RETRACTED ARTICLE: Microenvironment characterization for a novel biocompatible hybrid carbon-silicon material

The compatible carbon-silicon complex materials originated from precursor diglycerylsilane (DGS) and sugar-modified silane N-(3-triethoxysilylpropyl)gluconamide (GLS) have gained substantial popularity by demonstrating admirable properties to stabilize entrapped biomolecules. The microenvironment inside these materials, especially the distribution of sugar moieties inside the matrix, which is likely the most critical factor determining compatibility of these materials, still remains unclear. To deeply investigate the biocompatibility mechanism of these materials, we have adopted two different preparation routes for these materials by introducing GLS into the starting DGS sol stage, but things are different after the DGS gel is formed. A fluorescence probe rhodamine 6G is introduced herein in the DGS sol to monitor the distribution of GLS moieties, as well as the evolution of the microenvironment inside resulting materials. All in all, the findings demonstrated that the timing of GLS addition plays a critical role in controlling the evolution of the inner structure of materials, suggesting that this factor provides a promising route to tune the properties of the resulting materials. Supported by the National Natural Science Foundation of China (Grant No. 20876176), Scientific Research Foundation for the Returned Overseas Chinese Scholars by the State Education Ministry, Key Project of Chinese Ministry of Education (Grant No. 109100), Doctoral Project of Shandong Province (Grant No. 2008BS09013), Research Foundation of Key Laboratory of Carbon Materials, Institute of Coal Chemistry, CAS (Grant No. KFJJ0506), and Natural Science Foundation of Shandong Province (Grant No. Q2007B02)     

Breakdown-quenching characteristics and mechanisms for silicon photomultipliers

Some deviant breakdown-quenching characteristics of silicon photomultipliers are demonstrated and their physical mechanisms are explored. “Twice breakdown” phenomenon, “flat-topped” avalanche pulses and the determination method of the real breakdown voltage of the detector are analyzed. These characteristics are explained by the integration model in terms of avalanche threshold current based on the Haitz's equivalent circuit model. The reasoning results show that the maximum over-voltage for a normal operating silicon photomultiplier equals the product of the avalanche threshold current and the quenching resistor of the avalanche photo-diode (APD) pixel, approximately. Moreover, the model and results can be extended to other small avalanche junctions with quenching resistor.     

An online method combining a Gasbench II with continuous flow isotope ratio mass spectrometry to determine the content and isotopic compositions of minor amounts of carbonate in silicate rocks

An online method using continuous flow isotope ratio mass spectrometry (CF‐IRMS) interfaced with a Gasbench II device was established to analyze carbon and oxygen isotopic compositions and to estimate the content of minor amounts of carbonate in silicate rocks. The mixtures of standard materials and high‐purity quartz are firstly used to calibrate different quantities of carbonate in silicates. The results suggest that the accuracy and precision of the online analysis are both better than those obtained using an offline method. There is a positive correlation between the carbonate weight and the Mass44 ion beam intensity (or peak area). When the weight of carbonate in the mixtures is greater than 70 µg (equal to ～1800 mV Mass44 ion beam intensity), the δ¹³C and δ¹⁸O values of samples usually have accuracy and precision of ±0.1‰ and ±0.2‰ (1σ), respectively. If the weight is less than 70 µg, some limitations (e.g., not perfectly linear) are encountered that significantly reduce the accuracy and precision. The measured δ¹⁸O values are systematically lower than the true values by ?0.3 to ?0.7‰; the lower the carbonate content, the lower the measured δ¹⁸O value. For samples with lower carbonate content, the required phosphoric acid doses are higher and more oxygen isotope exchanges with the water in the phosphoric acid. To guarantee accurate results with high precision, multiple analyses of in‐house standards and an artificial MERCK sample with δ¹³C values from ?35.58 to 1.61‰ and δ¹⁸O from 6.04 to 18.96‰ were analyzed simultaneously with the unknown sample. This enables correction of the measured raw data for the natural sample based on multiple‐point normalization. The results indicate that the method can be successfully applied to a range of natural rocks. Copyright © 2010 John Wiley & Sons, Ltd.     

Multi-scales association modeling of membrane water resistance indexes

In order to quantify and predict the water resistance of membrane, a multi-scales association model was built up based on the Fick’s second law. Two water resistance indexes, balance time and seepage velocity, were put forward and calculated by the model for measuring the property of membrane water resistance. The association model linked macro-scale factors and micro-scale parameters together. The influence of macro-scale factors, environmental temperature and membrane thickness, and micro-scale parameters, water molecules diffusivity, membrane saturated water absorption rate and water escape concentration, were discussed. The properties of water resistances for two groups including 10 waterborne acrylate membranes samples were measured for validating the indexes calculated by the model. The well consistency between the results of calculations and experiments proved that the method of multi-scales association modeling for quantifying and predicting the membrane water resistance was feasible.     

126.5 GPa准静水压下的光谱学实验

 本文介绍了作者利用国内加工的金刚石压砧装置及组建的微区光谱系统进行100 GPa（百万大气压）准静水压光谱学实验的概况，证明压力产生装置和微区光谱系统的多功能性是充分可靠的。实验中遇到的压力产生能力超过压力测量能力的事实，反映了高压光谱学实验在压力范围扩大时所遇到的挑战。文中对高压下的拉曼、发射、吸收及反射光谱的实验原理和实验方法也作了概略的介绍。     

长焦距光学系统杂光系数测试仪

报告了一种新的长焦距光学系统杂光系数测量装置,该装置除具有避免了制作大直径积分球的优点外,还能精确测量轴外杂光系数,分析各部分杂光源对杂光系数的影响.     

单位球上F(p,q,s)空间到Bloch型空间的复合算子

该文分别给出了单位球B上空间F(p, q, s)到空间β^α之复合算子C_{varphi}为有界算子和紧算子的充要条件.同时作为推论获得了Bloch型空间的相应结果.     

螺旋管锅炉反应器管内汽液两相流压力降脉动研究

本又根据闭式循环热动力推进系统中锅炉反应器的各种可能的航行方向及运行参数，对螺旋管内汽液两相流压力降脉动特性进行了系统的试验研究，首次区分了两类不同特征的压力降脉动并得到了各主要因素的影响现律和发生脉动的界限准则。     

On the GLY Conjecture of upper estimate of positive integral points in real right-angled simplices

The GLY (Granville-Lin-Yau) Conjecture is a generalization of Lin, Xu and Yau's results. An important application of GLY is its use in characterizing an affine hypersurface in Cn as a cone over a nonsingular projective variety. In addition, the Rough Upper Estimate Conjecture in GLY, recently proved by Yau and Zhang, implies the Durfee Conjecture in singularity theory. This paper develops a unified approach to prove the Sharp Upper Estimate Conjecture for general n. Using this unified approach, we prove that the Sharp Upper Estimate Conjecture is true for n=4,5,6. After giving a counter-example to show that the Sharp Upper Estimate Conjecture is not true for n=7, we propose a Modified GLY Conjecture. For each fixed n, our unified approach can be used to prove this Modified GLY Conjecture.