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排序方式: 共有177条查询结果,搜索用时 15 毫秒
81.
Pham X Vittadini E Levin RE Chinachoti P 《Journal of agricultural and food chemistry》1999,47(12):4976-4983
A sugar transport defected strain of Aspergillus nidulans (biA-1 sorA-2) was tested for spore germination in nutrient media containing various water activity (a(w)) values and varying amounts of non-nutritive, nontoxic carbohydrates (L-sorbose and cellulose). Freeze-dried media [containing the same nutrient level but different in sorbose/cellulose (s:c) ratio] were adjusted to 0.75-0.97a(w) at 25 degrees C before inoculation. Minimum a(w) for germination varied with s:c ratio. Because both sorbose and cellulose were not metabolizable and unable to be transported into the cells, the results reflected the molecular mobility of water. (2)H NMR T(2) relaxation time correlated well with spore germination time, and it distinguished the difference between water sorbed to cellulose and water in a solution associated with dissolved sorbose. On the other hand, mold germination time correlated poorly with a(w). It was highly dependent on the s:c ratio. Water mobility was found to correlate better with biological activity than a(w) because it differentiated the availability between water in dissolved sorbose and adsorbed water in cellulose. 相似文献
82.
Marthin Tarigan Michael J. Wingfield Yosep M. A. N. Marpaung Alvaro Durán Nam Q. Pham 《Forest Pathology》2023,53(5):e12829
The Eucalyptus plantation industry in Indonesia has expanded rapidly during the last few decades. During routine nursery disease surveys, symptoms of a leaf and shoot blight disease were detected on Eucalyptus mother plants. Isolates were obtained from symptomatic tissues and identified using DNA sequence analyses. Phylogenetic analyses showed that the isolates were those of Quambalaria eucalypti. Pathogenicity tests were conducted with isolates of Q. eucalypti on clones of E. pellita and E. grandis × E. pellita hybrids. These resulted in symptoms similar to those observed on naturally infected plants. Eucalyptus genotypes tested showed variation in their susceptibility, highlighting the potential to select and breed for resistance and thus to manage future outbreaks of the disease. This is the first report of the pathogen in Indonesia as well as in Southeast Asia. 相似文献
83.
R K Singh K M Kooreman C F Babbs J F Fessler S C Salaris J Pham 《American journal of veterinary research》1992,53(10):1822-1829
The scavenging of superoxide radicals by endogenous and therapeutically administered superoxide dismutases may prevent superoxide-mediated oxidative stress leading to lipid peroxidation, membrane lysis, and cell death in a wide variety of normal and pathologic states. Simple inorganic manganous salts such as MnCl2 also have superoxide dismutase-like activity and are extremely inexpensive, compared with enzymatic superoxide dismutase preparations. In this study, we explored the use of Mn salts as antioxidant drugs. We used the percentage of inhibition of nitroblue tetrazolium reduction by superoxide as a measure of the amount of superoxide dismutase-like activity. We found concentration-related increases in superoxide scavenging activity in simple buffer solutions upon addition of 1.25, 2.5, and 5.0 microM MnSO4. To determine whether Mn salts can inhibit oxidative damage in tissues, we used an in vitro model of lipid peroxidation in ischemic and reoxygenated rat liver slices. Concentrations of 10, 100, and 1000 mumoles MnCl2/L of buffer significantly decreased indicators of lipid peroxidation believed to be initiated by intracellular superoxide. We then determined the effectiveness of MnCl2 as a superoxide scavenger in conscious horses by measuring the superoxide scavenging ability of equine plasma before and during intravenous infusions of 1.0 L volumes of 0.9% saline solution containing 0, 12.5, or 25 mM MnCl2. Plasma Mn concentrations, which were determined by atomic absorption spectrophotometry, increased as a function of time and dose. Intravenously administered MnCl2 concomitantly produced dose-related increases in superoxide scavenging ability of equine plasma at 15, 30, 45, and 60 minutes after the onset of infusion, compared with preinfusion control values.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
84.
Breeding orchids through traditional means is a lengthy process. Therefore, it would be advantageous if transgenic technologies could be applied for orchids to improve important traits such as novel flower colour, fragrance and shape, cut-flower longevity and flowering control, abiotic stress tolerance and resistance to pests and diseases. Even though there are several genetic transformation techniques available to orchid breeders, only two (Agrobacterium-mediated transformation and particle bombardment) have been successfully and consistently used thus far. This review aims to capture the full range of studies conducted on orchid transformation with a view of providing new perspectives for future molecular breeding programmes. 相似文献
85.
Climate and vegetation determine soil organic matter status in an alpine inner-tropical soil catena in the Fan Si Pan Mountain,Vietnam 总被引:1,自引:0,他引:1
P. Podwojewski J. Poulenard Minh Luu Nguyet A. de Rouw Van Thiet Nguyen Quang Ha Pham Duc Toan Tran 《CATENA》2011
High mountain ecosystems are generally considered to be particularly sensitive to global climate change. Studies of pedogenesis associated with altitudinal variation, vegetation type and soil carbon content on the same type of parent rock are very limited in inter-tropical mountain areas. Therefore the altitudinal variation of soil pedogenesis through 9 selected profiles from the altitude of 1340 m to 3143 m asl, the summit of the Fan Si Pan Mountain, in the north of Vietnam was examined. Fan Si Pan Mountain is composed of a homogenous alkaline granite rock and is the highest point of the Inter-tropical Continental Asia. The Soil Organic Matter properties (C, N, δ13C and δ15N contents) of the different grain-size fractions of the topsoil of 4 selected profiles corresponding to different ecosystems were also examined. 相似文献
86.
Yamada K Lim J Dale JM Chen H Shinn P Palm CJ Southwick AM Wu HC Kim C Nguyen M Pham P Cheuk R Karlin-Newmann G Liu SX Lam B Sakano H Wu T Yu G Miranda M Quach HL Tripp M Chang CH Lee JM Toriumi M Chan MM Tang CC Onodera CS Deng JM Akiyama K Ansari Y Arakawa T Banh J Banno F Bowser L Brooks S Carninci P Chao Q Choy N Enju A Goldsmith AD Gurjal M Hansen NF Hayashizaki Y Johnson-Hopson C Hsuan VW Iida K Karnes M Khan S Koesema E Ishida J Jiang PX Jones T Kawai J Kamiya A Meyers C Nakajima M 《Science (New York, N.Y.)》2003,302(5646):842-846
87.
Bharathan G Goliber TE Moore C Kessler S Pham T Sinha NR 《Science (New York, N.Y.)》2002,296(5574):1858-1860
KNOTTEDI-like homeobox (KNOXI) genes regulate development of the leaf from the shoot apical meristem (SAM) and may regulate leaf form. We examined KNOXI expression in SAMs of various vascular plants and found that KNOXI expression correlated with complex leaf primordia. However, complex primordia may mature into simple leaves. Therefore, not all simple leaves develop similarly, and final leaf morphology may not be an adequate predictor of homology. 相似文献
88.
Binh Thanh Nguyen Vinh Ngoc Nguyen Tong Xuan Nguyen My Hoang Nguyen Hao Phu Dong Gai Dai Dinh Nghia Van Nguyen Tan-Viet Pham 《Soil Use and Management》2023,39(1):415-428
Although most studies have indicated that biochar can boost rice (Oryza sativa) growth, the material may also suppress it, depending on ratios of carbon (C) to nitrogen (N) and available N to available phosphorous (P). The current study sought to examine the impacts of biochar on rice growth and to identify underlying mechanisms. A pot experiment was conducted using two soils of high (3.05%) and low (0.54%) organic carbon (OC) content, mixed with 0, 1.5, 3, 6, and 12% biochar and planted with rice. Rice growth components, five rice tissue nutrients, and nine soil properties were measured. The results showed that the response of rice growth to biochar rates could be described using an exponential-growth function in high-OC soil but an inverted U-shaped curve in low-OC soil. In high-OC soil, the 12% biochar rate led to the greatest total biomass, increased by 47%, whereas in low-OC soil, the 3 and 6% rates exhibited the highest total biomass, increased by 44%, compared to the no-biochar added soils. Biochar elevated the C:N ratio from 11.5 to 39.1, with an optimal range of 20–30 corresponding to the highest rice growth. Biochar declined the ratio of NH4-N to Mehlich-1 P, causing N deficiency. In brief, high biochar rates may suppress rice growth when the soil C:N ratio exceeds 30. The applied biochar rate should be considered based on soil properties typically OC and N content to obtain the C:N ratio between 20 and 30 for optimal rice growth. 相似文献
89.
Ky Xuan Pham Masafumi Amano Noriko Amiya Yutaka Kurita Akio Shimizu Kunio Yamamori 《Fisheries Science》2007,73(5):1113-1122
ABSTRACT: To clarify the possible roles of gonadotropin-releasing hormone (GnRH) in the reproduction of Japanese flounder Paralichthys olivaceus , localization of salmon GnRH (sGnRH), chicken GnRH-II (cGnRH-II), and sea bream GnRH (sbGnRH) immunoreactive (ir) cell bodies and fibers in the brain and pituitary were examined together with follicle stimulating hormone (FSH) and luteinizing hormone (LH)-ir cells in the pituitary by immunohistochemistry. sGnRH-ir cell bodies were localized in the ventromedial part of the rostral olfactory bulb and cGnRH-II-ir cell bodies were restricted to the midbrain tegmentum, while sbGnRH-ir cell bodies were evident in the preoptic area. sGnRH-ir fibers were distributed throughout the brain, especially abundant in the forebrain. cGnRH-II-ir fibers were also scattered in many areas of the brain with abundance in the midbrain, but sbGnRH-ir fibers were observed in the preoptic–hypothalamic area and innervated the pituitary. In the pituitary, neither sGnRH-ir fibers nor cGnRH-II-ir fibers were found, but sbGnRH-ir fibers were profuse in the neurohypophysis and invaded the proximal pars distalis, targeting FSH and LH cells. These results suggest that three GnRH systems can play different physiological roles in the brain of Japanese flounder. Among them, sbGnRH is considered to be involved in reproduction by stimulating gonadotropin secretion, while sGnRH and cGnRH-II can function as a neurotransmitter and/or neuromodulator within the brain in this species. 相似文献
90.
Hua Thai Nhan Truong Quynh Nhu Pham Minh Duc Hon Jung Liew Harry Ako Rajesh Jha 《Aquaculture Nutrition》2020,26(5):1771-1779
This study investigated the effect of dietary arachidonic acid (ARA, 20:4n‐6) on final maturation, spawning performance and composition of the gonad of black sea urchin (Diadema setosum). Four different dietary ARA levels of 0.3 g/kg (Control diet), 1.4 g/kg (ARA 1.4), 2.5 g/kg (ARA 2.5) and 3.7 g/kg (ARA 3.7) were prepared and tested in this feeding trial for 90 days. The result showed that growth in terms of weight was not relatively affected by dietary ARA. Gonadosomatic Index (GSI) of animals were gradually increased in all the diets throughout the trial. The highest GSI level (25.7 ± 3.16%) was observed in animals fed with the diet ARA 1.4. ARA content in the gonad proportionally increased with dietary ARA levels. The highest larval survival rate (85.5 ± 5.67%) was found in diet ARA 2.5. The results of this study indicate that ARA plays an important role in the reproduction functions of black sea urchin and supplementing an appropriate level of ARA in the broodstock diet could induce the final maturation and improve reproduction of black sea urchin, but a higher level of ARA (3.7 g/kg) seems to have a negative effect on both growth rate and GSI. 相似文献