基于回转输运试验的煤散料离散元接触参数修正

为获取精确的刮板输送机离散元模拟结果，基于回转输运试验，通过响应面法对煤料的接触参数进行修正.采用Plackett-Burman试验考察接触参数对受力及堆积角的影响，发现煤-钢静摩擦系数、煤-煤摩擦系数具有显著正效应.根据爬坡试验结果，以受力及堆积角为响应值规划Box-Behnken试验，建立受力、堆积角与显著项间的二次回归多项式，以实测数据为目标值求得最佳参数:煤-钢静摩擦系数为0.401，煤-煤静摩擦系数为0.333，煤-煤滚动摩擦系数为0.041.通过不同输运条件下的回转试验验证了参数的准确性，为刮板输送机的离散元研究提供参考.     

基于无条件分位回归的民营上市公司高管薪酬问题研究

高级管理人员的薪酬作为现代企业委托代理关系中的核心问题一直是社会的焦点.本文以我国民营上市公司为样本,首先研究了公司规模、每股收益、营业收入、流动负债和高管持股比例作用于高管薪酬不同分位点处的条件分位偏效应,结果表明它们在不同分位水平下的影响各异;然后为了获得这些因素的一般边际影响,利用无条件分位回归分析了它们的无条件分位偏效应,结果指出公司规模、每股收益和营业收入与各个分位水平的高管薪酬呈不同程度的正相关而流动负债则为负相关,高管持股比例与低分位水平的高管薪酬正相关而对中高分位水平的影响不显著;最后对相关结果进行了对比,发现每个影响因素的条件和无条件分位偏效应有所区别,并且无条件分位偏效应的解释意义更具有现实价值.     

基于概率图模型的危险驾驶罪刑期预测

针对司法实践中对于可解释性及预测性能的需求, 本文提出了一种基于概率图模型的量刑智能辅助方法. 该方法以量刑要素为基石建立含有隐节点的概率图模型, 由极大似然准则估计刑期分布的参数, 进而计算分布的数学期望得到预测值. 关于危险驾驶罪的实验结果表明, 概率图模型的预测准确率优于基于决策树和神经网络等的模型, 且具有良好的可解释性.     

美国人效能增强技术发展应用

 美国一直在进行士兵“超级”能力方面的研究，采用多项举措推动人效能增强技术发展。从顶层战略设计、科研机构任务、经费持续投入3个方面对美国人效能增强技术发展特点进行了综合分析，概述了美国人效能增强技术在体能、技能、智能等领域研究成果与进展，并分析了美国人效能增强技术的发展趋势和可能导致的社会伦理学问题。     

多维度深海鱼类识别算法

针对深海光线分布不均匀导致鱼类识别检测困难的问题,提出了符合视觉认知的多维度深海鱼类识别算法.该方法从时间维度优化传统的高斯混合模型(GMM)初步确定变化区域,从空间维度构建目标特征,完整提取运动目标,从时空关联维度建立深度学习的鱼类识别框架,试验结果表明:本算法可在多种复杂条件下准确提取运动目标,面积交迭度(AOM)达到80％以上,优于当前主流算法.     

Multifunctional artificial nacre via biomimetic matrix-directed mineralization

Natural nacre, one of the most studied biological structural materials with delicate hierarchical structures and extraordinary performance, has inspired the design and fabrication of artificial structural ceramics with high fracture toughness. However, to meet the diverse requirements of different applications, future structural materials must be multifunctional with superior mechanical properties, such as strength, hardness, and toughness. Herein, based on the matrix-directed mineralization method for producing biomimetic structural materials, we introduce nanoparticles with different inherent functions into the platelets of artificial nacre via the co-mineralization of aragonite and the nanoparticles. Besides their enhanced mechanical properties, the obtained artificial nacre materials also exhibit different functions depending on the type of the nanoparticles. To extend the versatility of this strategy, the effects of nanoparticles of different sizes and zeta potentials on mineralization are also analyzed. This universal strategy can be applied to the fabrication of other types of functionalized biomimetic structural ceramics that have potential applications in various fields, such as biomedical science.     

浅论气象术语标准研制的问题与对策

为避免气象术语中出现循环定义、定义不协调、定义与术语不匹配、定义重复术语名称或使用代词等问题,运用术语学原理分析,提出研制术语时要注意“语料收集、定义研制、术语分类、辨析关系”的对策建议,这对提高术语研制质量,增强表达交流效果,完善气象标准体系具有重要作用。     

后殖民动物批评视域下的《与狼共度》解读

加拿大当代著名生态作家法利·莫厄特的纪实文学作品《与狼共度》颠覆了西方哲学和文化对狼的偏见和误解,彻底扭转了狼在公众面前的形象。从后殖民动物批评的视角解读该作品展示了狼从传统"象征符号"到"生命主体"的再现,解构了基于二元论的人类中心主义和物种主义思想,颠覆了笛卡尔的"动物机器论",表达了作者反对人类的殖民霸权、尊重自然界一切生命的生态伦理观。     

Defining G protein-coupled receptor peptide ligand expressomes and signalomes in human and mouse islets

Introduction

Islets synthesise and secrete numerous peptides, some of which are known to be important regulators of islet function and glucose homeostasis. In this study, we quantified mRNAs encoding all peptide ligands of islet G protein-coupled receptors (GPCRs) in isolated human and mouse islets and carried out in vitro islet hormone secretion studies to provide functional confirmation for the species-specific role of peptide YY (PYY) in mouse islets.

Materials and methods

GPCR peptide ligand mRNAs in human and mouse islets were quantified by quantitative real-time PCR relative to the reference genes ACTB, GAPDH, PPIA, TBP and TFRC. The pathways connecting GPCR peptide ligands with their receptors were identified by manual searches in the PubMed, IUPHAR and Ingenuity databases. Distribution of PYY protein in mouse and human islets was determined by immunohistochemistry. Insulin, glucagon and somatostatin secretion from islets was measured by radioimmunoassay.

Results

We have quantified GPCR peptide ligand mRNA expression in human and mouse islets and created specific signalomes mapping the pathways by which islet peptide ligands regulate human and mouse GPCR signalling. We also identified species-specific islet expression of several GPCR ligands. In particular, PYY mRNA levels were ~ 40,000-fold higher in mouse than human islets, suggesting a more important role of locally secreted Pyy in mouse islets. This was confirmed by IHC and functional experiments measuring insulin, glucagon and somatostatin secretion.

Discussion

The detailed human and mouse islet GPCR peptide ligand atlases will allow accurate translation of mouse islet functional studies for the identification of GPCR/peptide signalling pathways relevant for human physiology, which may lead to novel treatment modalities of diabetes and metabolic disease.

     

轴向磁场作用下平均Taylor涡对湍流脉动的影响

采用基于高精度电流守恒格式的直接数值模拟方法，对轴向磁场作用下导电流体的湍流Taylor-Couette流动进行计算.在等电势边界条件的同心圆筒中，磁场与感生电流引起的反向周向速度分布、以及其对平均流动的影响被揭示出来.采用两种不同的湍流流场平均方法，将湍流中的全部脉动划分为平均流动(Taylor涡)的贡献和湍流的贡献.通过计算不同磁场强度下的湍动能的分布，对比分析轴向磁场对平均Taylor涡流和湍流两种贡献方式的影响.