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排序方式: 共有347条查询结果,搜索用时 15 毫秒
71.
Sorption of P to the filter material Filtralite-P was examined at a small, medium and large scale. In the small- and meso-scale laboratory models, the sorbed amount of total phosphorus (P) was heterogeneously distributed with more P sorbed in the inlet zone and the bottom layers. The full-scale system had, on the other hand, the highest sorbed concentration in the outlet region. The overall P sorption capacity of the material was 8030, 4990 and 521 mg P kg(-1) Filtralite-P for Box 1, Box 2 and meso scale, respectively. This equals 4.4, 2.8 and 0.29 kg P m(-3) material, respectively. However, the maximum sorption capacities found were 2500, 3887 and 4500 mg P kg(-1) Filtralite-P for the two small-scale box systems and the meso-scale container, respectively. In the full-scale system the overall P sorption capacity of the material was 52 mg P kg(-1) Filtralite-P (0.029 kg P m(-3) Filtralite-P with a maximum sorbed amount of P of 249 mg P kg(-1). Results from both the small- and meso-scale system show that when a constructed wetland (CW) is saturated, i.e. when the outlet concentration has reached its maximum allowed concentration of 1.0 mg P l(-1), only parts of the filter material will have reached the sorption capacity. Sequential extractions of Filtralite-P showed that the loosely bound P, Ca-P and Al-P were the primary P sorption pools both in the small-scale models and in the full-scale CW. However, the proportion of these three fractions varied with time and change in pH. A white product precipitated in the outlet zone of both the small-scale box models as well as the onsite CW. The surface of these precipitation particles was identified by X-ray diffraction and SEM method as CaCO3 and precipitated Ca- and Mg-phosphates. 相似文献
72.
73.
Adhan Pilon Prof. Julia Lorenzo Sergi Rodriguez-Calado Dr. Pedro Adão Prof. Ana M. Martins Dr. Andreia Valente Dr. Luis G. Alves 《ChemMedChem》2019,14(7):770-778
New cyclam derivatives (HOCH2CH2CH2)2(PhCH2)2Cyclam and (HOCH2CH2CH2)2( PhCH2)2Cyclam, as well as their CuII and FeIII complexes, were synthesized and characterized and their stability in cellular media was assessed. The cytotoxic effect of all compounds was examined on human cervical cancer (HeLa) cells, revealing strong anticancer activity. After 24 h, only complexes with the (HOCH2CH2CH2)2( PhCH2)2Cyclam ligand are cytotoxic, whereas after incubation for 72 h all compounds show significant antiproliferative effects. Notably, compounds containing PhCH2 pendant arms on the cyclam ring revealed the most activity, with cytotoxicity values up to 12 times higher than those of cisplatin. All metal complexes seem to induce cell death through the formation of reactive oxygen species. 相似文献
74.
Hubert A. M. G. Vaessen Cor G. van de Kamp Ad. A. Jekel 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1988,186(4):308-310
Summary A 1-year stability study of ampouled polycyclic aromatic hydrocarbon (PAH) solutions was carried out. Two solutions of seven pure PAHs were prepared, one in acetonitrile and one in toluene, and ampouled. Solutions were tested for mass concentration and impurities before and after ampouling. No differences were found. After 0, 3, 6, 9 and 12 months, three ampoules were selected for analysis from the acetonitrile and the toluene lots stored at +20° and at –20 °C. The acetonitrile solution was analysed by high performance liquid chromatography and the toluene solution by glass capillary gas chromatography. The results demonstrate that both solutions were stable and no contamination. occurred during storage.
This study has been carried out on behalf of the Community Bureau of Reference (BCR) Brussels/Belgium — Commission of the European Communities Contract BCR 2093/1/5/204/85/2-BCR-NL(10) of April 12th. 1985 相似文献
Herstellung und Stabilität von polycyclischen aromatischen Kohlenwasserstofflösungen in Ampullen
Zusammenfassung Für eine einjährige Studie über die Stabilität von PAK-Lösungen in Ampullen wurde je eine Lösung von sieben reinen polycyclischen aromatischen Kohlenwasserstoffen in Acetonitril und in Toluol hergestellt und in Ampullen eingeschlossen. Die Lösungen wurden vor und nach dem Einschluß in Ampullen auf ihren Gehalt und ihre Zusammensetzung untersucht, wobei keine Abweichungen festgestellt wurden. Nach 0, 3, 6, 9 und 12 Monaten wurden jeweils drei Ampullen der bei –20 °C and +20 °C gelagerten Lösungen untersucht, und zwar die Acetonitrillösung mit Hochdruckflüssigchromatographie und die Toluollösung mit Capillar-Gaschromatographie. Die Ergebnisse zeigen, daß beide Lösungen während der ganzen Lagerungszeit stabil und kontaminationsfrei waren.
This study has been carried out on behalf of the Community Bureau of Reference (BCR) Brussels/Belgium — Commission of the European Communities Contract BCR 2093/1/5/204/85/2-BCR-NL(10) of April 12th. 1985 相似文献
75.
The photodegradation of raw natural rubber and natural rubber compound film were studied using an artificial solar energy simulator. The properties of degraded rubber sheets containing benzophenone (BP) were determined by solution viscosity, 1H‐NMR, and FTIR analyses. In the case of rubber compounds containing BP, the changes of tensile strength and crosslinking density were determined. It was found that BP could amply accelerate the photodegradation of rubber. To control the release rate of BP, it was necessary to encapsulate BP with urea–formaldehyde as a matrix. The encapsulated BP or capsule was formed by an interfacial polycondensation reaction between formaldehyde and urea. The kinetic of release rate of BP from urea–formaldehyde capsule was markedly observed within 15 days of release time; after that the rate of BP released from urea–formaldehyde microcapsule was very slow. At the same concentration of BP, the degradation rate of rubber compound by adding BP directly was faster than that of the rubber containing encapsulated BP. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 297–305, 2003 相似文献
76.
WM Mulder PL Stern MJ Stukart E de Windt RM Butzelaar S Meijer HJ Adér AM Claessen JB Vermorken CJ Meijer J Wagstaff RJ Scheper E Bloemena 《Canadian Metallurgical Quarterly》1997,3(11):1923-1930
The purpose of this study was to investigate the prognostic value of the expression of intercellular adhesion molecule 1 (ICAM-1), leukocyte function antigen 3 (LFA-3), human leukocyte differentiation antigen (HLA)-ABC, HLA-DR, and 5T4 with regard to disease-free survival in Dukes' B and C colorectal carcinoma patients. Forty-one patients (28 Dukes' B and 13 Dukes' C) were entered into this study. Immunocytochemistry was performed on cytospin preparations of enzymatically digested colorectal carcinoma cell suspensions. The frequency of metastases and the duration of disease-free survival were compared between the 25% lowest expressers and the 75% remaining patients for ICAM-1, LFA-3, HLA-ABC, and HLA-DR, and between the 25% highest expressers and the 75% remaining patients for 5T4. Low numbers of ICAM-1-expressing tumor cells were associated with a shorter disease-free survival (P < 0. 001), independent of Dukes' stage. High numbers of 5T4-expressing tumor cells were associated with shorter disease-free survival in Dukes' B patients (P = 0.04). Cox proportional hazard analysis indicated that low numbers of ICAM-1(+) and high numbers of 5T4(+) cells were independent prognostic factors with relative risks of 13. 0 (P = 0.0002) and 4.7 (P = 0.02), respectively. The combination of 5T4 and ICAM-1 marker information identified subgroups of patients with a good (high ICAM-1) or poor (low ICAM-1/high 5T4) prognosis. Neither a lack of HLA-ABC and LFA-3 expression nor the presence of HLA-DR on the tumor cells gave additional prognostic information. These findings demonstrate that low ICAM-1 and high 5T4 expression on tumor cells are prognostic markers, additional to Dukes' stage, for reduced disease-free survival in Dukes' B and C colorectal carcinoma patients. 相似文献
77.
Interfacial areas and gas hold-ups were determined at pressures of up to 1.7 MPa in a glass vessel, 88 mm in diameter and of standard geometry. Superficial gas velocities between 0.25 and 2.0 cm/s were used and the stirring speed varied between 4 and 30 rps. The interfacial areas were determined by the chemical method, using the model reaction between CO2 and aqueous diethanolamine (DEA). Hold-ups were determined by observation of differences in height. In contrast to literature indications, the gas hold-up was found to be independent of reactor pressure. This is also true for the interfacial area. 相似文献
78.
The use of cardiopulmonary bypass (CPB) in children is associated with significant morbidity due to the accumulation of an excessive amount of water. This can be decreased by massive diuresis, peritoneal dialysis, or conventional ultrafiltration technique (CUF) during bypass. However, we were dissatisfied with their effect on the outcome of our young patients, and recently began to use the modified technique of ultrafiltration (MUF) with good results. MUF was carried out for 15 min after completion of CPB to a hematocrit of 40%. Eighty patients were equally divided into two groups--MUF (group A) and control (group B)--and prospectively studied. There was one death in group A and two deaths in group B. The chest was left open in one patient in group A and in three patients in group B. At the end of MUF, the cardiac size was smaller, performance was better, and systemic blood pressure was higher in group A. Hematocrit levels in the two groups were similar during preoperative and CPB time, but post-CPB hematocrit in group A was significantly higher, 39.4% mean (range 35-50) vs. 28.5 (range 22-38) in group B (P <0.05). Blood loss was 10.56 ml/kg per 24 h (2-48.7) in group A vs. 20.8 (4.5-105.6) in group B (P <0.05). Blood transfused was 7.2 ml/kg per 24 h (0-29) in group A vs. 17.3 (3.1-49) in group B (P <0.05). Colloids transfused were 16.7 ml/kg per 24 h (0-64) in group A vs. 27.5 (0-58.6) in group B (P <0.05). No significant difference was found in urine output or the use of diuretics between the two groups. MUF results in better hemodynamic status in children, with the added advantage of less transfused blood and blood products. We believe that the use of accepted surgical techniques in combination with MUF will further improve the outcome of complex cardiac malformations. 相似文献
79.
80.
Serhan Uruş Hamza Adıgüzel Mustafa Keleş İbrahim Karteri 《Fullerenes, Nanotubes and Carbon Nanostructures》2017,25(2):133-141
The novel multi-walled carbon nanotube (MWCNT) supported bis(diphenylphosphinomethyl)amine [MWCNT@CHO-NHArN(CH2PPh2)2 type] ligands and their Ru(II) complexes have been synthesized and characterized with Fourier Transform Infrared Spectrometry (FT-IR), Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray (EDX), Transmission Electron Microscopy (TEM), Ultraviolet-Visible Spectrometry, X-Ray Diffraction Spectrometry (XRD), and Thermal analysis (TG/DTA) techniques. In addition, MWCNT@CHO-NHArN(CH2PPh2)2Ru(p-cymene)Cl2 type complexes were tried as catalysts in the catalytic transfer hydrogenation reactions of acetophenone derivatives. The crystallite size and lattice strain of the MWCNT-based compounds were calculated by the Scherrer's equation. The optical parameters of the MWCNT-based structures were analyzed and the band gap enhanced from 4.42 eV to 4.98 eV. It was confirmed that the reduction of bromo and chloro acetophenone derivatives using all the catalysts, the conversions were high. The results showed that MWCNT-supported Ru(II) complexes were efficient catalysts in the reduction of bromo and chloro acetophenone derivatives with 99% efficiency in K2CO3 media at 80 °C. 相似文献