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991.
以油茶籽粕为原料,通过发酵法制备乙醇。通过单因素实验和响应面优化油茶籽粕发酵制备乙醇的工艺条件。结果表明:钙镁离子比和酵母接种量的交互作用对乙醇得率的影响高度显著;钙镁离子比和氯化铵添加量交互作用对乙醇得率的影响显著。油茶籽粕发酵制备乙醇的最优条件为发酵初始pH 5.0、钙镁离子比0.90∶1、氯化铵添加量0.75%、酵母接种量0.40%,在此条件下乙醇得率为94.3%。 相似文献
992.
煤炭利用是中国大气污染物的主要来源。煤炭在民用燃煤、工业锅炉、火电领域作为燃料,在煤化工领域的利用则作为原料。根据学者对中国以上领域煤炭利用污染物排放的研究,比较了不同产品的污染物排放强度,我们得到:降低民用散煤利用,改用型煤或低污染物排放燃料以减低污染物的排放;加强工业锅炉除尘和电力脱硝以降低颗粒物和NO_X的排放;在煤焦化行业,全面推广脱硫除尘技术;现代煤化工CO_2排放强度大,应关注其捕获利用,但其污染物排放均优于其他利用领域。根据不同产品的污染排放系数和煤耗,我们比较了不同应用领域的煤炭污染物排放强度:煤炭作为燃料,其碳几乎完全转化为CO_2,但作为原料部分碳转移到产品中,同时,作为原料时其他污染物排放也远低于作为燃料的排放。煤NO_X、SO_2和颗粒物排放因子分别在火电、工业锅炉和民用燃煤和焦化行业最高,我们应相应地在这些领域加强其脱硝、脱硫和除尘工程。 相似文献
993.
在间歇反应釜中,以超低酸(硫酸质量分数为0.05%)水解的方法对5类15种农作物秸秆进行评价,并考察了温度与时间对不同秸秆水解的影响.结果表明:相同条件下,不同种类、同种类不同地区秸秆水解后还原糖浓度有很大差异,这与纤维素、半纤维素及木质素的含量及转化率有关.黑龙江的稻草、玉米秸秆及山东小麦秸秆的还原糖浓度较高,4种棉花秸秆的还原糖浓度都较低;还发现,木质素含量较高的秸秆,超低酸水解还原糖浓度较低,只是水解了部分半纤维素及极少量的纤维素. 相似文献
994.
The Clean Development Mechanism (CDM) of the Kyoto Protocol represents an opportunity to involve all developing countries in the effort to reduce greenhouse gas emissions while also promoting sustainable development. To date, however, the majority of CDM projects have gone to emerging markets such as China, India, Brazil, and Mexico, while very few least developed countries have hosted projects. This paper investigates the differential distribution of CDM activities across countries. We develop a conceptual model for project profitability, which helps to identify potential country-level determinants of CDM activity. These potential determinants are employed as explanatory variables in regression analysis to explain the actual distribution of projects. Human capital and greenhouse gas emission levels influenced which countries have hosted projects and the amount of certified emission reductions (CER) created. Countries that offered growing markets for CDM co-products, such as electricity, were more likely to be CDM hosts, while economies with higher carbon intensity levels had greater CER production. These findings work against the least developed countries and help to explain their lack of CDM activity. 相似文献
995.
Greenhouse gas emissions from international maritime transport are exempt from liabilities under the Kyoto Protocol. Research into quantifying these emissions is ongoing, and influences policy proposals to reduce emissions. This paper presents a cargo-based analysis of fuel consumption and greenhouse gas emissions from New Zealand's international maritime transport of goods. Maritime transport moves 99.5% (by mass) of New Zealand's internationally traded products. It is estimated that 73% of visiting vessels' activity can be directly attributed to the movement of goods in and out of New Zealand. A cargo-based methodology was used to estimate that the international maritime transport of New Zealand's imports and exports consumed 2.5 million tonnes (Mt; 2.6 billion litres) of fuel during the year 2007, which generated 7.7 Mt of carbon dioxide (CO2) emissions. Double-counting of emissions would occur if a similar method was applied to all New Zealand's trading partners. In contrast, since few large vessels refuel in New Zealand, the National Greenhouse Gas Inventory listed 2007 international maritime transportation emissions as 0.98 Mt of CO2, calculated from fuel bunkered for international transport. The results, therefore, show a significant difference between activity-based and bunker-fuel methodologies in quantifying New Zealand's emissions. International policy implications are discussed. 相似文献
996.
Carlos A. García Alfredo Fuentes Anna Hennecke Enrique Riegelhaupt Fabio Manzini Omar Masera 《Applied Energy》2011
The purpose of this work was to estimate GHG emissions and energy balances for the future expansion of sugarcane ethanol fuel production in Mexico with one current and four possible future modalities. We used the life cycle methodology that is recommended by the European Renewable Energy Directive (RED), which distinguished the following five system phases: direct Land Use Change (LUC); crop production; biomass transport to industry; industrial processing; and ethanol transport to admixture plants. Key variables affecting total GHG emissions and fossil energy used in ethanol production were LUC emissions, crop fertilization rates, the proportion of sugarcane areas that are burned to facilitate harvest, fossil fuels used in the industrial phase, and the method for allocation of emissions to co-products. The lower emissions and higher energy ratios that were observed in the present Brazilian case were mainly due to the lesser amount of fertilizers applied, also were due to the shorter distance of sugarcane transport, and to the smaller proportion of sugarcane areas that were burned to facilitate manual harvest. The resulting modality with the lowest emissions of equivalent carbon dioxide (CO2e) was ethanol produced from direct juice and generating surplus electricity with 36.8 kgCO2e/GJethanol. This was achieved using bagasse as the only fuel source to satisfy industrial phase needs for electricity and steam. Mexican emissions were higher than those calculated for Brazil (27.5 kgCO2e/GJethanol) among all modalities. The Mexican modality with the highest ratio of renewable/fossil energy was also ethanol from sugarcane juice generating surplus electricity with 4.8 GJethanol/GJfossil. 相似文献
997.
In this study, CO2 emissions of Turkish manufacturing industry are calculated by using the fuel consumption data at ISIC revision 2, four digit level. Study covers 57 industries, for the 1995–2001 period. Log Mean Divisia Index (LMDI) method is used to decompose the changes in the CO2 emissions of manufacturing industry into five components; changes in activity, activity structure, sectoral energy intensity, sectoral energy mix and emission factors. Mainly, it is found that changes in total industrial activity and energy intensity are the primary factors determining the changes in CO2 emissions during the study period. It is also indicated that among the fuels used, coal is the main determining factor and among the sectors, 3710 (iron and steel basic industries) is the dirtiest sector dominating the industrial CO2 emissions in the Turkish manufacturing industry. 相似文献
998.
Two Euro 3 commercial trucks fuelled with a 30% v/v biodiesel/diesel fuel blend (B30) and pure diesel fuel were tested in laboratory under the standard driving conditions (UDC and EUDC driving cycles) and the CADC “URBAN” test cycle, in order to evaluate the fuel consumption, regulated (CO, HC, NOx, PM) and unregulated emissions (aldehydes and polycyclic aromatic hydrocarbons). 相似文献
999.
The cogeneration of heat and power by means of a fuel cell based CHP unit is a promising option for efficient residential power supply. For most applications natural gas is used as fuel. One main component of such a CHP unit is a fuel processor in order to generate hydrogen from the natural gas with hydrogen thermal power output of about 6 kW. Usually the steam reforming process is used for hydrogen production. In order to meet the heat demand of the endothermic steam reforming process the fuel processor is equipped with a burner, which has to work with natural gas during start up phase and mainly with the low calorific anodic off gas of the fuel cell stack during normal operation.The presented work is focused on aspects of the main pollutant emissions (carbon monoxide and nitrogen oxide) of burners integrated into the reformer. Experimental investigations of two different burners, which were developed and adapted to the steam reformer requirements, in a real fuel processor environment show, that it is possible to operate both burner concepts with high and low calorific gases with very low pollutant emissions in order to compete with emissions of current heating boilers, which are in the range of 15 mg kWh−1 for CO and of 20 mg kWh−1 for NOx by adjusting suitable excess air ratios in the range of 1.2-1.4.But it is also demonstrated, that the efficiency of the fuel processor is influenced by the excess air ratio. An increase of the air ratio from 1.05 to 1.45 leads to an decrease of the efficiency from 80% to 76%. This results in a conflict of objectives between low pollutant emissions and high system efficiencies. The choice of a suitable burner concept and the definition of a suitable operation strategy can be based on the presented results. Additionally, aspects like fuel processor geometry, flame monitoring, pressure drop in the burner feed gas line as well as in the flue gas duct, investment costs and safety items have also to be considered for the burner selection. 相似文献
1000.