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排序方式: 共有173条查询结果,搜索用时 31 毫秒
141.
Ahjin Lee Moon Hwo Seo Seungdo Yang Joonseok Koh Hyungsup Kim 《Fibers and Polymers》2008,9(1):101-106
The role of mechanical action on the washing process was studied. The experimental apparatus was designed to simulate each
mechanical action such as the hydrodynamic flow action, the fabric flexing action, the abrasion action during washing process.
The influence of mechanical action strongly depends on the property and attached state of each soil. The abrasion action was
found as the most effective mechanical action for soil removal. 相似文献
142.
Seung Ju Lee Mikyoung Rha Wonbang Koh Woojoon Park Chiho Lee Young An Kwon Jae‐Kwan Hwang 《Cereal Chemistry》2002,79(6):838-842
Stickiness of cooked noodles, generally defined as a maximum force in tension after compression, depends on the compression force, contact area, and physical properties of the noodles. In the conventional method of measuring stickiness, only compression force was set as a standard, neglecting the other probable influencing factors. A modified method was developed for measuring contact area between noodles and a probe, in addition to the compression force. Four specimens with varying starch contents (0, 30, 60, and 90%) were tested to evaluate the new method for measuring cooked noodle stickiness. Contact area calculated from the displacement of probe at the compression condition was not consistent among the noodle samples. A corrected stickiness and a corrected compression force were defined as a simple stickiness directly measured for the contact area and the compression force measured for the contact area, respectively. This method proved to be a more effective means in differentiating the stickiness among noodle samples (than using just compression force factors). The order in the corrected stickiness magnitudes among the noodles was consistent regardlessof specimen amount used in the measurements, whereas that of the simple stickiness was inconsistent when different size samples were used. The corrected compression force estimated from a fixed simple compression force, which is a true compression stress, varied among the noodles. Accordingly, the corrected compression force was a more accurate criteria for stickiness measurements than was the simple compression force, which subjects the specimens to only differences in compression for stickiness comparison. The corrected stickiness results showed greater relationship to sensory stickiness and starch content than the simple stickiness measurement. 相似文献
143.
This research focused on the improvement of the physical properties of biopolyurethane (BPU) using cellulose nanowhisker (CNW). For the study, BPU was synthesized by one-shot polymerization from corn sugar-based polyol and methylene diiscocyanate (MDI). CNW was prepared via conventional acid hydrolysis of pulp using sulfuric acid. The synthesized BPU was mixed with the CNW and then electrospun. The addition of CNW improved simultaneously the hydrophilicity and the mechanical properties of BPU. The improved properties will give more opportunity to BPU for medical applications. 相似文献
144.
Jellyfish cause a range of problems: they sting beach vacationers in the summer, block nuclear power plant intakes (thus disrupting the supply of electricity), decrease fishery catches, cause fishing activities to be delayed, decrease product value, and damage fishing gear. This study gauged the types and amount of damage directly caused by jellyfish. Using jellyfish monitoring data, the decreases in catch and product value for each fishery type as well as the estimated damage to each fishery type caused by jellyfish were evaluated. The results showed that the decrease in catch ranged between 6.5 and 33.7?%, and the decrease in product value ranged between 6.8 and 25.3?%, depending on fishery type. The annual direct damage caused by jellyfish was estimated to be between US$ 68.2 million and US$ 204.6 million. This corresponds to a minimum of 2.1?% and a maximum of 25?% of the annual production value, demonstrating that jellyfish cause considerable damage to the fishing industry. 相似文献
145.
Ivan Chong Chu Koh Daisuke Tanaka Takayoshi Itagane Masaharu Tsuji Yasushi Tsuchihashi Hiromi Ohta 《Aquaculture Research》2012,44(1):59-66
This study examined the usage of a dry shipper for cryopreservation of Epinephelus septemfasciatus (Thunberg) spermatozoa. Milt was diluted 1:49 with 5% dimethyl sulfoxide plus 95% foetal bovine serum for cryopreservation. Computer‐assisted sperm analysis was used to analyse sperm motility, while fertilization and hatching trials were conducted to gauge the applicability of the cryopreservation method for aquaculture. We showed that cooling rates of the dry shipper were stable for 14 days and could be manipulated by the use of different sized freezing straws and use of a simple polystyrene foam container (5 × 5 × 12 cm and 1 cm thickness on all sides with the upper layer exposed). Dry shipper cryopreserved spermatozoa had significantly lower post‐thaw per cent motility and velocity than fresh sperm, but linearity of movement was unchanged. Fertilization and hatching rates were not significantly different at all tested sperm to egg ratios (3000:1–243000:1). The results indicated that 0.33 mL of milt when cryopreserved was sufficient to fertilize up to 450 g of oocytes. Application of this technology will help improve seed production in aquaculture and further develop breeding and genetics studies. 相似文献
146.
Bock‐Gie Jung Sun‐Ju Cho Hong‐Bum Koh Dong‐Un Han Bong‐Joo Lee 《Veterinary dermatology》2010,21(2):184-191
Maesil (Prunus mume Siebold & Zucc.), a potential source of free radical scavengers and inhibitor of pro‐inflammatory mediators, is used in traditional Korean medical preparations as a remedy for skin disorders as have probiotics. The action of a probiotic fermented Maesil preparation on the development of atopic dermatitis (AD)‐like skin lesions was determined in a NC/Nga mouse model as an initial step towards the development of a therapeutic feed supplement for use in dogs. Continuous ingestion of the experimental feed markedly inhibited the development of the AD‐like skin lesions, as evidenced by a marked decrease in skin signs and reduced inflammation within the skin lesions. Efficacy was confirmed by significant decreases in eosinophil ratio and serum IgE concentration, and a reduction in the number of Staphylococcus aureus recovered from the ear. Relative mRNA expression levels of IL‐4, interferon‐γ and tumour necrosis factor‐α in the spleens of the experimental animals were also decreased and there was an increased serum concentration of IL‐10 with a concurrent decreased IL‐4 concentration in comparison to a control group. Taken together, the results indicate that some component(s) of fermented Maesil have the ability to suppress the development of AD‐like skin lesions, possibly by stimulation of IL‐10. Beneficial effects of fermented Maesil may thus be expected in dogs with AD, although this and the nature of the active pathway remain to be explored. 相似文献
147.
Koh Hasegawa 《Ecology of Freshwater Fish》2020,29(3):419-428
Many species of salmonids have been stocked into waters outside of their native range. The invasiveness and impact of these species on native species varies depending on their biological traits, and on environmental conditions, such as climate. In Japan, rainbow trout and brown trout, both listed in 100 of the world's worst invasive alien species by the International Union for Conservation of Nature, occur as non-native species. The invasiveness of these two species is thought to be related to seasonal flooding, given flood waters can physically damage fry and prevent population establishment. Rainbow trout have successfully invaded waters in Hokkaido, northern Japan, where the likelihood of flooding is low between June and July, when their fry emerge, but successful invasions are rare in regions south of Hokkaido. Brown trout, however, have successfully invaded waters not only in Hokkaido, but also other regions. Since brown trout have a similar life history to the native white-spotted charr and masu salmon, with fry emerging before the flood season, they are more suited to the Japanese climate than Rainbow trout. Rainbow and brown trout interact with native species in various ways, but a common outcome of these interactions is the displacement of native charr species. Legal regulations of non-native salmonids should be based on understandings of the ecological traits of each invasive species and regional impacts on native species. Given the ongoing nature of climate change, the nature and extent of the effects of rainbow and brown trout on native species might also change. 相似文献
148.
1. Circadian variations in heat production (HP) rate and respiratory quotient (RQ) were measured in growing broilers maintained at 5 ambient temperatures (14 degrees, 17 degrees, 22 degrees, 27 degrees and 32 degrees C) and at 5 rates of feeding [ad libitum intake and 75%, 50%, 25% and 0% (fasting) of ad libitum intake]. 2. In most cases, the HP rate decreased from 10.30 h just after food was given) until 00.30 h (the 1-h dark period), showed an overshoot just after the 1-h dark period and then changed little. 3. Circadian variation in RQ, except in the fasted group, showed a similar pattern, which consisted of increase, decrease and constant phases. 4. Food intake affected the pattern of circadian variation in RQ, although ambient temperature had little effect. Possible effects of food intake on the pattern of circadian variation in HP rate were discussed. 相似文献
149.
Andrew J. Tanentzap Dawn R. Bazely Saewan Koh Mika Timciska Edward G. Haggith Terry J. Carleton David A. Coomes 《Biological conservation》2011,(1):376-382
High levels of deer browsing can prevent canopy tree regeneration, but little is known about changes to forest size-structure following long-term deer herd reductions. We monitored changes in forest stand structure and composition in southwestern Ontario, Canada, over 28-years using permanent plots. Our study site was the largest remaining tract of Carolinian (deciduous) forest in Canada (11 km2), a habitat type that contains up to a fifth of Canada’s species at risk and is under intense anthropogenic pressures. We recorded declines in all tree size classes between 1981 and 1996, during which densities of white-tailed deer (Odocoileus virginianus) reached a peak of 55 deer km−2. Despite significant and sustained deer herd reductions between 1996 and 2009, which reduced deer densities to 7 deer km−2, there was limited recruitment of small trees and declines in basal area of tree species that were sensitive to deer browsing. Our results suggest that recovery from herbivory is a protracted process during which canopy tree regeneration may continue to decline despite a reduction in browsing pressure due to deer culling. Large declines in canopy-tree densities in Carolinian forests may lead to forest size-structures and herbaceous plant communities that resemble rare oak savanna habitat, creating difficult decisions for conservation managers aiming to protect rare and endangered species within native ecosystems. We recommend that managers protect Carolinian forest stands and encourage canopy tree regeneration by increasing seed sources of native trees. While deer control is essential in reducing forest damage, our results highlight the need to explore other forms of active management to expedite otherwise slow increases in tree density. 相似文献
150.
Janice Ser Huay Lee Lucy Rist Krystof Obidzinski Jaboury Ghazoul Lian Pin Koh 《Biological conservation》2011,(10):2512-2516
Societal concerns about the social and environmental impacts of biofuel production are driving producers to adopt better management practices. Existing certification schemes for sustainable biofuel production are, however, biased towards industrial-scale producers that have the financial capital and economies of scale to meet sustainability and certification objectives. Smallholder farmers in developing countries, by contrast, often lack the means and capacity to do so. Some of the challenges faced by smallholders include high certification costs, insufficient institutional capacity, inadequate financial and social incentives, poor group organization and lack of external support. Drawing lessons from existing certification programs, we argue that proponents of sustainable practices and standards must fully appreciate the complex realities of smallholder production systems. We provide policy recommendations for ensuring that no farmer is left behind in the quest to increase sustainable biofuel production. 相似文献