全文获取类型
收费全文 | 306篇 |
免费 | 23篇 |
专业分类
林业 | 18篇 |
农学 | 12篇 |
基础科学 | 5篇 |
59篇 | |
综合类 | 5篇 |
农作物 | 32篇 |
水产渔业 | 56篇 |
畜牧兽医 | 102篇 |
园艺 | 3篇 |
植物保护 | 37篇 |
出版年
2023年 | 1篇 |
2022年 | 9篇 |
2021年 | 16篇 |
2020年 | 18篇 |
2019年 | 20篇 |
2018年 | 15篇 |
2017年 | 23篇 |
2016年 | 15篇 |
2015年 | 12篇 |
2014年 | 14篇 |
2013年 | 16篇 |
2012年 | 18篇 |
2011年 | 13篇 |
2010年 | 12篇 |
2009年 | 9篇 |
2008年 | 11篇 |
2007年 | 6篇 |
2006年 | 2篇 |
2005年 | 10篇 |
2004年 | 9篇 |
2003年 | 8篇 |
2002年 | 9篇 |
2001年 | 2篇 |
2000年 | 4篇 |
1999年 | 4篇 |
1998年 | 4篇 |
1996年 | 2篇 |
1995年 | 5篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1989年 | 4篇 |
1988年 | 3篇 |
1987年 | 2篇 |
1986年 | 3篇 |
1985年 | 3篇 |
1984年 | 1篇 |
1983年 | 5篇 |
1981年 | 1篇 |
1980年 | 6篇 |
1979年 | 1篇 |
1977年 | 3篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1973年 | 1篇 |
1968年 | 1篇 |
排序方式: 共有329条查询结果,搜索用时 0 毫秒
71.
72.
Efficacy of using previously used controlled internal drug release (CIDR) insert on the reproductive performance,hormone profiles and economic measures of sheep 下载免费PDF全文
Ayman Abdel‐Aziz Swelum Islam M. Saadeldin Abdullah F. Moumen Mohamed A. Ali Hany Ba‐Awadh Abdullah N. Alowaimer 《Reproduction in domestic animals》2018,53(5):1114-1122
This study was conducted using 120 multiparous Awassi ewes during the breeding season to compare the effects of using previously used controlled internal drug release (CIDR) on the hormone profiles, reproductive performance and economic measures of ewes. Ewes were randomized to receive one of five previously used CIDR (previously used for 6, 12, 18, 24 or 30 days) or the new CIDR as a control for 6 days (CIDR6, CIDR12, CIDR18, CIDR24, CIDR30, and CIDR0 [control], respectively). Blood samples were collected on four occasions, at the time of CIDR insertion, after 3 days of insertion, and at the time of withdrawal and insemination. Serum estradiol (E2) and progesterone (P4) concentrations were measured. Timed insemination was performed 48 hr post‐CIDR withdrawal. Pregnancy was diagnosed by ultrasonography 23 days after insemination and confirmed on day 35. The heat detection rate was significantly (p < 0.05) higher in the CIDR0 and CIDR6 groups than in the CIDR18 and CIDR30 groups. The total pregnancy rate and fecundity were significantly (p < 0.05) higher in the CIDR6 group than in other groups. P4 level was significantly (p < 0.05) higher in the CIDR0 group than in the CIDR30 group at the time of removal. At each time point, the E2 level was significantly (p < 0.05) higher in the CIDR6 group than at the other groups. The total variable cost, total cost, return and net profit were higher in the CIDR6 and CIDR0 groups than in the other groups. In conclusion, although previously used CIDRs are efficient at synchronizing oestrus in ewes, the duration of previously usage significantly affected the reproductive parameters and economic profit. CIDRs previously used for 6 days and new CIDRs provided the highest fertility and fecundity rates, besides return and net profit. Economically, it is not advisable to use CIDRs that previously used for 12 days or more. 相似文献
73.
Mahmoud G. El Sebaei Nagah Arafat Reham A. El-Shafei Mohamed A. El-Adl Amany Farag Abeer E. Aziza Abdelfattah H. Eladl 《Journal of animal physiology and animal nutrition》2021,105(1):129-139
This study was carried out to evaluate the effects of induced urolithiasis by high dietary calcium (Ca) or protein levels on biochemical analyte levels, redox status, selected inflammatory cytokines and histopathology in chickens. A total of 90 one-day-old white Hy-Line chicks were fed basal control diets containing 20% crude protein (CP) and 1% Ca until they reached 44 days of age. After that, the birds were divided into three groups (30 birds per group). All management factors (light, temperature, ventilation, stock density and diet) were identical among the three groups throughout the study except for the dietary Ca and protein percentages. Group I was fed a control diet containing 20% CP and 1% Ca, group II was fed a high-Ca diet containing 5% Ca, and group III was fed a high-protein diet containing 25% CP. Our findings clearly demonstrated that dietary imbalance (caused by high-Ca or high-CP levels) per se in chickens was physiologically harmful, as it was accompanied by post-mortem lesions; biochemical, redox status and histopathological alterations; and upregulation of inflammatory cytokines (interleukin (IL)-1β and IL-6). In particular, the birds fed the high-Ca diet clearly exhibited the most obvious alterations in most of the endpoints. In conclusion, this study constitutes the first extensive investigation of the effects of high-Ca or high-protein diets induced urolithiasis on growth performance, redox status, inflammatory cytokine levels and pathological characterization in chickens. 相似文献
74.
Multiple seeded cocklebur has been found in the last decade in Texas, and described as a biotype of Xanthium strumarium L with up to 25 seeds per bur instead of the usual two. The multiple seeded bur typically produces up to nine seedlings, causing concern that it may be harder to control than normal seeded common cocklebur. The efficacies of a series of fungal and conventional commercial herbicides have been compared in the greenhouse on seedlings of multiple seeded cocklebur from Texas (MSC-TX) and normal common cockleburs from Texas (NCC-TX), Arkansas (NCC-AR), Illinois (NCC-ILL) and two from Mississippi (NCC-MS#1, NCC-MS#2). Three measures of herbicidal activity (reductions in plant height and dry weight, and mortality) were used. The fungal herbicide Alternaria helianthi (Hansf) Tubaki & Nishihara at 1 x 10(5) conidia ml(-1) + 2 g liter(-1) Silwet L-77 with an 8-h dew period was an effective herbicide with all biotypes, as were the commercial chemical herbicides chlorimuron (14.8 g ha(-1)), imazaquin (29.6 g ha(-1)), sodium hydrogen methylarsonate (MSMA; 279.1 g ha(-1)) and imazethapyr (39.5 g ha(-1)). The membrane-disrupting organic arsenical MSMA was effective with all biotypes, whereas commercial chemical herbicides which act by inhibiting branched-chain amino acid synthesis (chlorimuron, imazaquin and imazethapyr) were less effective against normal seeded common cocklebur biotypes with short stature. These studies showed that multiple seeded cocklebur was at least as susceptible to the biological agent A helianthi and to the conventional commercial herbicides studied as were normal seeded cockleburs, suggesting that existing methods should be adequate to control this novel biotype. 相似文献
75.
Hobbs-Chell H King AJ Sharratt H Haddadi H Rudiger SR Hailes S Morton AJ Wilson AM 《Research in veterinary science》2012,93(1):549-552
The use of externally fitted motion sensors to animal subjects has the potential for allowing researchers to investigate subtle changes in animal movement that may occur with the onset of specific diseases. However, it is crucial to consider whether or not the use of such technology has an effect on the variables measured. Here, we examine the effect of a body harness data logging device on the locomotive patterns of female Merino sheep, Ovis aries. We extracted locomotion variables typical of motion sensor data (stride frequency, stride length, gait type, speed, and limb velocity) from high-definition video collected under controlled conditions. We found no significant difference between the variables measured in the harnessed and unharnessed conditions. Overall, our experiment demonstrates that data-loggers carried on a harness do not adversely affect sheep locomotion, and extended periods of habituation post-instalment of devices should ensure consistency and accuracy of data in future experiments. 相似文献
76.
A.M.H. Abdel Dayem Karima Gh. M. Mahmoud M.F. Nawito M.M. Ayoub T.H. Scholkamy 《Livestock Science》2009,122(2-3):193-198
This study aimed to develop a system of in vitro assays based on zona pellucida binding and in vitro fertilization for predicting male fertility in buffalo bulls. Frozen–thawed semen from nine bulls was tested for motility, viability index, acrosomal integrity, zona pellucida binding and in vitro fertilizing ability. Differences in post-thaw sperm motility between bulls were not significant. Differences in viability indices and percentage of spermatozoa with detached acrosome between bulls was highly significant (P < 0.001). Sperm attached per ovum, fertilization rates and polyspermy percentages varied significantly (P < 0.01) among buffalo bulls. A significant (P < 0.01) positive correlation coefficient of 0.69 was evident between normal acrosome and sperm attached per ovum, while between normal acrosome and fertilization efficiency it was 0.72. Sperm from different buffalo bulls differs in their ability to bind and fertilize oocytes. This study provides a basis to predict and maximize the in vitro fertilization performance of individual bulls. 相似文献
77.
Effect of organic and inorganic selenium supplementation on semen quality and blood enzymes in buffalo bulls 下载免费PDF全文
Mohamed El‐Sharawy Entsar Eid Samy Darwish Ibrahim Abdel‐Razek Md. Rashedul Islam Kaiyu Kubota Nobuhiko Yamauchi Ibrahim El‐Shamaa 《Animal Science Journal》2017,88(7):999-1005
The present study aimed to evaluate the effect of organic and inorganic selenium (Se) supplementation on semen quality and blood serum profiles of buffalo bulls. Nine mature buffalo bulls were divided into three groups: control (non‐supplemented); organic Se (10 mg Sel‐Plex®/head twice weekly) and inorganic Se (10 mg sodium selenite/head twice weekly). Semen was collected twice a week for 3 months during Se supplementation. Semen properties were evaluated from fresh ejaculate. Moreover, fructose concentration, aspartate and alanine transaminase (AST and ALT) activities, total protein and total cholesterol were assayed in seminal plasma. Additionally AST, ALT, testosterone and Se levels were determined in the blood serum. Results showed that Se supplementation significantly (P < 0.05) influences the semen parameters during 3 months of treatment. Organic Se significantly (P < 0.05) increased the percentage of viable sperms compared to inorganic Se and the control group. Fructose concentration was significantly higher (P < 0.05) in the seminal plasma of organic Se‐treated bulls. Serum testosterone and Se concentrations were significantly (P < 0.05) increased in the Se supplemented groups than the control group. In conclusion, Se supplementation improved the parameters of buffalo bull semen and more precisely, organic Se was more effective for the improvement of semen quality and some blood components than inorganic Se. 相似文献
78.
Mansoorlakooraj H Saadati D Javadi R Heydari S Torki E Gholami H Fard RM 《Veterinary parasitology》2011,182(2-4):364-367
Data have been collected from slaughterhouses in three provinces across the Northern Iran (Gilan, Mazandaran and Golestan) from March 2004 to March 2008. These data were collected to evaluate the prevalence of hydatidosis in slaughtered cattle, sheep and goats. During the study, 3,347,797 animals were slaughtered. These included 621,686 cattle, 1,719,725 sheep and 1,006,386 goats. The prevalence of infection in cattle, sheep and goats was 12%, 14.6% and 10.1%, respectively. The association of condemnation rates with seasons was not proven statistically. 相似文献
79.
Keegan KG Arafat S Skubic M Wilson DA Kramer J Messer NM Johnson PJ O'Brien DP Johnson G 《Equine veterinary journal》2004,36(8):712-717
REASONS FOR PERFORMING STUDY: Subjective neurological evaluation in horses is prone to bias. An objective method of spinal ataxia detection is not subject to these limitations and could be of use in equine practice and research. HYPOTHESIS: Kinematic data in the walking horse can differentiate normal and spinal ataxic horses. METHODS: Twelve normal and 12 spinal ataxic horses were evaluated by kinematic analysis walking on a treadmill. Each body position signal was reduced to a scalar measure of uncertainty then fuzzy clustered into normal or ataxic groups. Correct classification percentage (CCP) was then calculated using membership values of each horse in the 2 groups. Subsequently, a guided search for measure combinations with high CCP was performed. RESULTS: Eight measures of body position resulted in CCP > or = 70%. Several combinations of 4-5 measures resulted in 100% CCP. All combinations with 100% CCP could be obtained with one body marker on the back measuring vertical and horizontal movement and one body marker each on the right fore- and hindlimb measuring vertical movement. CONCLUSIONS AND POTENTIAL RELEVANCE: Kinematic gait analysis using simple body marker combinations can be used objectively to detect spinal ataxia in horses. 相似文献
80.
Song Yi-Gang Walas Łukasz Pietras Marcin Sâm Hoàng Văn Yousefzadeh Hamed Ok Tolga Farzaliyev Vahid Worobiec Grzegorz Worobiec Elżbieta Stachowicz-Rybka Renata Boratyński Adam Boratyńska Krystyna Kozlowski Gregor Jasińska Anna K. 《European Journal of Forest Research》2021,140(6):1323-1339
European Journal of Forest Research - Pterocarya fraxinifolia, native to the southern Caucasus and adjacent areas, has been widely introduced in Europe. In this study, we investigate the following:... 相似文献