用煤反射率分布图指导煤场来煤的合理堆放

为指导煤场来煤合理堆放,建立了与煤随机反射率有关的煤岩指标:离异值、范围容纳度、分布图重叠度、煤堆中心值、分布范围等.介绍了这些指标的作用与判别准则,用堆放煤反射率分布图叠加形成的反射率分布图等分析煤堆煤在炼焦配煤中的作用.针对指导生产的时效性与对来煤的代表性,采用HD型全自动显微镜光度计软件可方便实施上述功能.     

Sequential Methods in Multi-Arm Clinical Trials

Abstract

In this overview article, I will focus on adaptive designs in “learn” clinical studies, the exploratory phase of the drug development process designed and carried out in order to establish drug efficacy and dose-response relationships. These designs directly address the goals of the learn-phase trial with respect to identification of dose to carry forward in the confirmatory phase, estimation of likelihood of success in confirmatory trial, and efficient early stopping for efficacy or for futility. A critical component of these designs is the dose-response model for efficacy and/or safety endpoints that capture prior information about the form and location of the clinically important dose response relationship. An additional ingredient in the Bayesian approach is a prior distribution for unknown parameters. Efficiency is gained by appropriate incorporation of longitudinal models that allow the efficient use of all available information.     

Adaptive Designs to Maximize Power in Clinical Trials with Multiple Treatments

Abstract

We consider a clinical trial with three competing treatments and study designs that allocate subjects sequentially in order to maximize the power of relevant tests. Two different criteria are considered: the first is to find the best treatment and the second is to order all three. The power converges to one in an exponential rate and we find the optimal allocation that maximizes this rate by large deviation theory. For the first criterion the optimal allocation has the plausible property that it assigns a small fraction of subjects to the inferior treatment. The optimal allocation depends heavily on the unknown parameters and, therefore, in order to implement it, a sequential adaptive scheme is considered. At each stage of the trial the parameters are estimated and the next subject is allocated according to the estimated optimal allocation. We study the asymptotic properties of this design by large deviations theory and the small sample behavior by simulations. Our results demonstrate that, unlike the two-treatments case, adaptive design can provide significant improvement in power.     

数字城市简论

数字城市是数字地球应用的重要部分之一，也是数字地球的重要层次。论述了数字城市的基本问题，同时提出了我国目前进行数字城市试验的几点建议。     

稀土金属有机化学的发展概况（上）

简要地介绍了稀土金属有机化学的发展概况,对这方面所取得的成果按稀土元素的不同价态作了分类总结和归纳。     

稀土金属有机化学的发展概况（下）

简要地介绍了稀土金属有机化学的发展概况。对这方面所取得的成果按稀土元素的不同价态作了分类、总结和归纳。     

Electrohydrodynamic Drying—A Concise Overview

Electrohydrodynamic (EHD) drying is a novel method of non-thermal processing. The drying can be carried out using either AC or DC high voltages. The thermodynamic considerations regarding the lowering of temperature under EHD drying include rapid rates of evaporation and exothermic interaction of the electric field with a dielectric material. Multi-point and plate electrode systems are efficient in accelerating drying of agricultural materials. Compared to hot air (convective) drying systems, EHD drying systems offer lower food production costs along with superior quality in terms of physiochemical properties such as color, shrinkage, flavor, and nutrient content. Compared to convective and freeze-drying, EHD drying systems, given their simpler design and lesser energy consumption, show great potential for bulk and industrial drying applications.     

From Pre-Clinical Studies to Clinical Trials: Generation of Novel Therapies for Pregnancy Complications

Complications of pregnancy represent a significant disease burden, with both immediate and lasting consequences for mother and baby. Two key pregnancy complications, fetal growth restriction (FGR) and preeclampsia (PE), together affect around 10%–15% of all pregnancies worldwide. Despite this high incidence, there are currently no therapies available to treat these pregnancy disorders. Early delivery remains the only intervention to reduce the risk of severe maternal complications and/or stillbirth of the baby; however early delivery itself is associated with increased risk of neonatal mortality and morbidity. As such, there is a pressing need to develop new and effective treatments that can prevent or treat FGR and PE. Animal models have been essential in identifying and screening potential new therapies in this field. In this review, we address recent progress that has been made in developing therapeutic strategies for pregnancy disorders, some of which are now entering clinical trials.     

有机化学机理解题思路与方法

机理就是讲述化合物A在给定的条件下如何转变成化合物B.学习如何为有机反应提出合理的机制很重要,因为机理使有机化学易于理解.如果不能将有机化学家熟悉的一系列令人困惑的反应归纳成几种基本的机理类型,我们将无法理解和记忆这些反应.本文通过分析有机反应过程中化学键的断裂与形成,提出极性反应三要素并以极性反应三要素为指导原则,结...