全文获取类型
收费全文 | 418篇 |
免费 | 35篇 |
专业分类
林业 | 28篇 |
农学 | 20篇 |
基础科学 | 4篇 |
82篇 | |
综合类 | 26篇 |
农作物 | 27篇 |
水产渔业 | 71篇 |
畜牧兽医 | 170篇 |
园艺 | 4篇 |
植物保护 | 21篇 |
出版年
2023年 | 9篇 |
2022年 | 8篇 |
2021年 | 28篇 |
2020年 | 14篇 |
2019年 | 14篇 |
2018年 | 16篇 |
2017年 | 17篇 |
2016年 | 18篇 |
2015年 | 18篇 |
2014年 | 27篇 |
2013年 | 26篇 |
2012年 | 35篇 |
2011年 | 42篇 |
2010年 | 15篇 |
2009年 | 25篇 |
2008年 | 24篇 |
2007年 | 24篇 |
2006年 | 25篇 |
2005年 | 15篇 |
2004年 | 11篇 |
2003年 | 17篇 |
2002年 | 11篇 |
2000年 | 2篇 |
1999年 | 1篇 |
1997年 | 1篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1988年 | 1篇 |
1985年 | 1篇 |
1977年 | 2篇 |
1944年 | 1篇 |
排序方式: 共有453条查询结果,搜索用时 15 毫秒
441.
Ceccarelli Viviana Lastra Sphyros Loor Solrzano Rey Gastn Chacn Walter Wenceslao Nolasco Mario Sotomayor Cantos Ignacio Antonio Plaza Avelln Luis Fernando Lpez Diana Aracelly Fernndez Anchundia Fabian Marcelo Dessauw Dominique Orozco-Aguilar Luis Thomas Evert 《Genetic Resources and Crop Evolution》2022,69(3):1283-1302
Genetic Resources and Crop Evolution - Cacao (Theobroma cacao L.) is among the most important cash crops in tropical countries. The existing cacao genetic diversity represents a key resource to... 相似文献
442.
Tatianne Leme Oliveira Santos Godoi Julia Dias Villas-Boas Norma Aparecida dos Santos Almeida Pablo Ignacio Trigo Fernando Queiroz de Almeida Magda Alves de Medeiros 《Journal of Equine Veterinary Science》2014
Acupuncture has been shown to have the beneficial effect of reducing stress responses in animals and humans. Pharmacopuncture is the injection of subclinical doses of drugs into acupoints to give therapeutic results without side effects. This study compared the effects of injecting the usual dose of acepromazine (ACP; 0.1 mg/kg, intramuscularly [I.M.]) with those of pharmacopuncture (1/10 ACP dose at the governing vessel 1 [GV 1] acupoint) on the stress responses of healthy horses undergoing road transport for 2.5 hours. Four different treatments were applied immediately before loading, with 8 animals/treatment: injection of saline or ACP (0.1 mg/kg, I.M.) at the base of the neck; and injection of saline or 1/10 ACP (0.01 mg/kg) at the GV 1 acupoint. The road transport increased heart rate (HR), respiratory rate, body temperature, and serum cortisol of the untreated horses (injected with saline at the base of the neck). Pharmacopuncture at GV 1 reduced the average HR and transport-induced increase in HR at unloading, without changing the other variables. On the other hand, ACP (0.1 mg/kg) produced significant sedation and reduced the transport-induced increase in respiratory rate but without preventing the stress-induced increase of cortisol. Other acupuncture points and drugs should be tested to verify the beneficial effect of this therapy to reduce stress in horses during road transport. 相似文献
443.
Pablo Casta?o Miguel Fuertes Ignacio Ferre Miguel Fernández Maria del Carmen Ferreras Javier Moreno-Gonzalo Camino González-Lanza Frank Katzer Javier Regidor-Cerrillo Luis Miguel Ortega-Mora Valentín Pérez Julio Benavides 《Veterinary research》2014,45(1):9
After oral administration of ewes during mid gestation with 2000 freshly prepared sporulated oocysts of T. gondii isolate M4, abortions occurred between days 7 and 11 in 91.6% of pregnant and infected ewes. Afterwards, a further infection was carried out at late gestation in another group of sheep with 500 sporulated oocysts. Abortions happened again between days 9 and 11 post infection (pi) in 58.3% of the infected ewes. Classically, abortions in natural and experimental ovine toxoplasmosis usually occur one month after infection. Few experimental studies have reported the so-called acute phase abortions as early as 7 to 14 days after oral inoculation of oocysts, and pyrexia was proposed to be responsible for abortion, although the underline mechanism was not elucidated. In the present study, all placentas analysed from ewes suffering acute phase abortions showed infarcts and thrombosis in the caruncullar villi of the placentomes and ischemic lesions (periventricular leukomalacia) in the brain of some foetuses. The parasite was identified by PCR in samples from some placentomes of only one sheep, and no antigen was detected by immunohistochemical labelling. These findings suggest that the vascular lesions found in the placenta, and the consequent hypoxic damage to the foetus, could be associated to the occurrence of acute phase abortions. Although the pathogenesis of these lesions remains to be determined, the infectious dose or virulence of the isolate may play a role in their development. 相似文献
444.
Miguel Angel ANGEL Maria Antonia GIL Cristina CUELLO Jonatan SANCHEZ-OSORIO Jesus GOMIS Inmaculada PARRILLA Jordi VILA Ignacio COLINA Marta DIAZ Josep REIXACH Jose Luis VAZQUEZ Juan Maria VAZQUEZ Jordi ROCA Emilio A. MARTINEZ 《The Journal of reproduction and development》2014,60(5):371-376
This study aimed to evaluate the effect of recipient-donor estrous cycle synchrony on recipient reproductive performance
after nonsurgical deep-uterine (NsDU) embryo transfer (ET). The transfers (N=132) were conducted in recipients sows that
started estrus 24 h before (–24 h; N=9) or 0 h (synchronous; N=31), 24 h (+24 h; N=74) or 48 h (+48 h; N=18) after the
donors. A total of 30 day 5 morulae or day 6 blastocysts (day 0=onset of estrus) were transferred per recipient. The highest
farrowing rates (FRs) were achieved when estrus appeared in recipients 24 h later than that in the donors (81.1%), regardless
of the embryonic stage used for the transfers. The FR notably decreased (P<0.05) when recipients were –24 h asynchronous
(0%), synchronous (61.3%) or +48 h asynchronous (50%) relative to the donors. No differences in litter size (LS) and piglet
birth weights were observed among the synchronous and +24 h or +48 h asynchronous groups. While a +24 h asynchronous
recipient was suitable for transfers performed with either morulae (FR, 74.3%; LS, 9.2 ± 0.6 piglets) or blastocysts (FR,
84.6%; LS, 9.8 ± 0.6 piglets), a + 48 h asynchronous recipient was adequate for blastocysts (FR, 87.5%; LS, 10.4 ± 0.7
piglets) but not for morulae (FR, 30.0%; LS, 7.3 ± 2.3 piglets). In conclusion, this study confirms the effectiveness of the
NsDU-ET technology and shows that porcine embryos tolerate better a less advanced uterine environment if they are
nonsurgically transferred deep into the uterine horn. 相似文献
445.
Ignacio García-Bocanegra Alberto Allepuz Julio José Pérez Anna Alba Armando Giovannini Antonio Arenas Luca Candeloro Alberto Pacios José Luís Saez Miguel Ángel González 《Veterinary journal (London, England : 1997)》2014,199(3):439-445
Six serological assays for the diagnosis of ovine brucellosis, due to Brucella melitensis were evaluated. Reference serum samples from sheep of known B. melitensis infection status (n = 118) were assessed using the Rose Bengal test (RBT), complement fixation test (CFT) and four commercial enzyme-linked immunosorbent assays (ELISAs), including two indirect ELISAs (iELISAs), one competitive ELISA (cELISA) and one blocking ELISA (bELISA).The highest differential positive rates (DPR) were obtained with the cELISA and bELISA, while the lowest DPR was estimated using iELISAs. A latent class analysis was performed to estimate the accuracy of the CFT, RBT and bELISA using 1827 sera from sheep undergoing testing as part of a surveillance and control programme. Lower sensitivity and specificity were obtained for the three serological tests when the field samples were used. A higher DPR was achieved by the CFT, compared to bELISA and RBT. The results suggest that ELISAs, and particularly the bELISA, might be suitable for inclusion in the European Union legislation on intra-community trade for diagnosing B. melitensis infection in sheep, as it has a similar test performance compared to the RBT. 相似文献
446.
Goikoetxea Alexander Servili Arianna Houdelet Camille Mouchel Olivier Hermet Sophie Clota Fréderic Aerts Johan Fernandino Juan Ignacio Allal François Vandeputte Marc Blondeau-Bidet Eva Geffroy Benjamin 《Fish physiology and biochemistry》2022,48(4):1117-1135
Fish Physiology and Biochemistry - In this study, we aimed to investigate the relationship between cortisol and the determination of sexual fate in the commercially important European sea bass... 相似文献
447.
Samir Demdoum Fernando Muñoz Ignacio Delgado José Valderrábano Ana Wünsch 《Genetic Resources and Crop Evolution》2012,59(2):253-260
EST-SSR from Medicago truncatula Gaertn. and Glycine max (L.) Merr. were tested for transferability in various species of Onobrychis (O. pyrenaica Sennen, O. argentea Boiss. and O. viciifolia Scop.). Repeatable amplification was obtained for 81% of the microsatellites and 52% were polymorphic. Six selected SSRs
from M. truncatula were used to fingerprint and estimate the genetic similarity of a set of 23 accessions of O. viciifolia. PCA analysis discriminated among the different Onobrychis species and the sainfoin accessions were clustered in a single major group. This grouping is discussed in terms of the history
of cultivation of sainfoin in Spain. The selected SSRs will allow fingerprinting and genetic studies in Onobrychis species, solving the lack of available SSR markers in this species. 相似文献
448.
ZHAO Shi-cheng L Ji-long XU Xin-peng LIN Xiao-mao Luiz Moro ROSSO QIU Shao-jun Ignacio CIAMPITTI HE Ping 《农业科学学报》2021,20(9):2502-2511
Nutrient balance is essential for attaining high yield and improving profits in agricultural farming systems, and crop nutrient uptake ratio and stoichiometry can indicate crop nutrient limitations in the field. We collected a large amount of field data to study the variations in yield, nutrient uptake and nutrient stoichiometry of peanut(Arachis hypogaea L.) in Southeast China(SEC), North-central China(NCC), and Northeast China(NEC), during 1993 to 2018. Peanut pod yield gradually increased from 1993 to 2018, with average yields of 4 148, 5 138, and 4 635 kg ha–1 in SEC, NCC, and NEC, respectively. The nitrogen(N) internal efficiency(NIE, yield to N uptake ratio) was similar among the three regions, but phosphorus(P) IE(PIE, yield to P uptake ratio) changed from low to high among regions: NCCSECNEC, while potassium(K) IE(KIE, yield to K uptake ratio) portrayed a different pattern of SECNCCNEC. Based on the nutrient IE, to produce 1 Mg of pod yield, the average N, P, and K requirements of the above-ground parts of peanut were roughly 47.2, 5.1, and 25.5 kg in SEC, 44.8, 5.7, and 20.6 kg in NCC, and 44.6, 4.4, and 14.7 kg in NEC, respectively. The N/P ratio changed in the sequence NCCSECNEC, and the N/K ratio was similar in NEC and NCC, but lower in SEC. The N harvest index(HI) and KHI declined with increasing nutrient uptake across all regions under high nutrient uptake. The low PIE and N/P ratios in NCC could be explained by the high P accumulation in stover, and high KIE and N/K ratios in NEC may be attributed to the low soil K supply. The frontier analysis approach provides a practical framework and allows documentation of a decline in nutrient HI as nutrient uptake increases. Lastly, this study reveals the limitation and surplus of nutrients of peanut in different regions of China. 相似文献
449.
Laura Moreno-Camarena Ignacio Domnguez-Vara Jos Brquez-Gastelum Juan Snchez-Torres Juan Pinos-Rodrguez Antonia Mariezcurrena-Berasain Ernesto Morales-Almarz Abdelfattah Z M Salem 《中国农业科学(英文版)》2015,(3)
The objective of this study was to evaluate supplemental organic chromium (Cr) to ifnishing lambs on growth performance, carcass characteristics, and meat quality. Eighteen Suffolk lambs (age (4.5±0.2)... 相似文献
450.
Andrs Escudero Jos R. Gonzlez Jos L. Benedito Felipe R. Prieto Ignacio Ayala 《Research in veterinary science》2009,87(3):458-461
Limited information exists regarding electrocardiographic parameters in clinically healthy donkeys. The study was carried out in 75 healthy adult animals (40 females and 35 males) using the Einthoven standard II and base-apex leads. The P wave showed usually a bifid shape deflection. The QRS complex of the donkeys appeared in several forms: QR and R were the most frequent in limb lead II, and QS and QR in the base-apex lead. Most T waves presented a simple negative configuration in lead II and biphasic shape in the base-apex one. Mean heart rate value was 52 beats per minute. The direction of the QRS vector in lead II had a mean value of 91.4°. We observed a lack of detected arrhythmias. Statistically significant differences were observed between sexes for several parameters. The electrocardiogram of Zamorano-leones donkey differs in several duration, amplitude and morphologic parameters from that of several breeds of horses and donkeys. This fact justifies obtaining values for a specific breed against which to compare values for the same breed. 相似文献