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Efficient spread space-time block coding scheme in multiple antenna systems

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Journal of Systems Engineering and Electronics 2006年第2期17卷 258-262页

作者： Qiu ling zheng Xiayu Dept. of EELS Univ. of Science and Technology of China Hefei 230027 P. R. China

Space-time coding is an important technique that can improve transmission performance at fading environments in mobile communication systems. In this paper, we propose a novel diversity scheme using spread spacetime block coding （SSTBC） in multiple antenna systems. At the transmitter, the primitive data are serial to parallel converted to multiple data streams, and each stream is rotated in constellation. Then Walsh codes are used to spread each symbol to all antenna space in a space-time block. The signals received from all receiver antennas are combined with the maximum ratio combining （MRC）, equalized with linear equalizer to eliminate the inter-code interference and finally demodulated to recover to transmit data by using the one-symbol maximum likelihood detector. The proposed scheme does not sacrifice the spectrum efficiency meanwhile maintains the transceiver with low complexity. Owing to the transmission symbols of different transmit antennas passing through all the spatial subchannels between transceiver antenna pairs, the system obtains the partial additional space diversity gain of all spatial paths. It is also shown that the diversity gain is better than the previous space-time block coding （STBC） schemes with full transmission rate.

关键词： multiple antennas spread space-time block coding (SSTBC) diversity full transmission rate.

FILTERING CHARACTERISTICS AND EXPERIMENTAL INVESTIGATION OF ONE-DIMENSIONAL PERIODIC RODS

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Chinese Journal of Mechanical Engineering 2008年第2期21卷 53-57页

作者： zheng ling LI Yinong BAZ Amr State Key Laboratory of Mechanical Transmission Chongqing University Chongqing 400044 China Department of Mechanical Engineering University of Maryland College Park MD20742 USA

Passive periodic structures exhibit unique dynamic characteristics that make the passive periodic structures act as mechanical filters for wave propagation. As a result, wave can propagate along the periodic structures only within specific frequency bands called the pass bands and wave propagation is completely blocked within other frequency bands called the “stop bands”. A theoretical method based on the transfer matrix formulation is developed in order to effectively investigate the influence of periodicity, variable geometry and material properties on the wave propagation characteristics of one-dimensional periodic rod. Several numerical examples are presented in order to illustrate their unique tunable filtering and localization characteristics. The experiments are conducted to verify the numerical predictions and to demonstrate the capability of the wavelet transform as a very powerful tool to uniquely identify and compare the energy distribution both in the time and frequency domain. The flexibility that the spectral width and location of the pass and stop bands can be tuned by introducing intentional variation in geometric and material properties for the individual substructure or cell is identified completely by both numerical predictions and experimental results. The results demonstrate the potential of such one-dimensional periodic structure in controlling the dynamics of wave propagation as a mechanical filter such as engine mount, gearbox support strut and other applications.

关键词： Periodic structure Rod Wave propagation Stop bands Wavelet

Viscosity Analysis on the Boltzmann Equation

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Acta Mathematica Sinica,English Series 2012年第10期28卷 2139-2152页

作者： Min ling zheng Xiao Ping YANG School of Science Huzhou Teachers College School of Science Nanjing University of Science&Technology

This paper is devoted to investigating the asymptotic properties of the renormalized so- lution to the viscosity equation δtfε ＋ v · △↓xfε = Q（fε, fε）＋ ε△vfε as ε →0＋. We deduce that the renormalized solution of the viscosity equation approaches to the one of the Boltzmann equation in L^1（（0, T） × RN × R^N）. The proof is based on compactness analysis and velocity averaging theory.

关键词： Viscosity Boltzmann equation renormalized solution viscosity coemcient defect measure

Design, Synthesis and Investigation of Bone Affinity of the Conjugates of 5-Fluorouracil and Hydroxybisphosphonate

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Chinese Chemical Letters 2005年第11期16卷 1434-1436页

作者： Liu Hua XU Hu zheng ling ling WENG West China School of Pharmacy Sichuan University Chengdu 610041

A series of novel bone-targeting antitumor agents-the conjugates of 5-fluorouracil and hydroxybisphosphonate were designed and synthesized their structures were confirmed by ^1H-NMR, ^13C-NMR, ^31P-NMR, MS, and elemen... 详细信息

关键词： 5-Fluorouracial hydroxybisphosphonate bone-targeting conjugate hydroxyapatide.

Warm water wake off northeast Vietnam in the South China Sea

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Acta Oceanologica Sinica 2014年第11期33卷 55-63页

作者： YAN Yunwei CHEN Changlin ling zheng College of Physical and Environmental Oceanography Ocean University of China State Key Laboratory of Satellite Ocean Environment Dynamics Second Institute of OceanographyState Oceanic Administration

Due to orographic blockage, a weak wind wake occurs in summer off northeast Vietnam in the South China Sea. Under the wind wake, warm water is observed from both high-resolution satellite data and hydrographic observations. The wake of warm water forms in June, continues to mature in July and August, starts to decay in September, and disappears in October. The warm water wake also shows robust diurnal variation – it intensifies during the day and weakens in the night. Warm water wakes can be generated through wind-induced mixing and thermal（latent heat flux） processes. In this paper, a mixed layer model is used to evaluate the relative importance of the two processes on seasonal and diurnal timescales, respectively. The results demonstrate that thermal processes make a greater contribution to the wake than wind-induced mixing processes on a seasonal timescale, while the warm water wake is dominated by wind-induced mixing processes on a diurnal timescale.

关键词： warm water wake wind-induced mixing processes thermal processes seasonal timescale diurnal timescale northeast Vietnam South China Sea

Winter coastal upwelling off northwest Borneo in the South China Sea

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Acta Oceanologica Sinica 2015年第1期34卷 3-10页

作者： YAN Yunwei ling zheng CHEN Changlin College of Physical and Environmental Oceanography Ocean University of China State Key Laboratory of Satellite Ocean Environment Dynamics Second Institute of OceanographyState Oceanic Administration

Winter coastal upwelling off northwest Borneo in the South China Sea （SCS） is investigated by using satellite data, climatological temperature and salinity fields and reanalysis data. The upwelling forms in Decem- ber, matures in January, starts to decay in February and almost disappears in March. Both Ekman trans- port induced by the alongshore winter monsoon and Ekman pumping due to orographic wind stress curl are favorable for the upwelling. Transport estimates demonstrate that the month-to-month variability of Ekman transport and Ekman pumping are both consistent with that of winter coastal upwelling, but Ek- man transport is two times larger than Ekman pumping in January and February. Under the influence of E1 Nino-Southern Oscillation （ENSO）, the upwelling shows remarkable interannual variability： during winter of El Nino （La Nina） years, an anticyclonic （a cyclonic） wind anomaly is established in the SCS, which behaves a northeasterly （southwesterly） anomaly and a positive （negative） wind stress curl anomaly off the north- west Borneo coast, enhancing （reducing） the upwelling and causing anomalous surface cooling （warming） and higher （lower） chlorophyll concentration. The sea surface temperature anomaly （SSTA） associated with ENSO off the northwest Borneo coast has an opposite phase to that off southeast Vietnam, resulting in a SSTA seesaw pattern in the southern SCS in winter.

关键词： coastal upwelling northwest Borneo South China Sea Ekman transport Ekman pumping,interannual variability

Battery aging-minimal speed control of autonomous heavy-duty electric trucks in adaptation to highway topography and traffic

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Science China(Technological Sciences) 2023年第10期66卷 2942-2957页

作者： ZHANG YongZhi WANG Chun YU QuanQing zheng ling College of Mechanical and Vehicle Engineering Chongqing UniversityChongqing 400044China School of Mechanical Engineering Sichuan University of Science and EngineeringZigong 643000China School of Automotive Engineering Harbin Institute of TechnologyWeihai 264209China

The development of battery electric(BE)heavy-duty trucks(HDTs)is highly limited to the short cycling life of *** this paper,we propose a battery aging-conscious control strategy for extended battery life by optimizing the speed trajectory of BE HDT.A state-space model is constructed by connecting the vehicle dynamics and battery state of charge,and a mechanism-based aging model of battery is then introduced to formulate the optimization problem for minimal battery aging and energy *** optimization problem is solved within a model predictive control framework for the real-time speed control of the vehicle.A non-cooperative platooning controller is further developed for the vehicle in adaptation to the traffic,where the intervehicular distance is controlled for reducing the air drag coefficient so that both the energy consumption and battery aging are *** results show that for the single-vehicle controller,the battery degradation and energy consumption are,respectively,reduced by up to 25.7%and 3.2%compared with the cruise control *** on the non-cooperative controller,the HDT is able to follow preceding vehicles with different parameters with battery aging and energy consumption further,respectively,reduced by 2%–5%and 9%–10%compared with those of the single-vehicle controller.

关键词： electric trucks speed trajectory planning battery aging model predictive control non-cooperative platooning

MgN_(4)掺杂石墨烯CO氧化催化活性的密度泛函研究

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原子与分子物理学报 2025年第2期42卷 57-62页

作者：袁利郑灵丹周慧颖徐先燕广州医科大学公共卫生学院广州511436 韶关学院化学与土木工程学院韶关512005

鉴于镁卟啉所呈现的催化活性,采用密度泛函理论考察了MgN_(4)结构掺杂石墨烯的CO氧化催化活性.研究发现MgN_(4)掺杂石墨烯具有良好的结构稳定性,O_(2)优先吸附在金属活性位点且不易解离.其CO氧化以Eley-Rideal(ER)机理实现,决速步能垒仅... 详细信息

鉴于镁卟啉所呈现的催化活性,采用密度泛函理论考察了MgN_(4)结构掺杂石墨烯的CO氧化催化活性.研究发现MgN_(4)掺杂石墨烯具有良好的结构稳定性,O_(2)优先吸附在金属活性位点且不易解离.其CO氧化以Eley-Rideal(ER)机理实现,决速步能垒仅为0.67 eV,与FeC_(3)、AlN_(4)掺杂石墨烯具有相当的催化活性.MgN_(4)掺杂石墨烯有望是一种具有潜在CO氧化催化活性的催化剂.

关键词： MgN_(4)掺杂石墨烯 CO氧化密度泛函理论

Regioselective Decomposition of 11-Substituted-16α,17α- methyleneazopregna-1,4-dien-3,20-dione

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Chinese Chemical Letters 2006年第1期17卷 12-14页

作者： Bing YANG Jun YANG ling ling WENG Hu zheng The West China School of Pharmacy Sichuan University Chengdu 610041

Regioselective decomposition of 11-substituted- 16α, 17α-methyleneazopregna- 1,4-dien- 3, 20-dione Ⅰ proceeded smoothly through thermal decomposition in the presence of BF3·Et2O or HClO4 with high yields. Ⅰ was converted to 11-substituted-16-methylpregna-1, 4, 16（17）-trien-3, 20-dione Ⅱ by the thermal decomposition, while with HClO4 ad a catalyst, 11-substituted-16α, 17α-methylenepregna-1, 4-dien-3, 20-dione Ⅲ was the main product. However, when BF3·Et2O was used as catalyst, a mixture of Ⅱ and Ⅲ（1 ： 3） was obtained.

关键词： Methyleneazopregnanes methylenepregnancs regioselective decomposition,