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81.
82.
Hannah Baars Julien Engel Lucas Mertens Daniela Meister Carsten Bolm 《Advanced Synthesis \u0026amp; Catalysis》2016,358(14):2293-2299
Carbamoyl fluorides are formed in reactions of hydroxylamines with difluorocarbene generated from sodium bromodifluoroacetate as readily available and non‐toxic carbene precursor. The process shows a high functional group tolerance, and the reaction path has been rationalized by computational calculations.
83.
德国KSP建筑设计事务所 《城市建筑》2010,(8):75-78
<正>经过慕尼黑火车总站走到阿努尔夫(Arnulf)大街上,可以看到美国ATMOS能源公司德国总部新办公楼。该办公楼的建设为慕尼黑市ArnulfPark区东部创造了一处开敞的空间环境,同时标志着这一地区新区建设的开始。ATMOS能源公司德国总部坐落在阿努尔夫大街与格拉瑟(Grasser)大街(也称作Hacker大桥)的交汇处,新办公楼就建于总部内,是园区内的第一栋建筑,该办公楼建成后成为公司新总部的标志。 相似文献
84.
David Ghezel-Ahmadi Alice Engel Lygia Therese Budnik Ulrich Frick Simone Hauser 《The Science of the total environment》2010,408(4):774-778
Background
Risks from electromagnetic devices are of considerable concern. Electrohypersensitive (EHS) persons attribute a variety of rather unspecific symptoms to the exposure to electromagnetic fields. The pathophysiology of EHS is unknown and therapy remains a challenge.Objectives
Heavy metal load has been discussed as a potential factor in the symptomatology of EHS patients. The main objective of the study was to test the hypothesis of a link between EHS and heavy metal exposure.Methods
We measured lead, mercury and cadmium concentrations in the blood of 132 patients (n = 42 males and n = 90 females) and 101 controls (n = 34 males and n = 67 females).Results
Our results show that heavy metal load is of no concern in most cases of EHS but might play a role in exceptional cases.Conclusions
The data do not support the general advice to heavy metal detoxification in EHS. 相似文献85.
Berge P Ratel J Fournier A Jondreville C Feidt C Roudaut B Le Bizec B Engel E 《Environmental science & technology》2011,45(15):6584-6591
The study investigated the feasibility of using volatile compound signatures of liver tissues in poultry to detect previous dietary exposure to different types of xenobiotic. Six groups of broiler chickens were fed a similar diet either noncontaminated or contaminated with polychlorinated dibenzo-p-dioxins/-furans (PCDD/Fs; 3.14 pg WHO-TEQ/g feed, 12% moisture), polychlorinated biphenyls (PCBs; 0.08 pg WHO-TEQ/g feed, 12% moisture), polybrominated diphenyl ethers (PBDEs; 1.63 ng/g feed, 12% moisture), polycyclic aromatic hydrocarbons (PAHs; 0.72 μg/g fresh matter), or coccidiostats (0.5 mg/g feed, fresh matter). Each chicken liver was analyzed by solid-phase microextraction - mass spectrometry (SPME-MS) for volatile compound metabolic signature and by gas chromatography - high resolution mass spectrometry (GC-HRMS), gas chromatography - tandem mass spectrometry (GC-MS/MS), and liquid chromatography - tandem mass spectrometry (LC-MS/MS) to quantify xenobiotic residues. Volatile compound signature evidenced a liver metabolic response to PAH although these rapidly metabolized xenobiotics are undetectable in this organ by the reference methods. Similarly, the volatile compound metabolic signature enabled to differentiate the noncontaminated chickens from those contaminated with PBDEs or coccidiostats. In contrast, no clear signature was pointed out for slowly metabolized compounds such as PCDD/Fs and PCBs although their residues were found in liver at 50.93 (±6.71) and 0.67 (±0.1) pg WHO-TEQ/g fat, respectively. 相似文献
86.
In many cases, hazardous wastes are subject to thermal treatment at elevated temperatures. Some types of wastes do not have a sufficient calorific value to cover the heat demand of the high temperature process. For thermal treatment of e.g. filter residues, dusts, sulfuric acid, aluminium dross, foundry sand, or waste water, supplementary energy supply is needed. The specific energy demand ranges from 0.5 to 2.5 kWh/kg (2–10 MJ/kg). An important aim of process optimisation is the reduction of (fossil) energy consumption and exhaust gas flow. Concentrated solar energy promises advantages when applied to high energy consuming waste treatment processes with regard to substitute fossil or electric energy consumption, to reduce CO2 emissions, and exhaust gas flow. In parallel to conceptional studies, a solar-heated rotary kiln mini-plant has been designed and constructed for tests in the DLR solar furnace. The tests will give indications of boundary conditions for solar thermal treatment or conversion of selected hazardous materials. 相似文献
87.
88.
Composite materials with vibrations damping qualities can be made of two steel sheets enclosing a viscoelastic plasticcorelayer. These sandwich sheets often need to be formed. Material parameters are determined to describe the forming process. Based on these parameters, pilot studies are carried out in order to develop recommendations for forming this class of material. 相似文献
89.
Stream Temperature Dynamics in Upland Agricultural Watersheds 总被引:1,自引:0,他引:1
A numerical model to compute the free-surface flow hydrodynamics and stream temperature dynamics by solving the depth-averaged, 1D unsteady flow and heat transport equations is presented. The hydrodynamics model considers the effects of arbitrary stream geometry, variable slopes, variable flow regimes, and unsteady boundary conditions. The thermal transport model accounts for the effects of solar radiation, air temperature, relative humidity, cloud cover, wind speed, heat conduction between water and streambed, subsurface flow, and shading by riparian vegetation. The model is verified with measurements in a stream in an upland agricultural watershed located in Indiana. Diurnal variations in the streamflow and stream temperatures are highly transient. The proposed model predicted well the streamflow and stream temperatures that were measured every 15 min over 25 days. The results of this study demonstrate that the solar (shortwave) radiation and subsurface inflow are the most significant contributors to the stream heat budget. 相似文献
90.
A standard problem in intensity modulated radiation therapy is the representation of a given intensity matrix, i.e. a matrix
of nonnegative integers, as a nonnegative linear combination of special 0-1-matrices, called segments. These segments can
be practically realized by multileaf collimators. One important aim is the minimization of the sum of the coefficients of
the linear combination, i.e. the delivery time. In this article, we study the question how much the delivery time can be reduced
if some small deviation from the given intensity matrix is allowed. We characterize the optimal solutions for one-row matrices
and show that the approximation can be carried out in an iterative way. The structural characterization yields a fast algorithm
that minimizes the delivery time and then also the deviation. Moreover, algorithms for the general case together with numerical
results are presented. 相似文献