粉状白钨酸的研究——ⅩⅤ.利用粉状白钨酸的离子交换性能直接制备一价阳离子的十聚钨酸盐

以粉状白钨酸为原料,利用它的离子交换性能制得了碱金属及铵的酸式十聚钨酸盐M_3HW_(10)O_(32)·11H_20(M=NH_4、Li、Na、K)。测定了它们的差热分析、X-射线粉末衍射、IR和UV光谱,在水溶液中的稳定性以及光致变色等性质。     

Significant effect of lanthanide doping on the texture and properties of nanocrystalline mesoporous TiO2

A systematic study of microstructure and photocatalytic properties of lanthanide doping of nanocrystalline mesoporous titanium dioxide is performed. The anatase-to-rutile (A-R) phase transformation of nanosized TiO₂ was significantly inhibited by lanthanide doping and the inhibitory effect was enhanced with the increase of the rare earth radius, i.e., La³⁺>Gd³⁺>Yb³⁺ for different lanthanide dopants. At high calcination temperatures, different texture lanthanide titanium oxides of Ln₄Ti₉O₂₄ (La³⁺, Pr³⁺, Nd³⁺), Ln₂Ti₂O₇ (Eu³⁺, Gd³⁺, Tb³⁺, Dy³⁺, Er³⁺), and Yb₂TiO₅ were developed, respectively, revealing that the structures of lanthanide titanium oxide developed in Ln/TiO₂ depend on the lanthanide radius. Larger radius lanthanides prefer to form higher coordination number lanthanide titanium oxide. In addition, the thermal stability of mesoporous structures of TiO₂ was remarkable improved by lanthanide doping. The photocatalytic properties were studied by employing the photodegradation of Rhodamine B (RB) as a probe reaction. The results indicate that the lanthanide doping could bring about significant improvement to the photoreactivity of TiO₂, and the improvement was sensitive to the atomic electronic configuration.     

不同炮制条件对禹粮石Fe^2＋溶出率的影响

采用正交设计法和分光光度法对矿物中药禹粮石在何种炮制条件下其有效成分Fe^2 溶出率最高，进行了实验研究．根据实验结果，确认在A2B1C2(即690℃、10min、醅淬1次)的条件下．Fe^2 有最大程度的溶出．即选择该条件为禹粮石的合理炮制条件．     

A new titanium tetrachloride mediated annulation of alpha-aryl-substituted carbonyl compounds with alkynes: A simple and highly efficient method for the regioselective synthesis of polysubstituted naphthalene derivatives

A new straightforward procedure has been developed for the synthesis of polysubstituted naphthalene derivatives. The reaction of alpha-aryl-substituted carbonyl compounds with terminal or internal alkynes in the presence of TiCl4 regioselectively generates substituted naphthalene derivatives in good to excellent yields.     

Minimax-rate adaptive nonparametric regression with unknown correlations of errors

Science China Mathematics - Minimax-rate adaptive nonparametric regression has been intensively studied under the assumption of independent or uncorrelated errors in the literature. In many...     

Bismuth Gadolinium Oxychloride with a Remarkable Visible-Light-Responsive O2 Evolution Activity Promoted by Iodine Doping

Visible-light-responsive bismuth-based oxyhalide has recently attracted extensive attention, however, the promotion of its charge separation is still challenging. Herein, we introduce iodine into Bi₂GdO₄Cl to synthetize I-doped Bi₂GdO₄Cl (denoted as yI−Bi₂GdO₄Cl, 0≤y≤2). The incorporation of I⁻ ions is found to enhance light absorption and to accelerate charge separation by combining various characterizations such as density functional theory calculation, photoelectrochemical test, electrochemical impedance spectroscopy, photoluminescence spectrum, and open-circuit voltage decay. The O₂-evolving performances of 1I−Bi₂GdO₄Cl with optimized dopant concentration of I⁻ ion and IrO₂ loaded 1I−Bi₂GdO₄Cl are tremendously enhanced by ca. 4 and 45 times compared to pristine Bi₂GdO₄Cl. Notably, The O₂ evolution rate reaches as high as 154.8 μmol ⋅ h⁻¹ with an apparent quantum efficiency of ∼1.1 % at 420 nm. The synthetic iodine-doped photocatalyst remains stable after long-term photoreaction, demonstrating its potential in the field of photocatalysis.     

An emphatic orthogonal signal correction-support vector machine method for the classification of tissue sections of endometrial carcinoma by near infrared spectroscopy

A new application of emphatic orthogonal signal correction (EOSC) for baseline correction of near infrared spectra from reflectance measurements of tissue sections is introduced. EOSC was evaluated and compared with principal component orthogonal signal correction (PC-OSC) by using support vector machine (SVM) classifiers. In addition, some exemplary synthetic data sets were created to characterize EOSC coupled to SVM for classification. Orthogonal experimental design coupled with analysis of variance (ANOVA) was used to determine the significant parameters for optimization, which were the OSC method and number of components for the model. EOSC combined with the SVM gave better predictions with respect to a larger number of components and was not as susceptible to overfitting the data as the classifier built with PC-OSC data. These results were supported by simulations using synthetic data sets. EOSC is a softer signal correction approach that retains more signal variance which was exploited by the SVM. Classification rates of 93 ± 1% were obtained without orthogonal signal correction with the SVM. PC-OSC and EOSC data gave similar peak prediction accuracies of 94 ± 1%. The key advantages demonstrated by EOSC were its resistance to overfitting, fine-tuning capability or softness, and the retention of spectral features after signal correction.     

一阶过程的预测函数控制

预测函数控制（PFC）是一种新颖的预测控制算法。本文应用PFC算法实现对一阶过程的控制。仿真结果表明，该算法具有较强的鲁棒性和抑制干扰能力。     

纯乙类音频功率放大电路的仿真分析

采用Prorel 99 SE对一款纯B类音频功率放大电路进行仿真并作了分析,对该电路提出了自己的看法,并作了修正.