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1.
Stenotrophomonas maltophilia was isolated from the rhizosphere of eggplant in the Nile Delta of Egypt, and its antagonistic potential against Ralstonia solanacearum race 3 biovar 2, the causal agent of potato brown rot, was in vitro evaluated on KB agar medium and in vivo on potato plants. In vitro, four isolates of S. maltophilia (PD3531, PD3532, PD3533, and PD3534) appeared antagonistic. The isolate (PD3533) was screened as the most promising antagonist for the in vivo tests. In the greenhouse, the antagonist was applied directly to soil or by bacterization of potato eyepieces. Stenotrophomonas maltophilia significantly suppressed potato brown rot in Egyptian clay soil but not in Dutch clay soil. Survival of a rifampicin and chloramphenicol-resistant S. maltophilia strain PD4560 was investigated in two pairs of clay soils, conventionally and organically managed, from Egypt and the Netherlands. The survival of S. maltophilia was significantly less in Dutch than in Egyptian soils, while the converse occurred for R. solanacearum. These results are in agreement with those obtained in the in vivo biocontrol tests. In conclusion, S. maltophilia may be useful for control of brown rot in the area where it was originally isolated, the Nile Delta in Egypt.  相似文献   
2.
Ileal indigestible protein may be an important factor for the occurrence of post weaning diarrhoea in piglets. Depending on the quantity of indigested protein, an imbalance in the microbial community can occur, resulting in an overgrowth of pathogens. Diet viscosity may influence nutrient digestibility and substrate availability for microbial growth. Therefore, we examined the effect of dietary viscosity in piglet nutrition. Carboxymethylcellulose (CMC) was added as a model substance in order to increase diet viscosity. The effect of 1% supplemented CMC on nutrient digestibility, morphological and physiological parameters was measured in piglets 3 weeks post weaning at 26 days of age. The main effects of inclusion of CMC were:
– A 10% slower gastric emptying rate (P = 0.18).

– An increased protein hydrolysis in the gastric fraction, measured as increased nitrogen concentration in the liquid phase of gastric contents (26% in control vs. 34% in experimental group; P = 0.13).

– An increased production of the protein hydrolysing enzyme amino-peptidase from 359 U/g protein for the control diet to 516 U/g protein for the experimental diet (P < 0.01).

– A numerical increase in apparent ileal protein digestibility by 6% from 75.2% to 79.5% (P = 0.22) and a significant increase in faecal protein digestibility by 5% (P = 0.044).

These results indicate that an optimized diet viscosity might be one factor exerting a beneficial influence on protein digestibility. We hypothesize that the effect of diet viscosity on gastric emptying rate is the major factor.  相似文献   

3.
讨论了运用CMC-80双板机控制成品油库发油计量的原理和实现方法,该控制装置已在实际系统中使用。  相似文献   
4.
Frozen bread dough: Effects of freezing storage and dough improvers   总被引:1,自引:0,他引:1  
This review focuses on the effects of freezing storage on the microstructure and baking performance of frozen doughs, and provides an overview of the activities of dough improvers, including emulsifiers, hydrocolloids and other improvers used in frozen dough applications. The overall quality of bread baked from frozen dough deteriorates as the storage of the dough at sub-zero temperatures increases due to several factors which are discussed. Lipid-related emulsifiers such as diacetyl tartaric acid esters of mono and diglycerides and sucrose esters employed as anti-staling agents, dough modifiers, shortening sparing agents, and as improvers for the production of high-protein bread have also been employed in frozen doughs. Hydrocolloids are gaining importance in the baking industry as dough improvers due to their ability to induce structural changes in the main components of wheat flour systems during breadmaking steps and bread storage Their effects in frozen doughs is discussed. Other dough improvers, such as ascorbic acid, honey and green tea extract, are also reviewed in the context of frozen doughs.  相似文献   
5.
本文论述了MCSYS系统的第二部分——CAM系统。该系统以CAD部分的数据为基础,按着线元数据生成数控加工指令,其特点是用通用算法语言实现了自动编程。通过简单运算,排除了刀具与工件间的相互干涉,在粗加工和精加工刀具路线生成后,给定具体加工条件即可生成实际的数控指令。  相似文献   
6.
[目的]探讨饥饿对麻雀体内纤维素酶活性的影响。[方法]采用DNS法,测定自由进食和饥饿组麻雀体内纤维素酶活性的变化,并研究了pH和温度对纤维素酶活的影响。[结果]随着饥饿时间的延长,麻雀胃和肠道内CMC酶活先迅速下降后有部分上升,但未达到对照组的水平。饥饿组BG酶的活性持续下降。肌胃、腺胃、前肠、后肠和直肠中CMC酶活的最适pH分别为3、4、4、6和5。肌胃、腺胃、后肠和直肠的最适温度均为50℃,前肠的最适温度为40℃。BG酶活的最适pH均为4,最适温度为40℃。[结论]饥饿使麻雀消化道内CMC酶活先下降后上升,BG酶的活性持续下降。  相似文献   
7.
玉米秸秆低温纤维素分解菌的筛选及分解效果测定   总被引:2,自引:1,他引:1  
在低温条件下,从腐烂的秸秆与土壤的混合样品中分离出降解纤维素能力强的4株菌株,测定这4株菌在玉米秸秆发酵中的CMC酶活。结果表明,菌株A14和A41在整个培养过程中CMC酶的活性比较高,分别为8.341 U/g和8.792 U/g。采用A14、A41处理玉米秸秆10 d,降解率分别达30.80%和31.52%。确定菌株A14和A41的最佳产酶条件为摇床转速150 r/min,接菌量为菌悬液(108个孢子/mL)与秸秆用量比1/10(质量比)。  相似文献   
8.
羧甲基纤维素钠的浓度、体系的pH值均会影响酸性乳饮料的稳定性.在浓度0%-0.6%、pH4.6-3.6范围内,体系的粘度随浓度增加、pH升高而增加;随CMC浓度增加,所能稳定的pH范围也增加,沉降量降低.在相同条件下,调酸型酸性乳饮料比发酵型易于稳定.  相似文献   
9.
十二烷基苯磺酸钠对五氯酚钠光解体系的影响   总被引:3,自引:0,他引:3  
研究了不同浓度的阴离子表面活性剂十二烷基苯磺酸钠(SDBS)对五氯酚钠在水溶液中光解的影响。结果表明,表面活性剂不直接参与五氯酚钠的光反应;在(ρSDBS)小于其临界胶束浓度(CMC)时,SDBS对五氯酚钠的光反应有抑制作用,而ρ(SDBS)大于其CMC时,SDBS胶束的形成对五氯酚钠的光反应有加速的趋势。推测是由于ρ(SDBS)在达到CMC之前,对光解的影响以光吸收作用为主,对五氯酚钠光解有一定的抑制;而达到CMC后,胶束内部类似有机相的环境,对五氯酚钠有富集作用,从而加速五氯酚钠的光反应。  相似文献   
10.
羧甲基纤维素/大豆分离蛋白复合膜涂膜保鲜蒜米   总被引:1,自引:0,他引:1  
以水分含量和硬度为指标,采用响应面分析优化CMC/大豆分离蛋白复合涂膜材料的工艺条件,结果表明,CMC/大豆分离蛋白最佳复配浓度为CMC:1.60%、大豆分离蛋白:1.00%、吐温20:2.00%。  相似文献   
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