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961.
湿式催化氧化(CWAO)法处理高浓度有毒、有害和非生物降解的有机物,具有独到优点。当进水COD大于2000mg/L,系统产能可自我维持。本文综述WAO发展过程,流程演变,原理,动力学模型和催化氧化的研究领域以及该技术的发展动向和应用前景。 相似文献
962.
YQ Lv S Ji X Chen D Xu XT Luo MM Cheng YY Zhang XL Qu Y Jin 《Reproduction in domestic animals》2020,55(8):1011-1020
Glycerol is used as a bovine semen osmotic cryoprotectant that greatly improves the quality of frozen and thawed bovine sperm. However, high glycerol concentrations can have a toxic effect on frozen and thawed bovine sperm. Therefore, this experiment investigated the effect of replacing a portion of the glycerol in a cryoprotectant solution with crocin on the sperm apoptosis, protamine deficiency and membrane lipid oxidation of frozen and thawed Yanbian yellow cattle sperm. The experiment included a control group (6% glycerol) and four treatment groups: I (3% glycerol), II (3% glycerol +0.5 mM crocin), III (3% glycerol + 1 mM crocin) and IV (3% glycerol + 2 mM crocin). Computer assisted semen analysis was used to detect sperm motility, Hoechst 33,342, propidium iodide, and JC-1 staining were used to analyse sperm viability and mitochondrial membrane potential, chromomycin A3 staining was used to detect protamine deficiency and DNA damage, flow cytometry was used for sperm membrane lipid disorder detection and analysis, and real-time quantitative RT-qPCR was used to detect the mRNA expression levels of protamine-related genes (PRM2, PRM3), sperm acrosome-associated genes (SPACA3), oxidative stress-related genes (ROMO1) and apoptosis-related genes (BCL2, BAX). Compared to the control group, replacing a portion of glycerol with 1 mM crocin significantly improved sperm motility, plasma membrane integrity, membrane lipid disorders (p < .05) and viability, mitochondrial membrane potential, protamine deficiency (p < .01). The expression level of PRM2, PRM3, SPACA3 and BCL2 significantly increased (p < .05), while the expression levels of ROMO1 and BAX significantly decreased (p < .05). Accordingly, the BCL2/BAX ratio significantly increased (p < .05). In summary, the substitution of a portion of glycerol with crocin in cryoprotective solution improved the quality of Yanbian yellow cattle sperm after freezing and thawing. 相似文献
963.
本试验旨在研究儿茶素对草鱼生长性能、血清抗氧化指标和肌肉品质的影响。试验选取平均体质量为(18.5±0.2)g的草鱼360尾,随机分为6组,分别饲喂在基础饲料中添加0(对照组)、0.1、0.3、0.5、0.7和0.9 g/kg儿茶素的6种饲料,每组3个重复,每个重复20尾。试验期60 d。结果表明:1)随着儿茶素的添加,各组间鱼体增重率和饲料系数无显著差异(P>0.05),添加0.5、0.7和0.9 g/kg儿茶素显著提高了鱼体肥满度(P<0.05),显著降低了血清丙二醛含量(P<0.05)。除0.1 g/kg组外,其余各儿茶素添加组血清超氧化物歧化酶活性均显著高于对照组(P<0.05),各组间在血清碱性磷酸酶和过氧化氢脱氢酶活性上无显著差异(P>0.05)。2)在肌肉游离氨基酸和脂肪酸组成方面,0.5、0.7 g/kg组的总氨基酸、呈味氨基酸含量和C20∶5、n⁃3不饱和脂肪酸含量显著高于对照组(P<0.05)。3)各组间在肌肉水分、粗蛋白质、粗脂肪、粗灰分含量及肌肉质构特性、肌肉失水率以及肌纤维密度和直径上差异均不显著(P>0.05),但0.7和0.9 g/kg组的肌肉胶原蛋白含量显著高于对照组(P<0.05)。上述结果显示,儿茶素对草鱼生长性能没有显著影响,可提高血清抗氧化能力,在一定程度上改善肌肉品质。草鱼饲料中儿茶素的推荐添加量为0.5~0.7 g/kg。 相似文献
964.
Mountains comprise an extensive and visually prominent portion of the landscape in the Mojave Desert, California. Landform surface properties influence the role these mountains have in geomorphic processes such as dust flux and surface hydrology across the region. The primary goal of this study was to describe and quantify land surface properties of arid-mountain landforms as a step toward unraveling the role these properties have in soil-geomorphic processes. As part of a larger soil-geomorphic study, four major landform types were identified within the southern Fry Mountains in the southwestern Mojave Desert on the basis of topography and landscape position: mountaintop, mountainflank, mountainflat (intra-range low-relief surface), and mountainbase. A suite of rock, vegetation, and morphometric land surface characteristic variables was measured at each of 65 locations across the study area, which included an associated piedmont and playa. Our findings show that despite the variation within types, landforms have distinct land surface properties that likely control soil-geomorphic processes. We hypothesize that surface expression influences a feedback process at this site where water transports sediment to low lying areas on the landscape and wind carries dust and soluble salts to the mountains where they are washed between rocks, incorporated into the soil, and retained as relatively long-term storage. Recent land-based video and satellite photographs of the dust cloud emanating from the Sierra Cucapá Mountains in response to the 7.2-magnitude earthquake near Mexicali, Mexico, support the hypothesis that these landforms are massive repositories of dust. 相似文献
965.
Frank Lehmkuhl Alexandra Hilgers Susanne Fries Daniela Hülle Frank Schlütz Lyudmila Shumilovskikh Thomas Felauer Jens Protze 《CATENA》2011
Mantles of silt- and sand-size particles, paleosols and fluvial deposits preserve valuable information on Holocene environmental change. These archives were used to reconstruct the landscape history in the upper Orkhon Valley close to the former capitals of the Uighurs (Kharbalgasin Tuur) and the Mongolian Empire (Karakorum) near the recent town of Kharkhorin, Central Mongolia. A holistic approach involving the use of high spatial resolution geomorphological mapping, sedimentological and geochemical analysis, palynology, and geochronology shows several phases of landscape activity and stability in the region. This includes phases of fluvial erosion, aeolian sedimentation, and soil formation. By using luminescence and radiocarbon dating, phases of landscape change, indicated by soil formation, occurred mainly at around 6.5–6 ka. Pollen data and a weakly humic horizon at around 1.0 ka probably indicate enhanced moisture supply in the region and a reduction of human activity between the time of the reigns of the Uighurs (8th–9th century AD) and the Mongols (1220–1388 AD). Since 3 ka, especially within the last two millennia of Historical Time (300 B.C.–present), a more intensified human occupation in the Upper Orkhon Valley occurred in this region. This included a more densely grazing of cattle to supply the growing population demands of the Uighurs and Mongols. This overgrazing caused an increase in erosion and the formation and deepening of fluvial gullies, together with soil deflation and subsequent deposition of aeolian sediments. Human activity, in addition to climate, has been dominant in driving landscape evolution of this region since the late Holocene. 相似文献
966.
967.
Macro-invertebrates (>2 mm in size) can play a key role in litter decomposition by influencing litter chemistry and other components of the decomposer community, thus affecting rates of decomposition, nutrient release, and primary production. However, in many ecosystems the influences of macro-invertebrates on key ecosystem processes have not been adequately addressed. We investigated the influence of the macro-invertebrate community in litter decomposition and the cycling of nutrients in a young rainforest site on the island of Hawaii by using litter bags with and without 2.5 cm holes to allow or prevent access by macro-invertebrates. Presence of macro-invertebrates increased rates of litter decomposition by 16.9% and rates of nutrient release for N and Mn by 33.2% and 30.3%, respectively. Macro-invertebrate activity thus has a major impact on N release accounting for 3.32 kg/ha/yr. This internal ecosystem transfer of N from the litter is greater than estimates of nitrogen inputs from rain water, dry deposition, volcanic sources, atmospheric dust, and nitrogen fixation for this ecosystem. These findings demonstrate that improved knowledge of the ecosystem effects of macro-invertebrates is necessary to understand how ecosystems function. 相似文献
968.
本文简要介绍电刷镀新技术的原理,工艺特点和应用范围。并以人造板机械“KG9”热磨机轴套应用刷镀强化和修复为例,阐述刷镀层的设计原则和主要内容,刷镀的工艺流程及其应用经济性等。 相似文献
969.
造纸黑液综合治理的研究进展 总被引:4,自引:0,他引:4
齐桂莲 《山东农业大学学报(自然科学版)》2006,37(3):486-488
造纸废水污染十分严重,其综合治理是国内外造纸工业和环保界的研究热点。综合国内外有关造纸废水,尤其是造纸黑液治理的技术方法,认为生物法是解决我国造纸工业水污染的最终出路。同时,将超临界水氧化技术应用于造纸黑液的治理,其具有潜在的可行性和十分重大的意义。 相似文献
970.