全文获取类型
收费全文 | 326篇 |
免费 | 14篇 |
国内免费 | 1篇 |
专业分类
林业 | 20篇 |
农学 | 6篇 |
基础科学 | 1篇 |
86篇 | |
综合类 | 38篇 |
农作物 | 7篇 |
水产渔业 | 22篇 |
畜牧兽医 | 149篇 |
园艺 | 5篇 |
植物保护 | 7篇 |
出版年
2023年 | 2篇 |
2021年 | 4篇 |
2020年 | 4篇 |
2019年 | 7篇 |
2018年 | 10篇 |
2017年 | 12篇 |
2016年 | 8篇 |
2015年 | 9篇 |
2014年 | 3篇 |
2013年 | 25篇 |
2012年 | 22篇 |
2011年 | 23篇 |
2010年 | 14篇 |
2009年 | 15篇 |
2008年 | 27篇 |
2007年 | 25篇 |
2006年 | 28篇 |
2005年 | 23篇 |
2004年 | 18篇 |
2003年 | 19篇 |
2002年 | 18篇 |
2001年 | 5篇 |
2000年 | 4篇 |
1999年 | 3篇 |
1997年 | 2篇 |
1996年 | 1篇 |
1993年 | 2篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1980年 | 1篇 |
1977年 | 1篇 |
1975年 | 1篇 |
1970年 | 1篇 |
1969年 | 1篇 |
排序方式: 共有341条查询结果,搜索用时 218 毫秒
281.
Fruit of Actinidia deliciosa have green flesh when ripe, whereas fruit of Actinidia chinensis often have yellow flesh when ripe. The outer and inner pericarps of A. deliciosa fruit retain their chlorophyll during ripening. In those fruit of A. chinensis that become yellow on ripening, the colour change is caused by the disappearance of chlorophylls unmasking the yellow carotenoids already present, rather than by increased synthesis of carotenoids. In fruit of A. deliciosa and those fruit of A. chinensis that remain green, the chloroplasts retain their typical morphology during ripening, whereas in fruit of A. chinensis that become yellow during ripening the chloroplasts of the immature green fruit are transformed into fully developed chromoplasts. 相似文献
282.
283.
Jean-Philippe?Costes Pak Lim?Ko Tony?Ji Cyrille?Decès-PetitEmail author Yusuf?Altintas 《Journal of Wood Science》2004,50(1):28-34
The experimental results of orthogonal cutting of maple and the modeling of the cutting mechanics are presented. The tool cutting forces were measured for different feed rates. A set of equations relating the tangential and feed forces to the tool edge width and feed rate (chip thickness) to calculate the chip and edge cutting force coefficients was developed. Then the chip force and edge force coefficients were calculated from experimentally obtained cutting forces and were plotted in a polar-coordinate system with respect to the fiber orientation of the maple disk. The polar-coordinate presentation of the cutting force results and the calculated cutting force coefficients provides an excellent visual appreciation of the relation between the cutting forces and the wood fiber orientation. Chips were also collected from various sectors of the wood disk. This analysis further identified the effects of fiber orientation and cutting forces on the types of chip formed and hence the cutting mechanics involved. By applying the calculated cutting coefficients for each tool orientation (in respect to the grain) it is possible to predict the feed and tangential forces for any feed rates. There is good agreement between the predicted and measured cutting forces. 相似文献
284.
Clore ER Freeman LM Bedenice D Buffington CA Anderson DE 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2011,25(3):598-604
Background: Parenteral nutrition is an important method of nutritional support in hospitalized animals, but minimal information has been published on its use in camelids. Hypothesis/Objectives: The purpose of this study was to characterize the use of total parenteral nutrition (TPN) in alpacas, evaluate the formulations used, and determine potential complications. Animals: Twenty‐two alpacas hospitalized at the Tufts Cummings School for Veterinary Medicine (site 1: n = 8) and the Ohio State University Veterinary Teaching Hospital (site 2: n = 14). Methods: A retrospective analysis of all alpacas that received TPN between 2002 and 2008 was performed to assess clinical indications, clinical and clinicopathologic data, and outcome. Results: The most common underlying diseases in animals receiving TPN were gastrointestinal dysfunction (n = 16), hepatic disease (n = 2), and neoplasia (n = 2). Several metabolic abnormalities were identified in animals (n = 20/22) before TPN was initiated, including lipemia (n = 12/22), hyperglycemia (11/22), and hypokalemia (n = 11/22). Median age was significantly lower for site 1 cases (0.1 years; range, 0.01–11.0) compared with those from site 2 (4.9 years; range, 0.1–13.7; P= .03). Animals at site 2 also had a longer duration of hospitalization (P= .01) and TPN administration (P= .004), as well as higher survival rate (P < .02). Twenty‐one of 22 alpacas developed at least 1 complication during TPN administration. Metabolic complications were most prevalent (n = 21/22) and included hyperglycemia (n = 8/21), lipemia (n = 7/21), hypokalemia (n = 3/21), and refeeding syndrome (n = 3/21). Conclusions and Clinical Importance: TPN is a feasible method of nutritional support for alpacas when enteral feeding is not possible. Prospective studies are warranted to determine optimal TPN formulations for alpacas. 相似文献
285.
Ryckebosch E Muylaert K Eeckhout M Ruyssen T Foubert I 《Journal of agricultural and food chemistry》2011,59(20):11063-11069
The influence of short-term storage and spray- and freeze-drying of fresh microalgal paste on the stability of lipids and carotenoids of Phaeodactylum tricornutum was investigated. Furthermore, the effects of storage time (14 and 35 days) and condition (vacuum packed vs non vacuum packed, -20 °C vs 4 °C vs 20 °C) after spray- and freeze-drying were studied. Total lipid content, free fatty acid content, carotenoid content and degree of lipid oxidation were measured. No effects of spray- and freeze-drying and subsequent storage were found on total lipid content, except for short-term storage of the fresh microalgal paste, which led to pronounced lipolysis and therefore a lower total lipid content. Freeze-dried microalgae were found to be more susceptible to lipolysis upon storage than spray-dried microalgae. On the other hand, spray-dried microalgae were more susceptible to oxidation than freeze-dried microalgae, possibly due to breakdown of protecting carotenoids upon spray-drying. Hardly any effect of storage condition was observed for any of the parameters tested. 相似文献
286.
Hadibarata Tony Yusoff Abdull Rahim Mohd Kristanti Risky Ayu 《Water, air, and soil pollution》2012,223(2):933-941
Utilization of microbes including white-rot fungi and bacterial strains for decolorization of synthetic dyes is one promising
strategy of an environmentally friendly and cost-competitive alternative to physico-chemical decomposition processes for treating
industrial effluents. In this study, the biodegradation ability of the white-rot fungi Polyporus sp. S133 that produce high laccase was investigated in order to decolorize anthraquinone-type dye. Parameter including pH,
temperature, and non-ionic surfactant were used to comparatively study the decolorizing effects on Remazol Brilliant Blue
R (RBBR). The purified laccase totally decolorized 200 mg L−1 initial concentration of RBBR dye when only 1.5 U L−1 of laccase was used in the reaction mixture. The optimal decolorization rates were achieved at pH 5 and at a temperature
of 50°C. N-hydroxybenzotriazole, a small molecular weight redox mediator, was found to accelerate the decolorization. Tween 20 inhibited
the decolorization while Tween 80 and Brij 35 showed no inhibition effect. Two compounds were identified as the intermediates
(m/z 304.3 and m/z 342.2). These results suggest that laccase from Polyporus sp. S133 is a powerful tool for the decolorization of anthraquinone dyes. A pathway for the metabolism of the RBBR by laccase
of Polyporus sp S133 was proposed. These proposed pathways could contribute to a better comprehension of the mechanisms used by oxidative
enzymes to transform organic compounds. 相似文献
287.
Tony Hadibarata Ameer Badr Khudhair Mohd Razman Salim 《Water, air, and soil pollution》2012,223(5):2201-2208
Polyporus sp. S133 fungi were selected based on their ability to degrade anthracene in liquid media. The degradation efficiency of anthracene increased by adding 0.5% Tween 80 to reach 71%; agitation at 120 rev/min increased the degradation to 92% after 30?days of incubation. Enzymes such as manganese peroxidase (MnP), lignin peroxidase (LiP), laccase, 1,2-dioxygenase and 2,3-dioxgenase were produced by Polyporus sp. S133 during incubation, and the highest enzyme activity was 182.3 U l?1 by 1,2-dioxygenase after 20?days of incubation. These results indicate that ligninolytic and dioxygenase enzymes secreted from Polyporus sp. S133 could play an important role in anthracene degradation efficiency. The metabolites detected through the degradation pathway were anthraquinone, phthalic acid, benzoic acid and catechol. 相似文献
288.
Tony Hadibarata Faizuan Abdullah Abdull Rahim Mohd Yusoff Razali Ismail Shamila Azman Norliyana Adnan 《Water, air, and soil pollution》2012,223(6):3125-3136
In order to observe the variation in land use changes, satellite images from the Landsat Thematic Mapper (TM) and the Enhanced Thematic Mapper (ETM) for 1991, 2000, 2005, and 2008 were used to compare the differences between selected water quality parameters, including heavy metal (Cd, Pb, and Zn) content in both water and green mussels or Perna viridis (Linnaeus.) before and after the increase in land use activities beginning from 2006. The samples were collected at 11 points for water and 4 points for green mussels between the Second Link and the Causeway Link at the Johor Strait in 2009 and were analyzed for pH, temperature degrees Celsius), dissolved oxygen, ammoniacal nitrogen, and heavy metal (Cd, Pb, and Zn) content. 相似文献
289.
Tony Parsons 《Land Degradation \u0026amp; Development》2012,23(2):203-203
290.
Mariano Makara Matthias Dennler Manuela Schnyder Rima Bektas Patrick Kircher Evelyn Hall Tony Glaus 《Veterinary radiology & ultrasound》2013,54(6):605-609
In dogs, a mean broncho‐arterial ratio of 1.45 ± 0.21 has been previously defined as normal. These values were obtained in dogs under general inhalational anesthesia using a single breath‐hold technique. The purpose of the study was to determine whether ventilation technique and bronchial diameter have an effect on broncho‐arterial ratios. Four healthy Beagle dogs were scanned twice, each time with positive‐pressure inspiration and end expiration. For each ventilation technique, broncho‐arterial ratios were grouped into those obtained from small or large bronchi using the median diameter of the bronchi as the cutoff value. Mean broncho‐arterial ratios obtained using positive‐pressure inspiration (1.24 ± 0.23) were statistically greater than those obtained at end expiration (1.11 ± 0.20) P = 0.005. There was a strong positive correlation between bronchial diameter and broncho‐arterial ratios for both ventilation techniques (positive‐pressure inspiration rs = .786, P < 0.0005 and end expiration rs = .709, P < 0.0005). Mean broncho‐arterial ratio for the large bronchi obtained applying positive‐pressure inspiration was 1.39 cm ± 0.20 and during end expiration was 1.22 cm ± 0.20. Mean broncho‐arterial ratio for the small bronchi obtained during positive‐pressure inspiration was 1.08 cm ± 0.13 and during end expiration was 1.01 cm ± 0.13. There was a statistically significant difference between these groups (F = 248.60, P = 0.005). Findings indicated that reference values obtained using positive‐pressure inspiration or from the larger bronchi may not be applicable to dogs scanned during end expiration or to the smaller bronchi. 相似文献