₄ and CO₂ productions (mL/g incubated and degraded DM) and proportional CH₄ production at all hours of incubation, except for CO₂ production (mL/g incubated DM). Aguamiel dose affected (P < .05) CO₂ production (mL/g incubated DM) and proportional CO₂ production at the incubated hours. Forage type × aguamiel dose interactions were observed (P < .05) for CO₂ production (mL/g incubated DM) and proportional CO₂ production at the incubated hours but had no impact on CH₄ production. It is concluded that addition of aguamiel to five forage species affected fermentation kinetics of gas production resulting in different in vitro cecal gas, CH₄ and CO₂ productions from these substrates.     

中亚天然气C线管道SPS仿真模拟

中亚天然气C线管道属于典型的输送压力高、流量大、管道跨度大、压气站数目多、输送工艺复杂的输气管道。为研究中亚天然气C线管道正常工况和事故工况下水热力参数的变化规律以及各种事故下管道的自救时间,采用SPS软件建立了中亚天然气C线管道仿真模型。模拟了正常工况下管道全线压力和温度参数,模拟结果与实际运行数据最大相对误差分别为1.90%和12.24%,验证了模型的可靠性;在此基础上分析了环境温度和管道粗糙度变化对全线输气效率的影响规律,确定了各种事故工况下管道最长的自救时间,可为中亚天然气长输管道运行管理提供参考。     

Effect of Partial Replacement of Steam Rolled Corn With Soybean Hulls or Prickly Pear Cactus in the Horse's Diet in the Presence of Live Saccharomyces cerevisiae on In Vitro Fecal Gas Production

The aim of the study was to evaluate the fecal fermentation of partial replacing steam rolled corn with soybean hulls (SH) or prickly pear cactus (PC) as energy source in horse diets, in the presence of Saccharomyces cerevisiae. Steam rolled corn was replaced with SH at 0% (control), 7.5% (SH75), and 15% (SH150) in the first trial, whereas it was replaced with PC at 0% (control; the same of the first trial), 7.5% (PC75), and 15% (PC150) in the second trial. Yeast of S. cerevisiae was added at 0, 2, and 4 mg/g dry matter (DM) of incubated substrates. Fecal inoculum was obtained from four adult English Thoroughbred horses fed on an amount of commercial concentrate and oat hay ad libitum. Interactions observed between PC rations and yeast doses for the asymptotic gas production (GP), the rate of GP and carbon dioxide (CO₂) production during some incubation hours. Moreover, with no effect due to SH rations (P > .05), increased (P < .05) rate of GP was observed with the ration PC75 compared with other rations. Besides, PC75 and PC150 rations with 0 mg yeast/g DM linearly decreased (P < .05) CO₂ production at some incubation hours. However, SH75 and SH150 ration had increased (P = .005) DM degradability (DMD). Yeast addition at 2 mg/g DM increased the asymptotic GP (P = .048) with the SH75 and PC150 rations. The level of 4 mg yeast/g DM increased the asymptotic GP (P = .048) from the SH150 ration. Yeast addition at 2 and 4 mg/g DM increased (P < .05) ​the asymptotic GP from PC75 and PC150 rations, respectively, with increasing DMD with the both doses. Yeast addition increased (P < .05) CO₂ production from SH75, SH150, PC75, and PC150 rations. It could be concluded that SH and PC can replace steam rolled corn at levels of 7.5% to 15% without negative effect of fermentation kinetics and with better fermentation performance in the presence of yeast at 2 mg/g DM of substrates.     

玉米不同自交系幼苗光合对 UV-B 辐射增强的响应

为了探讨玉米不同自交系对UV-B辐射增强的响应，在摸拟光照培养条件下，研究了增强UV-B辐射对玉米不同自交系气体交换参数的影响。结果表明，五叶期UV-B辐射处理6 d后，供试的48个自交系中近一半以上材料的幼苗叶片光合速率、气孔导度和蒸腾速率显著降低10％以上，其材料比例分别为64．6％，47．9％，54．2％；而有62.5％的材料胞间CO2浓度表现为显著增加；相关分析发现，气孔导度与蒸腾速率对UV-B辐射增强的响应值间存在极显著正相关关系；根据气体交换参数对UV-B辐射增强的响应程度将48个材料分成6类，其中对增强UV-B辐射反应比较敏感的材料和能够忍耐UV-B辐射增强的材料均占12．5％。说明玉米不同自交系幼苗叶片气体交换参数对UV-B辐射增强反应敏感程度具有显著的基因型差异，从中能够筛选出对UV-B辐射增强反应敏感和有忍耐能力的材料。     

城市垃圾填埋及沼气收集利用

本文针对目前我国日益严重的城市固体废物污染环境的问题，在对此填埋，焚烧和高温堆肥等处理处置方法的基础上，分析了填埋产沼技术的可行性，指出其兼有的废物处理与处置的双重性，具有处理量大、处理费用低、可还原利用上地、能回收能源等多种优点，在我国有广阔应用前景。     

微型摆式内燃发电机频率的计算与分析

针对所研制的微型摆式内燃发电机(MICSPG),阐述了各组成部分的工作过程及工作特点,建立了微型内燃发电系统的数学模型。在引入平均指示压力和线性气体弹簧分别对内燃机动力腔中由燃烧和最大预压缩压力而引起的气体压力进行线性化分析的基础上,得到了系统的传递函数,并据此研究和分析了微型摆式内燃机发电系统的稳定性和运动频率。研究结果为微型摆式内燃发电系统结构参数的确定和控制系统设计提供了有益的参考。     

中缅油气管道国内段砂土液化处理措施

中缅油气管道国内段沿线存在不连续的长距离砂土液化地带,砂土液化是地下管道遭受地震破坏的主要原因之一.为增强管道抵抗土壤液化的能力,通过对砂土液化现象及其危害进行分析,结合油气管道沿线砂土液化特点,对管道敷设深度内有中等、严重砂土液化趋势的地段采取平衡压袋稳管方式进行液化处理.该处理措施具有经济、环保、便于施工、不影响管道主体工程安装和总体工期等特点,而且对于避免和减轻地震灾害,确保油气管道的安全运行具有重要意义,在类似管道工程建设中值得推广应用.(表2,图3,参4)