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991.
B Nicholson T Sawamura T Masaki CL MacLeod 《Canadian Metallurgical Quarterly》1998,273(24):14663-14666
Arginine transport is important for a number of biological processes in vertebrates, and its transport may be rate-limiting for the production of nitric oxide. The majority of L-Arg transport is mediated by System y+, although several other carriers have been kinetically defined. System y+ cationic amino acid transport is mediated by proteins encoded by a family of genes, Cat1, Cat2, and Cat3. High affinity L-arginine transport was investigated in embryonic fibroblast cells derived from Cat1 knockout mice that lack functional Cat1. Both wild type and knockout cells transport arginine with comparable Km and Vmax. However, the apparent affinity for lysine transport was 2.4 times lower in Cat1(-/-) cells when compared with wild type cells, a property characteristic of Cat3-mediated transport. Northern analysis-documented Cat2 mRNA increased 2-fold, whereas Cat3 mRNA levels increased 11-fold in Cat1(-/-) relative to Cat1(+/+) cells. The low affinity Cat2a mRNA was not detectably expressed in these cells. Even though Cat3 expression is normally limited to adult brain, there was a large increase in the amount of Cat3 protein present at the plasma membrane of Cat1(-/-) embryonic fibroblast cells. These results suggest that Cat3 compensates for the loss of functional Cat1 in cells derived from Cat1 knockout mice and mediates the majority of high affinity arginine transport. 相似文献
992.
Many early vision tasks require only 6 to 8 b of precision. For these applications, a special-purpose analog circuit is often a smaller, faster, and lower power solution than a general-purpose digital processor, but the analog chips lack the programmability of digital image processors. This paper presents a programmable mixed-signal array processor which combines the programmability of a digital processor with the small area and low power of an analog circuit. Each processor cell in the array utilizes a digitally programmable analog arithmetic unit with an accuracy of 1.3%. The analog arithmetic unit utilizes a unique circuit that combines a cyclic switched-capacitor analog-to-digital converter (ADC) and digital-to-analog converter (DAC) to perform addition, subtraction, multiplication, and division, Each processor cell, fabricated in a 0.8-μm triple-metal CMOS process, operates at a speed of 0.8 MIPS, consumes 1.8 mW of power at 5 V, and uses 700 μm by 270 μm of silicon area. An array of these processor cells performed an edge detection algorithm and a subpixel resolution algorithm 相似文献
993.
Masaki Yamada Akihiro Suzuki Akihiko Iwata Toshiyuki Kikunaga Hajimu Yoshiyasu Kazuo Yamamoto Nobuhiko Hatano 《Electrical Engineering in Japan》2006,154(3):56-64
This paper presents the efficient operation method of the interdependent use of condenser energy on the new concept of voltage transient sag compensator. This compensator consists of the series connection inverter units, and each inverter unit generates a different output voltage by 2n times. The method proposed here, in any case of various levels of transient voltage sags on the power line, provides the efficient use of condenser energy of all these inverter units. The method of interdependent use of condenser energy is also verified by the experiment. © 2005 Wiley Periodicals, Inc. Electr Eng Jpn, 154(3): 56–64, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20290 相似文献
994.
Yoshiaki Hara Masaki Yoshida Masafumi Matsumura Noriaki Ichihashi 《Electrical Engineering in Japan》2006,154(2):52-57
The aim of this study is to evaluate the muscle activity of each muscle by integrated electromyogram (iEMG) signal in daily life. We have measured the iEMG signals from the medial vastus muscle, the semitendinosus muscle, the rectus femoris muscle, and the biceps femoris muscle. The muscle activity was calculated using iEMG signals. The muscle activity was evaluated by comparing the muscle activity in daily life to the activities of muscle in level walk of 10 steps. We compared the evaluation results of the muscle activity for each muscle. From these results, it has been proved that the muscle activity is different even if these muscles belong to the same group, which exerts the same action on one joint. This result suggests that the evaluation of each muscle activity should be useful for safety and efficient training of rehabilitation. © 2005 Wiley Periodicals, Inc. Electr Eng Jpn, 154(2): 52–57, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20076 相似文献
995.
KH Masaki IJ Schatz CM Burchfiel DS Sharp D Chiu D Foley JD Curb 《Canadian Metallurgical Quarterly》1998,98(21):2290-2295
BACKGROUND: Population-based data are unavailable concerning the predictive value of orthostatic hypotension on mortality in ambulatory elderly patients, particularly minority groups. METHODS AND RESULTS: With the use of data from the Honolulu Heart Program's fourth examination (1991 to 1993), orthostatic hypotension was assessed in relation to subsequent 4-year all-cause mortality among a cohort of 3522 Japanese American men 71 to 93 years old. Blood pressure was measured in the supine position and after 3 minutes of standing, with the use of standardized methods. Orthostatic hypotension was defined as a drop in systolic blood pressure (SBP) of >/=20 mm Hg or in diastolic blood pressure of >/=10 mm Hg. Overall prevalence of orthostatic hypotension was 6.9% and increased with age. There was a total of 473 deaths in the cohort over 4 years; of those who died, 52 had orthostatic hypotension. Four-year age-adjusted mortality rates in those with and without orthostatic hypotension were 56.6 and 38.6 per 1000 person-years, respectively. With the use of Cox proportional hazards models, after adjustment for age, smoking, diabetes mellitus, body mass index, physical activity, seated systolic blood pressure, antihypertensive medications, hematocrit, alcohol intake, and prevalent stroke, coronary heart disease and cancer, orthostatic hypotension was a significant independent predictor of 4-year all-cause mortality (relative risk 1.64, 95% CI 1.19 to 2.26). There was a significant linear association between change in systolic blood pressure from supine position to standing and 4-year mortality rates (test for linear trend, P<0.001), suggesting a dose-response relation. CONCLUSIONS: Orthostatic hypotension is relatively uncommon, may be a marker for physical frailty, and is a significant independent predictor of 4-year all-cause mortality in this cohort of elderly ambulatory men. 相似文献
996.
Masaki Ozawa Tatsuya Suzuki Shinichi Koyama Yasuhiko Fujii 《Progress in Nuclear Energy》2005,47(1-4):462-471
An electrolytic extraction method has been studied to separate fission products (Ru, Rh, Pd, Tc, Se, Te, etc.) from the nuclear spent fuel. Yet they are rare metal fission products (RMFP), most are long-lived (LLFP; Pd, Tc, Se, Te). In the applied electrochemical separation process, Pd2+ cation itself would not only be easily deposited from various nitric acid solutions, but enhance also the deposition of RuNO3+ and ReO4− by acting as a catalyst (as Pdadatom). Such Catalytic Electrolytic Extraction (CEE) method was found to be applicable in the case of TcO4− deposition. The quaternary-, Pd-Ru-Rh-Re, deposit Pt electrodes showed the highest cathodic current corresponding to the hydrogen evolution reaction, ca. twice superior to that of the Pt electrode in artificial sea water as well as in alkaline solution. Adsorption / desorption behavior of 106Ru, etc. on the tertiary pyridine resin, being set as a pre-separation step to the CEE process, was newly confirmed by the reprocessing experiments with a highly irradiated fast reactor MOX fuel. The promising utilization of recovered RMFP will be a “FP-catalyst” for electrolytic hydrogen production, where they would be circulating material to bridge nuclear and hydrogen energy systems. 相似文献
997.
Y Utsunomiya K Ahmed N Rikitomi M Ruhulamin M Hanif H Masaki K Kawakami K Watanabe SK Saha T Nagatake 《Canadian Metallurgical Quarterly》1998,44(6):338-342
A high-performance liquid chromatographic system, combining solid-phase extraction and automated precolumn derivatization is described for the routine determination of methotrexate in human plasma. The sample extraction and elution onto the analytical column were performed automatically and concomitantly using the column-switching technique and a protein-coated precolumn. Cerium (IV) trihydroxyhydroperoxide (CTH) was introduced as a packed oxidant before the analytical column for the conversion of methotrexate into highly fluorescent products. The oxidative-cleavage of methotrexate occurs during the flow of 0.04 M phosphate buffer (pH 3.5) containing plasma sample through CTH column with a flow rate of 0.5 mL/min at 40 degrees C. The fluorescent products were transferred to the protein-coated precolumn, which was then flushed with the same buffer for clean-up and enrichment from plasma sample. The trapped substances were desorbed from the precolumn and eluted onto the ODS/TM analytical column by isocratical elution with a mobile phase containing 0.05 M phosphate buffer, pH 6.6 and acetonitrile (90-10, v/v) for subsequent separation. The fluorescent products were detected fluorimetrically at excitation and emission wavelengths of 367 and 463 nm, respectively. The complete analysis was achieved within 15 min per sample. The calibration graph was linear in the range of 50-500 ng/mL of methotrexate and there was no interference from endogenous components. 相似文献
998.
999.
Ikuo Tsushima Yuji Ogasawara Masaki Shimokawa Tomonori Kindaichi Satoshi Okabe 《Water science and technology》2007,55(8-9):9-17
The anaerobic ammonium oxidation (Anammox) process is a new efficient and cost effective method of ammonium removal from wastewater. Under strictly anoxic condition, ammonium is directly oxidised with nitrite as electron acceptor to dinitrogen gas. However, it is extremely difficult to cultivate Anammox bacteria due to their low growth rate. This suggests that a rapid and efficient start-up of Anammox process is the key to practical applications. To screen appropriate seeding sludge with high Anammox potential, a real-time quantitative PCR assay with newly designed primers has been developed. Thereafter, the seeding sludge with high abundance of Anammox bacteria (1.7 x 10(8) copies/mg-dry weight) was selected and inoculated into an upflow anaerobic biofilters (UABs). The UABs were operated for more than 1 year and the highest nitrogen removal rate of 24.0 kg-N m-3 day(-1) was attained. In addition, the ecophysiology of Anammox bacteria (spatial distribution and in situ activity) in biofilms was analysed by combining a full-cycle 16S rRNA approach and microelectrodes. The microelectrode measurement clearly revealed that a successive vertical zonation of the partial nitrification (NH4+ to NO2-), Anammox reaction and denitrification was developed in the biofilm in the UAB. This result agreed with the spatial distribution of corresponding bacterial populations in the biofilm. We linked the micro-scale information (i.e. single cell and/or biofilm levels) with the macro-scale information (i.e. the reactor level) to understand the details of Anammox reaction occurring in the UABs. 相似文献
1000.
Local Fracture Toughness of Si3N4 Ceramics Measured using Single‐Edge Notched Microcantilever Beam Specimens
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Junichi Tatami Masaki Katayama Masahiro Ohnishi Tsukaho Yahagi Takuma Takahashi Takahiro Horiuchi Masahiro Yokouchi Kouichi Yasuda Do Kyung Kim Toru Wakihara Katsutoshi Komeya 《Journal of the American Ceramic Society》2015,98(3):965-971
Local fracture toughness gives us useful and important information to understand and improve mechanical properties of bulk ceramics. In this study, the local fracture toughness of silicon nitride (Si3N4) ceramics was directly measured using single‐edge notched microcantilever beam specimens prepared by the focused ion beam technique. The measured fracture toughness of grain boundary of the Si3N4 ceramics is higher than the fracture toughness of SiAlON glass, which exists in the grain boundaries of Si3N4 ceramics. It is also shown that the fracture toughness of grain boundary depends on the rare earth oxide added as a sintering aid, which is expected in terms of the difference in the grain‐boundary structure. The fracture toughness of a single β‐Si3N4 grains is higher than the grain‐boundary fracture toughness. It was also higher than the value estimated from ab initio calculations and surface energy, which means that any dissipative energy should be included in the fracture toughness of a grain in spite of the brittle fracture in Si3N4. The fracture toughness of polycrystals of Si3N4 ceramics measured using single‐edge notched microcantilever beam specimens is intermediate between those of grains and grain boundaries, and it agrees with the estimated initial value of the Rcurve, KI0, in Si3N4 ceramics. 相似文献