全文获取类型
收费全文 | 150篇 |
免费 | 7篇 |
国内免费 | 3篇 |
专业分类
林业 | 8篇 |
农学 | 26篇 |
基础科学 | 1篇 |
34篇 | |
综合类 | 6篇 |
农作物 | 13篇 |
水产渔业 | 28篇 |
畜牧兽医 | 19篇 |
园艺 | 5篇 |
植物保护 | 20篇 |
出版年
2023年 | 1篇 |
2022年 | 5篇 |
2021年 | 4篇 |
2020年 | 2篇 |
2019年 | 5篇 |
2018年 | 9篇 |
2017年 | 6篇 |
2016年 | 12篇 |
2015年 | 6篇 |
2014年 | 12篇 |
2013年 | 14篇 |
2012年 | 9篇 |
2011年 | 7篇 |
2010年 | 2篇 |
2009年 | 5篇 |
2008年 | 7篇 |
2007年 | 5篇 |
2006年 | 4篇 |
2005年 | 3篇 |
2004年 | 3篇 |
2003年 | 7篇 |
2002年 | 1篇 |
2001年 | 4篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1996年 | 3篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1988年 | 5篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1979年 | 2篇 |
1972年 | 1篇 |
排序方式: 共有160条查询结果,搜索用时 15 毫秒
61.
Reena Sellamuthu Gui Fu Liu Chandra Babu Ranganathan Rachid Serraj 《Field Crops Research》2011,124(1):46-58
Drought is a major constraint for rice production and yield stability in rainfed ecosystems, especially when it occurs during the reproductive stage. Combined genetic and physiological analysis of reproductive-growth traits and their effects on yield and yield components under drought stress is important for dissecting the biological bases of drought resistance and for rice yield improvement in water-limited environments. A subset of a doubled haploid (DH) line population of CT9993-5-10-1-M/IR62266-42-6-2 was evaluated for variation in plant water status, phenology, reproductive-growth traits, yield and yield components under reproductive-stage drought stress and irrigated (non-stress) conditions in the field. Since this DH line population was previously used in extensive quantitative trait loci (QTLs) mapping of various drought resistance component traits, we aimed at identifying QTLs for specific reproductive-growth and yield traits and also to validate the consensus QTLs identified earlier in these DH lines using meta-analysis. DH lines showed significant variation for plant water status, reproductive-growth traits, yield and yield components under drought stress. Total dry matter, number of panicles per plant, harvest index, panicle harvest index, panicle fertility, pollen fertility, spikelet fertility and hundred grain weight had significant positive correlations with grain yield under drought stress. A total of 46 QTLs were identified for the various traits under stress and non-stress conditions with phenotypic effect ranging from 9.5 to 35.6% in this study. QTLs for panicle exsertion, peduncle length and pollen fertility, identified for the first time in this study, could be useful in marker-assisted breeding (MAB) for drought resistance in rice. A total of 97 QTLs linked to plant growth, phenology, reproductive-growth traits, yield and its components under non-stress and drought stress, identified in this study as well as from earlier published information, were subjected to meta-analysis. Meta-analysis identified 23 MQTLs linked to plant phenology and production traits under stress conditions. Among them, four MQTLs viz., 1.3 for plant height, 3.1 for days to flowering, 8.1 for days to flowering or delay in flowering and 9.1 for days to flowering are true QTLs. Consensus QTLs for reproductive-growth traits and grain yield under drought stress have been identified on chromosomes 1 and 9 using meta-QTL analysis in these DH lines. These MQTLs associated with reproductive-growth, grain yield and its component traits under drought stress could be useful targets for drought resistance improvement in rice through MAB and/or map-based positional analysis of candidate genes. 相似文献
62.
63.
Proteinase inhibitors (AsPIs) with high activity against serine proteinases were purified from seeds of the tree legume, Acacia senegal by ammonium sulfate precipitation followed by DEAE-Sephadex A-25 column and evaluated against Helicoverpa armigera larvae by in vitro and in vivo methods. The molecular weight of AsPIs was found to be approximately 19.58 ± 1.00 and 21.23 ± 1.00 kDa for PI and 18.16 ± 1.00 kDa for PII on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The AsPIs (5 μg/ml) inhibited approximately 70% of midgut trypsin and 61% of elastase-like chymotrypsin. In vitro studies showed that AsPIs have remarkable inhibitory activity towards total gut proteolytic enzymes followed by trypsin and chymotrypsin. The IC50 of AsPIs for midgut trypsin was 0.1 μg/ml and for chymotrypsin was 2.0 μg/ml. The inhibition of gut proteinase enzymes was of the non-competitive type. In larval feeding studies, AsPIs were found to retard growth and development of H. armigera and also affects the fecundity of the pest. The results advocate the use of AsPIs in transgenic technology to develop plant resistance to H. armigera. 相似文献
64.
Sirirat Kiatpathomchai P. Michael Schmitz T. S. Amjath Babu Sutonya Thongrak 《Paddy and Water Environment》2008,6(3):319-326
Rice and shrimp farming are two important economic activities in rural southern Thailand that compete each other in land allocation
leading to land use conflicts. Moreover, it can be observed that the conversion of rice fields to shrimp farms is already
extended from coastal areas to the inlands. These conversions are making more area be saline which is essential condition
for shrimp cultivation but deleterious for rice farming. We are looking at the unidirectional externalities originating from
the conversion which brings the productivity of adjacent rice fields further down. This study attempts to quantify the external
effects on rice yield and efficiency of rice farming by constructing three models. Model I, we assess the rice yield function
by using the multiple linear regression while in Model II, we attempt to delineate the technical efficient frontier of rice
farms by using an input oriented non-parametric approach, so called data envelopment analysis. Model III, we probe into the
factors influencing technical efficiency scores using the Tobit regression. Database of the study is constituted by primary
survey data from 120 rice farms in Songkhla province for the crop year 2004/2005. The 30 out of 120 sample farms have been
affected by externality of shrimp farming. The empirical results of all three models show that shrimp farming externalities
caused a production drop of 467–515 kg paddy rice per ha and significantly affect the technical efficiency of rice farms.
The measures of internalizing this externality are discussed. 相似文献
65.
Suresh Babu G. Farooq M. Ray R. S. Joshi P. C. Viswanathan P. N. Hans R. K. 《Water, air, and soil pollution》2003,144(1-4):149-157
Organochlorine pesticides were used earlier for agricultureproduction. Their residues may still be present in soil and mayaccumulate in food crops, posing potential health problems to consumers. DDT, HCH, their isomers and metabolites were analyzedin samples of soil and rice plants collected from ten differentvillages of a well-known Basmati rice growing area in Dehradun.Residues of both pesticides were found in all samples ofsoil and different parts of rice plants except for a few grainsamples. Maximum residue was observed in husk and minimum ingrains. The average concentration of DDT in soil ranged from0.013 to 0.238 ppm. p,p′-DDE was the major metabolite (>63%). Theaverage concentration of DDT in rice grain varied from 0.002 to 0.040 ppm. o,p′-DDT was the main isomer (>93%). Theaverage concentration of HCH in soil ranged from 0.122 to 0.638 ppm. β-HCH was the predominant (43%) isomerfollowed by α-HCH (21%). The average HCH concentrationin rice grain ranged between 0.013 and 0.113 ppm. All four isomers were present in grains. The levels of DDT and CHCin grains were similar in magnitude as those from differentIndian states, but well below the maximum residue limit of 0.1 ppm for DDT and 0.05 ppm for HCH prescribed by the Government ofIndia and WHO/FAO. As such, the pesticide residue levels in thisexport commodity are not of hazardous nature. 相似文献
66.
谷氨酰胺合成酶(glutamine synthetase, GS)是一种广泛分布在动植物体内的酶,并参与细胞多种代谢调控。在甲壳动物中,GS在能量代谢和渗透压调节过程中起着重要作用。实验克隆了罗氏沼虾GS基因。GS基因cDNA全长1 965 bp,开放读码框(ORF)为1 086 bp,编码361个氨基酸(aa),分子量大小为40.75 ku,等电点为5.81。进化树分析发现,罗氏沼虾GS基因与凡纳滨对虾、斑节对虾和中国明对虾GS聚为一支,氨基酸相似性达到95%。氨基酸多序列比对分析结果显示,罗氏沼虾GS属于无脊椎动物分支的GSⅡ群,有5个保守区域。实验对罗氏沼虾GS蛋白进行表达并制备了多克隆抗体。采用荧光定量PCR技术(qRT-PCR)和免疫印迹(Western blot)对罗氏沼虾蜕壳前后的不同组织GS表达进行检测。qRT-PCR结果显示,GS基因在所检测的8个组织中均有表达;蜕壳前,其相对表达量顺序为:肝胰脏肌肉胃肠鳃心脏脑血淋巴。蜕壳后和蜕壳前GS基因在组织中的差异表达比较结果显示,除了在肝胰脏表达下调外,其他7个组织都表达升高,其相对表达量的差异顺序为:脑鳃胃肠肌肉心脏血淋巴。Westernblot结果显示,蜕壳后GS蛋白在鳃和肌肉组织表达量上调,与其mRNA表达一致。此外,罗氏沼虾蜕壳后肝胰脏GS酶的活性和谷氨酰胺的含量下调,而其在鳃、肌肉和血淋巴中上调,结果与其基因表达一致。研究表明,GS基因在不同组织中表达的差异可能和罗氏沼虾的能量代谢、渗透压调节有关。 相似文献
67.
V L Ramya R Sharma P Gireesh‐Babu S R Patchala A Rather P C Nandanpawar S Eswaran 《Journal of fish diseases》2014,37(9):815-824
The protective efficacy of a DNA construct containing extra small virus antisense (XSVAS) gene of nodavirus encapsulated with chitosan nanoparticles (NPs) was investigated in giant freshwater prawn Macrobrachium rosenbergii (De Man, 1879). The delivery was carried out using oral and immersion methods. A plasmid concentration of 100 ng μL?1 when conjugated with chitosan NPs was found to be more effective in increasing the survivability of the infected prawn. The particle mean size, zeta potential and loading efficiency percentage were 297 nm, 27 mV and 85%, respectively. The ability of the chitosan to form a complex with the plasmid was studied by agarose gel electrophoresis. The NPs were characterized by atomic force microscopy (AFM). Persistence study showed the presence of the DNA construct up to 30th day post‐treatment. The oral treatment was found to be better than the immersion treatment for delivery of the chitosan‐conjugated DNA construct. This is probably the first report on the delivery of nanoconjugated DNA construct in M. rosenbergii, against nodavirus. 相似文献
68.
Molecular characterization,tissue distribution of Follicle‐Stimulating Hormone (FSH) beta subunit and effect of kisspeptin‐10 on reproductive hormonal profile of Catla catla (Hamilton, 1822)
下载免费PDF全文
![点击此处可从《Aquaculture Research》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Mohd Ashraf Rather Irfan Ahmad Bhat Niti Sharma Rupam Sharma Gireesh‐Babu P Aparna Chaudhari Jeetendra Kumar Sundaray 《Aquaculture Research》2016,47(7):2089-2100
Gonadotropin (GTH) hormones are glycoprotein which stimulates gonadal maturation in vertebrates. Follicle stimulating hormone is involved in initiation of gametogenesis and regulation of gonadal growth. FSHβ has been cloned and characterized from the brain of Catla catla. The FSHβ full‐length of cDNA sequence of 523 bp comprised 3, 394 and 128 bp of 5′‐UTR, open reading frame (ORF) 3′‐UTR respectively. The coding region of C. catla FSHβ encoded a peptide of 130 amino acids. Phylogenetic analysis of C. catla FSHβ deduced amino acid sequence showed high similarity with Gobiocypris rarus followed by goldfish, Carassius auratus. The qPCR result shows that FSHβ mRNA is mainly expressed in pituitary while moderate and low expression was observed in testis and ovary respectively. Chitosan‐nanoconjugated kisspeptin‐10 (CK‐10) of particle size 125 nm, polydispersity index of 0.335 to 0.65 and zeta potential of ?34.95 mV were synthesized and evaluated at against naked kisspeptin‐10 for their reproductive hormonal profile. Treatment of fish with CK‐10 showed controlled and sustained surge of the reproductive hormones (FSH & LH) with peak at 12 h. The hormone levels of naked kisspeptin‐10 treated fish decline after 6 h. The sustained release of this CK‐10 will help in reducing maturation age, synchronization of ovulation and spawning in fish. This is the first report on use of chitosan‐nanoconjugated kisspeptin‐10 (CK‐10) for reproduction in fish. 相似文献
69.
Babu Lal Meena Raj Kumar Rattan Siba Prasad Datta 《Communications in Soil Science and Plant Analysis》2017,48(9):1059-1067
This study was conducted to determine the solubility of iron (Fe) and identify the solid phases responsible for controlling its solubility in these soils by using Baker soil test (BST) computer program. The results indicated that the ferric ion (Fe3+) activity in all the soils, except the acidic ones, nearly approached the theoretical solubility line of known minerals, namely soil-Fe, amorphous-Fe, maghemite, and lepidocrocite. Solubility of Fe in acid soils of Ranchi (soil 3) and Cooch-Behar (soil 6) did not match the theoretical solubility lines of any of the known minerals. The acidic soils of Ranchi and Cooch-Behar were sufficient for Fe with respect to both quantity and intensity factor based on BST rating, while alkaline (soil 1) and calcareous (soil 5) were sufficient in reserve Fe; deficiency of iron still could be suspected because of high pH. These findings elucidate the role of solid phase controlling iron solubility in soil solution of degraded soils. 相似文献
70.