全文获取类型
收费全文 | 302篇 |
免费 | 5篇 |
专业分类
林业 | 29篇 |
农学 | 6篇 |
基础科学 | 2篇 |
56篇 | |
综合类 | 21篇 |
农作物 | 20篇 |
水产渔业 | 22篇 |
畜牧兽医 | 142篇 |
园艺 | 3篇 |
植物保护 | 6篇 |
出版年
2022年 | 4篇 |
2021年 | 8篇 |
2020年 | 6篇 |
2019年 | 11篇 |
2018年 | 12篇 |
2017年 | 3篇 |
2016年 | 11篇 |
2015年 | 7篇 |
2014年 | 7篇 |
2013年 | 19篇 |
2012年 | 41篇 |
2011年 | 14篇 |
2010年 | 7篇 |
2009年 | 9篇 |
2008年 | 15篇 |
2007年 | 14篇 |
2006年 | 12篇 |
2005年 | 13篇 |
2004年 | 12篇 |
2003年 | 5篇 |
2002年 | 8篇 |
2001年 | 3篇 |
2000年 | 5篇 |
1999年 | 6篇 |
1998年 | 4篇 |
1997年 | 5篇 |
1996年 | 5篇 |
1995年 | 6篇 |
1994年 | 4篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 3篇 |
1984年 | 1篇 |
1983年 | 3篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1974年 | 1篇 |
1968年 | 1篇 |
1966年 | 1篇 |
1962年 | 1篇 |
1956年 | 1篇 |
1955年 | 1篇 |
1949年 | 1篇 |
1948年 | 1篇 |
1946年 | 1篇 |
1945年 | 1篇 |
排序方式: 共有307条查询结果,搜索用时 15 毫秒
161.
Gad?G.?Yousef Mary?H.?Grace Jorge?L.?Guerrero?Medina Scott?Neff Ivette?Guzman Allan?F.?Brown Ilya?Raskin Mary?Ann?LilaEmail author 《Plant foods for human nutrition (Dordrecht, Netherlands)》2014,69(4):317-324
Co-delivery of edible proteins with health-protective fruit (muscadine grape) and vegetable (kale) phytoactive compounds was accomplished in a biofortified ingredient for use in convenient, portable food formulations. Polyphenolics were concentrated (10–42 mg/g range) in dry muscadine-protein matrices. Kale-fortified protein matrices also captured polyphenolics (8 mg/g), carotenoids (69 μg/g) and glucosinolates (7 μmol/g). Neither total phenolics nor glucosinolates were significantly diminished even after long term (6 months) storage at 4, 20, or 37 °C, whereas carotenoids degraded over time, particularly at higher temperatures. Dry biofortified phytoactive-protein ingredients allowed delivery of immunoprotective compounds from fruits and vegetables in a stable, lightweight matrix. 相似文献
162.
163.
EK Gee EC Firth PCH Morel PF Fennessy ND Grace TD Mogg 《New Zealand veterinary journal》2013,61(6):448-456
AIMS: To determine the influence of copper (Cu) supplementation by injection of mares in late gestation on the frequency and severity of osteochondrosis (OC) lesions in their foals at around 160 days of age. To determine if there was any influence of the concentration of Cu in the liver, growth rate, birthweight, weight at 160 days of age, fatness, sex, or year of birth of the foal on the frequency and severity of OC lesions. To determine the influence of dam's age, and sex and birthweight of the foal on the growth rate from birth to 160 days of age, and weight at 160 days of age. METHODS: Thirty-three Thoroughbred foals, born in two consecutive years, were weighed every 2 weeks from birth. The dams had been supplemented with parenteral Cu or saline during late gestation, and the supplementation regimens were different in each year. Foals had liver biopsies harvested at birth for determination of Cu concentration. Pasture samples were collected every 4–8 weeks for analysis of concentration of Cu and zinc (Zn). At 160 days of age, articular cartilage of long bones was examined. Gross lesions were counted and scored, then sawn and radiographed, and processed for histopathology. Lesions were given radiographic scores and histopathological scores. Maximum scores for each lesion were combined to give a total OC score for each joint and each foal. The fatness of 20 foals (10 each from Years 1 and 2) at 160 days of age was determined chemically. RESULTS: Supplementation of dams with Cu had no significant effect on the concentration of Cu in the liver of foals at birth, or on the frequency or severity of lesions in articular cartilage at 160 days of age. The Cu and Zn concentrations of pasture were similar in Years 1 and 2, and were lower than current recommendations. All foals in Year 2, and 9/10 foals in Year 1 had irregularities in cartilage that was confirmed histologically to be indicative of OC. The average number of lesions per foal was 4.7 (SD 1.1) and 5.7 (SD 1.1) in Years 1 and 2, respectively. However, the severity of the lesions was considered mild, and no foals showed any clinical evidence of OC while alive. The number of lesions in the tarsocrural (TC) joint and the TC OC score at 160 days were positively associated with average daily weight gain (ADG) in the previous 4 weeks (p=0.005 and p=0.001, respectively). There was no significant effect of sex, fatness, birth-weight, weight at 160 days of age, or year of birth of the foal on the frequency and severity of OC lesions. CONCLUSIONS: Many of the lesions classified as OC, using classification systems described by other authors, were likely to be normal variations of the process of endochondral ossification. Despite the high frequency of such lesions, they were considered to be of minor significance and none were clinically evident. The distribution of lesions was not typical, and most probably reflected the subtlety of the lesions. These results support the hypothesis that Cu is an over-emphasised factor in the aetiopathogenesis of OC. The relationship between subtle macroscopic lesions and lesions resulting in clinical signs of disease requires further investigation. 相似文献
164.
The study was carried out to determine the characteristics of snail farming in Edo South Agricultural Zone of Edo State Nigeria. The interview schedule was used to collect data from 60 snail farmers randomly selected from six cells in the study area. Information on the socioeconomic status of the farmers, production system, management practices and production constraints in the snail farms were elicited. The constraints were determined using a four-point Likert-type scale; a mean score of ≥2.5 was considered as a production constraint. Majority (85.0 %) of the respondents were part-time snail farmers. The major species of snails reared were Achatina achatina and Archachatina marginata, reared by 43.3 and 26.7 % of the farmers, respectively. Semi-intensive system of production was practised by 40.0 % of the farmers. Majority (78.0 %) of the respondents used car tyres to house their snails. About 56 % of the respondents kept their snails for 1–2 years before sale. Up to 51.7 % of the respondents separated their snails into different pens according to their size/age. The most commonly used feeds were vegetables (71.2 %), plant leaves (67.8 %) and kitchen waste (59.3 %). Records of snail production activities were kept by 75.0 % of respondents. The major constraints identified were lack of capital (3.31), inability to get good laying stock (3.00), lack of formulated feed to buy (2.98) and slow growth rate of snails (2.52). The potentials of snail farming in the study area have not been fully exploited as farmers produced at subsistence level. 相似文献
165.
Mrs Grace W. Suckung 《New Zealand veterinary journal》2013,61(1-2)
Extract Sir:- As Public Relations Officer for the Small Animal Society I have been carrying out surveys each week in Auckland on the current N.Z. distemper epidemic. It appears from reports received that probably every province in the North Island will become infected in due course. It will only be a matter of time before an infected dog crosses to the South Island. The cold dry environment of the Auckland winter favoured the survival of the virus away from the dog and it was hoped that the onset of warm moist weather would reduce the spread. This has not happened. In fact there has been a marked acceleration of spread throughout the country, especially in urban areas, probably due to a large susceptible unvaccinated dog population. 相似文献
166.
This study is focused on investigating the feasibility of using silver(I) ions loaded poly(acrylonitrile)-grafted silk fibers
as antibacterial dressing material. The optimum grafting conditions for ceric ammonium nitrate induced graft-copolymerization
of acrylonitrile onto silk fibers were found to include initiator concentration of 35 mM, catalyst HNO3 concentration of 0.40 M and initiation time of 10 min. The poly(acrylonitrile)-grafted silk fibers were loaded with silver(I)
ions by equilibration method. The resulting fibers were investigated for their biocidal action against E. coli, by using zone inhibition and colonies counting method. 相似文献
167.
Etienne Baras Grace V. Montalvan Naranjos Dustin V. Silva del Aguila Fred Chu Koo Rémi Dugué Carlos Chavez Fabrice Duponchelle Jean‐François Renno C. Carmen Garcia‐Dávila Jesus Nuñez 《Aquaculture Research》2012,43(12):1764-1776
Food intake (FI) and gut evacuation (Rg) were measured in larvae of Pseudoplatystoma punctifer (4.5–18.4 mm SL) fed Artemia nauplii, taking advantage of the translucence of their abdominal region to achieve this in a non‐destructive way, using digital photographs and mathematical reconstruction of gut volume content (ellipsoidal and cylindrical models for stomach and intestine respectively). The inaccuracy of the method, with reference to counts of nauplii following fish dissection, was low (2.9 ± 1.5%) and independent of fish size (P = 0.6153). Pigmentation hampered measurement in fish >18–19 mm SL. Anaesthesia was needed in fish >9.5 mm SL, thereby preventing the measurement of Rg in individual fish. The FI increased rapidly during the ontogeny, passing from <7% M at 0.6 mg, to 14% M at 1 mg and 21% M at 15–40 mg, and then decreased slightly in larger fish. At 28.5°C, Rg (% M h?1) was modelled as Rg = ?8.22 + 12.11 log FI + 6.30 log M – 12.67 (log M)2 (R2 = 0.904, d.f. = 27, with FI in% M and M in mg). Extrapolations of Rg over 24 h gave estimates of daily food rations that fit well with those measured in cannibalistic P. punctifer. 相似文献
168.
Apigenin di-C-glycosides (ACGs) are present in the grain of bread wheat and other related cereals primarily as one or two sets of Wesseley-Moser isomers containing either arabinose and glucose (ACG1) or arabinose and galactose (ACG2) on the A ring of apigenin. These compounds may contribute to the yellow colour of wheat-based products made under alkaline conditions and in addition, have possible roles in a number of plant physiology processes and human health. The aims of this investigation were to survey genetic variation for ACG content and composition in hexaploid bread wheat (Triticum aestivum L.) and to examine ACGs in the putative progenitors of hexaploid wheat and available genetic stocks as a first step towards understanding the mechanisms involved in their biosynthesis and genetic control. Substantial variation in both grain ACG content and the ratio, ACG1/ACG2, were identified within bread wheat cultivars and related species. Genotype controlled the major portion of the variation. ACG content appeared to be a multigenic trait whereas variation in ACG1/ACG2 was associated with a limited number of chromosomes, in particular chromosomes 1B, 7B and 7D. The results suggest that it should be possible to manipulate both ACG content and composition traits through breeding. 相似文献
169.
170.
JN Nyangaga D Grace V Kimani MW Kiragu AK Langat G Mbugua G Mitoko EK Kang'ethe 《Tropical animal health and production》2012,44(Z1):47-51
A study was undertaken to investigate and mitigate the risk from zoonotic Cryptosporidium associated with dairy farming in Dagoretti division, Nairobi, Kenya. Outcome mapping (OM), a relatively new tool for planning and evaluation, was used to foster and then monitor changes in farmer management of health risks. Elements of the OM framework, including the vision, mission and expected progress markers, were developed in participatory sessions and a set of progress markers was used for monitoring behaviour change in farmers participating in the project (the boundary partners). Behaviour change (the outcome challenge) was supported by a range of awareness and educational campaigns, working with strategic partners (extension agents and administrative leaders). The farmers the project worked with made considerable progress according to the markers; they demonstrated an understanding of cryptosporidiosis, established or maintained clean and well drained cattle sheds, and took conscious effort to reduce possible infection. Farmers who did not participate in the project (non-contact farmers) were found to be less advanced on the progress marker indicators. Non-contact farmers who carried out risk-reducing practices had done so independently of the project team. The administration leaders, as strategic partners, had a positive attitude towards the project and confidence in their ability to support project objectives. The study demonstrates the utility of OM in helping to identify and support behavioural change. 相似文献