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101.
介绍了金融业对辽阳经济发展的支持情况,剖析了存在的问题,提出了对策和建议。 相似文献
102.
《Journal of power sources》2006,153(2):265-273
Electrolytic manganese dioxide (EMD) is made in aqueous sulfuric acid and neutralized or ion exchanged with aqueous lithium hydroxide before use in Li batteries. Solid state Li NMR studies show that Li is present on surface and vacancy sites and migrates into Mn (III) related sites after heat treatment to remove water. During heat treatment the MnO2 rearranges from ramsdellite/pyrolusite intergrowth EMD to a defect pyrolusite heat-treated manganese dioxide (HEMD). EMD exhaustively treated with lithium hydroxide solution has 40–50% of the protons in EMD exchanged for Li ions to produce a structurally unchanged γ-MnO2. Li magic angle spinning (MAS) NMR reveals that this lithiated material contains lithium in cation vacancy and Mn (III) related sites in the MnO2 lattice in addition to ionic Li on the surface. During heat treatment, the vacancy lithium content prevents the ramsdellite to pyrolusite rearrangement in HEMD formation. Instead, an ordered ramsdellite/pyrolusite intergrowth of lithiated manganese dioxide (LiMD) is formed with an approximate composition of 50% ramsdellite and 50% pyrolusite. Li MAS NMR of LiMD shows Li resonances near 280 and 560 ppm, consistent with Li transition from surface and cation vacancy sites into the ramsdellite lattice.LiMD discharged against lithium shows two processes, one near 3.1 V, the other about 2.8 V. Li MAS NMR studies show the initial reduction results a lithium resonance near 560 ppm associated with Li near a mixed valence Mn (III/IV) environment followed by appearance of a resonance near 100 ppm consistent with a Li environment near Mn (III). TEM studies of the reduced material show initial expansion of the ramsdellite lattice accompanied by a loss in crystallinity in the 3.1 V discharge process followed by disappearance of the pyrolusite content via conversion to ramsdellite in the second discharge process. 相似文献
103.
《Materials Letters》2007,61(19-20):4128-4130
BaMgAl10O17:Eu2+ doped with 0–6% additional Mg2+ were synthesized by co-precipitation method. Their photoluminescence and thermal stability were investigated under ultraviolet (UV) and vacuum ultraviolet (VUV) excitation. The additional Mg2+-doped samples exhibited stronger emission intensity and better thermal stability than the sample without additional Mg2+ under 254 or 147 nm excitation. After thermal degradation, the 4% additional Mg2+-doped sample had the highest emission intensity which was 12.7% and 16.6% stronger than that of the sample without additional Mg2+ under 254 and 147 nm excitation, respectively. Moreover, the improvement mechanisms on emission intensity and thermal stability were discussed. 相似文献
104.
Rapid determination of soil organic matter content based on soil colour obtained by a digital camera
Caiwu Wu Jianxin Xia Yue Yang Yuecong Zhang Fuwei Cheng 《International journal of remote sensing》2013,34(20):6557-6571
ABSTRACTSoil organic matter (SOM) is an important component of soil and a significant criterion in determining the dynamics of soil quality. A rapid, low-cost method to measure SOM content is needed to support the development of precision agriculture. This article studied the quantitative relationship between SOM and soil colour using a digital camera, which is relatively inexpensive and easy to operate, as a portable tool for obtaining colour information of the soil surface. The results show that mixed samples with different soil particle sizes reduce the noise of the image and are more suitable than uniform soil samples for predicting the SOM. Among the three bands of red, green, and blue (RGB), the red band had the best correlation with SOM, and its reciprocal correlation coefficient (r) reached 0.75. The reciprocal regression model of the RGB colour model provided good prediction results for mixed soil samples, with a coefficient of determination (R2) of 0.76 and a root mean square error (RMSE) of 0.55, and the validation result had an excellent predictive ability (R2val = 0.85 and RMSEval = 0.53). The single-variation predictive model of CIELa*b* colour space model through transformation of the RGB colour space model performed well. The model built by colour intensity values had a strong stability and forecasting capacity. Thus, a digital camera can be used as an alternative tool to rapidly measure SOM. 相似文献
105.
106.
利用雷诺方程和RNG k-ε紊流模型,对排放源在圆柱形水工建筑上游和下游两种工况下的尾流浓度场进行数值模拟,从污染物时均浓度、浓度脉动强度和浓度半宽度3个方面比较了污染源位置对圆柱形水工建筑下游污染物浓度分布特性的影响。结果表明:随流程的增大,两种工况下污染物时均浓度横向断面分布先后经历双峰结构、过渡阶段和高斯分布3个阶段;排放源在上游时,浓度脉动强度先增大后减小;排放源在下游时,浓度脉动强度一直减小;两种工况的浓度半宽度变化规律一致,当1≤x/D15时浓度半宽度呈非线性增长,当15≤x/D≤30时呈线性增长。 相似文献
107.
Multi-pattern matching with variable-length wildcards is an interesting and important problem in bioinformatics, information retrieval and other domains. Most of the previously developed multi-pattern matching methods, such as famous Aho–Corasick and Wu–Manber algorithms, aimed to solve some classical string matching problems. However, these algorithms are not efficient for patterns with flexible wildcards or do-not-care characters. In this paper, we propose two efficient algorithms for multi-pattern matching with variable-length wildcards based on suffix tree, called MMST-L and MMST-S, according to the length of exact characters in a pattern. Experimental results show that the two MMST algorithms, in most cases, outperform other various versions of comparing algorithms. 相似文献
108.
Low-cost photocatalysts of CdS combined with nickel oxides were prepared by a simple in situ photodeposition method. The activity of photocatalytic hydrogen evolution under visible-light (λ > 400 nm) on CdS was enhanced significantly by loading nickel oxides, and reached to the maximum rate of 445.6 μmol h− 1, being about 41 times and 1.9 times of the H2 evolution on pure CdS and CdS loaded with 1.5 wt.% Pt, respectively. The characterizations of X-ray photoelectron spectroscopy and transmission electron microscopy with energy dispersive spectrometer indicated that the nickel oxides were loaded on CdS particles in the formation of Ni2O3 species, which acted as electron traps and facilitated the charge separation. 相似文献
109.
《Inorganic chemistry communications》2007,10(7):767-771
Two novel metal coordination polymers, [Zn(nic)(isonic)]n (1) and [Cu(nic)(isonic)]n (2) (H2nic = nicotinic acid, H2isonic = isonicotinic acid), have been hydrothermally synthesized and characterized by elemental analysis, IR, and single crystal X-ray diffraction. X-ray single-crystal structural analyses reveal that 1 and 2 are isomorphous, two-dimensional interpenetrating (4, 4) frameworks bridged by nic and isonic ligands, and further assembled into a three-dimensional supramolecular structure via π–π stacking interaction. Moreover, 1 displayed photoluminescent properties in the blue range at room temperature. 相似文献
110.
《Catalysis communications》2007,8(8):1214-1218
A green route for the synthesis of multi-substituted quinolines using catalytic amounts of Lewis acids via Friedlander annulation is described. Zr(NO3)4 and Zr(HSO4)4 were found to be more efficient than other investigated Lewis acids in the catalyzed condensation of o-aminoaryl ketones or o-amino benzonitrile with ketones or β-diketones in water under reflux conditions. 相似文献