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排序方式: 共有145条查询结果,搜索用时 15 毫秒
1.
Four promising woody crops (Populusmaximowiczii x nigra (NE388), P.trichocarpa x deltoides (Nll), P.tremuloides, and SweetgumLiquidambar styraciflua) were pretreated by dilute sulfuric acid and evaluated in the simultaneous saccharification and fermentation (SSF) process for ethanol production. The yeastSaccharomyces cerevisiae was used in the fermentations alone, and in mixed cultures with β -glucosidase producingBrettanomyces dausenii. Commercial Genencor 150L cellulase enyme was either employed alone or supplemented with β- glucosidase. All SSFs were run at 37 …C for 8 d and compared to saccharifications at 45…C under the same enzyme loadings.S. cerevisiae alone achieved the highest ethanol yields and rates of hydrolysis at the higher enzyme loadings, whereas the mixed culture performed better at the lower enzyme loadings without β -glucosidase supplementation. The best overall rates of fermentation (3 d) and final theoretical ethanol yields (86–90%) were achieved with P.maximowiczii x nigra (NE388) and SweetgumLiquidambar styraciflua, followed by P.tremuloides and P.trichocarpa xdeltoides (N1l) with slightly slower rates and lower yields. Although there were some differences in SSF performance, all these pretreated woody crops show promise as substrates for ethanol production.  相似文献   
2.
The herbaceous crops that may provide fermentable carbohydrates for production of fuels and chemicals also contain 10–20% protein. Protein coproduction with biomass-derived fuels and chemicals has important advantages: (1) food and fuel production can be integrated, and (2) protein is a high-value product that may significantly improve overall process economics. We report the results of an integrated approach to producing protein and fermentable sugars from one herbaceous species, Coastal Bermudagrass (CBG). The ammonia fiber explosion (AFEX) process makes possible over 90% conversion of cellulose and hemicellulose to simple sugars (about 650 mg reducing sugars/g dry CBG) at 5 IU cellulase/g vs < 20% conversion for untreated CBG. The AFEX treatment also improves protein extraction from CBG; over 80% protein recovery is possible from AFEX-treated CBG vs about 30% recovery from untreated CBG.  相似文献   
3.
The production of biogas for reducing fossil CO2 emissions is one of the key strategic issues of the German government and has resulted in the development of new process techniques and new technologies for the energetic use of biogas. Progress has been made in cultivating energy crops for biogas production, in using new reactor systems for anaerobic digestion, and in applying more efficient technologies for combined heat and power production. Recently, integration of fuel cells within the anaerobic digestion process was started, and new technologies for biogas upgrading and conversion to hydrogen were tested. This article describes the trends in Germany for achieving more efficient energy production.  相似文献   
4.
用阜阳市区中、西清河垃圾污水培养几种农作物种子,探讨污水培养下幼苗对污水中N、P、Cl等营养盐的吸 收特性.结果表明:菜豆和玉米在萌芽阶段的抗污水胁迫能力要高于上海青和荆荠种子,荆荠和上海青种子虽能萌 芽但不能长成幼苗.从同一种种子萌苗也可以看出两条河流水质的污染状况:西清河水质污染状况比中清河严重.N 和Cl在菜豆和玉米幼苗内都是随着污水浓度升高而增加;但玉米幼苗在自来水、2种污水培养中P的含量却呈现负 增加.菜豆对N、P、Cl元素的吸收率均高于玉米,这表明菜豆对N、P、Cl元素的吸收效果要比玉米好.  相似文献   
5.
再论生物安全   总被引:3,自引:1,他引:3  
钱迎倩  魏伟 《广西科学》2003,10(2):126-128,134
生物安全是指既要避免或减轻由现代生物技术对生物多样性保护和其持续利用以及人类健康可能带来的不利影响,同时也承认现代生物技术在提高人类生活质量,特别是在满足食物、农业及卫生保健方面所具有的极大潜力。认为重视生物安全的人都是对转基因生物的反对派,甚至提到是坚决的反对派,这种观点是极端错误的、有害的。基因污染事件已经在加拿大及墨西哥发生,对转基因作物及其产品使用得最多的美国,事实上也是在采用预先防范的原则来处理生物安全,因此,发展生物技术应强调生物安全。  相似文献   
6.
提出以植株体电阻作为农作物需水信息的新方法,设计一种测定体电阻的专用传感器,研制对农作物植株体电阻进行实时、快速测量的微机检测系统.实验结果表明,本系统亏水诊断结果与其他方法诊断结果基本吻合.  相似文献   
7.
试论厄尼诺与山东降水作物产量的关系   总被引:2,自引:0,他引:2  
厄尼诺现象使山东夏季降水偏少,强度越大,干旱越重,用降水与分离的气候产量进行回归分析的到需水量,进而评价其满足程度。厄尼诺强年所有作物减产,弱年与发生时间有关。  相似文献   
8.
粮食作物古汉名训诂(一)   总被引:3,自引:2,他引:3  
我国古代典籍中记述有许多粮食作物名称,由于历史变迁,古今名称大都不一致,影响科学文化的继承与传播.本文选取了8种主要粮食作物,对其古汉名进行了考证,沟通古今,沟通中外,在拯救、继承与弘扬古文化方面具有现实意义.  相似文献   
9.
粮油作物及茶叶中农药多残留检测的前处理技术进展   总被引:2,自引:0,他引:2  
综述了粮油作物和茶叶中农药多残留检测的前处理技术,包括超临界流体萃取、加速溶剂萃取、搅拌棒吸附萃取、分散固相萃取、固相微萃取和在线凝胶渗透色谱等样品前处理方式,并详细介绍了各种方法的原理、优点及适用范围,可为粮油作物和茶叶中农药多残留检测技术的发展提供参考。  相似文献   
10.
Globally, many developing countries are facing silent epidemics of nutritional deficiencies in human beings and animals. The lack of diversity in diet, i.e., cereal-based crops deficient in mineral nutrients is an additional threat to nutritional quality. The present review accounts for the significance of biofortification as a process to enhance the productivity of crops and also an agricultural solution to address the issues of nutritional security. In this endeavor, different innovative and specific biofortification approaches have been discussed for nutrient enrichment of field crops including cereals, pulses, oilseeds and fodder crops. The agronomic approach increases the micronutrient density in crops with soil and foliar application of fertilizers including amendments. The biofortification through conventional breeding approach includes the selection of efficient genotypes, practicing crossing of plants with desirable nutritional traits without sacrificing agricultural and economic productivity. However, the transgenic/biotechnological approach involves the synthesis of transgenes for micronutrient re-translocation between tissues to enhance their bioavailability. Soil microorganisms enhance nutrient content in the rhizosphere through diverse mechanisms such as synthesis, mobilization, transformations and siderophore production which accumulate more minerals in plants. Different sources of micronutrients viz. mineral solutions, chelates and nanoparticles play a pivotal role in the process of biofortification as it regulates the absorption rates and mechanisms in plants. Apart from the quality parameters, biofortification also improved the crop yield to alleviate hidden hunger thus proving to be a sustainable and cost-effective approach. Thus, this review article conveys a message for researchers about the adequate potential of biofortification to increase crop productivity and nourish the crop with additional nutrient content to provide food security and nutritional quality to humans and livestock.  相似文献   
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