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71.
Katheryn L. Cerny Tom V. Little Charles F. Scoggin Robert J. Coleman Mats H.T. Troedsson Edward L. Squires 《Journal of Equine Veterinary Science》2014
The current field study used thoroughbred stallions and mares from central Kentucky to investigate the occurrence of potentially pathogenic bacteria on the stallion's external genitalia, based on cultures, and investigated the occurrence of bacteria and type of isolate in the mare's uterus after breeding by live cover to stallions with or without positive bacterial cultures. Fifteen thoroughbred stallions and 206 mares from two central Kentucky thoroughbred farms were used during the 2010 and 2011 breeding seasons. Samples for bacteriological evaluation were taken from the prepuce and postejaculate urethra (n = 201) of stallions. Uterine swabs (n = 264) were collected 12-18 hours postbreeding. For statistical analyses, a chi-squared test was used to test the relationship between stallion culture results and postbreeding uterine culture results, as well as the effect of bacterial types found on the stallion cultures with bacterial types found on the postbreeding uterine cultures. Of stallion cultures, 22.4% were positive for potentially pathogenic bacteria, with Streptococcus equi subspecies zooepidemicus (51.1%) being the most common isolate. Uterine cultures resulted in a 29.2% positive rate for potentially pathogenic bacteria, with S. equi subsp. zooepidemicus (90.9%) being the most common. There was no difference (P > .05) in the occurrence of bacteria or type of isolate found on uterine cultures after breeding stallions with or without positive cultures. In conclusion, potentially pathogenic bacteria found on the stallion's external genitalia did not affect the occurrence and type of bacterial isolate found in the mare's uterus after breeding by live cover. 相似文献
72.
Allison M. Kiser Steven P. Brinsko Charles C. Love Dickson D. Varner Kendrick Sudderth Terry L. Blanchard 《Journal of Equine Veterinary Science》2014
This study evaluated measures of sperm quality in relation to fertility achieved with fresh semen or semen cooled and stored. Semen from 1 stallion was collected and processed to provide 3 treatments: group 1 received fresh semen; group 2 received cooled semen containing 50% seminal plasma (SP) stored for 4 days; and group 3 received cooled semen containing 50% SP stored for 1 day, then centrifuged and resuspended in fresh extender containing 10% SP on days 1 to 3. Inseminates were evaluated for sperm motion characteristics and the percentage of sperm with intact membranes (SMI). Mares (n = 34) in estrus were treated with an ovulation-inducing drug and inseminated with 100 million membrane-intact sperm on the following day. Pregnancy status was determined via transrectal ultrasonography 2 weeks after ovulation. The mean percentage of SMI was higher in group 1 (81%, initial) than in group 2 (74%, day 4) or group 3 (74%, day 4) (P < .05). The median percentages of total sperm motility differed among the groups (77%, 5%, 59% for groups 1, 2, and 3 respectively; P < .05). Median values for the percentages of progressively motile sperm and curvilinear velocity for group 1 (55%, 216 μm/s) and 3 (37%, 186 μm/s) were higher than for group 2 (1%, 73 μm/s) (P < .05). Pregnancy rates did not differ among groups (5 of 11, 45% in group 1; 5 of 11, 45% in group 2; and 7 of 12, 58%, in group 3; P = .77). These data suggest that, at least for this stallion, sperm membrane integrity may be a more valuable means of assessing potential fertility of cooled-stored semen than sperm motion characteristics. 相似文献
73.
Undulations in weather patterns have caused climate shifts of increased frequency and duration around the world. The need for additional research and model data on this pressing problem has resulted in a plethora of research groups examining a particular tree species or biome for negative effects of climate change. This review aims to (1) collect and merge recent research data on regeneration within old- and new-growth forests, (2) highlight and expand upon selected topics for additional discussion, and (3) report how shade tolerance, drought toler- ance, and inherent plasticity affect tree growth and development. Al- though shade and drought tolerance have been well studied by a number of research groups, this review reveals that in-depth analysis of a single or a few species in a given area will not generate the data required to implement a successful regeneration plan. Studies using historical accounts of previous species composition, information regarding site sea- sonality, species competition, and individual responses to drought and shade are needed to (1) develop best management plans and (2) ensure future modeling experiments are focused on a greater variety of species using more innovative methods to evaluate climate change effects. 相似文献
74.
75.
The present study was carried out using juveniles of silver pomfret, Pampus argenteus, produced in the hatchery by stripping eggs from spawners collected from the wild during 2004 and 2005 culture period. The experiments carried out during 2004 investigated the efficiency of using salmon feed mixed with cyclopeeze, salmon feed mixed with shrimp meat, salmon feed alone, and shrimp meat alone in the diet using 1 m3 capacity round fiberglass tanks in three replicates for each treatment with flow‐through seawater. The results showed that inclusion of shrimp meat in the diet either with salmon feed or alone give significantly high (P < 0.01) weight gain of up to 1.10 ± 0.06 g/fish/d and significantly lower (P < 0.001) feed conversion ratio compared to that of feeds without shrimp meat. The experiments carried out during 2005 investigated the use of commercially available feeds with feed additives. The results showed that feeding with “Gemma” feed with 54.0% crude protein and 19.0% crude fat or salmon feed with 41.4% crude protein and 23.9% crude fat give significantly high (P < 0.01) growth rates compared to that of pompano feed with 43.0% crude protein and 6.0% crude fat. The results of these investigations although show high growth rate of the fish compared to that of previous observations; there is yet an urgent need to formulate a suitable feed for this fish species for commercial ventures. 相似文献
76.
Nicolas Blouin Fei Xiugeng Jiang Peng Charles Yarish Susan H. Brawley 《Aquaculture (Amsterdam, Netherlands)》2007,270(1-4):77-91
Nets in traditional Porphyra mariculture are seeded with conchospores derived from the conchocelis phase, and spend a nursery period in culture tanks or calm coastal waters until they reach several centimeters in length. Some species of Porphyra can regenerate the foliose phase directly through asexual reproduction, which suggests that the time, infrastructure, and costs associated with conchocelis culture might be avoided by seeding nets with asexual spores. Here, we present work from a short-term mariculture study using nets seeded with asexual spores (neutral spores) of a native Maine species of Porphyra. Porphyra umbilicalis (L.) Kützing was selected for this proof of concept research because of its reproductive biology, abundance across seasons in Maine, and evidence of its promise as a mariculture crop. We studied the maturation, release, and germination of the neutral spores to develop an appropriate seeding protocol for nets, followed by development of a nursery raceway to provide an easily manipulated environment for the seeded nets. Neutral spores were produced throughout the year on the central Maine coast; however, there was a temporal variability in the number and survival of released neutral spores, depending upon thallus position in the intertidal zone. Small thalli were strictly vegetative, but most thalli reproduced by neutral spores; sexual reproduction was absent. Neutral spores germinated quickly at 10 and 15 °C, but germination was delayed at 5 °C. Unlike some algal zygotes and spores, neutral spores of P. umbilicalis required light to germinate; however, irradiances of 25 and 100 μmol photons m− 2 s− 1 were equally sufficient for germination. Rafts of seeded nets were deployed in Cobscook Bay, Maine, at two distances from salmon aquaculture pens and at a control site on a nearby, fallow aquaculture site (no salmon). There was no difference in nitrogen content of harvested thalli; however, both the density and the surface area of harvested thalli were different among the sites. The possible causes of these differences are discussed in the context of potential use of P. umbilicalis in IMTA. 相似文献
77.
Charles M. Adams Sherry L. Larkin Donna J. Lee 《Aquarium Sciences and Conservation》2001,3(1-3):25-36
The marine life fishing industry in Florida is defined by the state as the non-lethal harvest of marine plants, finfish, and invertebrates that are sold live for commercial purposes (primarily into the saltwater aquarium industry). Approximately 330 different species of finfish and invertebrates are harvested by marine life collectors in Florida, including 180 species of finfish and 150 species of invertebrates and plants. In 1998, the total dockside value of these species was approximately US$1.9 million. The industry is highly regulated via limits on gear, handling methods, harvest sizes, and trip/bag/possession limits. Entry into the industry has been recently curtailed by the implementation of a moratorium on marine life endorsements. The total number of licensed harvesters exceeded 700 in 1998. Approximately 70 wholesales buyers also participated in the market during 1998. The majority of the dockside value is generated in south Florida, with the majority of the remaining value accruing from the region including and north of Tampa Bay. Over 80% of the total value associated with both finfish and invertebrates is generated by only 10 species within each group. Dockside prices vary considerably among the various species landed, with those landed in greater volumes exhibiting the lower prices. 相似文献
78.
Active habitat selection by pre-settlement reef fishes 总被引:10,自引:0,他引:10
John Charles Montgomery Nicholas Tolimieri & Olivia Sophie Haine 《Fish and Fisheries》2001,2(3):261-277
Our understanding of habitat selection by reef fish larvae has changed dramatically in the last 10 years. Fish larvae have long been considered passive particles at the mercy of ocean currents, tides and weather events. For reef fishes, ecological evidence has shown that passive dispersal alone often cannot explain larval distributions, suggesting active behaviour by reef fish larvae. While behaviourally modified passive transport may be important, recent work demonstrates that some reef fish larvae have the capability to actively swim to settlement habitat. They can orientate to reefs from distances of at least 1 km and can swim at speeds of 13.5 cm s?1 for several days. The question then becomes, what are the cues that fish larvae use to orientate to reefs? Ambient reef sound has been shown to be attractive to reef fish larvae, and current research aims to understand better the nature and use of these acoustic cues. Other potential cues include chemoreception/olfaction, wave cues and visual location of reefs. A better understanding of active habitat selection and the underlying sensory and behavioural mechanisms will improve our knowledge of recruitment processes in reef fish ecology, and may have implications for active management of reef fish populations. 相似文献
79.
Juvenal Kanani ;Dirk Philipp ;Kenneth P Coffey ;Elizabeth B Kegley ;Charles P West ;Shane Gadberry ;John Jennings ;Ashley N Young ;Robert T Rhein 《畜牧与生物技术杂志(英文版)》2014,(3):310-317
Background: The potential for acid-detergent insoluble ash (ADIA), alkaline-peroxide lignin (APL), and acid-detergent lignin (ADL) to predict fecal output (FO) and dry matter digestibility (DMD) by cattle offered bermudagrass [Cynodon doctylon (L) Pers.] hays of different qualities was evaluated. Eight ruminally cannulated cows (594 ± 35.5 kg) were allocated randomly to 4 hay diets: low (L), medium low (ML), medium high (MH), and high (H) crude protein (CP) concentration (79, 111,131, and 164 g CP/kg on a DM basis, respectively). Diets were offered in 3 periods with 2 diet replicates per period and were rotated across cows between periods. Cows were individually fed 20 g DM/kg of body weight in equal feedings at 08:00 and 16:00 h for a 10-d adaptation followed by a 5-d total fecal collection. Actual DM intake (DMI), DMD, and FO were determined based on hay offered, ort, and feces excreted. These components were then analyzed for ADL, APL, and ADIA concentration to determine marker recovery and marker-based estimates of FO and DMD. Results: Forage DMI was affected by diet (P = 0.02), and DMI from MH and H was greater (P 〈 0.05) than from L. Apparent DMD tended (P = 0.08) to differ among diets while FO (P = 0.20) was not affected by diet treatments. Average ADL recovery (1.16) was greater (P 〈 0.05) than that of ADIA (1.03) and APL (1.06), but ADIA and APL did not differ (P = 0.42). Estimates of FO and DMD derived using APL and ADIA were not different (P≥0.05) from total fecal collection while those using ADL differed (P 〈 0.05). There was no diet by marker interaction (P≥ 0.22) for either FO or DMD. Conclusion: Acid-detergent insoluble ash and APL accurately predicted FO and DMD of cattle fed bermudagrass hay of varying nutrient composition. These internal markers may facilitate studies involving large numbers of animals and forages. Results from such studies may be used to develop improve 相似文献
80.
J. Charles Delbeek 《Aquarium Sciences and Conservation》2001,3(1-3):171-181
There Have Been Significant Technical Advances in Marine Aquarium Maintenance in The Last 20 Years. It is Now Possible to Maintain, Grow and Reproduce in Aquaria Many of the Coral Species Found on Coral Reefs. Due to the increased Demand For Live Corals and Other Reef Invertebrates, The Commercial Production of these Organisms for the Home Aquarium Market Has Become Feasible. This Paper Describes the Early Beginnings of Live Coral Propagation, Current Coral Propagation Facilities Located in Europe, North America, and the Pacific Basin Followed by a Discussion of an Example of the Possible Future for Coral Farming, Namely Propagation by Sexual Reproduction. Suggestions for Areas of Further Research in Captive Coral Propagation are Also Presented. 相似文献