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991.
非接触式的医疗健康监测系统解决了用户依从性问题,避免了佩戴电极、传感设备进行监测带来的不舒适感,更有助于将健康监测融入日常生活。非接触式监测手段具有持续地监测用户健康状况的潜力,能够在突发急性医疗事件出现时及时示警,且能够满足新生儿、烧伤患者、传染病患者等特殊人群的监测需求。调频连续波(FMCW)雷达能够同时捕获雷达视场内目标的距离、速度信息,可用于非接触式地监测用户的心率、呼吸率等生理体征及跌倒等行为动作,且从技术上易于单片集成,成本可控,因此在医疗健康监测领域有着重要的应用价值。该文首先阐述了将FMCW雷达应用于非接触式医疗健康监测技术的理论基础,然后系统性地归纳了该领域中的典型前沿应用,最后总结了基于FMCW雷达的医疗健康应用这一领域的研究现状及局限性,并对其应用前景与潜在的研究方向进行了展望。 相似文献
992.
拉曼光谱体现了物质中不同分子基团的振动情况,可以精确地进行物质的定性和定量分析.凭借着这样的优势,拉曼光谱技术已经成功应用在化工生产、管道传输、生化反应监测等工业在线分析领域.然而,在线拉曼分析很容易受到宇宙射线的干扰.宇宙射线在拉曼谱图上体现为一系列峰宽较窄的尖锐的峰,也被称为spike.这些spike使待测物质的拉... 相似文献
993.
Petropoulou SS Tsarbopoulos A Siskos PA 《Analytical and bioanalytical chemistry》2006,385(8):1444-1456
A gas chromatography–tandem mass spectrometric (GC-MS/MS) method has been developed for the determination of carbofuran (2,3-dihydro-2,2-dimethylbenzofuran-7-yl
methylcarbamate), carbaryl (1-naphthyl-N-methylcarbamate) and their main metabolites in human blood plasma. Optimization of
the isolation of the compounds from plasma matrix included the precipitation, denaturation and digestion of plasma proteins.
Derivatization was achieved by the use of trifluoroacetic acid anhydride and was optimized for temperature, time and volume
of derivatization agent. In the proposed method, a mild precipitation technique was applied using β-mercaptoethanol and ascorbic
acid in combination with solid-phase extraction technique using Oasis HLB (Hydrophobic Lipophilic Balance) cartridges for
further clean up of samples. Carbamate linkage was not hydrolyzed to its phenol product, but both carbamate phenol and ketones
were transformed into trifluoroacetyl derivatives in order to become volatile compounds and were determined using tandem mass
spectrometry. The linearity of the method was shown for nine concentrations in the range of 0.50–250 ng mL−1 in fortified plasma aliquots. Limits of detection (LODs) for all compounds ranged from 0.015–0.151 ng mL−1. Inter-day and intra-day assays (RSD) for all compounds, at three concentration levels of 2.5, 25 and 100 ng mL−1 (n=3) in fortified plasma samples were less than 18%. Accuracy (%E
r) was calculated at three concentration levels, 8, 80 and 160 ng mL−1 (n=3), and ranged from −12.0 to 15.0%. Matrix effect was evaluated so mean recoveries were calculated for all compounds and
ranged from 81–107%. Specificity for the use of this method to biological monitoring studies was achieved including four main
metabolites of CF, 1-naphthol and 2-naphthol from the naphthalene metabolism pathways, and both the parent compound of carbofuran
and carbaryl. The proposed method was applied to plasma samples of pesticide users. 相似文献
994.
KANG Meng ZOU Xue LU Yan WANG Hongmei SHEN Chengyin JIANG Haihe CHU Yannan 《高等学校化学研究》2016,32(4):565-569
Real-time and on-line monitoring volatile organic compounds(VOCs) are valuable for real-time evalua- ting air quality and monitoring the key source of pollution. A self-developed proton transfer reaction-mass spectrometer(PTR-MS) was constructed and applied to on-line monitoring trace VOCs in ambient air in Hefei, China. With the help of a self-developed catalytic converter, the background signal of the instrument was detected and the stability of the instrument was evaluated. The relative standard deviation of signal at m/z 21 was only 0.74% and the detection limit of PTR-MS was 97 part per trillion(97×10-12, volume ratio). As a case of the air monitoring in Hefei, the ambient air at Dongpu reservoir spot was on-line monitored for 13 d with our self-developed PTR-MS. Meanwhile, a solid-phase micro-extraction(SPME) technique coupled to gas chromatography-mass spectrometry/mass spectrometry (GC-MS/MS) was also used for the off-line detection of the air. The results show that our self-developed PTR-MS can be used for the on-line and long-term monitoring of VOCs in air at part per trillion level, and the change trend of VOCs concentration monitored with PTR-MS was consistent with that detected with the conventional SPME-GC-MS. This self-developed PTR-MS can fully satisfy the requirements of air quality monitoring and real-time monitoring of the key pollution sources. 相似文献
995.
The recursive network design used in this paper to monitor traffic flow ensures accurate anomaly identification. The suggested method enhances the effectiveness of cyber attacks in SDN. The suggested model achieves a remarkable attack detection performance in the case of distributed denial-of-service (DDoS) attacks by preventing network forwarding performance degradation. The suggested methodology is designed to teach users how to match traffic flows in ways that increase granularity while proactively protecting the SDN data plane from overload. The application of a learnt traffic flow matching control policy makes it possible to obtain the best traffic data for detecting abnormalities obtained during runtime, improving the performance of cyber-attack detection. The accuracy of the suggested model is superior to the MMOS, FMS, DATA, Q-DATA, and DEEP-MC by 19.23%, 16.25%, 47.61%, 16.25%, and 12.04%. 相似文献
996.
Tingting Yan Yixian Zhang Lu Liu Zhuo Shi Tao Sun Juan Yang Liang Xue Xiangxiang Shi Ning Sha 《中国化学会会志》2023,70(9):1835-1846
997.
Mayara Cristina Mombach Lorenz Leandro Silva de Almeida Ana Paula de Oliveira Lopes Inacio Flávio Manoel Rodrigues da Silva Júnior Eliézer Quadro Oreste Daiane Dias 《Electroanalysis》2023,35(7):e202200354
Nowadays, carbon-based materials applied to the development of chemically modified sensors have been highlighted once they can generate methods with high sensitivity, stability, conductivity, accuracy and low cost. Hence, these sensors have been used in environmental monitoring in aneco-friendlyy, sensitive, fast, efficient, inexpensive and robust way. In this review, firstly we described about carbon-based materials and their derivatives, followed by the chemically modified carbon-based sensors manufacturing overview and their applications in environmental analytical chemistry related to inorganic and organic compounds determinations. Future perspectives on trends of the carbon-based materials applications in the sensor modifications are also described. 相似文献
998.
A novel technique to overcome the long-term drift and hysteresis of a scanning Fabry–Perot filter was developed and applied to wavelength and power monitoring of DWDM system. By using the comb peaks generated by a temperature-stabilized, near threshold-biased Fabry–Perot diode laser as wavelength reference for the scanning Fabry–Perot filter, wavelength and power measurement accuracy of better than ±10 pm and 0.2 dB, respectively, were achieved. 相似文献
999.
Using column-switching liquid chromatography/tandem mass spectrometry (LC-MS/MS), we developed an improved analytical method of urinary estriol glucuronides. This new method is derived predominantly from maternal and fetal precursors in pregnancy. We used in the following procedure: first, we filtered urine samples with a membrane filter. Next, we directly injected the 50 microL aliquot of urine samples onto a pre-column. Then, after activating the column-switching valve, we backflushed the loaded samples onto the C(18) analytical column. Urine samples can be assayed within 20 min without any sample preparation steps. We monitored separated estriol glucuronides by negative electrospray ionization (ESI) and selected-reaction monitoring (SRM). The calibration range of estriol-3-glucuronide (E3-3G) and estriol-16-glucuronide (E3-16G) was 0.1-20 microg/mL and the linearity of the method was 0.9984 for E3-3G and 0.9987 for E3-16G. The limits of detection at a signal-to-noise (S/N) ratio of 3 were 10 ng/mL (E3-3G) and 5 ng/mL (E3-16G). The analytical recovery was over 85% and, in general, inter-day and intra-day variability for precision and accuracy were less than 10%. When applied to a pregnancy urine sample to biomedical monitoring of the function of the maternal/fetal unit, the proposed method allowed rapid and sensitive screening for the detection of E3-3G and E3-16G. 相似文献
1000.