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1.
Climate change effects caused by an increasing concentration of CO2 and ozone represent an issue of major concern both for scientists and policy-makers. In a concerted program funded by the Commission of the European Union, a European network of experiments (in open-top chambers (OTC), and free air carbon dioxide enrichment systems (FACE)) and modelling was carried out to investigate the effects of increasing atmospheric CO2 and ozone concentrations, under different climatic conditions, on potato (Solanum tuberosum L. cv. Bintje). This contribution describes the experimental network and the standard protocol set-up for the assessments that served to improve and to validate process oriented potato growth simulation models leading to scenarios of future productivity of potato in Europe.  相似文献   
2.
Out of a total of 224 bovine eye secretions, 126 Moraxella bovis and 64 Neisseria ovis strains were isolated. The pathogenesis and histological lesions caused by Neisseria ovis have been studied on the eyes of three calves naturally affected with IBK, using electron microscopy.

Neisseria ovis caused in 1–12 weeks old calves acute, transient and mostly benign serous conjunctivitis with only slight affection of the cornea. More rarely erosions and even ulceration of the cornea have been observed.

Moraxella bovis and Neisseria ovis strains proved nearly unanimously sensitive in vitro to chloramphenicol, neomycin, oxytetracyclin, nitrofurantoin, erythromycin and cefoperazone. Other antibiotics and chemotherapeutics inhibited the growth of these agents only partly or were ineffective.

Experimental therapy has been carried out using a single i.m. injection of Terramycin/LA inj. (Pfizer) in a dose of 20 mg/kg body mass, repeated if necessary after 72–96 h. This formulation proved more effective and practical than treatments used earlier.  相似文献   

3.
利用OTC平台和青菜盆栽实验,探索[CO2]、[O3]或[CO2+O3]升高条件下,土壤理化性质、微生物量和土壤酶活性的变化,以期获得未来大气CO2或/和O3升高对土壤微生态系统的风险性。结果表明,[CO2]升高不同程度地提高了土壤的可溶性有机碳(DOC)、可溶性有机氮(DON)、总磷(TP)、总碳(TC)、铵态氮(AN)、硝态氮(NN)含量和含水量(SWC),进而不同程度地提高了土壤微生物量碳(MBC)、微生物量氮(MBN)含量以及土壤蛋白酶(PRA)、蔗糖酶(SA)、脲酶(UA)、多酚氧化酶(POA)、酸性磷酸酶(APA)和中性磷酸酶(NPA)活性。相反,[O3]升高不同程度降低了土壤DOC、TP、TK、TC、TN、AN、NN、SWC、MBC和MBN含量,提高了MBC/MBN比值,在不同程度上降低了土壤PRA、SA、UA、POA、APA和NPA酶活性。而[CO2+O3]在一定程度上消减了[O3]对土壤微生物量和酶活性的抑制作用,也降低了[CO2]升高对土壤微生物量和酶活性的刺激效应。因此,土壤微生物量和土壤酶活性的变化可用于评价未来大气CO2或/和O3升高对菜地土壤微生态环境的影响。  相似文献   
4.
A solution culture experiment was performed to investigate the effects of oxytetracycline (OTC) on wheat (Triticum aestivum L.) growth,chlorophyll contents,and photosynthesis at five levels of 0,10,20,40,and 80 mmol L-1 OTC.OTC is toxic to wheat.The wheat growth,especially wheat root was significantly decreased.Further OTC also significantly decreased root activity,chlorophyll contents,and photosynthetic parameters except for intercellular CO2 concentrations.The different responses of indicators such as root number,root activity and so on to OTC were also observed.The IC50 values for the tested indicators to OTC ranged from 7.1 to 113.4 mmol L-1 OTC.The order of indicator sensitivity to OTC was root number > stomatal conductance > chlorophyll a > total chlorophyll > photosynthetic rates > total surface area >transpiration rate > chlorophyll b > fresh weight of root > dry weight of root > total length > dry weight of shoot =fresh weight of shoot> total volume.The root number was more sensitive than other indicators with the ICs0 value of 7.1 mmol L-1 OTC,and could be taken as the sensitive indicator to predict the hazards of OTC to wheat.  相似文献   
5.
为明确西藏冬青稞生长发育及产量对增温和CO2浓度升高的实际响应,以西藏冬青稞主栽品种‘冬青18’为试验材料,设置开放式气室(OTC)内无增温且无增施CO2为对照(CK)、增温(T)和增温+增施CO2(T+CO2)3个处理,经连续2个生长季全生育期增温控制试验,观察记录冬青稞生育时期、旗叶叶绿素含量和产量及其构成因素。结果表明:1)T和T+CO2处理使‘冬青18’全生育期显著缩短,缩短12~20 d,主要集中于播种-出苗期和抽穗-成熟期。2)灌浆期旗叶叶绿素含量总体呈先增加后降低趋势,各处理之间无显著差异。3)T处理降低‘冬青18’产量,同时增加CO2有弥补产量的效果,主要是因为T处理的主穗粒数、穗粒重及千粒重均降低,增温同时增加CO2使千粒重和穗粒数有所增加。因此,全球气候变暖对于冬青稞生长整体表现为穗粒数、粒重和千粒重均降低等减产效应,而增加CO2可在一定程度上缓解减产趋势,未来该地区冬青稞生产栽培可通过调整播期及筛选耐高温品种来应对全球气候变暖。  相似文献   
6.
为探究全球气候变暖对青藏高原高寒草甸的影响,本文采用开顶式生长室(Open-top chambers,OTC)增温方式进行不对称季节性模拟增温,设置全年增温(T1)、夏秋冬季增温(T2)和春夏秋季增温(T3)3组不同处理,分析高寒草甸的群落组成及群落特征的变化。结果表明,增温后群落的优势种发生变化;群落的平均高度增加,其中T1和T3处理的群落平均高度显著增加;群落平均盖度无显著变化,但禾本科植物的高度和盖度增加;不同季节增温后群落的Patrick丰富度、Shannon-Wiener多样性指数、Simpson优势度指数均有不同程度的变化,Pielou均匀度指数则无明显变化,表现为T1处理的群落丰富度、多样性指数和优势度指数显著降低,T3处理的丰富度和多样性指数显著降低。高寒草甸植物群落对不同季节增温处理的响应程度有所不同。  相似文献   
7.
8.
Potato cv. Bintje was grown in open-top-chambers and free-air-CO2-enrichment systems at 7 sites across Europe for 2 years (1998–99). The effect of different treatments (CO2 enrichment and O3 fumigation) on the chlorophyll content of fully expanded upper and lower canopy leaves was investigated collecting Minolta SPAD-502 meter readings. In both CO2 treated and O3 fumigated plants, leaves had lower chlorophyll content than those in ambient air controls; season-long chlorophyll averages were 9.3% lower in the ‘CO2’ treatments, 9.1% lower in ‘O3’ treatments and 12.3% lower in ‘CO2+O3’ treatments. The analysis of chlorophyll content in three different growth phases (Emergence–Tuber Initiation; Tuber Initiation–Maximum Leaf Area; Maximum Leaf Area–Harvest) showed that in the early growth period, i.e. before tuber initiation there was a slight indication for an higher chlorophyll content at elevated CO2 (+3.8%) or O3 (+1.7%). However, from tuber initiation onwards the leaves of plants grown under elevated CO2 or O3 showed a progressively lower chlorophyll content (−4.8% for CO2 treatments and −2.6% for O3 treatments) indicating a faster senescence of leaves that increased during the late growth period (−12.8% for CO2 treatments and −12.7% for O3 treatments) and that was enhanced by CO2–O3 interaction (−17.8%).  相似文献   
9.
高效液相色谱法分析鲤鱼体内土霉素残留的研究   总被引:4,自引:0,他引:4  
研究了鲤鱼体内土霉素(Oxytetracycline,OTC)的高效液相色谱分析方法。确定了合适的提取方法和色谱分析条件。该方法灵敏度高,检测限为0.01μg/g。0.05、0.1、0.2μg/g各浓度组的平均回收率分别为94.0%、102.4%、88.8%。在0.02~0.12μg/ml浓度范围内工作曲线有较好的线性,相关系数为0.9994。  相似文献   
10.
大气CO2和O3升高对菜地土壤酶活性和微生物量的影响   总被引:2,自引:2,他引:0  
利用OTC平台和青菜盆栽实验,探索[CO_2]、[O_3]或[CO_2+O_3]升高条件下,土壤理化性质、微生物量和土壤酶活性的变化,以期获得未来大气CO_2或/和O_3升高对土壤微生态系统的风险性。结果表明,[CO_2]升高不同程度地提高了土壤的可溶性有机碳(DOC)、可溶性有机氮(DON)、总磷(TP)、总碳(TC)、铵态氮(AN)、硝态氮(NN)含量和含水量(SWC),进而不同程度地提高了土壤微生物量碳(MBC)、微生物量氮(MBN)含量以及土壤蛋白酶(PRA)、蔗糖酶(SA)、脲酶(UA)、多酚氧化酶(POA)、酸性磷酸酶(APA)和中性磷酸酶(NPA)活性。相反,[O_3]升高不同程度降低了土壤DOC、TP、TK、TC、TN、AN、NN、SWC、MBC和MBN含量,提高了MBC/MBN比值,在不同程度上降低了土壤PRA、SA、UA、POA、APA和NPA酶活性。而[CO_2+O_3]在一定程度上消减了[O_3]对土壤微生物量和酶活性的抑制作用,也降低了[CO_2]升高对土壤微生物量和酶活性的刺激效应。因此,土壤微生物量和土壤酶活性的变化可用于评价未来大气CO_2或/和O_3升高对菜地土壤微生态环境的影响。  相似文献   
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