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On a Class of Weak Nonhomogeneous Affine Bi-frames for Reducing Subspaces of L^2(R^d)

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Acta Mathematica Sinica,English Series 2017年第10期33卷 1339-1351页

作者： jian ping zhang Yun zhang LI College of Applied Sciences Beijing University of Technology Beijing 100124 P. R. China

For refinable functiombased affine bi-frames, nonhomogeneous ones admit fast algorithms and have extension principles as homogeneous ones. But all extension principles are based on some restrictions on refinable functions. So it is natural to ask what are expected from general refinable functions. In this paper, we introduce the notion of weak nonhomogeneous affine bi-frame （WNABF）. Under the setting of reducing subspaces of L2（Rd）, we characterize WNABFs and obtain a mixed oblique extension principle for WNABFs based on general refinable functions.

关键词： Frame reducing subspace weak affine bi-frame weak nonhomogeneous affine bi-frame,extension principle

Layered space time codes and capacity analysis in correlated fading channels with distributed antenna system

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The Journal of China Universities of Posts and Telecommunications 2011年第1期18卷 28-35页

作者： XIONG Fei zhang jian-hua zhang ping Wireless Technology Innovation Institute Key Laboratory of Universal Wireless Communication Ministry of Education 13eijing University of Posts and Telecommunications Beijing 100876 China

In this paper we have investigated the performance of downlink generalized distributed antenna system （GDAS）. Under the assumption of spatial correlated fading conditions, we have derived the numeric expression of correlated coefficients according to series of Bessel function, and have lifted the range restriction of the mean angle of incident. Moreover, the architecture of distributed generalized layered space time codes （GLST） has been considered in order to achieve both multiplexing gain and diversity gain while we have used basis vector from null space instead of orthogonal set to obtain the same system performance but with lower complexity. Furthermore, in order to maximize the capacity, Gerschgorin circles based fast antenna selection algorithms have been evaluated including a discussion of those simulation results.

关键词： GDAS GLST capacity correlated fading channel

Indoor channel characteristics based on wideband MIMO measurements at 5.25 GHz

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The Journal of China Universities of Posts and Telecommunications 2008年第4期15卷 46-50页

作者： GAO Xin-ying zhang jian-hua zhang ping Key Laboratory of Universal Wireless Communications Ministry of Education Wireless Technology Innovation Institute Beijing University of Posts and Telecommunications Beijing 100876 China

Extensive indoor channel measurements were conducted in Beijing with wideband multiple-input multiple-output （MIMO） sounder at 5.25 GHz. Both line-of-sight （LOS） and non-line-of-sight （NLOS） propagation were measured in the indoor office and hotspot scenarios. On the basis of measured data, statistical channel characteristics are presented in this article, including the empirical path loss （PL） models, three excess delay parameters, circular azimuth spread （CAS）, and circular elevation spread （CES）. Comparative analysis of different propagation mechanisms in two scenarios is conducted. These values are significant for indoor coverage and technical research of MIMO and orthogonal frequency division multiplexing （OFDM） for the international mobile telecommunications-advanced （IMT-Advanced） system.

关键词： channel measurement wideband MIMO path loss excess delay circular azimuth spread circular elevation spread IMT-Advanced

Digestive tract reconstruction options after laparoscopic gastrectomy for gastric cancer

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World Journal of Gastrointestinal Oncology 2020年第1期12卷 21-36页

作者： jian Shen Xiang Ma Jing Yang jian-ping zhang Department of General Surgery The Second Affiliated Hospital of Nanjing Medical UniversityNanjing 210011Jiangsu ProvinceChina Cardiovascular Center The Second Affiliated Hospital of Nanjing Medical UniversityNanjing 210011Jiangsu ProvinceChina

In addition to the popularity of laparoscopic gastrectomy(LG),many reconstructive procedures after LG have been *** resection and lymphatic dissection determine long-term survival;however,the election of a reconstruction procedure determines the postoperative quality of life for patients with gastric cancer(GC).Presently,no consensus exists regarding the optimal reconstructive *** this review,the current state of digestive tract reconstruction after LG is *** to the determining influence of the tumor site on the procedures of surgical resection and reconstruction,we divide these reconstruction procedures into three categories consistent with the resection *** focus on the technical tips of every reconstruction procedure and examine the surgical outcomes(length of surgery and blood loss)and postoperative complications(anastomotic leakage and stricture)to facilitate gastrointestinal surgeons to understand the merits and demerits of every reconstruction procedure.

关键词： Digestive tract reconstruction Laparoscopic gastrectomy Gastric cancer Quality of life

Controlling oxygen content in electro-slag remelting steel by optimizing slag-steel reaction process

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China Foundry 2023年第6期20卷 503-510页

作者： Dian-dong Sun Yong Wang Lei Jin Zong-xu Pang jian Huang jian-ping zhang Iron&Steel Research Institutes of Ansteel Group Corporation Anshan 114009LiaoningChina State Key Laboratory of Metal Material for Marine Equipment and Application Anshan 114009LiaoningChina Shenyang Research Institute of Foundry Co. Ltd.CAMNational Key Laboratory of Advanced Casting TechnologiesShenyang 110022China

The thermodynamic equilibrium of deoxidation reactions between molten slag and steel was calculated using a slag-steel coupling thermodynamic model and the mass conservation model based on the ion-molecular coexistence *** study focused on the effects of slag composition and deoxidizer type on the oxygen content of low alloy steel during the electroslag remelting(ESR)*** measured and predicted values of the oxygen content in remelted ingots,and the contents of FeO and MnO in slags were compared and *** show that the measured content of total oxygen has a certain correlation with the trend of dissolved oxygen predicted by the model when using Ca-Si alloys as deoxidizer,but it is not correlated with the trend of dissolved oxygen predicted by the model when using Al as *** deoxidation mechanisms of Ca-Si and Al are ***-Si alloy directly reacts with FeO and MnO in slag to reduce the oxygen potential of slag,hence it can inhibit the transfer of oxygen from the slag to molten ***,when Al deoxidizer is used,the oxygen content in steel is mainly reduced through floating up the alumina *** to Al,utilizing Ca-Si alloy as a deoxidizer is more effective in reducing the oxygen content and the amount of inclusions in ESR ingot.

关键词： ion-molecular coexistence theory slag-steel reaction deoxidation electro-slag remelting

Triplet excitation dynamics of β-carotene studied in three solvents by ns flash photolysis spectroscopy

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Chinese Chemical Letters 2017年第1期28卷 83-88页

作者： Ying Jia Ying Shi Peng Wang jian-ping zhang Department of Chemistry Renmin University of China Beijing 100872 China

Upon anthracene-sensitizing, triplet excitation dynamics of β-carotene（β-Car） were studied in nhexane, in methanol, and in acetonitrile, respectively, by ns flash photolysis spectroscopy. In n-hexane,only the bleaching of the ground state absorption（GSB） and the excitation triplet（^3Car＊） absorption were observed, and there were no cationic species detected. In both methanol and acetonitrile, similar excitation dynamics were observed, i.e.,^3Car＊ having a similar lifetime to that in n-hexane, and the immediate generation of the cation dehydrodimer（^#[Car]2^＋） upon excitation following transformation into the radical cation Car＊^＋, since Car＊^＋ has much longer lifetime in acetonitrile than in methanol. The results prove that both solvent and carotenoid structure determine the triplet excitation mechanism.

关键词： β-Carotene Triplet excitation dynamics Solvent effect ns Flash photolysis

An Improved Frequency Synchronizer for Mobile OFDMSystems

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The Journal of China Universities of Posts and Telecommunications 2005年第4期12卷 26-31页

作者： QIANG jian-feng zhang ping Department of Telecommunications Engineering Beijing University of Posts and Telecommunications Beijing 100876 P.R. China

Orthogonal Frequency Division Multiplexing （ OFDM） system is sensitive to Carrier Frequency Offset （ CFO ）. In this paper, traditional Maximum Likelihood Estimators （MLE） for CFO of OFDM are introduced first. Then, averaging method and a-filter are introduced as Low Pass Filter （LPF） to improve the performance of cyclic prefix estimator. The bandwith of LPF is determined by the coherence time of radio channel. Estimation performance in multipath channel is analyzed. Outlier picking-out scheme is proposed to improve performance further. Performance of close-loop structure is presented briefly, which is worse than that of open-loop structure. Finally, a parallel switch structure of frequency synchronizer is proposed for mobile OFDM systems. The scheme ezcploits training sequence and cyclic prefix. The proposed synchronizer has a wide acquisition range. It is accurate and robust in both AWGN channel and multipath channels. The complexity is low due to functionality of a-filter. A better performance of frequevlcy synchronization is obtained comparing to that of existing Maximum Likelihood Estimator（ MLEs）. We achieve these advantages without loss of bandwidth efficiency.

关键词： OFDM frequency synchronizer parallel switch structure MLE Low Pass Filter (LPF) open-loop structure

Na^+ and Water Uptake in Relation to the Radial Reflection Coefficient of Root in Arrowleaf Saltbush Under Salt Stress

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Journal of Integrative Plant Biology 2007年第9期49卷 1334-1340页

作者： Xin-Fu Bai jian-Jun Zhu ping zhang Yan-Hua Wang Li-Qun Yang Lei zhang College of Life Sciences Ludong University Yantai 264025 China

The response of halophyte arrowleaf saltbush （Atriplex triangularis Willd） plants to a gradient of salt stress were investigated with hydroponically cultured seedlings. Under salt stress, both the Na^＋ uptake into root xylem and negative pressures in xylem vessels increased with the elevation of salinity （up to 500 mol/m^3） in the root environment. However, the increment in negative pressures in root xylem far from matches the decrease in the osmotic potential of the root bathing solutions, even when the osmotic potential of xylem sap is taken into consideration. The total water potential of xylem sap in arrowleaf saltbush roots was close to the osmotic potential of root bathing solutions when the salt stress was low, but a progressively increased gap between the water potential of xylem sap and the osmotic potential of root bathing solutions was observed when the salinity in the root environment was enhanced. The maximum gap was 1.4 MPa at a salinity level of 500 mol/m^3 without apparent dehydration of the tested plants. This discrepancy could not be explained with the current theories in plant physiology. The radial reflection coefficient of root in arrowleaf saltbush decreased with the enhanced salt stress was and accompanied by an increase in the Na^＋ uptake into xylem sap. However, the relative Na^＋ in xylem exudates based on the corresponding NaCl concentration in the root bathing solutions showed a tendency of decrease. The results showed that the reduction in the radial reflection coefficient of roots in the arrowleaf saltbush did not lead to a mass influx of NaCl into xylem when the radial reflection coefficient of the root was considerably small; and that arrowleaf saltbush could use small xylem pressures to counterbalance the salt stresses, either with the uptake of large amounts of salt, or with the development of xylem pressures dangerously negative. This strategy could be one of the mechanisms behind the high resistance of arrowleaf saltbush plants to

关键词： anti-osmosis arrowleaf saltbush (Atriplex triangularis Willd) radial reflection coefficient of root salt stress xylem pressure

Temporal variations of CO_2 concentration near land surface and its response to meteorological variables in Heihe River Basin, northwest China

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Journal of Environmental Sciences 2006年第4期18卷 708-715页

作者： CHEN Ren-sheng KANG Er-si JI Xi-bin YANG jian-ping zhang Zhi-hui YANG Yong Laboratory of Watershed Hydrology and Ecology Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy ofSciences Lanzhou 730000 China

Atmospheric CO2 concentration （CC） near land surface and meteorological variables have been measured at four sites, named Yeniugou （alpine meadow and permafrost）, Xishui （mountainous forest）, Linze （oasis edge） and Ejina （lower desert）, respectively, in Heihe River Basin, northwest China. The results showed that, the half hourly CC at night was larger than in daytime, and the daily averaged CC was the largest in winter. The averaged CC of 932 d at the Linze was about 418 ppm, was about 366 ppm in the 762 d at the Ejina. In the same period from September 23 to November 9, 2004, the averaged CC was about 625,334, 436 and 353 ppm, at Yeniugou, Xishui, Linze and Ejina, respectively. The linear relationship between daily averaged CC and air temperature T was negative, between CC and relative humidity （RH） was positive. The linear CC-atmospheric pressure （A P） relationship was negative at the Linze and Yeniugou, was positive at the Ejina. The relationship between CC and global radiation R was exponent, and soil temperature Ts was negative linear, and soil water content was complex. The correlation between CC and wind speed was not existent. Using meteorological variables together to simulate CC, could give good results.

关键词： CO2 concentration meteorological variables Heihe River Basin