Navier-Stokes方程的一类粘性分离算法

本文提出了一类求解Navier-Stokes方程的粘性分离算法,在每一时间层内,将原方程分解为线性 Euler方程和非定常Stokes方程,证明了空间连续格式和完全离散格式的收敛性,并给出了最优阶误差估计。     

结霜与微尺度表面特性的实验研究

针对翅片式蒸发器表面的结霜问题，提出了一种新的实验研究方法，即利用CSPM2000(扫描探针显微镜)对两类材料冷表面进行扫描记录，同时利用专门的CCD摄像与显微镜系统，观测两类材料表面的整个结霜过程，从而探讨微观表面结构与材料表面霜层形成的关系．实验结果表明，材料的表面粗糙度对结霜有很大影响，表面光洁度好，霜沉降量较小。     

甲烷其它相态及其意义

对水溶和水合这两种不为人熟知的甲烷相态进行了介绍，分析了水溶甲烷量估算方法和影响因素、以及对矿井安全生产可能构成的潜在威胁。根据水合状态的瓦斯分解需要吸收大量的热而难以在短时间内大量集中涌出的物理化学特性，结合初步试验结果论述了利用水合机理防治矿井瓦斯事故的可行性。理论研究与初步实验表明，利用水合技术防治矿井事故的技术路线是可行的。另外，随着采深的增加，水溶甲烷将对煤矿安全生产构成威胁。     

Transient transition behaviors of fractional-order simplest chaotic circuit with bi-stable locally-active memristor and its ARM-based implementation

This paper proposes a fractional-order simplest chaotic system using a bi-stable locally-active memristor. The characteristics of the memristor and transient transition behaviors of the proposed system are analyzed, and this circuit is implemented digitally using ARM-based MCU. Firstly, the mathematical model of the memristor is designed, which is nonvolatile, locally-active and bi-stable. Secondly, the asymptotical stability of the fractional-order memristive chaotic system is investigated and some sufficient conditions of the stability are obtained. Thirdly, complex dynamics of the novel system are analyzed using phase diagram, Lyapunov exponential spectrum, bifurcation diagram, basin of attractor, and coexisting bifurcation, coexisting attractors are observed. All of these results indicate that this simple system contains the abundant dynamic characteristics. Moreover, transient transition behaviors of the system are analyzed, and it is found that the behaviors of transient chaotic and transient period transition alternately occur. Finally, the hardware implementation of the fractional-order bi-stable locally-active memristive chaotic system using ARM-based STM32F750 is carried out to verify the numerical simulation results.     

顺丰、菜鸟之争:意在数据

缘起:顺丰、菜鸟之争 2017年6月1日,菜鸟网络在其官方微博发布《菜鸟关于顺丰暂停物流数据接口的声明》,声称:菜鸟切入物流是为了合作,而非竞争,部分快递企业"不务正业",意图切入电商市场;顺丰关闭了物流数据接口;此前菜鸟对全网物流数据进行信息安全升级,将加强对海淘、快件柜等物流数据的多重交叉验证,但顺丰及丰巢拒不配合,菜鸟紧急建议商家暂停使用顺丰发货.     

煤升温氧化过程特征的热重分析

用热重方式进行了煤在常规条件下的热重实验,分别用TG/DTG曲线描述了煤燃烧的整个过程,分析了煤升温氧化过程的特征参数,得到了各种煤的着火温度等特征温度.结果表明,煤样的特征温度与挥发分存在一定的规律性,特征温度下的失重值受挥发分的影响,着火温度随挥发分增加呈线性下降.     

卡博替尼与血清白蛋白的相互作用研究

采用紫外可见光谱和荧光光谱考察了卡博替尼(CBZ)与牛血清白蛋白(BSA)间相互作用,结果表明CBZ主要借助疏水作用力与BSA形成1:1的配合物,导致BSA内源性的荧光发生淬灭,其类型为动、静态同时存在的联合淬灭.上述结合作用的动态淬灭常数KSV和表观结合常数Ka分别为5.223×104 L·mol-1和5.06×10...     

X-ray phase-sensitive microscope imaging with a grating interferometer: Theory and simulation

A general theoretical framework is presented to explain the formation of the phase signal in an x-ray microscope integrated with a grating interferometer, which simultaneously enables the high spatial resolution imaging and the improved image contrast. By using this theory, several key parameters of phase contrast imaging can be predicted, for instance, the fringe visibility and period, and the conversion condition from the differential phase imaging (DPI) to the phase difference imaging (PDI). Additionally, numerical simulations are performed with certain x-ray optical components and imaging geometry. Comparison with the available experimental measurement [Appl. Phys. Lett. 113 063105 (2018)] demonstrates the accuracy of this developed quantitative analysis method of x-ray phase-sensitive microscope imaging.     

猴年"红包大战":移动支付谁主沉浮?

刚刚过去的猴年春节,让全国人民沐浴在互联网巨头主导的"红包雨"中.从年初造势到除夕夜几番登场,支付宝与微信的"红包大战"不断升级,而QQ、百度、微博跟进参战,又为这项"新民俗"平添了几分热闹.其实红包漫天背后,各家有备家的诉求,无论用户群导入,还是移动支付黏合度,巨头们最终图谋的都是移动支付入口.     

富士康勾画金融服务蓝图

2015年,互联网企业进军金融市场的消息甚嚣尘上:百度与中信银行携手推出百信银行,着手“直销银行”布局;微众银行的高级管理层不断变动;新融资消息频频曝出.而富士康涉足内地金融服务,又会为产业格局带来哪些变数? 金融服务:下一个风口? 数据显示,富士康近年已在中国内地市场成立了6家金融服务公司,主要目的是为电子零部件供应商提供贷款和其他金融服务.