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991.
Yanhe Li Xiaoming Li Xin Li Suiqun Yang Bingui Wang Honglei Li 《International journal of molecular sciences》2022,23(10)
Six novel verrucosidin derivatives, namely, poloncosidins A–F (1–6), together with one known analogue (7), were isolated and identified from the deep-sea-derived fungus Penicillium polonicum CS-252, which was obtained from cold-seep sediments collected in the South China Sea at a depth of 1183 m. Their structures were mainly established on the basis of a detailed interpretation of NMR spectroscopic and mass spectrometric data. The relative and absolute configurations of compounds 1–6 were determined by ECD calculations and a DP4+ probability analysis. Compounds 1–5 represent the first examples of verrucosidins with a 2,5-dihydrofuran ring which is uncommon among the known analogues. These compounds exhibited inhibitory activities against several human and aquatic pathogens with MIC values ranging from 4 to 32 μg/mL. 相似文献
992.
Yao Yu Lu Ma Xinying Wang Zhi Zhao Wei Wang Yunxin Fan Kunquan Liu Tingting Jiang Ziwei Xiong Qisheng Song Changqing Li Panting Wang Wenjing Ma Huanan Xu Xinyu Wang Zijing Zhao Jianfei Wang Hongsheng Zhang Yongmei Bao 《International journal of molecular sciences》2022,23(10)
Rice blast is one of the main diseases in rice and can occur in different rice growth stages. Due to the complicated procedure of panicle blast identification and instability of panicle blast infection influenced by the environment, most cloned rice resistance genes are associated with leaf blast. In this study, a rice panicle blast resistance gene, Pb2, was identified by genome-wide association mapping based on the panicle blast resistance phenotypes of 230 Rice Diversity Panel 1 (RDP1) accessions with 700,000 single-nucleotide polymorphism (SNP) markers. A genome-wide association study identified 18 panicle blast resistance loci (PBRL) within two years, including 9 reported loci and 2 repeated loci (PBRL2 and PBRL13, PBRL10 and PBRL18). Among them, the repeated locus (PBRL10 and PBRL18) was located in chromosome 11. By haplotype and expression analysis, one of the Nucleotide-binding domain and Leucine-rich Repeat (NLR) Pb2 genes was highly conserved in multiple resistant rice cultivars, and its expression was significantly upregulated after rice blast infection. Pb2 encodes a typical NBS-LRR protein with NB-ARC domain and LRR domain. Compared with wild type plants, the transgenic rice of Pb2 showed enhanced resistance to panicle and leaf blast with reduced lesion number. Subcellular localization of Pb2 showed that it is located on plasma membrane, and GUS tissue-staining observation found that Pb2 is highly expressed in grains, leaf tips and stem nodes. The Pb2 transgenic plants showed no difference in agronomic traits with wild type plants. It indicated that Pb2 could be useful for breeding of rice blast resistance. 相似文献
993.
Ning-Wei Lai Zhi-Chao Zheng Dan Hua Jiang Zhang Huan-Huan Chen Xin Ye Zeng-Rong Huang Jiuxin Guo Lin-Tong Yang Li-Song Chen 《International journal of molecular sciences》2022,23(10)
Low pH-induced alterations in gene expression profiles and organic acids (OA) and free amino acid (FAA) abundances were investigated in sweet orange [Citrus sinensis (L.) Osbeck cv. Xuegan] leaves. We identified 503 downregulated and 349 upregulated genes in low pH-treated leaves. Further analysis indicated that low pH impaired light reaction and carbon fixation in photosynthetic organisms, thereby lowering photosynthesis in leaves. Low pH reduced carbon and carbohydrate metabolisms, OA biosynthesis and ATP production in leaves. Low pH downregulated the biosynthesis of nitrogen compounds, proteins, and FAAs in leaves, which might be conducive to maintaining energy homeostasis during ATP deprivation. Low pH-treated leaves displayed some adaptive responses to phosphate starvation, including phosphate recycling, lipid remodeling, and phosphate transport, thus enhancing leaf acid-tolerance. Low pH upregulated the expression of some reactive oxygen species (ROS) and aldehyde detoxifying enzyme (peroxidase and superoxidase) genes and the concentrations of some antioxidants (L-tryptophan, L-proline, nicotinic acid, pantothenic acid, and pyroglutamic acid), but it impaired the pentose phosphate pathway and VE and secondary metabolite biosynthesis and downregulated the expression of some ROS and aldehyde detoxifying enzyme (ascorbate peroxidase, aldo-keto reductase, and 2-alkenal reductase) genes and the concentrations of some antioxidants (pyridoxine and γ-aminobutyric acid), thus disturbing the balance between production and detoxification of ROS and aldehydes and causing oxidative damage to leaves. 相似文献
994.
利用废弃蛋壳制备碳羟磷灰石(简称CHAP),并用作去除废水中Pb^2+的吸附剂。考查了pH值、吸附时间、温度、吸附剂用量以及Pb^2+初始浓度等因素对吸附效果的影响。结果表明:0.6g/L的CHAP对750mg/L的Pb^2+的去除率高达99.9%,吸附容量达到1243.75mg/g。CHAP对Pb^2+吸附的吸附等温线均符合Freundlich和Langmuir两种模式,从Freundlich方程中的常数1/n=0.0184可知,该吸附反应为吸热自发反应,且反应速率快。 相似文献
995.
通过爆炸应力波在高陡边坡体远场传播的三自由度动力学模型,利用Matlab仿真了其动态响应过程。单点爆源的爆炸应力波激励的仿真结果表明,边坡岩体介质位移响应下部的最大,中部的次之,上部的最小,之间呈幂律关系衰减,同时具有明显的滞后效应;频率响应与位移响应相同,随着步长增加,高频成份迅速衰减。多点爆源的爆炸应力激励仿真结果表明,边坡岩体介质位移响应上部的最大,中间的次之,下部的最小,爆炸应力波在边坡顶部呈动力放大效应;频率响应则相反,下部最大,中部的次之,上部最小。仿真结果与现场测试结果相符。 相似文献
996.
对攀钢高炉大规模使用钒钛酸性氧化球团矿工业试验与生产实践进行了总结,结果表明,用钒钛球团矿大规模代替钒钛烧结矿试验与生产是成功的.当球团矿配比最高达到32%时,高炉没有出现不适应,利用系数提高,焦比降低.综合考虑攀钢炉料结构,"高碱度低钛烧结矿+全钒钛精矿酸性球团矿"是最佳炉料结构,烧结中加入普通粉矿质量最佳,全钒钛磁铁精矿球团矿质量最好,钒钛磁铁精矿的最佳利用方式是生产球团矿,不适合于生产烧结矿. 相似文献
997.
998.
999.
1000.
针对制药与装药分建的半连续化乳化炸药生产线的一些工艺参数,如析晶点、pH值、适宜频率、压力、出口温度、发泡温度等工艺参数进行了讨论,分析了生产中易存在的问题,认为通过在生产实践中不断总结完善工艺参数的系统控制,可以使乳化炸药的质量趋于稳定。 相似文献