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61.
甲基叔丁基醚与苯酚在改性HY分子筛催化剂上合成2,4-二叔丁基苯酚的研究 总被引:1,自引:0,他引:1
对改性HY分子筛催化剂研究表明,每种改性物均存在一个最佳含量.P2O5改性后HY催化剂的性能最优越。苯酚的转化率达99.60%,2,4-二叔丁基苯酚(2,4-DTBP)选择性达63.90%:这一结果是目前分子筛作催化剂合成(2,4-IDTBP)的最好结果,具有潜在的应用前景,采用常压连续流动固定床反应器,克服了釜式反应操作麻烦的缺点:使用HY分子筛催化剂,无污染、无腐蚀,为工业生产提供了艮好的环境、以MTBE做为烷基化试剂,使工业生产叔丁基苯酚可以因地制宜地扩大原料来源:MTBE价格低廉易得,运输方便,进而可以降低产品成本 相似文献
62.
MMA-ST乳液共聚合成核阶段的数学模型 总被引:2,自引:1,他引:2
研究了MMA-ST乳液共聚合动力学规律,提出了成核阶段数学模型,进行了计算机模拟,并对模型预计结果与实验数据进行了比较和讨论 相似文献
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64.
Crespo JF Retzek M Foetisch K Sierra-Maestro E Cid-Sanchez AB Pascual CY Conti A Feliu A Rodriguez J Vieths S Scheurer S 《Molecular nutrition & food research》2006,50(3):282-290
Oranges are clinically relevant allergenic foods. To date, orange allergens have not been characterized in detail. The study is aimed at analyzing the sensitization profile in orange-sensitized subjects with and without clinical allergy, and to identify orange allergens. Fifty-six sensitized subjects with self-reported reactions to orange were grouped into reactors (anaphylaxis or multiple episodes of immediate reactions and/or positive challenge tests) and non-reactors (negative open food challenge tests). Allergens were characterized by IgE immunoblotting, N-terminal sequencing, IgE-inhibition assays, and mediator release assays were performed to determine the allergenic potency of orange profilin. Of 56 subjects, 23 were classified as orange allergic showing mainly an oral allergy syndrome. Of 23 subjects classified as orange allergic, 22 were sensitized to profilin, Cit s 2. In patients with mono-sensitization to profilin in vitro histamine releases up to 75% from basophils were induced using orange extract and purified plant profilins. Of the allergic patients 78% were sensitized to germin-like protein, Cit s 1. Both allergens showed retained IgE reactivity in heat-processed orange juice. Interestingly, subjects with and without clinical allergy showed a comparable sensitization profile. Profilin and germin-like proteins are major orange allergens. The potential clinical relevance of orange profilin was indicated by its strong capacity to release histamine from basophils. However, a predominant sensitization to both allergens in subjects without symptoms also indicates a high frequency of clinically insignificant sensitization. 相似文献
65.
An LC-ESI-MS/MS method was developed for the quantitative detection of postharvest fungicide residues in citrus juices and reported in this paper. The analyses of thiabendazole (TBZ), carbendazim (MBC), thiophanate methyl (TPM), imazalil (IMZ) and prochloraz (PCZ) residues were performed by using a gradient elution in conjunction with positive ionization mode electrospray ionization tandem mass spectrometry. Fungicides were extracted from citrus juices with recoveries ranging from 79.8 to 101.2% and relative standard deviation better than 15%. The quantification limits ranged from 0.01 μg/kg IMZ to 0.06 μg/kg for MBC. The LC-MS-MS method was applied to commercial citrus juices, detecting MBC, TBZ and IMZ residues in the 90% of the samples. Prochloraz residues were detected only in one of the multifruit juice (orange, lemon and carrot) samples. 相似文献
66.
对甲乙酮原料及生产效益做了预测,着重讨论了建设甲乙酮装置应采用硫酸法的工艺路线,并对市场做了初步预测,对设备腐蚀问题也做了较为深刻的讨论。结果认为建设甲乙酮装置是有利可图的 相似文献
67.
Shou-Yi Li Zhen-Lai Liu Gen-Xiang Xiang Bao-Hong Ma Xiao-Ding Meng Yong-Lin He 《Ceramics International》2019,45(1):767-776
Herein, a novel hierarchical TiO2 pinecone-like structure (TPS) has been successfully fabricated for the first time by self-assembling anodic oxidation methods on the Ti plate. Then it was constructed that a series of CdS-TPS nanocomposites with different cycles CdS modifying by a successive ionic layer adsorption and reaction (SILAR) after different temperature annealing in air. The structures and properties of the CdS-TPS were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Current-voltage (I-V), ultraviolet-visible (UV–vis/DRS). The results shown that the optical properties of the CdS-TPS could be rationally tailored by adjusting the CdS-modified cycles and annealing temperature, which significantly enhanced photocatalytic activity. To be used in photocatalytic organic pollutant removal after optimizing both the CdS modification cycles and annealing temperature. The 15-CdS-TPS-500?°C exhibited significantly improved photocatalytic activities of methyl orange (MO) degradation under simulated sunlight irradiation. With 180?min, 85% of the MO (0.05?mM/L, 5?mL) was photodegraded and its kinetic constant reached to 0.0104?min?1, which is the 3.0 times and 3.6 times quicker than that of 5-CdS-TPS-500?°C and 15-CdS-TPS-0?°C, respectively. This could be ascribed to the result of the synergy effects of the suitable quantity of CdS nanoparticles modifier, the special surface structure, excellent crystallinity, higher electrical conductivity, and band structure matching. The possible photocatalytic mechanism of the CdS-TPS sample is investigated as well. 相似文献
68.
Cu/Al2O3 催化臭氧氧化降解水中甲草胺的研究 总被引:1,自引:0,他引:1
研究了在Cu/Al2O3存在下臭氧氧化降解水中一种具有内分泌干扰作用的有机污染物--甲草胺的效能及主要影响因素.研究证明,Cu/Al2O3具有明显的催化臭氧氧化效能.对催化臭氧氧化降解前后水的TOC、电导及内分泌干扰活性等指标进行的测定结果表明,在Cu/Al2O3催化剂的作用下,反应溶液的TOC比O3单独氧化处理的TOC有更大程度的降低,即对甲草胺的矿化程度大大提高;矿化程度的提高使溶液的电导有所提高进而促进对甲草胺的处理.催化臭氧氧化处理后水的内分泌干扰活性比非催化过程的有明显降低,说明Cu/Al2O3催化剂可有效去除甲草胺的中间氧化产物,能彻底去除水中甲草胺这种内分泌干扰物质. 相似文献
69.
70.
采用浸渍法及共沉淀法分别制备丙酮一步法合成甲基异丁基酮催化剂Cu-MgO-Al2O3,通过考察催化剂的催化性能,研究不同方法制备催化剂对其活性的影响。结果表明,催化剂中碱性组分与金属组分含量匹配合适才能得到最佳的反应结果,共沉淀法催化剂比浸渍法催化剂具有更大的比表面积和孔体积,进料速率高,活性好。 相似文献