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We investigated the physicochemical properties of the thermal gel of water‐washed pork meat (WWM) in the presence of the soluble fraction of porcine sarcoplasmic protein (SP) obtained with ammonium sulfate at 75 percent saturation. Two precipitated fractions of SP were obtained at 0–50 percent and 50–75 percent saturation, named SP‐f1 and SP‐f2, respectively, and the soluble fraction obtained at 75 percent saturation, SP‐f3, was used. Sodium dodecyl sulfate‐polyacrylamide gel electrophoresis showed that SP‐f3 contained mainly glyceraldehyde‐3‐phosphate dehydrogenase (GAPDH), while SP‐f1 and SP‐f2 had other SPs such as phosphorylase b, enolase, actin and phosphoglycerate mutase. The gel strength of WWM was greater when SP‐f3 rather than one of various animal proteins such as bovine plasma (BP), egg white, or whey protein isolates (WPI), was added and SP‐f3 had a gel‐enhancing effect as good as that of polyphosphate (PP). The gel strength of WWM with added SP‐f3 increased significantly with NaCl at 0.15 mol/L or more, but not in the absence of NaCl (0 mol/L). The effect of SP‐f3 was evident at neutral pH and maximum gel strength was obtained at a pH above 6.0. Differential scanning calorimetric (DSC) analysis showed that an endothermic peak corresponding to myosin heads in WWM shifted to a lower temperature with the addition of SP‐f3, as in the case of PP, though there was no such shift in the presence of other animal proteins (BP, egg white and WPI), suggesting that SP‐f3 increases the gel strength of WWM through the dissociation of actomyosin similar to PP. Scanning electron microscopy (SEM) revealed wall‐like structures among the protein strands in the WWM gel matrix in the presence of SP‐f3. The results of DSC and SEM indicated that the formation of a gel network in meat products is reinforced with GAPDH in SP after the interaction between GAPDH and myofibrillar protein. 相似文献
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旨在建立一种以重组酶聚合酶扩增技术(RPA)为基础的快速检测方法,用于小鹅瘟病毒的快速检测。小鹅瘟是一种常见的水禽传染病,严重危害我国养鹅业的健康发展。为了快速准确对小鹅瘟进行诊断,减少该病的危害,本研究以小鹅瘟病毒VP3基因保守片段为靶点,利用重组酶聚合酶扩增技术(RPA)建立了一种准确高效的小鹅瘟病毒RPA恒温快速检测方法,并对检测方法的灵敏度、特异性进行评价,并与传统PCR和传统RT-PCR方法进行比较。结果表明,该检测方法具有较高的灵敏度,可检测到10 copies/μL的病毒核酸;具有良好的特异性,只特异性地扩增鹅细小病毒,而与鹅副黏病毒、鹅源鸭瘟病毒、小鹅流行性感冒病毒、鹅副伤寒病毒、大肠杆菌和曲霉菌均未发生交叉反应;同时该方法重复性检测的变异系数低于6%,具有很好的重复性。阳性符合试验表明该检测方法与荧光定量PCR符合率为99%。该方法可以很好地应用于小鹅瘟的大规模临床样本检测,为小鹅瘟病毒的高通量检测和流行病学调查提供技术手段。 相似文献
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为了研究硅溶胶和聚磷酸铵(APP)复配后的阻燃性能,真空常压方法下分别用APP、硅溶胶以及两者复配后的阻燃剂浸渍辐射松木材,分析各改性材的增重、增容率以及热解燃烧性能,并用扫描电镜(SEM)分析改性后的残炭形貌。研究结果表明:氧指数由高到低是APP-硅溶胶、APP、硅溶胶和素材;由APP处理和APP-硅溶胶联合处理材的初始分解温度、最大失重率温度均提前,残炭率提高,硅溶胶处理材的初始分解温度和最大失重率与素材相近。经锥形量热测试结果显示:由APP处理和APP-硅溶胶联合处理材的热释放速率峰值分别比素材降低了232.8和150.3 kW·m-2,总释放热降低29.63和17.98 MJ·m-2,而由硅溶胶处理的效果不明显。与其他3种试材相比,硅溶胶处理材的COP最低,说明硅溶胶对CO的生成有抑制作用。处理材的火灾蔓延指数(FGI)均比素材降低;扫描电镜显示,经浸渍处理过的残炭结构更加致密,表面更加光滑。结果说明了硅溶胶的加入可以降低CO毒气的生成,APP的加入使木材的阻燃性达到了难燃级。 相似文献
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M. A. Gooding E. A. Flickinger J. L. Atkinson I. J. H. Duncan A. K. Shoveller 《Journal of animal physiology and animal nutrition》2014,98(3):596-607
High‐fat (HF) or high‐carbohydrate (HC) diets (30% fat, 18.9% carbohydrate; HF and 10% fat, 46.3% carbohydrate; HC) and lengths of adaptation were investigated in cats (Felis catus; 10 ± 2 months, 3.6 ± 0.3 kg). Cats randomly received each treatment for 14 days in a crossover design with a 14‐day washout period between each diet. Three 22‐h indirect calorimetry studies were conducted after acute (day 0), semichronic (day 4) and chronic (day 13) dietary exposure. Blood samples were collected after a 24‐h fast on days 1, 5 and 14. When cats consumed the HC and HF diet, oxidation of the restricted nutrient exceeded intake while oxidation of the nutrient in excess matched intake. Mean max energy expenditure (EE) of cats consuming the HF and HC diet were 107 and 102 kcal/kg0.67/day and occurred at a mean of 4 and 12 h post‐feeding respectively. Maximal fat (0.90 g/h) and carbohydrate (carbohydrate; 1.42 g/h) oxidation were attained at 26 min and 10.4 h post‐feeding respectively. The changes observed in macronutrient oxidation and EE suggest that cats adapt whole‐body nutrient metabolism in response to changes in dietary macronutrient content, but may require longer than 14 day to adapt to a macronutrient that is present at a lower concentration in the diet. 相似文献
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络合滴定黑荆栲胶中单宁含量的新方法 总被引:8,自引:0,他引:8
利用单宁分子结构中酚羟基能与Pb^2+络合的原理,以K2CrO4为指示剂,PAM作终点增敏剂,用Pb^2+标准溶液络合滴定黑荆栲胶中单宁的新方法。该法比皮粉法快速、准确。 相似文献
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U. Reh W. Kratz G. Kraepelin C. Angehrn-Bettinazzi 《Biology and Fertility of Soils》1990,9(2):188-191
Summary Changes in the physicochemical properties of three kinds of litter (Prunus serotina leaves, Carpinus betulus leaves, and Pinus sylvestris needles) were analyzed by differential scanning calorimetry and differential thermogravimetry after decomposition for 12 to 27 months under field conditions. As expected, holocellulose was always decomposed to a larger extent than the corresponding lignin components, leading to an enrichment of lignin in the residue. These lignins were more or less modified depending on the plant species. Moreover, the results suggest that energy-rich crystalline cellulose accumulates during decomposition at the expense of easier degradable amorphous cellulose and hemicelluloses. The quotient Q, from the corresponding calorimetry and thermogravimetry values, was introduced to estimate the specific energy content as a measure for the decomposition of litter components.Dedicated to the late Prof. Dr. W. Kühnelt 相似文献