全文获取类型
收费全文 | 138篇 |
免费 | 9篇 |
专业分类
林业 | 4篇 |
农学 | 8篇 |
23篇 | |
综合类 | 34篇 |
农作物 | 12篇 |
水产渔业 | 6篇 |
畜牧兽医 | 50篇 |
园艺 | 3篇 |
植物保护 | 7篇 |
出版年
2023年 | 2篇 |
2022年 | 2篇 |
2021年 | 3篇 |
2020年 | 1篇 |
2019年 | 3篇 |
2018年 | 8篇 |
2017年 | 9篇 |
2016年 | 2篇 |
2015年 | 2篇 |
2014年 | 6篇 |
2013年 | 5篇 |
2012年 | 2篇 |
2011年 | 14篇 |
2010年 | 5篇 |
2009年 | 5篇 |
2008年 | 8篇 |
2007年 | 8篇 |
2006年 | 2篇 |
2005年 | 3篇 |
2004年 | 4篇 |
2003年 | 1篇 |
2002年 | 8篇 |
2001年 | 1篇 |
1999年 | 4篇 |
1998年 | 3篇 |
1996年 | 3篇 |
1994年 | 1篇 |
1992年 | 3篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1983年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1978年 | 3篇 |
1975年 | 1篇 |
1971年 | 1篇 |
1970年 | 1篇 |
1967年 | 2篇 |
1966年 | 1篇 |
1965年 | 2篇 |
1934年 | 2篇 |
1927年 | 2篇 |
1926年 | 1篇 |
1925年 | 1篇 |
1915年 | 2篇 |
1911年 | 2篇 |
排序方式: 共有147条查询结果,搜索用时 15 毫秒
71.
72.
Chol D. T. Abel Saroj K. Sharma Yona N. Malolo Sung Kyu Maeng Maria D. Kennedy Gary L. Amy 《Water, air, and soil pollution》2012,223(8):5205-5220
Soil aquifer treatment (SAT) is a cost-effective natural wastewater treatment and reuse technology. It is an environmentally friendly technology that does not require chemical usage and is applicable to both developing and developed countries. However, the presence of organic matter, nutrients, and pathogens poses a major health threat to the population exposed to partially treated wastewater or reclaimed water through SAT. Laboratory-based soil column and batch experiments simulating SAT were conducted to examine the influence of temperature variation and oxidation?Creduction (redox) conditions on removal of bulk organic matter, nutrients, and indicator microorganisms using primary effluent. While an average dissolved organic carbon (DOC) removal of 17.7?% was achieved in soil columns at 5?°C, removal at higher temperatures increased by 10?% increments with increase in temperature by 5?°C over the range of 15 to 25?°C. Furthermore, soil column and batch experiments conducted under different redox conditions revealed higher DOC removal in aerobic (oxic) experiments compared to anoxic experiments. Aerobic soil columns exhibited DOC removal 15?% higher than that achieved in the anoxic columns, while aerobic batch showed DOC removal 7.8?% higher than the corresponding anoxic batch experiments. Ammonium-nitrogen removal greater than 99?% was observed at 20 and 25?°C, while 89.7?% was removed at 15?°C, but the removal substantially decreased to 8.8?% at 5?°C. While ammonium-nitrogen was attenuated by 99.9?% in aerobic batch reactors carried out at room temperature, anoxic experiments under similar conditions revealed 12.1?% ammonium-nitrogen reduction, corresponding to increase in nitrate-nitrogen and decrease in sulfate concentration. 相似文献
73.
C Abel 《Archiv fuer experimentelle veterinaermedizin》1975,29(5):705-710
A group of young hamsters was injected subcutaneously in the neck region with allantoic fluid containing CELO virus. A second group received transplants of cells from tumours induced by CELO virus. Tumours developed in both groups. The latent period was shorter after transplantation than after virus inoculation. The tumours grew progressively, histologically resembling fibrosarcoma. It is recommended that hatching eggs infected with CELO virus should not be used in vaccine production. 相似文献
74.
75.
González-Domínguez Sandra Santillán-Galicia Ma. Teresa Guzmán-Franco Ariel W. Avila-García Clemente de Jesús López-Buenfil José Abel Romero-Rosales Felipe 《Phytoparasitica》2023,51(2):241-253
Phytoparasitica - We studied the species diversity of mites in five blackberry orchards [Rubus ulmifolius Schott (Rosales:Rosaceae)], three using organic production techniques and two conventional.... 相似文献
76.
Dawrin Pech-Puch Abel M. Forero Juan Carlos Fuentes-Monteverde Cristina Lasarte-Monterrubio Marta Martinez-Guitian Carlos Gonzlez-Salas Sergio Guilln-Hernndez Harold Villegas-Hernndez Alejandro Beceiro Christian Griesinger Jaime Rodríguez Carlos Jimnez 《Marine drugs》2022,20(5)
Three new diterpene alkaloids, (+)-8-epiagelasine T (1), (+)-10-epiagelasine B (2), and (+)-12-hydroxyagelasidine C (3), along with three known compounds, (+)-ent-agelasine F (4), (+)-agelasine B (5), and (+)-agelasidine C (6), were isolated from the sponge Agelas citrina, collected on the coasts of the Yucatán Peninsula (Mexico). Their chemical structures were elucidated by 1D and 2D NMR spectroscopy, HRESIMS techniques, and a comparison with literature data. Although the synthesis of (+)-ent-agelasine F (4) has been previously reported, this is the first time that it was isolated as a natural product. The evaluation of the antimicrobial activity against the Gram-positive pathogens Staphylococcus aureus, Streptococcus pneumoniae, Enterococcus faecalis showed that all of them were active, with (+)-10-epiagelasine B (2) being the most active compound with an MIC in the range of 1–8 µg/mL. On the other hand, the Gram-negative pathogenes Acinetobacter baumannii, Pseudomonas aeruginosa, and Klebsiella pneumoniae were also evaluated, and only (+)-agelasine B (5) showed a moderate antibacterial activity with a MIC value of 16 μg/mL. 相似文献
77.
MR Luz CC de Holanda JJ Pereira PMC Freitas AEP Salgado J Di Giorgio Giannotti SB de Oliveira NS Teixeira CR de Freitas Guaitolini 《Reproduction in domestic animals》2011,46(4):724-727
The embryonic collection techniques in dogs present a vast methodological variation and low recovery rates. The objectives were to compare and describe two techniques as to the recovery of canine embryos, on the 12th day after the first mating or artificial insemination. Embryos were recovered through uterine horn flushing in vivo, before performing the ovariohysterectomy (OHE) (Group 1; n = 9) or ex vivo, immediately after the OHE (Group 2; n = 9). In total, 43 and 47 embryonic structures were recovered in Groups 1 and 2, respectively. There was no significant difference (p > 0.05) between groups on recovery rates (72.8% and 81.0%, respectively). We inferred that both in vivo and ex vivo techniques allow a high rate of embryonic recovery; in the collection technique prior to the OHE, it is essential to carefully handle the reproductive system during the trans‐surgical period and that the 12th day (D12) after the first mating/artificial insemination is an efficient option for the high recovery rate of morulae and blastocysts. 相似文献
78.
This study investigated whether a precise and repeatable quantification of Heterakis gallinarum egg excretion, which considerably reflects the actual worm burdens, can be achieved based on collection of the daily total amount of faeces from chickens. Three-week-old birds (N=64) were infected with 200 embryonated eggs of H. gallinarum, and placed into individual cages 3 wk after infection for 5 wk to collect daily faeces (N=2240). The total daily faeces was mixed and a randomly taken sample per bird was analyzed to estimate the numbers of eggs per gram of faeces (EPG) and total number of eggs excreted within 24h (EPD). A total of 235 daily faecal collections were randomly selected and further examined to determine between and within sample variations of EPG counts as a measure of precision. For this, two random faecal samples were taken from the daily produced faeces by a bird, and the EPG was determined for each of the samples (EPG1 and EPG2). The second faecal sample was analyzed once more to determine a parallel EPG2 count (EPG2a) of the suspended sample. Precision of an EPG count was defined as its relative closeness to the average of two EPG counts using a relative asymmetry index (Index(EPG)). At an age of 11 wk, i.e. 8 wk p.i. the birds were slaughtered and their worm burdens were determined. There were no significant differences between EPG1 and EPG2 (P=0.764) nor between EPG2 and EPG2a (P=0.700), suggesting that the differences between or within the samples were not different from zero. Correlations between EPG counts, as between and within sample coherences, were r=0.85 and r=0.86, respectively. Precision of EPG counts, as measured by Index(EPG), was not influenced by consistency (P=0.870) and total amount of faeces (P=0.088). However, concentration of eggs in faeces (mean EPG) had a significant effect on the precision of the EPG counts (P<0.001). Similar results were also observed for the within sample precision (Index(EPG2)). A segmented regression analysis indicated an abrupt change in the precision of EPG counts as the response to changing egg concentration in the examined faecal samples. The precision of analyses remarkably heightened up to a breakpoint with an EPG count of ≤ 617. A similar breakpoint was also determined for within sample precision (EPG2 ≤ 621). Moderate repeatabilities (R=0.49) for EPG and EPD were estimated in the first week of egg excretion, whereas the estimates were higher (R=0.67-0.84) in the following weeks. Correlations between number of female worms with daily measured EPG and EPD increased to an almost constant level (r ≥ 0.70; P<0.05) in a few days after the nematode excreted eggs and predominantly remained so for the rest of the sampling period. It is concluded that mixing daily total faeces provides samples with random homogenous distribution of H. gallinarum eggs. Precision of the EPG counts increases as the egg concentration in faecal sample increases. Egg excretion of H. gallinarum, quantified either as EPG or EPD, is highly repeatable and closely correlated with the actual worm burden of birds starting as early as in 5 th wk of infection. 相似文献
79.
CJ MORROW † IG BELL† SB WALKER§ PF MARKHAM† BH THORP¶ KG WHITHEAR† 《Australian veterinary journal》1990,67(4):121-124
This report describes the first isolations of Mycoplasma synoviae from the synovial sheaths and joints of commercial chickens affected with synovitis in Australia. Over 4 years 3 separate outbreaks were investigated in which up to 20% of birds exhibited clinical signs of poor growth and "hot foot" syndrome (swollen inflamed footpads). Once an outbreak occurred, chronic infection of the farm usually ensued. Grossly the hocks and footpads were swollen by a purulent exudate and associated inflammatory changes with histological features of a severe acute synovitis. Seroconversion of the flocks occurred at the time of the development of lesions. M. synoviae specific antibodies were demonstrated by ELISA in the joint fluid of affected birds. It is concluded that the cases described are similar to avian infectious synovitis syndrome caused by M. synoviae previously described overseas. 相似文献
80.
Angel H. Alvarez Abel Gutiérrez-Ortega Rodolfo Hernández-Gutiérrez 《Canadian journal of veterinary research》2015,79(4):339-342
Mannheimia haemolytica and Histophilus somni are frequently isolated from diseased cattle with bovine respiratory disease (BRD). They compromise animal lung function and the immune responses generated are not sufficient to limit infection. Identification of specific immunogenic antigens for vaccine development represents a great challenge. Immunogenic proteins were identified by immunoproteomic approach with sera from cattle immunized with a commercial cellular vaccine of M. haemolytica and H. somni. Proteins of M. haemolytica were identified as solute ABC transporter, iron-binding protein, and hypothetical protein of capsular biosynthesis. Histophilus somni proteins correspond to porin, amino acid ABC transporter, hypothetical outer membrane protein, cysteine synthase, and outer membrane protein P6. Although these antigens share strong similarities with other proteins from animal pathogens, the ABC system proteins have been associated with virulence and these proteins could be considered as potential vaccine candidates for BRD. 相似文献