咪唑啉酮氧苯氧羧酸酯类化合物的合成

用含二茂铁基的叠氮化物与三苯基膦反应制得膦亚胺，再与芳基异氰酸酯、取代酚发生串连aza-Wittig反应，合成了5个新的含二茂铁基的咪唑啉酮氧苯氧羧酸酯类化合物。用元素分析、IR、^1HNMR表征了它们的结构。     

Evaporative Heat Transfer of Annular Two-phase Flow of Air-water in a Small Vertical Tube

The evaporative heat transfer of the non-boiling annular two-phase flow of air-water in a small vertical tube with uniform wall heat flux was studied both theoretically and experimentally. A simplified two-phase flow boundary layer model was used to calculate the thickness of the water film attached to the wall, and from the liquid film thickness the evaporative heat transfer coefficients of the annular two-phase flow were obtained. Theoretical equations and semi-theoretical equations were proposed for predicting the evaporative heat transfer of the annular two-phase flow of air-water in a small vertical tube. The semi-theoretical prediction agrees well with the experimental data. The mechanism of the heat transfer enhancement is the evaporation of the thin liquid film attached on the wall.     

Game-based creativity assessment system: the application of fuzzy theory

“Creative development” and “creativity” have become important topics in the field of education research. The assessment of creativity is a key to understanding how instructional strategies influences the creative process and the output of learners. At present, most methods of assessing creativity are paper-and-pencil tests scored by individuals. Despite the professional training of evaluators, subjectivity in scoring assessments remains inevitable. Therefore, a completely objective tool of measurement is crucial for the progress of education to eliminate the subjectivity in manual grading. This paper presents at first place a review of the literature related to the development of creativity, the assessment of creativity, and further on the means of measuring creativity, particularly in a digital game environment. Our focus is on the application of computing technologies for the assessment of creativity, while exploring the possibility of using computerized systems such as fuzzy logic and hybrid methods to produce objective measurement results. The results of Pearson correlation coefficient between the fuzzy inference scores and the Williams CAP scores is 0.805, which shows the strong construct validity. Additionally, the fuzzy inference system can eliminate subjectivity in scoring and provide analysis results to enhance creativity, unlike paper-and-pencil scores provided without explanations.     

Sampling average approximation method for a class of stochastic Nash equilibrium problems

We consider a class of stochastic Nash equilibrium problems (SNEP). Under some mild conditions, we reformulate the SNEP as a stochastic mixed complementarity problem (SMCP). We apply the well-known sample average approximation (SAA) method to solve the SMCP. We further introduce a semismooth Newton method to solve the SAA problems. The comprehensive convergence analysis is given as well. In addition, we demonstrate the proposed approach on a stochastic Nash equilibrium model in the wholesale gas–oil markets.     

结合位置指纹和行人航迹的室内定位技术

主要对室内定位技术展开研究,首先通过手持智能设备收集指定范围样本点的坐标及wifi热点信息;然后应用位置指纹定位方法进行绝对定位;为了提高行走过程中定位的准确性和实时性,采用行人航迹推算算法,即通过手机传感器采集并经处理的数据进行步频检测、步长估算和方向检测,实现相对位置变化的估算.行人航迹算法克服位置指纹定位的不稳定性,而位置指纹定位算法及时调整行人航迹算法带来的累积误差.实验结果表明两种室内定位技术的结合有效提高了室内定位的准确性,能充分应用到实际生活中.     

A gradient-domain-based edge-preserving sharpen filter

As one of the most fundamental operations in computer graphics and computer vision, sharpness enhancement can enhance an image in respect of sharpness characteristics. Unfortunately, the prevalent methods often fail to eliminate image noise, unrealistic details, or incoherent enhancement. In this paper, we propose a new sharpness enhancement approach that can boost the sharpness characteristics of an image effectively with affinity-based edge preserving. Our approach includes three gradient-domain operations: sharpness saliency representation, affinity-based gradient transformation, and gradient-domain image reconstruction. Moreover, we also propose an evaluation method based on sharpness distribution for analyzing all sharpness enhancement approaches in respect of sharpness characteristics. By evaluating the sharpness distribution and comparing the visual appearance, we demonstrate the effectiveness of our sharpness enhancement approach.     

A review on land subsidence caused by groundwater withdrawal in Xi’an,China

Bulletin of Engineering Geology and the Environment - This paper presents a review on the land subsidence caused by groundwater withdrawal in Xi’an, China. With the increasing demands of...     

Synthesis of anatase TiO_2 with exposed {001} and {101} facets and photocatalytic activity

Anatase titanium(Ⅳ) oxide(TiO_2) particles with exposed {001} and {101} facets were prepared by hydrothermal treatment of amorphous TiO_2 with H_2O_2-NH_3 solution. Crystal phase, shape, and size of TiO_2 particles are found to be greatly dependent on the ratio of H_2O_2-NH_3 solution. The prepared TiO_2 particles with specific exposed crystal faces show higher photocatalytic activity for acetaldehyde decomposition than commercial spherical TiO_2 particles. This result implies that recombination is prevented by spatial separation of redox sites in the particles because of selective migration of electrons and positive holes to specific exposed crystal faces and/or different reactivity of electrons and positive holes on the specific exposed crystal face.     

Investigation of maximum proton energy for qualified ground based evaluation of single-event effects in SRAM devices

Existing standards show a clear discrepancy in the specification of the maximum proton energy for qualified ground-based evaluation of single-event effects,which can range from 180 to 500 MeV. This work finds that the threshold linear energy transfer of a tested device is a critical parameter for determining the maximum proton energy. The inner mechanisms are further revealed. Highenergy deposition events(10 MeV) in sensitive volumes are attributed to the interaction between protons and the tungsten vias in the metallization layers.     

食品加工新型杀菌技术研究进展

食品杀菌是食品加工过程不可或缺的环节之一。本文介绍了食品工业中新型杀菌技术和设备的研究进展,重点阐述了超高压杀菌、微波杀菌、高压脉冲电场杀菌、辐照杀菌、脉冲强光杀菌等新型杀菌技术与装备的研究发展进程,并扼要地介绍了相关技术特点。新型杀菌技术特别是冷杀菌技术可以更好地保持食品品质和风味,保证食品质量安全。