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61.
Gene Stevens Matthew Rhine Zach Straatmann David Dunn 《Communications in Soil Science and Plant Analysis》2016,47(18):2148-2155
Most laboratories make potassium (K) fertilizer recommendations based on field research calibrated with soil K from atomic absorption spectroscopy, flame emission spectroscopy, or inductively coupled plasma mass spectrometry. Information is needed to interpret readings from K+ meters on cotton. The objective was to compare soil and cotton plant sap potassium content from a Laqua Twin? K+ meter to results from standard tests. Aluminum sulfate solution was used with the meter to extract K from 10 soil samples from the North America Proficiency Testing program. A linear relationship (R2 = 0.86) was found between K measured with a K+ meter and K measured with 138 labs using ammonium acetate or Mehlich-3. Using a factor of 1.4754 to adjust readings, fertilizer recommendations with the K+ meter were similar to results from atomic absorption spectroscopy. A linear relationship was found between petiole K measured in the lab and petiole sap measured with the K+ meter. 相似文献
62.
63.
S.R. Boysen M. Bozzetti L. Rose M Dunn D.S.J. Pang 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2009,23(5):1123-1125
Background: Glucocorticoids affect carbohydrate and lactate metabolism.
Hypothesis: Administration of prednisone to healthy dogs will result in clinically relevant hyperlactatemia.
Animals: Twelve healthy adult Beagle dogs.
Methods: Prospective, controlled experimental study. Twelve healthy adult Beagles were divided into 2 groups (3 of each sex per group). One group served as control. The other group received 2 treatments: low, 1 mg/kg prednisone PO q24h for 2 weeks; high, 4 mg/kg prednisone PO q24h for 2 weeks. A washout period of 6 weeks separated the treatments. Blood samples were drawn for whole blood lactate measurement on day (D) 0, D4, and D14 and measured in duplicate.
Results: Compared with the control group, low and high groups had significantly higher blood lactate concentrations at D4 and D14. There was no difference at D0. There was no effect of time within the control group. In the low and high groups, blood lactate concentration was increased at D4 and D14 versus D0. Blood lactate concentration was greater in the high group than the low group at D14 only.
Conclusions and Clinical Importance: Dogs treated with prednisone experience statistically significant increases in blood lactate concentrations, which can result in type B hyperlactatemia. In such cases, improving tissue perfusion, treatment for the commonest form of hyperlactatemia (type A) would be unnecessary. 相似文献
Hypothesis: Administration of prednisone to healthy dogs will result in clinically relevant hyperlactatemia.
Animals: Twelve healthy adult Beagle dogs.
Methods: Prospective, controlled experimental study. Twelve healthy adult Beagles were divided into 2 groups (3 of each sex per group). One group served as control. The other group received 2 treatments: low, 1 mg/kg prednisone PO q24h for 2 weeks; high, 4 mg/kg prednisone PO q24h for 2 weeks. A washout period of 6 weeks separated the treatments. Blood samples were drawn for whole blood lactate measurement on day (D) 0, D4, and D14 and measured in duplicate.
Results: Compared with the control group, low and high groups had significantly higher blood lactate concentrations at D4 and D14. There was no difference at D0. There was no effect of time within the control group. In the low and high groups, blood lactate concentration was increased at D4 and D14 versus D0. Blood lactate concentration was greater in the high group than the low group at D14 only.
Conclusions and Clinical Importance: Dogs treated with prednisone experience statistically significant increases in blood lactate concentrations, which can result in type B hyperlactatemia. In such cases, improving tissue perfusion, treatment for the commonest form of hyperlactatemia (type A) would be unnecessary. 相似文献
64.
The purpose of this study was to determine the effectiveness of dry heat, steam, and microwave treatments in decreasing lipase activity, while retaining antioxidant activity, to stabilize whole wheat flour against lipid degradation during storage. Bran was heat‐treated in 230‐g batches using four levels (exposure times) for each of the three treatment methods. Lipase activity and antioxidant activity were quantified for all treatment combinations. None of the treatments significantly decreased antioxidant activity; the levels determined to be optimal, inasmuch as further heating did not significantly decrease lipase activity, were 25 min of dry heat, 60 sec of microwave (1000W), and 60 sec of steam. These treatments effectively decreased lipase activity by 74, 93, and 96%, respectively. Optimum treatments were evaluated for acceptance using a consumer sensory panel during a 12‐month storage period. No significant differences in acceptance were found between the control and any of the samples either at baseline or after storage. This suggests that whole wheat flour can be stabilized against lipolysis by utilizing the treatments described in this study without decreasing antioxidant activity, and that manufacturers may utilize these treatments without risking decreased consumer acceptance. 相似文献
65.
Gene Stevens David Dunn Matthew Rhine 《Communications in Soil Science and Plant Analysis》2018,49(8):958-966
Portable instruments have reduced on-site testing costs for soil pH and potassium in isolated locations. Acids could not be shipped to a remote Africa field laboratory. Bray-1 phosphorus (P) testing is difficult because hydrochloric (HCl) is required in the extraction solution and sulfuric acid (H2SO4) is used in color development stock solutions. Muriatic HCl acid and battery H2SO4 were available in a local stores. The objectives of this study were to evaluate the accuracy of P soil testing using diluted, non-reagent HCl for making modified Bray1-P extractant and non-reagent H2SO4 for color development. Experiment 1 was conducted with soil samples from fields using Sunnyside? and Klean Strip? HCl muriatic acids. Soil samples extracted with diluted reagent HCl were closely related to P results using diluted Klean Strip (R2 = 0.96) and Sunnyside (R2 = 0.84) HCl. In Experiment 2, two commercial brands of H2SO4 acid used to refill car battery cells were evaluated. Test results suggested that the battery H2SO4 acids are not suitable for making color development solution. In Experiment 3, a small battery powered spectrometer for P testing aquarium water was calibrated for soils. Samples from the Soil Science Society of America –North American Proficiency Testing program (NAPT) were tested with the meter and non-reagent HCl. Fiske-Subbarrow reducing agent and HCl were used in a variation procedure which does not require H2SO4 for color development. Eight of 10 samples tested proficient based on NAPT limits (2.5 x Median Absolute Deviation). 相似文献
66.
Bruce L. Dunn Hardeep Singh Mark Payton Sean Kincheloe 《Journal of plant nutrition》2018,41(13):1674-1683
There are various optical sensors in the market for precision nitrogen (N) management, which estimate leaf N status from chlorophyll content of leaves. However, readings may also be affected by the amounts of other nutrients in the plant leaves like potassium (K) and phosphorus (P), as well as sampling location within a plant or leaf. SPAD-502 and atLEAF optical sensors were used on Salvia ‘Vista Red’ plants grown with 0N-7.9P-0K, 41N-0P-0K, 0N-0P-31.6K, 0N-7.9P-0K + 41N-0P-0K, 0N-7.9P-0K + 0N-0P-31.6K, 41N-0P-0K + 0N-0P-31.6K, or 0N-7.9P-0K + 41N-0P-0K + 0N-0P-31.6K fertilizer plus a control. Both sensors were correlated with leaf N and each other. However, both sensor readings were affected by the presence or absence of P and K in the leaves, and thus these nutrients should be analyzed and reported along with leaf N values. Sensor readings were found to vary within a leaf and within leaf canopy location, so sampling needs to be consistent. 相似文献
67.
HY Jang YH Kim BW Kim IC Park HT Cheong JT Kim CK Park HS Kong HK Lee BK Yang 《Reproduction in domestic animals》2010,45(6):943-950
Melatonin, the major secretory product of the pineal gland, scavenges a variety of reactive oxygen and nitrogen species in vivo and in vitro, indicating that melatonin is a potent function as an antioxidant. The objective of this study was to investigate the effect of melatonin in the presence or absence of hydrogen peroxide (H2O2) on sperm characteristics (motility, viability, survival rate, membrane integrity, lipid peroxidation (LPO) and mitochondria activity) and also to examine the developmental rates to the blastocysts stage of porcine oocytes fertilized in vitro with semen treated with or without melatonin (100 nm ) in the presence or absence of H2O2 (250 μm ). The sperm were treated with melatonin in the presence or absence of H2O2 for 3, 6, 9 and 12 h at 37°C and then analysed for the sperm characteristics. The porcine embryos were produced by in vitro maturation and in vitro fertilization (IVM/IVF) using semen treated with or without melatonin (100 nm ) in the presence or absence of H2O2 (250 μm ) for 6 h. The semen characteristics, including motility, viability, survival rate, membrane integrity and mitochondria activity, were higher in the groups that were treated with melatonin in comparison to other groups, irrespective of incubation periods. Malondialdehyde levels in control, melatonin and melatonin + H2O2 groups were lower than H2O2 only group. A positive correlation was shown among motility, viability, survival rate and membrane integrity, but a negative correlation was observed between LPO and the other evaluation methods. The developmental rates to blastocysts of IVM/IVF porcine oocytes fertilized by semen treated with melatonin were significantly increased compared with any other groups, with the cell number of blastocysts shown to have a similar trend to the developmental rates. These results demonstrate that melatonin can improve the semen characteristics during in vitro storage and support the developmental ability of IVM/IVF embryos in pigs. 相似文献
68.
HY Jang SJ Ji YH Kim HY Lee JS Shin HT Cheong JT Kim IC Park HS Kong CK Park BK Yang 《Reproduction in domestic animals》2010,45(6):967-974
The aim of the present study was to elucidate the fundamental mechanism of bovine oviduct epithelial cell (BOEC) co‐culture on developmental capacity of bovine in vitro oocyte maturation/in vitro fertilization (IVM/IVF) embryos. We examined the effects of astaxanthin against nitric oxide‐induced oxidative stress on cell viability by MTT assay, lipid peroxidation (LPO) by using thiobarbituric acid (TBA) reaction for malondialdehyde (MDA) and the expression of antioxidant genes (CuZnSOD, MnSOD and Catalase) or apoptosis genes (Bcl‐2, Caspase‐3 and Bax) by RT‐PCR in BOEC. We also evaluated the developmental rates of bovine IVM/IVF embryos co‐cultured with BOEC pre‐treated with astaxanthin (500 μm ) in the presence or absence of sodium nitroprusside (SNP, 1000 μm ) for 24 h. Cell viability in BOEC treated with SNP (50–2000 μm ) lowered, while astaxanthin addition (50–500 μm ) increased it in a dose‐dependent manner. Cell viability in astaxanthin plus SNP (1000 μm ) gradually recovered according to the increase in astaxanthin additions (100–500 mm ). The LPO in astaxanthin group (50–500 μM) gradually decreased in a dose dependent manner and among SNP or astaxanthin plus SNP group, SNP alone and astaxanthin (50 μM) plus SNP shown a significant increase than other groups (p < 0.05). Expression of apoptosis or antioxidant genes was detected by RT‐PCR. Bcl‐2 and antioxidant genes were detected in astaxanthin or astaxanthin plus SNP group, and Caspase‐3 and Bax genes were only found in SNP group. When bovine IVM/IVF embryos were cultured for 6–7 days under co‐culture system such as BOEC treated with astaxanthin in the presence or absence of SNP, the developmental ability to blastocysts in 500 μm astaxanthin group was the highest of all groups. These results suggest that astaxanthin has a antioxidative effect on cell viability and LPO of BOEC, and development of bovine IVM/IVF embryos due to the induction of antioxidant genes and suppression of apoptosis genes. 相似文献
69.
Barry H. Dunn Alexander J. Smart Roger N. Gates Patricia S. Johnson Martin K. Beutler Matthew A. Diersen Larry L. Janssen 《Strength and Conditioning Journal》2010,63(2):233-242
Conventional wisdom among rangeland professionals has been that for long-term sustainability of grazing livestock operations, rangeland should be kept in high good to low excellent range condition. Our objective was to analyze production parameters, costs, returns, and profit using data generated over a 34-yr period (1969–2002) from grazing a Clayey range site in the mixed-grass prairie of western South Dakota with variable stocking rates to maintain pastures in low–fair, good, and excellent range condition classes. Cattle weights were measured at turnout and at the end of the grazing season. Gross income · ha?1 was the product of gain · ha?1 and price. Prices were based on historical National Agricultural Statistics Services feeder cattle prices. Annual variable costs were estimated using a yearling cattle budget developed by South Dakota State University agricultural economists. All economic values were adjusted to a constant dollar using the Bureau of Labor Statistics' Consumer Price Index. Stocking rate, average daily gain, total gain, net profit, gross revenue, and annual costs · ha?1 varied among range condition classes. Net income for low–fair range condition ($27.61 · ha?1) and good range condition ($29.43 · ha?1) were not different, but both were greater than excellent range condition ($23.01 · ha?1). Over the life of the study, real profit (adjusted for inflation) steadily increased for the low–fair and good treatments, whereas it remained level for the excellent treatment. Neither drought nor wet springs impacted profit differently for the three treatments. These results support generally observed rancher behavior regarding range condition: to maintain their rangeland in lower range condition than would be recommended by rangeland professionals. Ecosystem goods and services of increasing interest to society and associated with high range condition, such as floristic diversity, hydrologic function, and some species of wildlife, come at an opportunity cost to the rancher. 相似文献
70.
Jeffrey Gillespie Narayan Nyaupane Brittany Dunn Kenneth McMillin 《Agriculture and Human Values》2016,33(4):911-927
This paper addresses the reasons why US meat goat producers selected to engage in meat goat production. A mail survey of US meat goat producers was conducted. Potential reasons for entering meat goat production included those associated with lifestyle, farm management, productivity, and economics. Reasons for entering meat goat production were assessed and analyzed using ordered probit models. The most important reasons for entering meat goat production included enjoyment working with goats, goat production fitting well into the farm management plan, goats could be raised on a relatively small acreage, goat grazing preferences were different from other species, and the family could be involved in the goat enterprise. The 12th and 13th most important reasons were goat production profitability and low cost associated with purchasing and raising goats. Larger-scale farmers were more likely to have selected meat goat production for profitability and productivity reasons while smaller-scale farmers were more likely to have selected it for lifestyle reasons. Farmer demographics, farm characteristics, and farm location also impacted reasons why the farmer selected the goat enterprise. Results have implications for development of the meat goat industry. 相似文献