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排序方式: 共有329条查询结果,搜索用时 15 毫秒
191.
甘蓝型油菜原生质体培养和植株再生   总被引:1,自引:0,他引:1  
从甘蓝型油菜试管苗下胚轴和幼叶分离的原生质体,在含2.4-D0.8mg/1,NAA0.5mg/1,6-BA0.5mg/1的改良BG培养基中浅层液体和固体平板培养6天,分裂细胞为8%-20%,至15天形成32细胞的细胞团。愈伤组织在含NAA0.2mg/1,IBA0.1mg/1,6-BA1.0mg/1的MS分化培养基上培养基上培养3-4周,产生不定芽,并在附加IBA0.5mg/1,6-BA0.2m...  相似文献   
192.
The aim of this study was to investigate the influence of isoenergetic substitution between the three energy delivering macronutrients in pre‐starter diets on performance and intermediary nutrient metabolism in broiler chickens. From hatch until 5 days of age, 600 chicks, collected during peak of hatch, were fed one of the three experimental pre‐starter diets with isoenergetic (13 MJ metabolisable energy/kg) substitutions between fat (43 vs. 108 g/kg), protein (126 vs. 240 g/kg) and carbohydrates (391 vs. 510 g/kg). After 5 days, commercial grower and finisher diets were provided. Pre‐starter composition influenced body weight until slaughter age, although not statistically verifiable. Broilers fed the low protein (LP) pre‐starter had the lowest body weight in relation to chickens on the low carbohydrate or low fat pre‐starter diet. After hatch, chicks on the LP pre‐starter diet were able to use the residual yolk sac more rapidly to fulfil their protein requirement, which is reflected in small intestine and liver development. Also, plasma metabolite levels were influenced mostly by the LP pre‐starter, indicating that the main focus for the requirements of newly hatched chicks should be on proteins. Furthermore, optimal nutrition during the first day’s post‐hatch should take into account the contribution of the yolk.  相似文献   
193.
以枇杷胚性培养物(Eriobotrya japonica embryonic cultures)为材料,采用同源克隆方法,从其mRNA中分离得到ACC氧化酶(ACO)基因EjACO-1,在GenBank中登录号为GQ377219。结果表明:EjACO-1大小为 1 160 bp,编码322个氨基酸。枇杷EjACO-1与苹果、桃和梨等蔷薇科植物同源性较高,而与水稻、石斛兰等单子叶植物距离较远。此外,从枇杷基因组DNA中分离了转录为EjACO-1 mRNA的基因gACO,大小为1 517 bp,在GenBank中的登录号为GU233743。生物信息学分析显示,gACO基因中含有3个内含子,大小分别为114、240、194 bp,均符合真核生物内含子通用的GT-AG法则。EjACO基因的克隆为以后研究乙烯在枇杷中的功能奠定基础。  相似文献   
194.
Lentils (Lens culinaris L.) are an important component of the dryland farming systems in the western USA. Optimum nitrogen (N) management can enhance yield and quality of lentils. We conducted a field (at two locations, one with previous history of lentil and the other one without lentil history) and a greenhouse study to evaluate response of lentil to the application of rhizobium inoculant and starter N (control, 22 kg N ha?1 in the form of urea [U], 22 kg N ha?1 in the form of slow-release or environmentally safe nitrogen [ESN], and 22 kg N ha?1 U + 22 kg N ha?1 ESN). In both, the field and the laboratory studies, lentil yield did not respond positively to the experimental treatments. Lentil average yield was 1216 and 1420 kg ha?1 at the field condition. In this rain-fed system, lentil yield was mainly limited by moisture availability, and the application of an external N did not contribute to the yield enhancement. Both of these treatments, however, increased protein content. Compared to the control, the application of rhizobium plus U and ESN enhanced protein content by about 34% (from 23.1 to 30.9%). The application of U+ESN also considerably increased postharvest residual nitrate (NO3)-N in the soil, which can be easily leached and creates environmental pollution. Briefly, the application of U+ESN increases lentil protein content, but more efforts are needed to optimize N management in lentils in order to reduce the environmental concerns in the shallow soil.  相似文献   
195.
Extracts obtained from liquid mycelial fermentations of Chilean species of the Stereum genus showed antifungal activity against Botrytis cinerea. Thirty-six strains were evaluated in vivo and in vitro assays, 25 belonging to Stereum hirsutum (Sh) and 11 to Stereum rameale (Sr). Two types of extracts were obtained: EtOAc-extract (liquid phase) and MeOH-extract (mycelial phase). Plate diffusion assay showed that EtOAc-extracts were more active than MeOH-extracts. S. hirsutum included 4 strains with the highest antifungal activity (Sh134-11, Sh144-11, Sh152-11, Sh155-11) and S. rameale highlighted with two strains (Sr25-11, Sr27-11). Effects on the mycelial growth of B. cinerea showed that EtOAc-extracts produced by S. hirsutum (Sh134-11, Sh152-11) inhibited from 1000 μg mL−1, reaching 67 and 49%, respectively. At 2000 μg mL−1, these strains inhibited nearly 80% of mycelial growth. EtOAc-extract of Sh134-11 was more effective to control the sporogenesis, inhibiting in 100% the sporulation at 500 μg mL−1. Assays showed that Sh134-11 and Sh152-11 exhibited a minimal fungicidal concentration (MFC) of 50 and 100 μg mL−1 respectively and minimal inhibitory concentration (MIC) at 20 μg mL−1. EtOAc-extracts of Sr25-11 and Sr27-11 showed MFC value at 100 μg mL−1 and MIC at 20 and 50 μg mL−1, respectively. Strawberries treated with 1000 μg mL−1of Sh134-11 and Sr25-11 reached 82 and 72% of decay inhibition, respectively. Treatments with 2000 μg mL−1 showed a decay inhibition of 90% approximately. In vivo tests are in accordance with the results obtained in vitro assays, confirming the efficacy of Sh134-11 and Sr25-11 to control B. cinerea. Differences in antifungal activities observed in the different strains suggested that the ability to produce bioactive compounds is not homogenously distributed among S. hirsutum and S. rameale. Our study would suggest that submerged fermentations of Chilean S. hirsutum strain Sh134-11 produce extracts, which could be used as possible biofungicides and an alternative to synthetic fungicides.  相似文献   
196.
This study aimed to evaluate the relationship between early nutrition and the incidence of wooden breasts (WB) in broilers. Sixteen male and twenty female neonatal ROSS 308 broiler chicks were divided equally into four flocks. From 0–12 days of age, starter diet H, composed of 22.4% crude protein (CP), 6.6% crude fat (CF), 1.25% lysine, 0.48% methionine, and ≥3,070 kcal/kg metabolizable energy (ME), was fed to two flocks, and starter diet L, composed of 19.9% CP, 2.5% CF, 1.04% lysine, 0.38% methionine, and ≥2,930 kcal/kg ME, was fed to the remaining two flocks. All the flocks were fed the same commercial finisher diet, composed of 20.3% CP, 7.5% CF, 1.18% lysine, 0.44% methionine, and ≥3,300 kcal/kg ME, from 12–47 days of age. The birds were weighed every 2–5 days, subjected to a wing-lift test, and histology was conducted on the pectoralis major muscle tissue samples from all the birds necropsied at 47 days of age. Significant differences in the mean body weight between groups H and L were observed during 6–16 days and 24–26 days of age in males and during 6–26 days of age in females. Regarding the score evaluation of the individual lesions reflecting wooden breast, the birds in which back-to-back wing contact was not possible had higher lesion scores than those in which back-to-back wing contact was possible. The absence of back-to-back wing contact appeared more frequently in flocks fed the starter diet L, particularly in males. These results indicate that inappropriate nutrition levels in the starter diet increase the incidence of WB. Therefore, avoiding early nutrition deficits is a cost-effective feeding strategy.  相似文献   
197.
顾亨森  张家藻 《园艺学报》1991,18(4):371-373
水仙是多年生草本植物,常规采用分球繁殖,繁殖率低。利用组织培养技术,通过愈伤组织增殖可以迅速扩大形成小植株的基础,但从愈伤组织产生的植株常发生变异(Hussey,G.1978,Science Progress)。本文报道,由鳞片愈伤组织培养物所繁殖的水仙在旱作条件下的性状。 材 料 与 方 法 材料 水仙(Narcissus tazetta var.chinensis Roem.)鳞片切块(带鳞茎盘)在附加BA 1mg/1和 2,4-D 0.1mg/1的MS培养基上诱导产生愈伤组织,并在相同的培养基上继代培养。将12和13代愈伤组织转至含NAA 0.1mg/1的MS培养基上,分化出不定芽,最终不定芽枯萎并在其基部形成休眠的小鳞茎。在水仙自然播种季节前约半个月,将小鳞茎转至含NAA 0.03mg/1的1/2 MS培养基上,抽叶生根后,移植田间,次年5月采挖,选取球径为1.8—2.2cm的小鳞茎50个作试验材料。  相似文献   
198.
Pathogenic isolates of Fusarium oxysporum applied on a non-host plant species, as soil-borne non-pathogenic isolates, are able to protect this plant against pathogenic strains inducing wilts. Several modes of action contribute to the biocontrol activity of these protective strains; however the genetic basis of the biocontrol mechanisms is far from being understood. The aim of this study was to identify genes involved in biocontrol activity of F. oxysporum using an original model made of Fom24, a strain protective on tomato and its mutant rev157 which has lost its protective capacity. A Rapid Subtractive Hybridization (RaSH) approach was chosen to identify genes up-regulated in the protective or in the non-protective interaction when germinated conidia of either Fom24 or rev157 are confronted to tomato cell cultures. A total of 86 up-regulated sequences were generated, 42 and 44 from the protective and the non-protective interaction respectively. Homology searches led to identification of both plant and fungal genes that were grouped according to their putative functions. Among plant genes, those involved in plant response to stresses were the most abundant. Expression profiles of genes homolog to a basic endochitinase, a ferredoxine-NADP(H) reductase (FNR), an ATP synthase and the RPM1-interacting protein 4 (RIN4) were confirmed by Northern blotting. A large proportion of fungal sequences were encoding genes of unknown function; among other, those involved in response to oxidative stress and a gene putatively encoding an enolase are the most promising to further study their potential role in the protective interaction between F. oxysporum and tomato.  相似文献   
199.
为缩短鸡粪基质化生产有机肥的堆肥发酵周期,提高其产品质量,采用接种发酵剂并添加农作物有机附产物的方法研究不同菌种配伍的发酵剂(C_1、C_2、_3、C_4及C_5)对鸡粪堆肥发酵的影响。结果表明:C_3和C_4处理的各项指标均较好。其中,其发酵初始气温37℃,第2天达40℃以上,并保持高温15d以上,发酵的第18天含水量降至35%以下;pH呈下降—上升—稳定的趋势,总体稍有上升,但变化幅度不大(0~0.5);发酵有机肥对油菜种子的发芽及生长较好,其发芽率、芽长及根长分别为100%和97.5%,15.94mm和14.57mm,45.97mm和39.44mm,市售菌剂的发芽率、芽长及根长分别为95%、14.18mm、39.03mm。有机肥的有机质含量、氮磷钾总量及pH分别为86.62%和85.17%,8.85%和8.22%,7.5和8.0,均符合行业标准NY525—2012。2种处理对新鲜鸡粪的发酵均能在20d内完成,符合规模化有机肥生产企业的生产要求。  相似文献   
200.
将筛选出的青霉、黑曲霉和根霉按1:1:1比例制得的发酵剂用于普洱茶发酵,添加量为1%,取得了较好的发酵效果。将发酵剂应用于生产中进行发酵验证,设发酵剂组和对照组2组。试验中首次对普洱茶发酵过程中的温度变化进行实时监控分析。发酵完成后,对2组茶进行了感官评审和主要成分分析,得出发酵剂组的各翻堆茶样在汤色、香气、滋味和叶底方面都较对照组好,且普洱茶的渥堆发酵成熟速度明显快于对照组;在温度变化方面,发酵剂组和对照组的茶坯中心温度基本维持在40~60℃之间,发酵剂组的温度高于对照组2℃左右;在主要成分变化方面,茶多酚、儿茶素、茶红素及水溶性总糖的含量是呈下降趋势的,而茶褐素、茶黄素经发酵后有明显的上升趋势,发酵剂组的变化曲线总是快于对照组。研究结果表明,本发酵剂用于普洱茶发酵过程中,可以提高普洱茶的品质,缩短发酵周期。  相似文献   
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