全文获取类型
收费全文 | 740篇 |
免费 | 40篇 |
国内免费 | 1篇 |
专业分类
林业 | 42篇 |
农学 | 44篇 |
116篇 | |
综合类 | 48篇 |
农作物 | 107篇 |
水产渔业 | 56篇 |
畜牧兽医 | 333篇 |
园艺 | 9篇 |
植物保护 | 26篇 |
出版年
2023年 | 5篇 |
2022年 | 22篇 |
2021年 | 26篇 |
2020年 | 15篇 |
2019年 | 13篇 |
2018年 | 18篇 |
2017年 | 25篇 |
2016年 | 22篇 |
2015年 | 30篇 |
2014年 | 39篇 |
2013年 | 46篇 |
2012年 | 43篇 |
2011年 | 51篇 |
2010年 | 30篇 |
2009年 | 28篇 |
2008年 | 59篇 |
2007年 | 47篇 |
2006年 | 38篇 |
2005年 | 43篇 |
2004年 | 39篇 |
2003年 | 36篇 |
2002年 | 29篇 |
2001年 | 20篇 |
2000年 | 14篇 |
1999年 | 7篇 |
1998年 | 2篇 |
1997年 | 5篇 |
1996年 | 3篇 |
1993年 | 2篇 |
1992年 | 7篇 |
1991年 | 2篇 |
1990年 | 4篇 |
1989年 | 1篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 3篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1968年 | 1篇 |
排序方式: 共有781条查询结果,搜索用时 0 毫秒
761.
Isolation and determination of anthocyanins in seed coats of black soybean (Glycine max (L.) Merr.).
M G Choung I Y Baek S T Kang W Y Han D C Shin H P Moon K H Kang 《Journal of agricultural and food chemistry》2001,49(12):5848-5851
Anthocyanin pigments in seed coats of black soybean (Glycine max (L.) Merr.) were extracted with 1% HCl-CH(3)OH, and the crude anthocyanin extract was purified by Shepadex LH-20 and Lichroprep RP-18 open-column chromatography. Three major anthocyanins were isolated, and their chemical structures were identified by spectroscopic methods (UV-visible, FABMS, (1)H and (13)C NMR, and by TLC). The complete structures of these anthocyanins were elucidated as delphinidin-3-glucoside, cyanidin-3-glucoside, and petunidin-3-glucoside. Among them, petunidin-3-glucoside was identified as a new anthocyanin in black soybeans. On the basis of RP-HPLC with a UV-vis detector, the contents of delphinidin-3-glucoside, cyanidin-3-glucoside, petunidin-3-glucoside, and total anthocyanins in seed coats of 10 black soybeans were found in the ranges of 0-3.71, 0.94-15.98, 0-1.41, and 1.58-20.18 mg/g, respectively. The results obtained in this study imply that the seed coats of black soybean can be used as a good source for cyanidin-3-glucoside and delphinidin-3-glucoside. 相似文献
762.
Mapping quantitative trait loci controlling soybean seed starch content in an interspecific cross of ‘Williams 82’ (Glycine max) and ‘PI 366121’ (Glycine soja) 下载免费PDF全文
Sanjeev K. Dhungana Krishnanand P. Kulkarni Cheol W. Park Hyun Jo Jong T. Song Dong‐Hyun Shin Jeong‐Dong Lee 《Plant Breeding》2017,136(3):379-385
Seed starch content (SSC) greatly affects the taste, flavour and processing properties of soy foods. The objective in this study was to identify quantitative trait loci (QTL) for SSC in soybean. A total in 169 recombinant inbred lines (RILs) derived from a cross in ‘Williams 82’ and ‘PI 366121’ were grown for three consecutive years. The SSC of the RILs displayed continuous variation with transgressive segregation and hence amenable for QTL mapping. Nine significant QTL exhibiting 5.6–11.3% of the total phenotypic variation (PVE) were identified. The QTL qSTR06_2 showed highest PVE (9.1–11.3%) at LOD values of 4.25–5.39. No stable QTL over 3 years were identified, indicating strong environmental influence on SSC. The QTL qSTR11_1 and qSTR20_1 were found to colocalize with some of the previously reported QTL for sucrose content in soybean, implying the interrelationship between starch and sucrose biosynthesis. As the carbohydrate components may affect key constituents such as oil and protein in soybean seed, findings of the study may be useful in breeding soybeans with improved seed composition. 相似文献
763.
Shin OKAMOTO Keiichiro INAFUKU Zhu TING Yoshizane MAEDA Dexing HOU Yang Feng TAMG Zhang Han YUN Wenbo XU Liming SHI Tsutomu HASHIGUCHI 《Animal Science Journal》2003,74(6):471-476
Blood samples were collected from four native breeds (Chahua chicken, Xishuangbanna Game chicken, Wuding chicken, and Yangbi Huang chicken) in the Yunnan province of China, and their protein polymorphisms were analyzed by using electrophoresies. Out of 16 loci examined, polymorphisms were found in the following eight loci: plasma esterase, plasma amylase, plasma alkaline phosphatase, plasma albumin, plasma transferrin, plasma postalbumin, and hemoglobin. The other eight loci, erythrocyte lactate dehydrogenase, erythrocyte 6‐phosphogluconate dehydrogenase, erythrocyte phosphoglucomutase, erythrocyte phosphohexose isomerase, erythrocyte tetrazolium oxidase, erythrocyte malate dehydrogenase, erythrocyte esterase and hemoglobin, were monomorphic. The proportion of the polymorphic loci and the expected average heterozygosity were estimated as 0.438–0.500 and 0.141–0.174, respectively. A dendrogram was drawn according to the genetic distance, which was calculated by the Nei's genetic distance matrix, among four Chinese native breeds. The results indicated that Chahua, Wuding and Yangbi Huang chickens were genetically remote from Xishuangbanna Game chicken. Moreover, the genetic distance was calculated among the Sri Lankan, Bangladeshi and Nepalese native fowl populations, and another dendrogram was constructed. In the latter dendrogram, Chahua, Wuding and Yangbi Huang chickens were genetically closer to Sri Lankan and Bangladeshi native fowls than Xishuangbanna Game chicken. 相似文献
764.
Larvicidal activity of isobutylamides identified in Piper nigrum fruits against three mosquito species 总被引:2,自引:0,他引:2
Park IK Lee SG Shin SC Park JD Ahn YJ 《Journal of agricultural and food chemistry》2002,50(7):1866-1870
The insecticidal activity of materials derived from the fruits of Piper nigrum against third instar larvae of Culex pipiens pallens, Aedes aegypti, and A. togoi was examined and compared with that of commercially available piperine, a known insecticidal compound from Piper species. The biologically active constituents of P. nigrum fruits were characterized as the isobutylamide alkaloids pellitorine, guineensine, pipercide, and retrofractamide A by spectroscopic analysis. Retrofractamide A was isolated from P. nigrum fruits as a new insecticidal principle. On the basis of 48-h LC(50) values, the compound most toxic to C. pipiens pallens larvae was pipercide (0.004 ppm) followed by retrofractamide A (0.028 ppm), guineensine (0.17 ppm), and pellitorine (0.86 ppm). Piperine (3.21 ppm) was least toxic. Against A. aegypti larvae, larvicidal activity was more pronounced in retrofractamide A (0.039 ppm) than in pipercide (0.1 ppm), guineensine (0.89 ppm), and pellitorine (0.92 ppm). Piperine (5.1 ppm) was relatively ineffective. Against A. togoi larvae, retrofractamide A (0.01 ppm) was much more effective, compared with pipercide (0.26 ppm), pellitorine (0.71 ppm), and guineensine (0.75 ppm). Again, very low activity was observed with piperine (4.6 ppm). Structure-activity relationships indicate that the N-isobutylamine moiety might play a crucial role in the larvicidal activity, but the methylenedioxyphenyl moiety does not appear essential for toxicity. Naturally occurring Piper fruit-derived compounds merit further study as potential mosquito larval control agents or as lead compounds. 相似文献
765.
Huong le D Shim JH Choi KH Shin JA Choi ES Kim HS Lee SJ Kim SJ Cho NP Cho SD 《Journal of agricultural and food chemistry》2011,59(15):8124-8131
Cruciferous vegetables have been shown to have the possibility to protect against multistep carcinogenesis. β-Phenylethyl isothiocyanate (PEITC) is one component of these vegetables demonstrated to help fight many types of cancer. The present study examined the apoptotic effects of PEITC and its molecular mechanism in human cervical cancer cell lines (HEp-2 and KB). PEITC induced apoptosis to inhibit cell proliferation. According to the protein chip assay, PEITC increased the expression of the death receptors (DR4 and DR5) and cleaved caspase-3 compared to the DMSO treatment group. PEITC also induced caspase-8 and truncated BID. PEITC down-regulated the phosphorylation of extracellular-related kinase (ERK)1/2, whereas neither phospho-c-Jun NH(2)-terminal kinases (JNK) nor phospho-p38 MAPK was changed. The role of ERK in PEITC-induced apoptosis was also investigated using MEK inhibitor (PD98059). PD98059 increased the expression of DR4 and DR5, activated caspase-3, and cleaved PARP. In addition, PEITC decreased the phosphorylation of MEK. Therefore, the apoptotic mechanism of PEITC in cervical cancer cells involves the induction of DR4 and DR5 through the inactivation of ERK and MEK. 相似文献
766.
Md. Shah?AlamEmail author Shin ichi?Teshima Dedy?Yaniharto Ophirtus?Sumule Manabu?Ishikawa Shunsuke?Koshio 《Aquaculture International》2005,13(4):369-379
Four semi-purified diets, containing crystalline amino acids (CAAs), were fed to juvenile red sea bream, Pagrus major in order to ascertain the ideal dietary amino acid pattern for this species. A control diet containing 50% casein–gelatin as protein sources, but no CAAs were fed to the fish. The other diets contained 30% casein–gelatin and 20% CAAs. CAAs were added to diets to simulate with amino acid pattern of the red sea bream eggs protein (REP), red sea bream larvae whole body protein (RLP), red sea bream juvenile whole body protein (RJP), and brown fishmeal protein (BFP). The juveniles (average initial body weight, 1.58 ± 0.01 g) were maintained in triplicate tanks and fed twice daily for 30 days. The highest weight gain was observed in juveniles fed the RJP diet. No significant difference was observed in juveniles fed the RLP and BFP diet. Feed efficiency ratio, protein efficiency ratio and amino acid retention in the whole body were significantly (p < 0.05) affected by the simulated dietary amino acid patterns. The essential amino acid profile and A/E ratios of the whole body after the growth trial showed little difference among the dietary treatments. The results suggest that red sea bream juveniles are able to utilize high amounts of CAA in coated form. The amino acid pattern of RJP could be used as an appropriate of reference dietary amino acid for this species. 相似文献
767.
Sang Ick Shin Hea Jin Choi Koo Min Chung Bruce R. Hamaker Kwan Hwa Park Tae Wha Moon 《Cereal Chemistry》2004,81(3):404-408
Effects of debranching time, storage time, and storage temperature on production and structural properties of slowly digestible starch (SDS) were investigated. Waxy sorghum starch was hydrolyzed by isoamylase for various times (0–24 hr), and the variously debranched products were stored at ‐30, 1, and 30°C for 1–6 days. Optimal conditions for SDS production were isoamylase treatment for 8 hr and storage at 1°C for three days, resulting in SDS content of 27.0% in the optimum product. Microscopic observation revealed that rapidly digestible starch (RDS) and SDS were removed from the edges and surfaces of the optimum product by α‐amylase digestion. Digestion conditions that removed RDS and SDS resulted in a residue with a higher transition temperature and enthalpy than raw starch on a differential scanning calorimetric thermogram. Removal of RDS alone did not cause distinct decrements of peak temperature (Tp) and enthalpy (ΔH) compared with stored starch. The optimum SDS product showed an amorphous type of X‐ray diffractogram. Digestive removal of RDS from the optimum product gave a residue with X‐ray peaks similar to B type, which supports that it is partly crystalline. Removal of RDS and SDS gave broader peaks in the X‐ray pattern. 相似文献
768.
Hidemi Oyama Kiyoto Imamura Shinichi Sakamoto Kazutaka Nishi Kotaro Kawabe Shin Okamoto Takeshi Honda Kenji Oyama Takeshi Shimogiri 《Animal Science Journal》2020,91(1)
Defective appearances, including white spotting (WS), tongue defect (TD), and nipple defect (ND), in Japanese Black cattle potentially lead to economic losses to farmers in Japan. We estimated genetic parameters of defective appearances using 553,433 records of Japanese Black heifer calves housed in the Kagoshima Prefecture. Variance and covariance were estimated using the Gibbs sampling algorithm. The estimated heritability ranged from 0.29 for TD to 0.76 for WS. Percent breeding value (%BV) estimates indicated high variation in WS and ND among sires, reflecting higher heritability. Furthermore, there was a positive linear relationship between the %BV estimate of a sire and the mean incidence rate of each defect in his female offsprings. TD was positively associated with other defects. Therefore, genetic factors strongly affect the incidence of defective appearances in Japanese Black cattle. 相似文献
769.
Lee AR Gautam M Kim J Shin WJ Choi MS Bong YS Hwang GS Lee KS 《Journal of agricultural and food chemistry》2011,59(16):8560-8567
Asian ginseng (Panax ginseng C.A. Meyer) is widely used as an Oriental medicine in the East Asian regions, particularly Korea and China. In the study, the strontium isotope ratios ((87)Sr/(86)Sr), multielements, and metabolite profiles of 35 ginseng samples collected from Korea and China were examined in an attempt to develop a method to distinguish the origin of ginsengs from the two countries. A multivariate statistical approach was performed to analyze the multielements and the (1)H nuclear magnetic resonance (NMR) data. Results of a t-test for Mg, Fe, Al, and Sc showed significant variation between Korean and Chinese ginsengs, indicating potential tracers for discriminating them. Discriminating between the ginsengs from the two countries was generally successful when both the (87)Sr/(86)Sr ratios and rare earth element (REE) contents were used together. Moreover, principal component analysis (PCA) derived from the (1)H NMR data revealed a significant separation between the ginsengs originating from the two countries. The major metabolites responsible for differentiation were sugars such as glucose, xylose, and sucrose. The results suggest that this multiplatform approach offers a comprehensive method to distinguish the origin of ginsengs. 相似文献
770.
P. Timothy Tate Won Sik Shin John H. Pardue W. Andrew Jackson 《Water, air, and soil pollution》2012,223(3):1115-1123
The massive oil release from the Deep Water Horizon disaster has reemphasized the need to remediate oil impacted marshes.
Due to the physically fragile nature of salt water marshes, bioremediation is often proposed as an appropriate technology
and nutrient amendment is often proposed as a means of accelerating biodegradation of crude oil. However, no information is
currently available concerning the efficacy of in situ nutrient amendments in Gulf Coast salt marshes. An experimental crude
oil spill (142 l over 100 m2) was conducted to evaluate the efficacy of nitrogen amendment to stimulate bioremediation in a Spartina alterniflora dominated Louisiana salt marsh. A randomized complete block design with replication (n = 10) was utilized to test the hypothesis that additions of fast-release ammonium nitrate (60 g N/m2) and slow-release urea (30 g N/m2) fertilizers could enhance biodegradation of selected crude oil components in the marsh. Crude oil degradation was monitored
by analyzing sediment samples for branched and unbranched alkanes over the 180-day study period. The compound/hopane ratio
was used to correct for nonbiological losses. No consistent statistically significant effect of fertilizer addition on degradation
rates was observed, despite success in increasing the porewater ammonium and NaCl-extractable ammonium over the time frame
of the trial. Intrinsic pseudo-first order degradation rates of alkanes in all plots were substantial (0.003–0.008 day−1). Existing, background levels of N did not appear to limit biodegradation rates in Spartina-dominated salt marshes. These results suggest that nutrient amendments will not be successful in stimulation biodegradation
of crude oil in these systems. 相似文献