自然科学学报的编排应注重版面的“信息密度”

自科版学报与其它期刊相比具有特殊性 .因此 ,在版式的编排上 ,既要根据文章内容来选用版式 ,又要依据“信息密度”的原则 ,考虑其容量 ,这样才能最大限度发挥期刊版面的实际效率 .

Near-surface velocity model construction based on a Monte-Carlo scheme

In tomographic statics seismic data processing, it 1s crucial to cletermme an optimum base for a near-surface model. In this paper, we consider near-surface model base determination as a global optimum problem. Given information from uphole shooting and the first-arrival times from a surface seismic survey, we present a near-surface velocity model construction method based on a Monte-Carlo sampling scheme using a layered equivalent medium assumption. Compared with traditional least-squares first-arrival tomography, this scheme can delineate a clearer, weathering-layer base, resulting in a better implementation of damming correction. Examples using synthetic and field data are used to demonstrate the effectiveness of the proposed scheme.

Study on Chironomid Larvae Recognition Based on DWT and Improved KNN

A chironomid larvae images recognition method based on wavelet energy feature and improved KNN is developed. Wavelet decomposition and color information entropy are selected to construct vectors for KNN that is used to classify of the images. The distance function is modified according to the weight determined by the correlation degree between feature and class, which effectively improves classification accuracy. The result shows the mean accuracy of classification rate is up to 95.41% for freshwater plankton images, such as chironomid larvae, cyclops and harpacticoida.

No-relationship Between Impossibility of Faster-Than-Light Quantum Communication and Distinction of Ensembles with the Same Density Matrix

It has been claimed in the literature that impossibility of faster-than-light quantum communication has an origin of indistinguishability of ensembles with the same density matrix. We show that the two concepts are not related.We argue that even with an ideal single-atom-precision measurement, it is generally impossible to produce two ensembles with exactly the same density matrix; or to produce ensembles with the same density matrix, classical communication is necessary. Hence the impossibility of faster-than-light communication does not imply the indistinguishability of ensembles with the same density matrix.

Video Scene Invariant Crowd Density Estimation Using Geographic Information Systems

Crowd density is an important factor of crowd stability.Previous crowd density estimation methods are highly dependent on the specific video scene.This paper presented a video scene invariant crowd density estimation method using Geographic Information Systems(GIS) to monitor crowd size for large areas.The proposed method mapped crowd images to GIS.Then we can estimate crowd density for each camera in GIS using an estimation model obtained by one camera.Test results show that one model obtained by one camera in GIS can be adaptively applied to other cameras in outdoor video scenes.A real-time monitoring system for crowd size in large areas based on scene invariant model has been successfully used in 'Jiangsu Qinhuai Lantern Festival,2012'.It can provide early warning information and scientific basis for safety and security decision making.

The Relationship between Forestland Soil Fertility and Gathering Firewood in the Zhuxi Watershed in the Red Soil Hilly Region of China

Declining soil fertility has become an increasingly urgent problem and gathering firewood is one of the important contributing factors.Due to the excessive exploitation of natural resources especially for firewood,the red soil hilly region has become one of the most vulnerable eco-environment regions in China.The pressure of gathering firewood on forestland soil fertility in forestland has been generally estimated by geographical information system and questionnaire method in this paper in the Zhuxi watershed of Changting County,Fujian Province,China,a typical representative in the red soil hilly region of China.The results of this study show that：i） Forestland soil fertility is negatively affected by gathering firewood,which is more intensive in the integrated buffer zone than out of zone.The forestland soil fertility grade,OM,total N,available N,total P,available P,total K,available K,pH and ＆lt;2μm clay content are lower and bulk density is higher in the integrated buffer zone than those out.ii） The forestland soil fertility grade,OM,total N,available N,total P,available P,total K,available K,pH and ＆lt;2μm clay content tend to be lower and bulk density tends to be higher in the village buffer zones than those out in Datian,Chenguang and Youfang respectively.iii） The population density,economic development and terrain might be the key driving forces contributing to the relationship between gathering firewood and forestland soil fertility.Higher population density leads to more massive firewood collection and imposes more pressure on forestland soil fertility.Decreasing the use of firewood stove may reduce firewood consumption and thus release the pressure of gathering firewood on forestland soil fertility.Terrain affects the accessibility to gathering firewood thus affects forestland soil fertility.Other driving forces influencing the relationship between gathering firewood and forestland soil fertility should also be taken into account in the further study.

A GIS-based Spatial Analysis of Housing Price and Road Density in Proximity to Urban Lakes in Wuhan City, China

As one of the essential urban open spaces, lakes usually contribute immensely to the quality of residents′ daily lives. Different from hedonic approach employed in existing researches on urban open spaces in China, this paper integrates housing price surface with road density to analyze the spatial characteristics in proximity to urban lakes in Wuhan City, China. With the expansion of Wuhan City, urban lakes became polluted, they shrunk or even disappeared, leading to unfavorable conditions for sustainable development of the city. To better understand the spatial relationship between the city and lakes, we classify the urban lakes in Wuhan central area into ′lakes in the urban center′ and ′lakes in urban fringe′. Based on housing price surface we explore the spatial characteristics in proximity to different lakes and differences between the lakes. We also use Geographic Information System(GIS) tool to calculate road density as a supplementary indicator to reflect the accessibility in proximity to urban lakes. The results indicate that relative independence exists between different towns, and the spatial characteristics are different depending on scales and locations. In most of cases, the road density is lower where closer to the lakeshore while the housing price exhibits an opposite pattern. We conclude that city governments and urban planners should give more considerations to these spatial differences, somewhere should be better planned and protected as an important waterfront and somewhere the control of unreasonable real estate development nearby should be strengthened.

Metric of States

Metric of quantum states plays an important role in quantum information theory. In this letter, we find the deep connection between quantum logic theory and quantum information theory. Using the method of quantum logic, we can get a famous inequality in quantum information theory, and we answer a question raised by S. Gudder.

Spatial Agglomeration of Exhibition Enterprises on a Regional Scale in China

During the past two decades, the exhibition industry in China has been developing rapidly and has become an important part of the modern service industry, particularly the agglomeration characteristics of exhibition enterprises highlighted on the regional scale. Although the development of theoretical research on the western exhibition industry has taken place over time, the spatial perspective has not been at the centre of attention so far. This paper aims to fill this gap and report on the agglomeration characteristics of exhibition enterprises and their influential factors. Based on data about exhibition enterprises in the Pearl River Delta(PRD) during 1991–2013, using the Ripley K function analysis and kernel density estimation, this research identifies that: 1) the exhibition enterprise on the regional scale is significantly characterized by spatial agglomeration, and the agglomeration density and scale are continuously increasing; 2) the spatial pattern of agglomeration has developed from a single-center to multi-center form. Meanwhile, this paper profiles the factors influencing the spatial agglomeration of exhibition enterprises by selecting the panel data of nine cities in the PRD in 1999, 2002, 2006 and 2013. The results show that market capacity, urban informatization level and exhibition venues significantly influence the location choice of exhibition enterprises. Among them, the market capacity is a variable that exerts a far greater impact than other factors do.

Freights loading optimization with balanced and unconcentrated loading constraints

The optimization of high density and concentrated-weight freights loading requires an even distribution of the freight's weight and unconcentrated loading on the floor of the car.Based on the characteristics of concentrated-weight category freights,an improvement method is put forward to build freight towers and a greedy-construction algorithm is utilized based on heuristic information for the initial layout.Then a feasibility analysis is performed to judge if the balanced and unconcentrated loading constrains are reached.Through introducing optimization or adjustment methods,an overall optimal solution can be obtained.Experiments are conducted using data generated from real cases showing the effectiveness of our approach: volume utility ratio of 90.4% and load capacity utility ratio of 86.7% which is comparably even to the packing of the general freights.

INFORMATION PACKAGING IN ENGLISH MEDICAL PAPERS PUBLISHED IN A CHINESE JOURNAL

科技论文的语篇信息包装是系统功能语言学家的重要研究方向之一。词汇密度和名物化是语法隐喻的两个重要概念,也是区别口语与书面语的重要标志。本文从词汇密度和名物化两方面比较并分析了英语本族语者和以英语为外语的医学论文作者(学习者)所发表的英文医学论文,从而希望可以对学习者的英语论文写作及我国医学英语教育起到一定的启示作用。

Quantum Fisher Information for Density Matrices with Arbitrary Ranks

We provide a new expression of the quantum Fisher information(QFI) for a general system.Utilizing this expression,the QFI for a non-full rank density matrix is only determined by its support.This expression can bring convenience for an infinite-dimensional density matrix with a finite support.Besides,a matrix representation of the QFI is also given.

Real-time reliability assessment based on acceleration monitoring for bridge

Bridge health monitoring （BHM） has become increasingly significant in the life-cycle of the structure such as maintenance, repair and rehabilitation. It is necessary to use BHM information efficiently to assess the working conditions of the bridge. The main objective of this study is to develop an effective method and establish a framework for the real-time reliability assessment based on BHM acceleration information. The first-passage probability and its further development have been proposed to as- sess the reliability probability. The first-passage probability shows the probability of that a scalar process exceeds a designated threshold during a given time interval. The advantage of the proposed method is the assessment of the real-time reliability probability based on the monitoring information during an assessment reference period. Furthermore, the velocity data and displacement data are calculated from the acceleration monitoring data using the relationships between their power spectral density （PSD） functions. The real-time reliability assessment of Donghai Bridge, which is the first large scale cross-sea bridge in China, demonstrates that the proposed method is efficient and effective.

Non-zero quantum discord at finite temperature

We investigate theoretically the quantum discord dynamics of a two-qubit composite system subject to a common finite-temperature reservoir by solving the Born-Markovian master equation analytically.The ultimate quantum discord,however,exhibits a relatively high stable value associated with the reservoir temperature despite the permanent disappearance of entanglement simultaneously.Further analysis shows that the unique characteristic depends strongly on the off-diagonal non-zero elements of the density matrix.Our result manifests the greater robustness of quantum discord compared with entanglement,which may be helpful in quantum-information technologies.