全文获取类型
收费全文 | 390篇 |
免费 | 26篇 |
专业分类
林业 | 28篇 |
农学 | 11篇 |
84篇 | |
综合类 | 29篇 |
农作物 | 18篇 |
水产渔业 | 8篇 |
畜牧兽医 | 201篇 |
园艺 | 15篇 |
植物保护 | 22篇 |
出版年
2024年 | 1篇 |
2023年 | 2篇 |
2022年 | 5篇 |
2021年 | 17篇 |
2020年 | 8篇 |
2019年 | 17篇 |
2018年 | 12篇 |
2017年 | 15篇 |
2016年 | 8篇 |
2015年 | 16篇 |
2014年 | 16篇 |
2013年 | 7篇 |
2012年 | 35篇 |
2011年 | 45篇 |
2010年 | 12篇 |
2009年 | 21篇 |
2008年 | 35篇 |
2007年 | 30篇 |
2006年 | 17篇 |
2005年 | 30篇 |
2004年 | 28篇 |
2003年 | 13篇 |
2002年 | 15篇 |
2001年 | 1篇 |
1999年 | 2篇 |
1998年 | 3篇 |
1997年 | 1篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1987年 | 1篇 |
1972年 | 1篇 |
排序方式: 共有416条查询结果,搜索用时 0 毫秒
411.
412.
Ronan Marrec Gaël Caro Paul Miguet Isabelle Badenhausser Manuel Plantegenest Aude Vialatte Vincent Bretagnolle Bertrand Gauffre 《Landscape Ecology》2017,32(12):2383-2398
Context
Agroecosystems are dynamic, with yearly changing proportions of crops. Explicit consideration of this temporal heterogeneity is required to decipher population and community patterns but remains poorly studied.Objectives
We evaluated the impact on the activity-density of two dominant carabid species (Poecilus cupreus and Anchomenus dorsalis) of (1) local crop, current year landscape composition, and their interaction, and (2) inter-annual changes in landscape composition due to crop rotations.Methods
Carabids were sampled using pitfall-traps in 188 fields of winter cereals and oilseed rape in three agricultural areas of western France contrasting in their spatial heterogeneity. We summarized landscape composition in the current and previous years in a multi-scale perspective, using buffers of increasing size around sampling locations.Results
Both species were more abundant in oilseed rape, and in landscapes with a higher proportion of oilseed rape in the previous year. P. cupreus abundance was negatively influenced by oilseed rape proportion in the current year landscape in winter cereals and positively by winter cereal proportion in oilseed rape. A. dorsalis was globally impacted at finer scales than P. cupreus.Conclusions
Resource concentration and dilution-concentration processes jointly appear to cause transient dynamics of population abundance and distribution among habitat patches. Inter-patch movements across years appear to be key drivers of carabids’ survival and distribution, in response to crop rotation. Therefore, the explicit consideration of the spatiotemporal dynamics of landscape composition can allow future studies to better evidence ecological processes behind observed species patterns and help developing new management strategies.413.
Snégaroff J Branlard G Bouchez-Mahiout I Laudet B Tylichova M Chardot T Pecquet C Choudat D Raison-Peyron N Vigan M Kerre S Laurière M 《Journal of agricultural and food chemistry》2007,55(24):9837-9845
Two genes of wheat low-molecular-weight glutenin subunits (LMW-GS), B16 and P73, were cloned and expressed in E. coli. They were homologous to proteins encoded respectively at Glu-B3 and Glu-D3 loci. The N-terminal and C-terminal halves of B16 (NB16 and B16C) and the two chimeras combining the halves of the two genes (B16-P73 and P73- B16) were also expressed. All these constructs were compared for their reactivity with IgE from 24 patients suffering from different forms of wheat allergies. The results confirmed that LMW-GSs bound IgE in all adult allergies tested. Strong differences in reactivity between all the constructs were observed. They were disease-dependent. In wheat-dependent exercise-induced anaphylaxis (WDEIA), the reactivity of the constructs depended partly on common epitopes with omega-5 gliadins but also on differences in molecule conformation. The presence of NB16 in the constructs greatly influenced their IgE reactivity. 相似文献
414.
Starkenmann C Le Calvé B Niclass Y Cayeux I Beccucci S Troccaz M 《Journal of agricultural and food chemistry》2008,56(20):9575-9580
Volatile sulfur compounds have a low odor threshold, and their presence at microgram per kilogram levels in fruits and vegetables influences odor quality. Sensory analysis demonstrates that naturally occurring, odorless cysteine- S-conjugates such as S-( R/ S)-3-(1-hexanol)- l-cysteine in wine, S-(1-propyl)- l-cysteine in onion, and S-(( R/ S)-2-heptyl)- l-cysteine in bell pepper are transformed into volatile thiols in the mouth by microflora. The time delay in smelling these volatile thiols was 20-30 s, and persistent perception of their odor occurred for 3 min. The cysteine- S-conjugates are transformed in free thiol by anaerobes. The mouth acts as a reactor, adding another dimension to odor perception, and saliva modulates flavors by trapping free thiols. 相似文献
415.
COMPARISON OF LUNG ATTENUATION AND HETEROGENEITY BETWEEN CATS WITH EXPERIMENTALLY INDUCED ALLERGIC ASTHMA,NATURALLY OCCURRING ASTHMA AND NORMAL CATS 下载免费PDF全文
Isabelle Masseau Alina Banuelos John Dodam Leah A. Cohn Carol Reinero 《Veterinary radiology & ultrasound》2015,56(6):595-601
Airway remodeling is a prominent feature of feline allergic asthma but requires biopsy for characterization. Computed tomography (CT) has appeal as a minimally invasive diagnostic test. The purpose of this prospective case–control study was to compare indices of airway remodeling between cats with experimentally induced, spontaneous asthma and healthy unaffected cats using CT. We hypothesized that experimental and spontaneous feline asthma would have similar CT airway remodeling characteristics and that these would be significantly different in healthy cats. Experimentally induced asthmatic research cats (n = 5), spontaneously asthmatic pet cats (n = 6), and healthy research cats (n = 5) were scanned unrestrained using a 64‐detector row CT scanner. Inspiratory breath‐hold CT scans were also performed in experimentally induced asthmatic and healthy cats. Mean ± extent variation of lung attenuation for each cat was determined using an airway inspector software program and CT images were scored for lung heterogeneity by a board‐certified veterinary radiologist who was unaware of cat group status. Groups were compared using one‐way ANOVA (unrestrained scans) and the Student's t‐test (anesthetized scans) with significance defined as P < 0.10. Experimentally asthmatic and spontaneously asthmatic cats had significantly (P = 0.028 and P = 0.073, respectively) increased lung attenuation compared to healthy cats. Heterogeneity scores were higher in experimentally induced asthmatic cat than in healthy cats. Objective quantification of lung heterogeneity and lung volume did not differ among the three groups (P = 0.311, P = 0.181, respectively). Findings supported our hypothesis. Inspiratory breath‐hold anesthetized CT scans facilitated discrimination between asthmatic and healthy cats in comparison to unrestrained CT scans. 相似文献
416.
Neuraxial morphine induced pruritus in two cats and treatment with sub anaesthetic doses of propofol
Thomas Gent Isabelle Iff Regula Bettschart‐Wolfensberger Martina Mosing 《Veterinary anaesthesia and analgesia》2013,40(5):517-520
HistoryTwo cats were presented for orthopaedic surgery.Physical ExaminationWith the exception of the orthopaedic injuries found, clinical examination showed no abnormality.ManagementAs part of anaesthetic management, one cat received intrathecal morphine, the other epidural morphine. Following recovery, intense grooming was observed. After ensuring adequate analgesia this behaviour was interpreted as pruritus.In the first cat, pruritus was initially managed with medetomidine constant rate infusion (CRI) at 1 and 1.5 μg kg?1 hour?1. The lower dose produced sedation and no relief from pruritus, the higher dose ablated pruritus but induced sedation. Two propofol (lipid emulsion formulation) boli of 0.1 mg kg?1 ablated pruritus without causing sedation. The second cat was successfully treated with four boli of 0.1 mg kg?1 propofol over 20 minutes.Follow–upFollowing treatment with propofol, pruritus did not recur in either cat and both were discharged from the hospital.ConclusionsThis is the first clinical report of morphine–induced pruritus in cats and management with low–dose propofol. These cases suggest an antipruritic mechanism for lipid–formulation propofol. 相似文献