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排序方式: 共有168条查询结果,搜索用时 15 毫秒
1.
Jnos Szanyi Ja Hun Kwak Sarah Burton Jose A. Rodriguez Charles H.F. Peden 《Journal of Electron Spectroscopy and Related Phenomena》2006,150(2-3):164-170
Adsorbed ionic NOx species formed upon the interaction of NO2 with dehydrated or hydrated Na- and Ba-Y, FAU zeolites were characterized using FT-IR/TPD, solid state NMR, and XANES techniques. NO2 disproportionates on both dehydrated catalyst materials forming NO+ and NO3− species. These ionic species are stabilized by their interactions with the negatively charged zeolite framework and the charge compensating cations (Na+ and Ba2+), respectively. Although the nature of the adsorbed NOx species formed on the two catalysts is similar, their thermal stabilities are strongly dependent on the charge compensating cations. In the presence of water in the channels of these zeolite materials new paths open for reactions between NO+ and H2O, and NO2 and H2O, resulting in significant changes in the adsorbed ionic species observed. These combined spectroscopic investigations afforded the understanding of the interactions between water and NO2 on these zeolite catalysts. 相似文献
2.
Hideki Namba Okihiro Tokunaga Tadashi Tanaka Yoshimi Ogura Shinji Aoki Ryoji Suzuki 《Radiation Physics and Chemistry》1993,42(4-6):669-672
The fundamental research work with simulated coal-fired flue gas was performed in JAERI to get basic data for electron beam treatment of flue gas from thermal power plants in Japan. The standard condition of the experiments was set to be the same as that of next large scale pilot test in Nagoya. The concentrations of NOx and SOx were 225 ppm and 800 ppm, respectively. The temperature of the system was 65°C. The effect of multiple irradiation was observed for NOx removal. The target SOx and NOx removals (94% and 80%, respectively) with low NH3 leakage (less than 10 ppm) were achieved at 9 kGy irradiation with 0.9 NH3 stoichiometry during 7 hours continuous operation. The facility for the pilot plant (12,000 Nm3/hr) has just built at the site of Shin-Nagoya power plant of Chubu Electric Power Company and will be started in full operation in November 1992. 相似文献
3.
Stephen P. Walch 《中国化学会会志》1995,42(2):221-231
Computed potential energy surfaces are often required for computation of such observables as rate constants as a function of temperature, product branching ratios, and other detailed properties. We have found that computation of the stationary points/reaction pathways using CASSCF/derivative methods, followed by use of the internally contracted CI method with the Dunning correlation consistent basis sets to obtain accurate energetics, gives useful results for a number of chemically important systems. Applications to complex reactions leading to NOx and soot formation in hydrocarbon combustion are discussed. 相似文献
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铁铈复合氧化物催化剂SCR脱硝的改性研究 总被引:1,自引:0,他引:1
利用共沉淀法制备了铁铈催化剂,考察添加钛、锆、钨和钼对其SCR脱硝的改性规律。结果表明,钨和钼的添加提高了铁铈催化剂高温脱硝性能,却使其低温活性有所降低;钛的添加对铁铈催化剂脱硝性能具有促进作用,尤其提高了其低温活性,并拓宽了其完全转化温度窗口,为最佳改性物。当钛的物质的量比逐渐由0.10增至0.40,铁铈钛催化剂低温脱硝效率先增大后减小,但其高温脱硝效率逐渐增大至100%,钛的最佳物质的量比为0.15。XRD和N2吸附分析结果表明,钛能优化铁铈催化剂的孔隙结构,增大其比表面积和比孔容,细化其孔径,并与催化剂中铁、铈氧化物形成良好的固溶体,从而提高了铁铈催化剂的SCR脱硝性能。Fe0.8Ce0.05Ti0.15Oz催化剂在150~400℃取得了高于90%的NOx转化率。 相似文献
6.
采用溶液燃烧法和浸渍法制备了铜铁矿结构的钴酸锂(LiCoO2)及其负载K的系列催化剂样品,并通过XRD、NOx-TPD、H2-TPR、程序升温反应等对其进行了结构表征与性能评价.结果表明LiCoO2是一种能有效同时去除碳烟(PM)和NOx的催化剂;K负载可提高其催化活性,其中10%K/LiCoO2具有最低的PM起燃温度(246℃)和最大NOx→N2转化率(35.9%);催化剂表面生成的O2-/O-活性氧物种以及较强的NOx吸附存储能力可能是K/LiCoO2催化活性提高的原因. 相似文献
7.
H2-SCR is served as the promising technology for the controlling of NOx emission, and the Pd-based derivative catalyst exhibited high NOx reduction performance. Effectively regulating the electronic configuration of the active component is favorable to the rational optimization of noble Pd. In this work, a series of Pr1-xCexMn1-yPdyO3@Ni were successfully synthesized and exhibited superior NO conversion efficiency at low temperatures. 92.7 % conversion efficiency was achieved at 200 °C over Pr0.9Ce0.1Mn0.9Pd0.1O3@Ni in the presence of 4 % O2 with a GHSV of 32000 h−1. Meanwhile, the outstanding performance was obtained in the resistance to SO2 (200 ppm) and H2O (8 %). Deduced from the results of XRD, Raman, XPS, and H2-TPR, the modification of d orbit states in palladium was confirmed originating from the incorporation in the B site of Pr0.9Ce0.1Mn0.9Pd0.1O3. The existence of higher valence (Pd3+ and Pd4+) than the bivalence in Pr0.9Ce0.1Mn0.9Pd0.1O3 catalyst was evidenced by XPS analysis. Our research provides a new sight into the H2-SCR through the higher utilization of Pd. 相似文献
8.
将碳纳米管(CNTs)载体分别经混酸与硝酸蒸气预处理并在不同温度下煅烧, 然后分别采用浸渍法及机械研磨法负载磷钨酸(HPW), 制备出HPW/CNTs催化剂, 对比考察了上述催化剂对NOx的吸附与分解效果. 在空速为10000 h-1、 吸附温度为200℃的条件下, 用0.5 g催化剂对1696 mg/m3的NOx进行吸附实验, 结果表明, 以硝酸蒸气预处理且经300℃煅烧后的CNTs为载体, 采用机械研磨负载法制备的催化剂HPW/CNTs对NOx的吸附率与吸附能力最高, 分别为54%与16.6 mg NOx/(g\5h). 对吸附NOx后的催化剂体系进行了催化分解NOx的程序升温脱附-质谱(TPD-MS)研究, 结果表明, 所吸附的NOx在快速升温过程中发生分解, 在此过程中有氧产生, 分解产物包括N2, O2及N2O. 采用电阻炉快速加热与微波辐射2种方式分别对吸附的NOx进行催化分解, 结果表明, 微波功率为700 W时, NOx分解为N2的收率为33.3%, 高于电阻炉以150℃/min快速升温的N2收率. 使用过的催化剂通水蒸气后可实现再生, 对再生后的催化剂进行循环使用研究, 结果表明, 再生后的催化剂吸附与催化分解NOx的性能未有明显下降. 相似文献
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10.
ZheMingNI WeiHuaYU ShaoFenZHAO ZhongHuaGE 《中国化学快报》2004,15(8):989-992
Magnesium aluminium hydrotalcite (Mg-Al-HT) with molar ratio of Mg-to-Al of 3 to 1 was prepared and characterized by X-ray diffraction (XRD) and infrared spectra (IR). The performances of Mg-Al-HT for the adsorption and desorption of NOx were studied. The results indicated that the adsorption capacity of the hydrotalcite for NOx was 1398.2mg/g, and it was higher than the acticarbon‘s. The adsorption capacities depended on adsorption time and temperature.Mg-Al-HT could be regenerated by thermal decomposition, and the adsorption efficiency had not changed markedly after three cycles. 相似文献