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71.
Using soybean hull residue after the soluble dietary fiber being removed during the soybean processing industry as crude material, a novel absorbent modified soybean hulls is prepared. Its adsorption behavior for Pb2+ is studied. The adsorbent has a large and efficient adsorpuon capacity for Pb-, uv to 20% of the mass of dry adsorbent. Its maximum adsorption capacity for Pb2+ reaches 217 mg.g-1 at initial Pb2+ concentration of 2000 mg.L-1,which is twice that of yeast absorbent and threefold greater than that of chitosan absorbent. The adsorption ability is sensitive to pH value in the solution and the optimal pH for adsorption of Pb2+is 7.0. In the presence of other metal ions (Ca2+, Mg2+and Na+) in the solution, their effect on the adsorption capacity for Pb2+is not obvious. After 5 cycles of adsorption, 80% adsorption capacity of Pb2+ is maintained. Compared with various available commercial resins, the modified soybean hulls are a plentiful, inexpensive and effective medium for the capture of dissolved Pb2+ from waste streams. 相似文献
72.
Qingfeng Wu Qiang Li Xiaodong Jin Xinguo Liu Zhongying Dai 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2011,269(2):153-158
Although radiation-induced bystander effects have been well documented in a variety of biological systems, whether irradiated cells have the ability to generate bystander signaling persistently is still unclear and the clinical relevance of bystander effects in radiotherapy remains to be elucidated. This study examines tumor cellular bystander response to autologous medium from cell culture irradiated with high-linear energy transfer (LET) heavy ions at a therapeutically relevant dose in terms of clonogenic cell survival. In vitro experiments were performed using human hepatoma HepG2 cell line exposed to 100 keV/μm carbon ions at a dose of 2 Gy. Two different periods (2 and 12 h) after irradiation, irradiated cell conditioned medium (ICCM) and replenished fresh medium were harvested and then transferred to unirradiated bystander cells. Cellular bystander responses were measured with the different medium transfer protocols. Significant higher survival fractions of unirradiated cells receiving the media from the irradiated cultures at the different times post-irradiation than those of the control were observed. Even replenishing fresh medium for unirradiated cells which had been exposed to the ICCM for 12 h could not prevent the bystander cells from the increased survival fraction. These results suggest that the irradiated cells could release unidentified signal factor(s), which induced the increase in survival fraction for the unirradiated bystander cells, into the media sustainedly and the carbon ions triggered a cascade of signaling events in the irradiated cells rather than secreting the soluble signal factor(s) just at a short period after irradiation. Based on the observations in this study, the importance of bystander effect in clinical radiotherapy was discussed and incorporating the bystander effect into the current radiobiological models, which are applicable to heavy ion radiotherapy, is needed urgently. 相似文献
73.
高强高导电铜合金的研究及进展 总被引:26,自引:0,他引:26
高强高导铜合金在现代电子技术和电工等领域具有广阔的应用前景,因而成为铜合金材料的研究热点之一,综述了获得高强高导电铜合金的方法,介绍了发展该类使铁最新技术及其研究现状。 相似文献
74.
本文讨论了在给定数字轮廓线顶点数目为N的情况下,从其上选择k个点来构造拟和多边形来近似原图,使得物体轮廓线的形状丢失最小。本文的贡献在于1)本文的轮廓线拟和是以物体轮廓线的形状的信息丢失最小为目标的。而传统的方法是以拟和多边形和原图的面积差距最小。2)本文认为每一个点具有一定的形状信息,然后建立了一个以丢失的形状信息最小的0—1规划模型:3)使用了两种方:去对轮廓线进行了多边形拟合,并把两个结果进行了比较。 相似文献
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在物联网智能家居系统中,将按功能分立的抄表网、环境网、电控网、安防网等分立子网,融合成按信息流向的感知网、控制网。本文介绍了采用NXP Cortex-M3/M0系列ARM微处理器设计开发物联网智能家居系统的技术要点。 相似文献
78.
This essay examines a politically engaged research genre, which follows the biography of the author who founded two journals: one on mathematical models published in English (Quality and Quantity) and one on politically committed social and economic research published in Italian (Inchiesta). The research considered focuses on Italy in the 1950s, the research by Lazarsfeld in Vienna in the 1920s and in the United States in the 1950s and 1960s, and post-1968 politically committed research in Italy. The analysis of such politically committed types of research (all very different from one another in terms of the interpretative model of reality, the methods used and the relations with the tendering party and the people observed) allows one to understand how this kind of research can be performed with very different methods—all of which do, however, seek to modify reality on the grounds of the research results. The metaphor of the crystal and the flame presented by Italo Calvino in order to classify facts and ideas and styles and feelings can also be used to visualise the polarity (and the difficulty/impossibility of contact) that has always been present in sociology between two different tendencies: towards a discipline that offers the most abstract and objective interpretative model of reality possible with the use of mathematical models (the crystal), and, instead, towards a discipline in which an interpretative model of reality is central, one that produces a social change and in which the qualitative and quantitative methods utilised are at the service of this change (the flame). This polarity thus allows us to separate first and foremost all the politically committed research performed by others for different purposes (market research, research to verify some theoretical hypotheses, etc.) but the same polarity also lies within the politically committed research. We can, indeed, identify a type of politically committed research in an area that has, at one extreme, research tending towards the utmost objectivity and scientific quality of the results and where the co-ordinators try to have all the information on the subjects maintaining the greatest possible distance (the subjects must not know they are being observed); at the other extreme, there is a type of research in which the coordinator completely involves the subjects in the gathering of information that will serve to realise a piece of research whose political aims are explicitly shared. For the identification of a sufficiently articulated typology it has been important to consider five dimensions of politically committed research: (a) the characteristics of the research coordinator (his/her belonging to the type and the academic/non-academic professional status) and his/her interpretative model of reality (b) some general characteristics of the research (the tender and funding, the topic choice, the aims, the contributions to the sociological theory, the duration); (c) the research coordinators relations with the political actors (the intensity of the relations, the political use of the research); (d) the relations of the research co-ordinator with the research subjects; (e) the methodological choices (the basic strategies, the methods used, the use of mathematical procedures). The research that exemplifies this typology is all politically committed to the left and was realised in different times and contexts. I start by considering a kind of politically engaged research (co-research) that appeared in Italy in the 1950s; I then analyse two types of politically engaged research realised in Austria at the end of the 1920s and one in the United States in the 1950s; there then follow two kinds of research realised in the 1960s and 1970s in the United States and a further two kinds realised in Italy in the 1970s and early 1980s. In order to have other kinds of research please refer to the two Journals of which I am the editor: one is an English language journal of mathematical models (Quality and Quantity, International Journal of Methodology, founded in 1966 and published today by Kluwer of Amsterdam), and a politically engaged review (Inchiesta, founded in 1971 and still published today by Dedalo of Bari). 相似文献
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80.
采用石墨炉原子吸收光谱法(GFAAs)测定锂离子电池正极材料LiMn2O4中杂质Pb和Cd的含量.探讨了HNO2浓度、Pb和Cd的灰化温度和原子化温度、基体改进剂对测定结果的影响.该方法的操作简单,准确度高,Pb的回收率为91.22%~93.75%,Cd的回收率为96.5%~108.6%;精密度好,两种元素测定的相对标准偏差RSD(n=lO)<5%. 相似文献