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81.
Hongsheng Yang Xiutang Yuan Yi Zhou Yuze Mao Tao Zhang & Ying Liu 《Aquaculture Research》2005,36(11):1085-1092
To investigate the effects of body size and water temperature on feeding and growth in the sea cucumber Apostichopus japonicus (Selenka), the maximum rate of food consumption in terms of energy (Cmaxe; J day?1) and the specific growth rate in terms of energy (SGRe; % day?1) in animals of three body sizes (mean±SE) – large (134.0±3.5 g), medium (73.6±2.2 g) and small (36.5±1.2 g) – were determined at water temperatures of 10, 15, 20, 25 and 30°C. Maximum rate of food consumption in terms of energy increased and SGRe decreased with increasing body weight at 10, 15 and 20°C. This trend, however, was not apparent at 25 and 30°C, which could be influenced by aestivation. High water temperatures (above 20°C) were disadvantageous to feeding and growth of this animal; SGRe of A. japonicus during aestivation was negative. The optimum temperatures for food consumption and for growth were similar and were between 14 and 15°C, and body size seemed to have a slight effect on the optimal temperature for food consumption or growth. Because aestivation of A. japonicus was temperature dependent, the present paper also documented the threshold temperatures to aestivation as indicated by feeding cessation. Deduced from daily food consumption of individuals, the threshold temperature to aestivation for large and medium animals (73.3–139.3 g) was 24.5?25.5°C, while that for small animals (28.9–40.7 g) was between 25.5 and 30.5°C. These values are higher than previous reports; differences in sign of aestivation, experimental condition and dwelling district of test animals could be the reasons. 相似文献
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84.
Maize gluten (a byproduct from the starch industry) was used at four different levels (5, 10, 15 and 20% w/w) replacing the
fish meal, a component of supplementary diet, under a semi-intensive culture system. The impact of different diets on the
physico-chemical parameters of water, growth and flesh quality of catla, Catla catla; rohu, Labeo rohita; and mrigal, Cirrhina mrigala was studied. Growth in terms of body weight gain was highest when fed a diet having 5% maize gluten (replacing fish meal
at 25% level) for all the fish species. However, incorporation of maize gluten at higher levels led to decline in growth,
since maize gluten is deficient in essential amino acids like methionine, lysine and threonine, etc. The flesh quality in
terms of total protein, total lipid, total sugar, moisture and total ash was also determined at the termination of the experiment
to see whether there was any significant variation with the incorporation of maize gluten or not. 相似文献
85.
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在Banta液(牛粪1.5 g 干稻草2 g 沃土20 g 水1000 ml)、酵母、小球藻三种培养条件下,比较研究了蚤状的脂肪酸组成。用GC/MS法分析后结果表明:它们的总脂量变化不大,依次为5.23%、5.46%和6.01%。共检测到15种脂肪酸,其中饱和脂肪酸(SFA)5种,单不饱和脂肪酸(MUFA)4种,多不饱和脂肪酸(PUFA)6种。蚤状以小球藻培养条件下的C 20∶5(EPA)和C 18∶3的含量最高,PUFA占总脂肪酸的34.79%;Banta液组的SFA含量最高,为53.89%;面包酵母组的MUFA含量最高,达60.65%,且富含C 16∶1(n-7)和C 18∶1(n-9),这两种不饱和脂肪酸约占总脂肪酸的56.73%。EPA的含量以小球藻组最高,为14.43%,与自然环境中蚤状的含量相近。酵母组最低,为2.05%。蚤状和其它饵料生物一样,其脂肪酸组成主要随食物特点而变化,也决定于其本身的吸收与合成能力。 相似文献
87.
南沙岛礁周围水域主要鱼类食物网 总被引:5,自引:0,他引:5
在南沙岛礁周围水域收集了43种主要鱼类,共940个胃含物,根据对它们的食性分析,并依其食料生物的生态类群以及消化器官特点,一般可划分为浮游生物食性、底栖动物食性、游泳动物食性、浮游生物兼底栖动物食性、底栖动物兼游泳动物食性等5种食性类型。根据食物网中各营养级的相互关系,初步划分为4个营养级,即初级生产者(海洋植物)、草食性动物和杂食性动物、低级肉食性动物和中级肉食性动物、高级肉食性动物。并根据这些营养级的划分,南沙岛礁周围水域43种主要鱼类可分低级肉食性鱼类,中级肉性鱼类和高级肉食性鱼类,它们的比为28105。灰裸顶鲷是南沙岛礁周围水域三重剌网举足轻重的捕捞对象,从食物网的观点出发,应加强灰裸顶鲷幼鱼期敌害鱼和其竞食者的捕捞,为低级肉食性经济鱼类除害,灰裸顶鲷就有可能增加资源量。 相似文献
88.
89.
Marine fisheries target and catch fish both for direct human consumption (DHC) as well as for fishmeal and fish oil, and other products. We derived the fractions used for each for 1950–2010 by fishing country, and thus provide a factual foundation for discussions of the optimal use of fisheries resources. From 1950 to 2010, 27% (~20 million tonnes annually) of globally reconstructed marine fisheries landings were destined for uses other than DHC. Importantly, 90% of fish destined for uses other than DHC are food‐grade or prime food‐grade fish, while fish without a ready market for DHC make up a much smaller proportion. These findings have implications for how we are using fish to feed ourselves or, more appropriately, how we are not using fish to feed ourselves. 相似文献
90.
不同开口饵料对克氏原螯虾幼虾发育及消化酶活性的影响 总被引:3,自引:0,他引:3
实验采用丰年虫无节幼体、草鱼鱼糜、水蚯蚓、1号人工配合饲料和2号人工配合饲料为克氏原螯虾的开口饵料,观察幼虾存活率和生长情况。经过40d的培育,对幼虾的胃蛋白酶、胰蛋白酶、淀粉酶和脂肪酶的活力进行测定。结果表明:投喂丰年虫无节幼体的实验组幼虾存活率最高,为75,增重率和增长率也最大,分别为4746.00和171.00。幼虾的胃蛋白酶活性与投喂的饵料密切相关,投喂丰年虫无节幼体组幼虾的胃蛋白酶和胰蛋白酶活性分别为2.18U/mgprot和0.96U/mgprot,极显著高于投喂草鱼鱼糜实验组。实验的5种开口饵料中,丰年虫无节幼体是克氏原螯虾幼虾的最佳开口饵料。摄食丰年虫无节幼体可能提高了主要消化酶的活性,从而促进了克氏原螯虾幼体的生长。 相似文献