Effect of Counterions on Synthesis of Mesoporous Silica by the Route of Template

Mesoporous silica materials with ordered hexagonal and parallel-arranged pore channel have been synthesized using cetyl trimethylammonium bromide as a template and Na₂SO₄ as counterions. Their ordered mesostructures were characterized by infrared spectroscopy, X-ray diffraction patterns, scanning electron microscopy, transmission electron microscopy, and nitrogen sorption analysis. The effects of Na₂SO₄ concentration on variations of morphology, specific surface area, and pore size were discussed; the results show that a high concentration of Na₂SO₄ induces the formation of crystal threads with a "tubules-within-tubule" structure, and also leads to mesoporous silica materials with spherical, fabaceous, sheet-like, or prismatic shapes. The results also show that a high concentration of Na₂SO₄ can make the pore size decrease, but cannot change pore wall thickness, demonstrating the stability of the hexagonal-shaped pores.     

基于生成对抗网络的文本生成图像算法

文本生成图像算法对生成图像的质量和文本匹配度有很高的要求. 为了提高生成图像的清晰度, 在现有算法的基础上改进生成对抗网络模型. 加入动态记忆网络、细节校正模块(DCM)、文本图像仿射组合模块(ACM)来提高生成图片的质量. 其中动态记忆网络可以细化模糊图像并选择重要的文本信息存储, 以提高下一阶段生成图像的质量. DCM纠正细节, 完成合成图像中缺失部分. ACM编码原始图像特征, 重建与文本描述无关的部分. 改进后的模型实现了两个目标, 一是根据给定文本生成高质量的图片, 同时保留与文本无关的内容. 二是使生成图像不再较大程度依赖于初始图像的生成质量. 通过在CUB-200-2011鸟类数据集进行研究实验, 结果表明相较之前的算法模型, FID (Frechet inception)有了显著的改善, 结果由16.09变为10.40. 证明了算法的可行性和先进性.     

Effects of MWCNTs on improving the hydrogen storage performance of the Li3N system

In this paper, the influence of multi-walled carbon nanotube (MWCNT)-doping on the hydrogen storage properties of the Li₃N system was systematically investigated. Compared with the pure Li₃N sample, the MWCNT-doped Li₃N sample shows faster hydrogen absorption and desorption kinetics and a drastically improved cycling stability. Along with increasing MWCNT content, the hydrogen storage improvement becomes more apparent. When the MWCNT doping level reaches 10 mol%, the enhancement effect is significant. The improved hydrogen storage properties of the Li₃N system by MWCNT-doping can be reduced to the physical effect of ball milling, the increased specific surface area and large pores as well as the good thermal conductivity of MWCNTs.     

Toward an explanation of cultural differences in in-group favoritism: The role of individual versus collective primacy.

Previous research conducted on a Western sample has shown that people are less apt to exhibit in-group favoritism when they perform well individually while their in-group performs poorly. The authors evaluated whether this finding would be moderated by the cultural dimension of individual–collective primacy, which refers to whether people give more weight to their personal interests rather than their in-group's interests when forced to choose between the two. The authors hypothesized that relative to their counterparts from the United States, participants from the People's Republic of China would have more of a collective-primacy orientation and therefore would exhibit more in-group favoritism when they performed well individually while their in-group performed poorly. The results supported the hypothesis. Implications for the literatures on in-group favoritism and cross-cultural differences are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Electrodeposition of B,Ni co-doped diamond-like carbon films on AZ91D magnesium alloy: Corrosion and wear resistance

Diamond-like carbon (DLC) possesses brilliant and excellent properties, including excellent corrosion resistance as well as outstanding wear resistance. Ni and B co-doped DLC films were deposited on AZ91D magnesium alloy by electrodeposition under mild conditions (300 V and 25°C). Uniform and dense morphology of co-doped DLC films were observed, and Ni and B were uniformly incorporated into the carbon-based films. Among all the electrodeposits, the appearance of D and G peaks near 1330 and 1570 cm⁻¹ revealed that the as-deposited films were typical DLC films. As the addition of Ni was increased to 0.05 g, the highest microindentation hardness, the lowest friction coefficient, and wear loss were achieved to be 164.5 HV, 0.3, and 0.6 × 10⁻⁵ kg/m, respectively. The amorphous carbon films fabricated at 0.05 g Ni had the lowest corrosion current density and the most positive corrosion potential, which was mainly due to the small and dense granular structure effectively hindering the penetration of corrosion media.     

Efficient delivery of clay-based nanovaccines to the mouse spleen promotes potent anti-tumor immunity for both prevention and treatment of lymphoma

Cancer therapeutic nanovaccines are ideal tools to inhibit tumor growth and provide the body with continuous protecting immune surveillance.However,the conventional subcutaneous(SC)vaccination normally induces limited anti-tumor immune responses with low therapeutic efficacy.Herein,we devised clay-based nanovaccines and directly delivered them to the spleen via intravenous(IV)injection to induce the stronger anti-tumor immunity with higher efficacy for tumor prevention and treatment.The clay,i.e.,layered double hydroxide(LDH)was prepared as nanoadjuvant with the average size from 77 to 285 nm and co-loaded with the model antigen ovalbumin(OVA)and bioadjuvant CpG to form CpG/OVA-LDH(CO-LDH)nanovaccines.We found that CO-LDH-215(the size of LDH was 215 nm)promoted dendritic cells to present the most antigen,and moreover showed the highest spleen enrichment(~1.67%of CO-LDH-215 enriched in the spleen at 24 h post IV injection).The in vivo immunologic data showed that CO-LDH-215 induced the most potent anti-tumor immune responses and completely prevented the growth of E.G7-OVA tumor in the mouse model.Furthermore,IV injected CO-LDH-215 nanovaccine more effectively delayed tumor growth than that SC injected,largely due to the direct and quick delivery of more nanovaccines to the spleen.This study demonstrates that the therapeutic efficacy of nanovaccines can be greatly enhanced by targeted delivery of nanovaccines to the spleen via the proper vaccination route.     

基于PCA扩展的判别性特征融合

提出两个判别性的特征融合方法——主成分判别性分析和核主成分判别性分析。基于主成份分析和最大间隔准则理论,构造一个多目标规划模型作为特征融合的目标。随后,该模型被转化成一个单目标规划问题并通过特征分解的方法求解。此外,将一个近似分块对角核矩阵K分成c(c为数据集中的类别数)个小矩阵,并求出它们的特征值和特征向量。在此基础上,通过向量代数处理得到一个映射矩阵α,当核矩阵K投影到α上,同类样本的相似信息能最大程度地得到保持。本文中的实验证实两种方法的有效性。     

单立领的领侧倾角与领口线关系分析

以领前部造型为直线型的单立领为例,采用立体剪裁的方法在人台上进行试验研究。将单立领的领上口、领下口、领侧倾角等组成要素数据化,利用一元线性回归模型进行统计分析,找出它们的关系,得出相应的线性方程。     

一种基于Markov逻辑网的中文地理名称实体解析方法

根据Markov逻辑网融合一阶谓词逻辑和概率图模型的复杂性及不确定性处理能力的优点,提出将Markov逻辑网和基于本体与WEB搜索的属性抽取算法相结合的命名实体解析方法(MLN_AENER),解决一般基于Markov逻辑网的实体解析方法对非结构化的命名实体解析效果不佳的问题,并将该方法针对中文地理名称解析问题进行相应设计和实验。实验结果表明该方法具有较好的解析效果。     

A Study on the Effect of Template Chain Length on the Synthesis of Mesoporous Silica in An Acidic Condition

Hexagonal mesoporous silica materials were synthesized in an acidic medium using different chain length of the quaternary ammonium surfactants as a template. The effects of chain length on the physical property, morphology of mesoporous materials, and the temperature on synthesis of materials in C _n TMBr–TEOS–HNO₃–H₂O ( n =12,14,16,18) system were systematically studied. The synthesized products were characterized by X-ray diffraction patterns, scanning electron microscopy, transmission electron microscopy, and nitrogen sorption analysis. It was found that degree of ordering, the d spacing values, and pore size all increase with an increase in the chain length of the template. The optimum synthesis temperature for mesoporous silica using C₁₈TMBr–TEOS–HNO₃–H₂O system is slightly higher than the Krafft point. The temperature and pH can all affect the expandability of micelles, and so an increase in temperature and decrease in pH all lead to an increase in the pore size. It is also found that the shear flow and chain length are two key factors inducing the formation of millimeter-scaled silica ropes and micrometer-scaled rope fibers.