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Local and non-local sources of airborne particulate pollution at Beijing——The ratio of Mg/Al as an element tracer for estimating the contributions of mineral aerosols from outside Beijing

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Science china Chemistry 2005年第3期48卷 253-264页

作者： HAN Lihui1, ZHUANG Guoshun1,2,3, SUN Yele1 & WANG Zifa3 1. The Center for atmospheric Environmental Study, department of Chemistry, Beijing Normal university, Beijing 100875, china 2. Center for atmospheric Chemistry Study, department of Environmental Science & engineering, Fudan university, Shanghai 200433, china 3. LAPC/NZC, Institute of atmospheric Physics, CAS, Beijing 100029, china 1. The Center for atmospheric Environmental Study Department of Chemistry Beijing Normal University 100875 Beijing China 2. Center for atmospheric Chemistry Study Department of Environmental Science & Engineering Fudan University 200433 Shanghai China 3. Institute of atmospheric Physics CAS LAPC/NZC 100029 Beijing China

A new element tracer technique has firstly been established to estimate the contri-butions of mineral aerosols from both inside and outside Beijing. The ratio of Mg/Al in aerosol is a feasible element tracer to distinguish between the sources of inside and outside Beijing. Mineral aerosol, inorganic pollution aerosol mainly as sulfate and nitrate, and organic aerosol are the major components of airborne particulates in Beijing, of which mineral aerosol accounted for 32%―67% of total suspended particles （TSP）, 10%―70% of fine particles （PM2.5）, and as high as 74% and 90% of TSP and PM2.5, respectively, in dust storm. The sources from outside Beijing contributed 62% （38%―86%） of the total mineral aerosols in TSP, 69% （52%―90%） in PM10, and 76% （59%―93%） in PM2.5 in spring, and 69% （52%―83%）, 79% （52%―93%）, and 45% （7%―79%） in TSP, PM10, and PM2.5, respectively, in winter, while only20% in summer and autumn. The sources from outside Beijing contributed as high as 97% during dust storm and were the dominant source of airborne particulates in Beijing. The contributions from outside Bei-jing in spring and winter are higher than those in summer, indicating clearly that it was related to the various meteorological factors.

关键词： mineral aerosol local sources non-local sources dust storm re-suspended dust element tracer technique.

Two-dimensional water-filling power allocation algorithm for MIMO-OFDM systems

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Science china(information sciences) 2010年第6期53卷 1242-1250页

作者： JIANG YongQuan 1 , SHEN MinFen 1 & ZHOU YuanPing 2 1 department of Electronic engineering, Shantou university, Shantou 515063, china 2 department of Electronic engineering, Sichuan university, Chengdu 610064, china 1. department of Electronic engineering Shantou University Shantou 515063 China2. Department of Electronic Engineering Sichuan University Chengdu 610064 China

Departing from the narrowband channel model, more and more researchers have recently considered the application of multiple-input multiple-output(MIMO) systems over frequency-selective fading channels in combination with the orthogonal frequency-division multiplexing(OFDM) *** this paper, we focus on the capacity of MIMO-OFDM systems and how to increase the *** has been proved that the capacity of a MIMO system with space-dimensional water-filling power allocation is greater than that of the system with uniform power *** MIMO-OFDM systems, there is an additional degree of freedom to allocate power with respect to MIMO systems:the OFDM sub-channels in *** the singular value decomposition(SVD) applied to the channel frequency response matrix, the two-dimensional water-filling power allocation algorithm for MIMO-OFDM systems is proposed based on the Lagrange method, and the corresponding capacity analysis formula is *** results show that the capacity of a MIMO-OFDM system with the proposed two-dimensional water-filling power allocation is greater than that of the system with uniform power allocation and also greater than that of the system with the one-dimensional water-filling power allocation.

关键词： MIMO-OFDM two-dimensional water-filling power allocation capacity analysis singular value decomposition(SVD)

Design of a novel low power 8-transistor 1-bit full adder cell

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Journal of Zhejiang university-Science C(Computers and Electronics) 2011年第7期12卷 604-607页

作者： Yi WEI,Ji-zhong SHEN (department of information Science and Electronic engineering,Zhejiang university,Hangzhou 310027,china) department of information Science and Electronic engineering Zhejiang University

An addition is a fundamental arithmetic operation which is used extensively in many very large-scale integration (VLSI) systems such as application-specific digital signal processing (DSP) and *** adder determines the overall performance of the circuits in most of those *** this paper we propose a novel 1-bit full adder cell which uses only eight *** this design,three multiplexers and one inverter are applied tominimize the transistor count and reduce power *** power dissipation,propagation delay,and power-delay produced using the new design are analyzed and com-pared with those of other designs using HSPICE *** results show that the proposed adder has both lower power consumption and a lower power-delay product (PDP) *** low power and low transistor count make the novel 8T full adder cell a candidate for power-efficient applications.

关键词： Full adder design Low power CMOS circuit Very large-scale integration (VLSI)

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Magnetic and dielectric properties of low temperature fired ferrite/ceramic composite materials

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Progress in Natural Science:Materials International 2011年第1期21卷 21-26页

作者： Wei-wei LING~(1,2),Huai-wu ZHANG~1,Ying HE~1,Yuan-xun LI~1,Yun-yan WANG~1 1.State Key Laboratory of Electronic Thin Films and Integrated Devices, university of Electronic Science and Technology of china,Chengdu 610054,china 2.department of Communication engineering,Chengdu university of information Technology, Chengdu 610225,china [a] State Key Laboratory of Electronic Thin Films and Integrated Devices University of Electronic Science and Technology of China Chengdu 610054 China [b] department of Communication engineering Chengdu University of Information Technology Chengdu 610225 China

Ni-Cu-Zn ferrite/CaTiO3and Ni-Cu-Zn ferrite/BaTiO3composites which can be applied in low temperature co-fired ceramic（LTCC） technology were synthesized by conventional solid-state reaction at temperature lower than 950℃.Influence of the microstructures and the gap parameterδ/D on the complex permeability of the above two composites was *** modifiedδ/D values of the above two composites show a good fit to the magnetic circuit *** dielectric properties of the composites were predicted by the Maxwell-Garnctt effective medium theory and the discrepancy between measured and calculated values was analyzed.

关键词： ferrite/ceramic composite low temperature co-fired ceramic(LTCC) solid-state reaction magnetic properties dielectric properties

Self-Organizing Neural Network Domain Classification for Fractal Image Coding

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The Journal of china Universities of Posts and Telecommunications 1999年第2期6卷 54-58页

作者： HUANG Yi YU Zhao-ming(information engineering department, nanjing university of Posts and Telecommunications, Naming, 210003. P R. china) information engineering department Nanjing University of Posts and Telecommunications Nanjing 210003 P. R China

This paper presents a scheme for improving encoding time for fractal image compression. The approachcombines feature extraction with domain classification using a selforganizing neural network. Feature extractionreduces the dimensionalics of the problem and enables the neural network to be trained on an image separate fromthe test image. The seaorganizing network introduces a neighborhood topology for classytcation, and alsoeliminates the need to specify a prior set of appropriate image classes. The network organizes itself according to thedistribution of the image features observed during the training. The paper presents results showing that thisclassification approach can reduce encoding time by two orders of magnitude while maintaining comparableaccuracy and compression performance.

关键词： neural networks image compression unsupervised learning fractals

维普期刊数据库

Linearly time-varying channel estimation and training power allocation for OFDM/MIMO systems using superimposed training

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Science china(information sciences) 2011年第7期54卷 1456-1470页

作者： ZHANG Han 1,DAI XianHua 2 & Pan DaRu 1 1 School of Physics and Telecommunication engineering,South china Normal university,Guangzhou 510006,china 2 department of information Science and Technology,SUN Yat-sen university,Guangzhou 510026,china 1. School of Physics and Telecommunication engineering South China Normal University Guangzhou 510006 China2. Department of Information Science and Technology SUN Yat-sen University Guangzhou 510026 China

We address the problem of estimating the linearly time-varying (LTV) channel of orthogonal frequency division multiplexing (OFDM)/multiple-input multiple-output (MIMO) systems using superimposed training (ST).The LTV channel is modeled by truncated discrete Fourier *** on this model,a two-step approach is adopted to estimate the LTV channel over multiple OFDM *** also present performance analysis of the channel estimation and derive a closed-form expression for the channel estimation *** is shown that the estimation variances,unlike that of the conventional ST-based schemes,approach to a fixed lower-bound as the training length increases,which is directly proportional to information-pilot power *** wireless communication systems with a limited transmission power,we optimize the ST power allocation by maximizing the lower bound of the average channel *** results show that the proposed approach outperforms the frequency-division multiplexed training schemes.

关键词： OFDM/MIMO systems linearly time-varying channel estimation superimposed training training power allocation

A New Method for the Development of Posts and Telecommunications information System

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The Journal of china Universities of Posts and Telecommunications 1997年第1期4卷 78-82页

作者： Zhang Feng and Yang Jing (department of Computer engineering, nanjing university of Posts and Telecommunications, nanjing 210003, P. R. china) ***

A new method for the development of post and telecommunication information systems (PTIS) is presented in the paper. The advantages of traditional methods such as life-cycle method, prototyping method, and object-oriented method are synthesized in the new method. By establishing a general model of PTIS, the new method makes the developing life cycle shorter, quicker and more flexible.

关键词： PTIS general model object-oriented life-cycle prototyping method reengineering requirement engineering

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Asymmetric encryption and signature method with DNA technology

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Science china(information sciences) 2010年第3期53卷 506-514页

作者： LAI XueJia1, LU MingXin2, QIN Lei3, HAN JunSong4 & FANG XiWen11department of Computer Science & engineering, Shanghai Jiao Tong university, Shanghai 200030, china 2School of National information Security, nanjing university, nanjing 210093, china 3BIOCOMPLEX, 4915 Bathurst St. Unit# 209-366, ON M2R 1X9, Canada 4National engineering Center for BioChip at Shanghai, Shanghai 201203, china 1. department of Computer Science & engineering Shanghai Jiao Tong University Shanghai 200030 China2. School of National Information Security Nanjing University Nanjing 210093 China3. BIOCOMPLEX 4915 Bathurst St. Unit# 209-366 Toronto ON M2R 1X9 Canada4. National Engineering Center for BioChip at Shanghai Shanghai 201203 China

This paper proposes DNA-PKC, an asymmetric encryption and signature cryptosystem by combining the technologies of genetic engineering and cryptology. It is an exploratory research of biological cryptology. Similar to conventional public-key cryptology, DNA-PKC uses two pairs of keys for encryption and signature, respectively. Using the public encryption key, everyone can send encrypted message to a specified user, only the owner of the private decryption key can decrypt the ciphertext and recover the message; in the signature scheme, the owner of the private signing key can generate a signature that can be verified by other users with the public verification key, but no else can forge the signature. DNA-PKC differs from the conventional cryptology in that the keys and the ciphertexts are all biological molecules. The security of DNA-PKC relies on diffcult biological problems instead of computational problems; thus DNA-PKC is immune from known attacks, especially the quantum computing based attacks.

关键词： cryptology asymmetric encryption digital signature biological cryptology DNA

Fast parallel algorithms for discrete Gabor expansion and transform based on multirate filtering

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Science china(information sciences) 2012年第2期55卷 293-300页

作者： TAO Liang1 & GU JuanJuan2 1School of Computer Science and Technology,Anhui university,Hefei 230039,china 2department of Electronic information and Electrical engineering,Hefei university,Hefei 230022,china 1. School of Computer Science and Technology Anhui University Hefei 230039 China2. Department of Electronic Information and Electrical Engineering Hefei University Hefei 230022 China

The Gabor transform has long been recognized as a very useful tool for the joint time and frequency analysis in signal *** real time applications,however,were limited due to the high computational complexity of the Gabor transform *** this paper,some novel and fast parallel algorithms for the finite discrete Gabor expansion and transform are presented based on multirate *** analysis filter bank is designed for the finite discrete Gabor transform(DGT)and a synthesis filter bank is designed for the finite discrete Gabor expansion(DGE).Each of the parallel channels in the two filter banks has a unified structure and can apply the FFT and the IFFT to reduce its computational *** computational complexity of each parallel channel does not change as the oversampling rate *** fact,it is very low and depends only on the length of the input discrete signal and the number of the Gabor frequency sampling *** computational complexity of the proposed parallel algorithms is analyzed and compared with that of the major existing parallel algorithms for the finite DGT and *** results indicate that the proposed parallel algorithms for the finite DGT and DGE based on multirate filtering are very attractive for real time signal processing.

关键词： discrete Gabor expansion discrete Gabor transform critical sampling and oversampling multirate filtering analysis and synthesis filter banks