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11.
按照生态农业工程理论和抗旱节水工程技术要求,对棉花转基因抗旱品种、不同密度、不同基肥N、P的施用量进行田间水分胁迫综合试验.经在关中灌区3年试验研究结果表明:密度以每公顷种植7.5万株比种植4.5、6万株分别增产671.854、83.30 kg,增产57.49%和41.36%.品种陕402(早熟)、陕576(中早熟)分别比中棉所41(中熟)增产16.62%和16.17%.施磷酸二铵比尿素增产,每公顷施1502、25 kg分别增产11.35%和10.53%.抗旱节水农业工程育种和农艺节水工程技术结合,不仅可降低生产成本44%~47%,还可提高产量和品质,增收1 050~5 000元/hm2,同时节约了水资源,保护了农业生态环境. 相似文献
12.
杨光华 《华北水利水电学院学报》2012,(1):24-26,39
近年来国内外学者对农田水利的研究集中在制度、组织合作等方面。综述了集体行动与农田水利,集体行动、制度对我国农田水利建设的影响,指出目前研究的不足:缺少对个案的深入细致调查研究。 相似文献
13.
桔槔井灌是最古老的灌溉方式之一。浙江省诸暨市赵家镇的桔槔井灌工程群是目前仍在使用的灌溉工程遗产。本文通过田野调查、文献考证等方法,分析了诸暨赵家桔槔井灌的历史演变、遗产构成、工程特性及其科技文化价值。研究认为,赵家镇桔槔井灌的延续使用有其特殊的自然和历史背景;其历史起源可追溯至12世纪,外来移民利用此地优越的地下水资源条件,因地制宜地使用简易而有效的桔槔提水、发展灌溉农业,逐渐繁衍形成村落。灌溉工程体系规划科学、设计完善、管理有效,并在发展过程中衍生出独具特色的文化。诸暨桔槔井灌遗产具有独特的历史、科技和文化价值,是早期灌溉文明的活化石,近几十年遗产范围快速萎缩,应予科学保护。 相似文献
14.
We present a bioeconomic modeling approach that links the biophysical crop growth model CropSyst to an economic decision model at field scale. The developed model is used in conjunction with a genetic algorithm to optimize management decisions in potato production in the Broye catchment (Switzerland) in the context of different irrigation policy scenarios. More specifically, we consider the effects of water bans, water quotas, and water prices on water consumption, profitability, and the financial risks of potato production. The use of a genetic algorithm enables the direct integration of the considered decision variables as management input factors in CropSyst. We employ the farmer's certainty equivalent, measured as the expected profit margin minus a risk premium, as the objective function. Using this methodological framework allows us to consider the potential impacts of policy measures on farmers' crop management decisions due to their effects on both expected income levels and income variability.Our results show that the region's current water policy, which frequently prevents irrigation during hot and dry periods by banning water withdrawal, causes high levels of income risk for the farmer and increases the average water demand in potato production. In contrast, the implementation of an appropriate water quota could significantly decrease water consumption in potato production while allowing the farmer's certainty equivalent to remain at the same level as it is under the current irrigation water policy. 相似文献
15.
Irrigation for smallholder farming systems is an important approach for sustainable intensification and increased productivity in Sub-Saharan Africa, provided investments in irrigation are properly targeted and accompanied by complementary improvements. Many GIS-based tools have been developed to identify suitable areas for investments in different types of small scale irrigation (SSI), but they do not explicitly address uncertainty on the data input and on the determination of factors that affect success of an investment in a given context. This paper addresses this problem by presenting an application of a decision-support targeting tool based on Bayesian networks (BNs) that can be used by non-expert policy-makers and investors to assess the potential success of specific technologies used for groundwater-based SSI. A case study application for the White Volta Basin in West Africa is presented to illustrate the BN approach. 相似文献
16.
Yields, water use efficiency and economic returns (net farm revenues) of biomass sorghum [Sorghum bicolor (L.) Moench] were investigated over two years (2012 and 2014) under limited water resource conditions. Energy sorghum was grown under four water supply regimes: rain-fed (or dry-land, level 1), 50% (level 2), 75% (level 3) and 100% (level 4) of crop evapotranspiration rates (% ETc). Biomass yields ranged from 5.8 to 16.6 Mg ha−1 (dry weight) after 126 days of growth. Average water use efficiencies ranged from 3.95 kg m−3 to 23.4 kg m−3. Net return was approximately 410 $ ha−1 with water depths above 400 ha-mm. These results suggest that it is possible to obtain more than 60 Mg ha−1 of sorghum biomass (wet basis) with at least 425 mm of water. While biomass yield under irrigation was greater than rain-fed conditions, there were no significant differences among irrigation treatments. Biomass chemical composition did not differ significantly among water treatments suggesting that biofuel quality would not be affected by water deficits. 相似文献
17.
A general optimization framework is introduced with the overall goal of reducing search space size and increasing the computational efficiency of evolutionary algorithm application to optimal crop and water allocation. The framework achieves this goal by representing the problem in the form of a decision tree, including dynamic decision variable option (DDVO) adjustment during the optimization process and using ant colony optimization (ACO) as the optimization engine. A case study from literature is considered to evaluate the utility of the framework. The results indicate that the proposed ACO-DDVO approach is able to find better solutions than those previously identified using linear programming. Furthermore, ACO-DDVO consistently outperforms an ACO algorithm using static decision variable options and penalty functions in terms of solution quality and computational efficiency. The considerable reduction in computational effort achieved by ACO-DDVO should be a major advantage in the optimization of real-world problems using complex crop simulation models. 相似文献
18.
To obtain the normal depth of parabolic section of open channels, multiple known parameters were incorporated into a comprehensive one by transforming basic equations, and a concept of the non-dimensional normal depth was introduced. The normal depth equations were simplified into a non-dimensional iterative formula that was proved to have a high velocity of convergence. By analyzing the comprehensive parameter and dimensionless normal depth under condition of usually adopted sizes of parabolic channels and through establishing their relationship, the iterative initial value of normal depth was obtained. The normal depth of parabolic channels was acquired by substituting the initial value into the iteration formula. The error analysis was made and a case study was provided as an application example. The case study showed that the iteration formula was very simple, convenient and precise for determining the normal depth of parabolic channels with the maximum relative error of normal depth being less than 0.34% when the ratio of width to depth was between 0.2 and 20. 相似文献
19.
塔里木灌区水库群实时调度研究 总被引:1,自引:0,他引:1
为缓和塔里木灌区引水与塔里木河的综合治理这一矛盾,以大系统分解协调技术与动态规划相结合的方法为基础建立了适合本灌区的自适应实时调度模型。为灌区水库实际控制应用提供了理论依据,对塔河的治理具有重要的现实意义。 相似文献
20.
石门灌区配套工程是我国延边州大型水利灌溉项目,结合石门灌区配套工程施工的实际情况,对渠道防渗施工技术、抗冻害等问题进行探讨,根据实践经验总结出我国东北地区大型灌区防渗渠道施工、抗冻害措施等建议,供大家参考。 相似文献