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111.
  • 1. A method has been developed for assessing the degree of human alteration of river flow regimes relative to near‐natural or reference conditions.
  • 2. The Dundee Hydrological Regime Alteration Method (DHRAM) utilizes the Indicators of Hydrologic Alteration approach of the US Nature Conservancy to classify the risk of damage to in‐stream ecology using a five‐class scheme compatible with the requirements of the EC Water Framework Directive.
  • 3. Separate methods have been developed for rivers and lakes, though only the former are considered in this paper.
  • 4. DHRAM uses daily mean flow time‐series data, representing un‐impacted and impacted situations for the site of interest, in relation to any type of anthropogenic hydrological impact such as impoundments, abstractions or flow augmentation.
  • 5. Procedures for coping with different levels of data availability are outlined, utilizing the Micro Low Flows computer package to generate synthetic series of daily mean flows, supplemented by flow alteration data as appropriate.
  • 6. The utility of DHRAM is demonstrated through a pair of Scottish case studies illustrating its ability in classifying regime alteration and supporting mapping, which will be of value to river basin managers.
  • 7. Finally, present and future issues relating to the calibration of DHRAM scores to levels of ecological damage are discussed.
Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   
112.
The major anthocyanins of boysenberry fruit, a cross between Rubus loganbaccus and Rubus baileyanus Britt., were isolated by preparative high-performance liquid chromatography (HPLC). The structures of cyanidin-3-[2-(glucosyl)glucoside] (1) and cyanidin-3-[2-(glucosyl)-6-(rhamnosyl)glucoside] (2) were determined by NMR in 1% DCOOD/D(2)O. An unusually high chemical shift (delta 2.5) is reported for H-5' ' of cyanidin-3-[2-(glucosyl)glucoside].  相似文献   
113.
Successful fisheries management systems tend to be underpinned by harvest strategies, specifying formally agreed data collection systems, assessment approaches and management measures used to regulate fishing pressure. While harvest strategies can be effective even in data- and capacity-limited (DCL) situations, their development remains challenging in such contexts. We present a process and decision-support tool, FishPath, to guide the identification of suitable harvest strategy component options given often debilitating conditions: (i) resource limitations and lack of technical management capacity; (ii) ‘uniqueness’ of DCL fisheries; (iii) the concept of harvest strategies is unfamiliar to managers and scientists, and the universe of options is hard to navigate; and (iv) the lack of an effective participatory process to identify solutions tailored to local contexts. These conditions can lead to either management paralysis or generic solutions that may be poor fits to specific conditions. The FishPath Tool uses a diagnostic questionnaire that elicits the key characteristics and specific circumstances of a fishery. It compares these with the requirements of alternative options from an inventory of possible harvest strategy components, identifies where these requirements are met and provides customised, transparent guidance on the appropriateness of component options of a harvest strategy, specific to the fishery of interest and its governance context. The FishPath Process is a facilitated multi-stakeholder, participatory engagement process aimed to set fisheries on the path to develop a harvest strategy. The FishPath Process and Tool combine to ensure a bottom-up, documented, transparent, replicable and efficient process.  相似文献   
114.
The efficacy of selamectin in the treatment and prevention of naturally acquired Toxocara canis infections and experimentally induced flea (Ctenocephalides felis felis) infestations in dams and their suckling pups was evaluated by administering selamectin to the adult females only, approximately 40 and 10 days before parturition and 10 and 40 days after parturition. Unit doses of the commercial formulation of selamectin were administered to the dams to provide at least the minimum recommended dosage of 6mgkg(-1) (range, 6-12mgkg(-1)). Dams and their pups were housed in carpeted environments able to support the flea life cycle. Flea infestations were established initially by experimental infestation before treatment administration and by repeated re-infestation of dams at approximately weekly intervals throughout the study, which was completed 45 days after parturition. There were no adverse drug experiences related to treatment with selamectin and no treatment-related mortalities. Percentage reductions in geometric mean T. canis faecal egg counts for the selamectin-treated dams, compared with those receiving the negative-control treatment (vehicle only) were 99.7% at the end of the study (P=0.0001). Geometric mean faecal egg counts in pups from selamectin-treated females were reduced by > or =96% on the 24th and 34th days after birth (P=0.0001), and the number of adult worms recovered from the gastrointestinal tract of pups from selamectin-treated dams was reduced by 98.2% (P=0.0001), compared with that for pups from dams treated with the vehicle only. Percentage reductions in geometric mean flea counts for selamectin-treated dams and their pups, compared with vehicle-treated dams and their pups, were > or =99.8% (P=0.0001) and 100% (P=0.0001), respectively, throughout the study. Thus, selamectin administered topically at a minimum unit dosage of 6mgkg(-1) to dams with naturally acquired T. canis infections and experimentally induced C. felis infestations was safe and highly effective in the treatment, control, and prevention of adult T. canis infection and C. felis infestation affecting both the dams and their pups.  相似文献   
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117.
The sesquiterpene alpha-farnesene (1) and its conjugated triene oxidation products accumulate in the skin of apples after harvest and are implicated as the causal agents of superficial scald. Conjugated triene oxidation products and analogues were synthesized and applied to the surface of Granny Smith apples either as vapors or in squalane. Farnesyl hydroperoxide (2a), trienol (2b), endoperoxide (3a), dehydronerolidol (5), and cumyl hydroperoxide (4) all produced the symptoms of superficial scald when applied at nanomolar doses. Scald-inducing activity was dependent on the mode of application. Farnesyl hydroperoxide (2a) was the most active conjugated triene when applied directly to the apple skin. Trienol (2b) also induced scald symptoms and partially reversed the inhibition of scald caused by diphenylamine.  相似文献   
118.
Trask NJ  Rowan LC 《Science (New York, N.Y.)》1967,158(3808):1529-1535
High-resolution photographs returned by Orbiters II and III typically show a surface pitted with small, perfectly circular craters as much as 50 meters in diameter, some of which are strongly clustered; these are superposed on larger, generally shallower craters and must be a mixture of primary and secondary impact craters. Rough terrain is less heavily cratered but is crossed by numerous closely spaced troughs and ridges up to 3 meters high. Terraces, which commonly occur at the base of steep slopes, are also crossed by these troughs and ridges and have relatively few craters. Fresh craters-craters whose exterior slopes are covered with material different from that of the intercrater areas-are rare and are surrounded by angular blocks up to 80 meters in diameter, in varying numbers; these craters apparently undergo gradual destruction to shallow gentle depressions. The frequency of craters 100 meters and more in diameter varies widely, even on level terrain; some of the highest concentrations of craters occur on rays.  相似文献   
119.
Acharya  Uma  Petheram  R. John  Reid  Rowan 《Small-Scale Forestry》2004,3(3):401-410
International and national development programs in Nepal place high priority on management of forests for biodiversity. Communities are expected to embrace and cooperate in this endeavour for biodiversity conservation, yet little research has been carried out to understand community viewpoints on biodiversity conservation, or even to ascertain people’s understanding of the concept of biodiversity. This paper explores perceptions and concepts related to biodiversity and its conservation held by people involved in community forestry in Nepal. Data were obtained from in-depth individual interviews and focus group discussions carried out in two contrasting geographical districts. The results show that the Western term ‘biodiversity’, translated into Nepalese as jaiwik bibidhata, is new and confusing to most forest people, who interpret the term in a variety of ways. People’s perceptions of biodiversity vary widely and a considerable gap exists between policy-makers and forest users in the understanding and interpretation of this Nepalese term and its related concepts. These findings have important implications for the design and implementation of development programs and in formulation of forest policy in Nepal.  相似文献   
120.
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