Water supply to a geotechnical centrifuge

The supply of water to a centrifuge experiment has always been important. This paper details a new system which has been successfully commissioned for use on the geotechnical centrifuge at University of Cambridge. High water pressures and large flow rates were delivered to an experimental package, for the modelling of water injection-aided pile jacking. The practicalities of such a system are discussed in relation to existing alternatives, in addition to the precautions taken to ensure safe centrifuge operation. A method for calculating water pressures in the system away from instrumented locations is also proposed, using a linear relationship between energy per unit volume and the flow rate squared. Experimental data are presented to support these relationships.

Orthogonal multipulse modulation for 64 gigabit fibre channel

Real-time orthogonal multipulse modulation is demonstrated at 56 Gb/s with transmission over 500 m of single-mode fiber. Up to 2 dBo power budget advantage is predicted relative to alternatives such as PAM4. © 2013 OSA.

Revealing lithium-silicide phase transformations in nano-structured silicon-based lithium ion batteries via in situ NMR spectroscopy.

Nano-structured silicon anodes are attractive alternatives to graphitic carbons in rechargeable Li-ion batteries, owing to their extremely high capacities. Despite their advantages, numerous issues remain to be addressed, the most basic being to understand the complex kinetics and thermodynamics that control the reactions and structural rearrangements. Elucidating this necessitates real-time in situ metrologies, which are highly challenging, if the whole electrode structure is studied at an atomistic level for multiple cycles under realistic cycling conditions. Here we report that Si nanowires grown on a conducting carbon-fibre support provide a robust model battery system that can be studied by (7)Li in situ NMR spectroscopy. The method allows the (de)alloying reactions of the amorphous silicides to be followed in the 2nd cycle and beyond. In combination with density-functional theory calculations, the results provide insight into the amorphous and amorphous-to-crystalline lithium-silicide transformations, particularly those at low voltages, which are highly relevant to practical cycling strategies.

Gaussian process volatility model

The prediction of time-changing variances is an important task in the modeling of financial data. Standard econometric models are often limited as they assume rigid functional relationships for the evolution of the variance. Moreover, functional parameters are usually learned by maximum likelihood, which can lead to over-fitting. To address these problems we introduce GP-Vol, a novel non-parametric model for time-changing variances based on Gaussian Processes. This new model can capture highly flexible functional relationships for the variances. Furthermore, we introduce a new online algorithm for fast inference in GP-Vol. This method is much faster than current offline inference procedures and it avoids overfitting problems by following a fully Bayesian approach. Experiments with financial data show that GP-Vol performs significantly better than current standard alternatives.

Assessing effects of site characteristics on remediation secondary life cycle impact with a generalised framework

The 'sustainable remediation' concept has been broadly embraced by industry and governments in recent years in both the US and Europe. However, there is a strong need for more research to enhance its 'practicability'. In an attempt to fill this research gap, this study developed a generalised framework for selecting the most environmentally sustainable remedial technology under various site conditions. Four remediation technologies were evaluated: pump and treat (P&T), enhanced in situ bioremediation (EIB), permeable reactive barrier (PRB), and in situ chemical reduction (ISCR). Within the developed framework and examined site condition ranges, our results indicate that site characteristics have a profound effect on the life cycle impact of various remedial alternatives, thus providing insights and valuable information for determining what is considered the most desired remedy from an environmental sustainability perspective. © 2014 © 2014 University of Newcastle upon Tyne.

Predictive entropy search for efficient global optimization of black-box functions

We propose a novel information-theoretic approach for Bayesian optimization called Predictive Entropy Search (PES). At each iteration, PES selects the next evaluation point that maximizes the expected information gained with respect to the global maximum. PES codifies this intractable acquisition function in terms of the expected reduction in the differential entropy of the predictive distribution. This reformulation allows PES to obtain approximations that are both more accurate and efficient than other alternatives such as Entropy Search (ES). Furthermore, PES can easily perform a fully Bayesian treatment of the model hyperparameters while ES cannot. We evaluate PES in both synthetic and real-world applications, including optimization problems in machine learning, finance, biotechnology, and robotics. We show that the increased accuracy of PES leads to significant gains in optimization performance.

Comparative cytogenetics of bats (Chiroptera): The prevalence of Robertsonian translocations limits the power of chromosomal characters in resolving interfamily phylogenetic relationships

Although the monophyly of Chiroptera is well supported by many independent studies, higher-level systematics, e.g. the monophyly of microbats, remains disputed by morphological and molecular studies. Chromosomal rearrangements, as one type of rare genomic changes, have become increasingly popular in phylogenetic studies as alternatives to molecular and other morphological characters. Here, the representatives of families Megadermatidae and Emballonuridae are studied by comparative chromosome painting for the first time. The results have been integrated into published comparative maps, providing an opportunity to assess genome-wide chromosomal homologies between the representatives of eight bat families. Our results further substantiate the wide occurrence of Robertsonian translocations in bats, with the possible involvement of whole-arm reciprocal translocations (WARTs). In order to search for valid cytogenetic signature(s) for each family and superfamily, evolutionary chromosomal rearrangements identified by chromosomal painting and/or banding comparison are subjected to two independent analyses: (1) a cladistic analysis using parsimony and (2) the mapping of these chromosomal changes onto the molecularly defined phylogenetic tree available fromthe literature. Both analyses clearly indicate the prevalence of homoplasic events that reduce the reliability of chromosomal characters for resolving interfamily relationships in bats.

Production of EUV power with SECRAL

The high power EUV source is one of key issues in the development of EUV lithography which is considered to be the most promising technology among the next generation lithography. However neither DPP nor LPP seems to meet the requirements of the commercial high-volume product. Insufficiency of DPP and LPP motivate the investigation of other means to produce the EUV radiation required in lithography. ECR plasma seems to be one of the alternatives. In order to investigate the feasibility of ECR plasma as a EUV light source, the EUV power emitted by SECRAL was measured. A EUV power of 1.03W in 4 pi sr solid angle was obtained when 2000W 18GHz rf power was launched, and the corresponding CE was 0.5%. Considering that SECRAL is designed to produce very high charge state ions, this very preliminary result is inspiring. Room-temperature ECR plasma and Sn plasma are both in the planned schedule.

不同森林管理预案下友好林业局森林景观的动态变化

Knowledge about cumulative effects of forest management alternatives on forest landscape is required to make forest management decision. In this paper,a spatially explicit landscape model,LANDIS,was applied to simulate forest landscape changes in 200 years under four management alternatives (no cutting,clearcutting,selective cutting I and II) in Youhao Forestry Bureau located in Small Khingan Mountains. APACK was used to calculate distribution area of the representative species and species age cohort for six species. The results showed:1) timber harvest decreased area percentage of representative conifer species,Pinus koraiensis,Picea koraiensis and Picea jezoensis,Larix gmelinii to some extent compared to no cutting. The most influencing cutting mode for the area percentage of Tilia amurensis and Quercus mongolica was selective cutting II,followed by selective cutting I and clearcutting. To the contrast,the change of area percentage of Betula phatyphylla was contrary to the management alternatives; 2) As to species age cohort composition,timber harvest significantly changed age structure,that is,it decreased over-matured age cohort of representative species,and increased seedling and middle-age cohort (B. phatyphylla was not included,because its area percentage of over-mature age cohort was the highest under clearcutting than other three scenarios).

Polar stationary phases for capillary electrochromatography

This review article summarizes the variety of polar stationary phases that have been employed for capillary electrochromatographic separations. Compared with reversed-phase stationary phases, the polar alternatives provide a completely different retention selectivity towards polar and charged analytes. Different types of polar stationary phases are reviewed, including the possible retention mechanisms. Electrochromato-graphic separations of polar solutes, peptides, and basic pharmaceuticals on polar stationary phases are presented.

燕沟流域特旱年粮食稳产示范研究

20 0 0年特旱年 ,燕沟流域通过推广抗旱保苗、调整作物种植结构、品种改良、增施肥料、大垄沟种植等技术措施 ,增产稳产效果显著 ,在全年降水量减少 36 .1%的情况下 ,粮食单产仍稳中有升 ,人均产粮达到了 5 2 5 .1kg。这对于黄土高原中部丘陵区坡改梯后保障食物安全生产、加快退耕还林还草步伐都具有一定的现实意义。

High-performance dye-sensitized solar cells based on solvent-free electrolytes produced from eutectic melts

Low-cost excitonic solar cells based on organic optoelectronic materials are receiving an ever-increasing amount of attention as potential alternatives to traditional inorganic photovoltaic devices. In this rapidly developing field, the dye-sensitized solar cell(1) (DSC) has achieved so far the highest validated efficiency of 11.1% (ref. 2) and remarkable stability(3).

聚类引导搜索的移动机器人路径规划方法

本文提出一种聚类引导搜索（cluster guide searching，CGS）的路径规划方法。采用基于最大最小距离的K均值聚类方法对样本进行离线聚类学习，学习结果以相似环境相似决策的知识形式进行存储。路径规划过程中，机器人在线整理环境信息，获得输入空间样本，通过与知识库匹配，检索到最近的类别，然后在该类别内部采用速度优先策略和方向优先策略交替的方式搜索输出空间。若知识不完备导致检索失败，可重启线性规划算法（linear programming，LP）进行在线路径规划，并更新聚类知识库。仿真结果表明该方法是一种有效的路径规划学习方法。

Quantitative Inference in a Mechanical Design Compiler

This paper presents the ideas underlying a program that takes as input a schematic of a mechanical or hydraulic power transmission system, plus specifications and a utility function, and returns catalog numbers from predefined catalogs for the optimal selection of components implementing the design. It thus provides the designer with a high level "language" in which to compose new designs, then performs some of the detailed design process for him. The program is based on a formalization of quantitative inferences about hierarchically organized sets of artifacts and operating conditions, which allows design compilation without the exhaustive enumeration of alternatives.

Creation of Computer Animation from Story Descriptions

This report describes a computer system that creates simple computer animation in response to high-level, vague, and incomplete descriptions of films. It makes its films by collecting and evaluating suggestions from several different bodies of knowledge. The order in which it makes its choices is influenced by the focus of the film. Difficult choices are postponed to be resumed when more of the film has been determined. The system was implemented in an object-oriented language based upon computational entities called "actors". The goal behind the construction of the system is that, whenever faced with a choice, it should sensibly choose between alternatives based upon the description of the film and as much general knowledge as possible. The system is presented as a computational model of creativity and aesthetics.