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71.
本研究应用安徽、江苏、江西、湖北、湖南、四川和云南7个自然隔离群日本血吸虫尾蚴感染家兔和小鼠的血清对同源及异源可溶性虫卵抗原(SEA)进行酶联免疫吸附试验(ELISA)。结果显示:用同源虫卵抗原检测各地感染血清,其抗体应答水平并不高于应用异源虫卵抗原的。各地虫卵抗原的抗原性并不一致。  相似文献   
72.
为提高大豆分离蛋白的表面活性,试验采用过氧乙酸控制性的打开蛋白质的二硫键,并在此基础上加入葡聚糖进行复合修饰。结果表明:随着二硫键断开程度的增加,接枝度明显提升,褐变度与其有相同的变化趋势。当二硫键断开率为46%时,表面活性最理想。其中乳化性和乳化稳定性提高107.56%和175%;起泡性和起泡稳定性提高83.63%和105%;荧光图谱表明随着二硫键断开率的增加,荧光强度出现先升高后降低的趋势,而糖基化复合产物荧光强度依次降低;SDS-PAGE进一步证实,在糖基化过程中7S亚基最先消失,二硫键断开后,可以加速11S酸性亚基与葡聚糖发生糖基化反应。  相似文献   
73.
 大麦黄矮病毒PAV株系由麦长管蚜和禾谷缢管蚜传毒。本研究通过RT-PCR、克隆和序列测定后,确认所得到的我国小麦PAV分离物的外壳蛋白基因片段由600个核苷酸组成,编码199个氨基酸。序列同源性比较结果显示,与BYDV的其它株系典型分离物的外壳蛋白基因同源性最高为74.5%,而与国外发表的PAV 8个分离物的CP基因核苷酸同源性为81%左右,且同源性比较的分值也较其它株系高。氨基酸序列的比较中,仅在46到60位氨基酸差别较大。  相似文献   
74.
Verticillium dahliae isolates from potato on the island of Hokkaido (potato isolates) and those belonging to pathotypes A (eggplant pathotype), B (tomato pathotype) and C (sweet pepper pathotype) were divided into three distinct groups by RAPD and REP-PCR. The three DNA groups I, II, III consisted of pathotypes A and C, pathotype B and potato isolates, respectively. The potato isolates were assigned to pathotype A on the basis of pathogenicity. Another set of potato isolates was further collected from eight potato cropping regions on Hokkaido to further examine the relationships among them in detail. Only one of these isolates was identified as DNA group II, but all the others were classified as DNA group III. Isolates from daikon, eggplant, and melon on Hokkaido also belonged to DNA group III. These results suggest that V. dahliae isolates from Hokkaido are unique at the DNA level and different from other pathotype A isolates in Japan. Received 28 February 2000/ Accepted in revised form 6 November 2000  相似文献   
75.
Soy protein isolate (SPI) mixed with soybean oil (SPIO) incubated at 100°C for 8 h was used to evaluate changes of solubility and digestibility of SPI in vitro and digestive function in broilers at an early age. Arbor Acres broilers were allocated to three groups with six replicates of 12 birds, receiving basal diet (CON), 8 h heat‐oxidized SPI diet (HSPI) and 8 h heat‐oxidized mixture of SPI and 2% soybean oil diet (HSPIO) for 21 days, respectively. Nitrogen solubility index (NSI) declined and soybean oil accelerated the decline of NSI during incubation (P < 0.05). Decreased in vitro digestibility of dry matter (DM) and crude protein (CP) were observed in SPIO (P < 0.05). HSPI and HSPIO decreased body weight gain, relative jejunum weight and pancreatic trypsin activity at day 21 (P < 0.05). HSPIO decreased anterior intestinal trypsin activity at day 14 and amylase and trypsin activity at day 21, pancreatic amylase activity at day 21 and apparent digestibility of DM, organic matter and CP of broilers from days 18 to 20 (P < 0.05). Heat treatment and soybean oil could induce oxidative modification of SPI, and oxidized SPI negatively affected growth and digestion of broilers. © 2016 Japanese Society of Animal Science  相似文献   
76.
The aim of this study was to investigate the optimal conditions of ultrasound‐assisted alkaline extraction (UAAE) on pork liver protein isolate (UPLPI) and its physico‐chemical properties. Response surface methodology was used to determine the optimal conditions for UAAE, which were at ultrasonic power 265 W, ultrasonic time 42 min, NaOH concentration 0.80%, temperature 50°C, and solvent/raw material ratio 70. The extraction yield and efficiency of UPLPI were significantly improved over the conventional alkaline extraction (PLPI). The results of amino acid composition showed that UAAE could increase serine (36.5 g/kg), arginine (38.1 g/kg), alanine (37.5 g/kg), proline (48.7 g/kg), phenylalanine (55.6 g/kg) and lysine (47.2 g/kg) elution amount. The changes in fourier transform infrared spectra indicated unfolding and destruction of the protein structure in UPLPI. The differential scanning calorimetry analysis presented UPLPI with a slightly lower onset and peak denaturation temperature over PLPI. Surface hydrophobicity increased and the microstructures presented larger and more pores of UPLPI, therefore, it had better in vitro digestibility than PLPI. Therefore, UPLPI might have a potential application prospect in the food field due to its changes on molecular structure as well as on the microstructure of protein by UAAE.  相似文献   
77.
以大豆分离蛋白为试验材料,优化糖基化大豆分离蛋白制备工艺并研究经过葡萄糖处理对大豆分离蛋白溶解度、凝胶强度、乳化性以及热稳定方面的影响。结果表明:糖基化大豆分离蛋白最佳制备工艺为反应温度69.49℃、反应时间46.64 min、糖的添加量10.64%,凝胶强度最高为76.03;在相同p H下,经葡萄糖处理后的大豆分离蛋白溶解度较大,沉淀较少,而未糖基化的大豆分离蛋白沉淀量增加。糖基化处理的大豆分离蛋白乳化稳定性(emulsifying stability,ES)和热稳定性均有所增强。糖基化改性过程可显著提高大豆分离蛋白的溶解性和乳化性能,这为拓宽其在食品工业中的应用提供了理论基础。  相似文献   
78.
 槟榔坏死环斑病(ANRSD)是近年来海南槟榔主产区发生广泛、危害严重的病毒病害,发病植株叶片表现严重坏死环斑、树势衰退,疑似与马铃薯Y病毒科(Potyviridae)槟榔坏死环斑病毒(areca palm necrotic ringspot virus, ANRSV)相关。本研究从海南定安槟榔种植区发现感病植株叶部表现轻微稀疏褪绿斑的病毒分离物(ANRSV-DAT),对其基因组序列全长克隆和分析。ANRSV-DAT与先前报道的强毒分离物ANRSV-XC1基因组核苷酸(nt)序列及其编码融合蛋白氨基酸(aa)序列的同源性分别为90.68%和97.91%;两者的融合蛋白之间存在63个aa变异,不同程度地分布在10个顺反子中(HCPro1、HCPro2、P3、7K、CI、9K、NIa-VPg、NIa-Pro、NIb和CP)。与ANRSV-XC1显著不同的是,ANRSV-DAT的5'非翻译区的5'末端缺失95-nt序列。该缺失序列是否导致ANRSV-DAT毒性弱化有待进一步研究。本研究报道的ANRSV轻症型分离株,以期为筛选弱毒株及后续交叉保护防治ANRSV提供重要宝贵材料。  相似文献   
79.
Pythium root rot (PRR) caused by Pythium spp. is an important root rot disease affecting common bean productivity. The objective of this study was to conduct a genome-wide association analysis of resistance to PRR in the common bean of Andean gene pool using single nucleotide polymorphism (SNP) markers. About 260 genotypes of the Andean diversity panel (ADP) were evaluated under screen house conditions using Pythium ultimum isolate MS61 in Uganda. Sixteen significant signals for resistance to PRR were detected on chromosomes Pv01, Pv02, Pv04, Pv05 and Pv09 using 260K GBS-based and 6K Beadchip SNPs. Common significant signals were detected on Pv02 and Pv09 for PRR. Positional candidate genes associated with significant SNPs on Pv02 were Phvul.002G119700, 16.97 kb near marker S02_25507837 (25.50 Mb), encoding Subtilase family protein, and Phvul.002G278400 near marker ss715645959 (44.79 Mb) encoding Defensin-like (DEFL) protein involved in plant defence responses. Based on the relatively high heritability estimates observed for PRR in this study, significant SNP markers associated with genomic regions for resistance to PRR could be validated for marker-assisted breeding in Andean beans.  相似文献   
80.
从新疆马兰荒漠地区土壤中分离出1株具有拮抗真菌作用的放线菌AF1,经16sDNA鉴定为链霉菌属的Strep-tomyces macrosporus种。在贝奈特琼脂培养基(Bennett's agar)中,利用异步十字交叉培养法的实验发现,其分泌的活性物质对黑曲霉、白曲霉、青霉等丝状真菌具有抗性,但对酵母菌和细菌无作用。  相似文献   
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