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Metal Ion Complexation of Bilirubin Monolayer

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Chinese Chemical Letters 1999年第6期10卷 507-510页

作者： jian-Ming OUYANG chuan LI Wei Han LING Wen Jie zheng (Department of Chemistry. Jinan University. Guangzhou 510632) Jinan Univ Dept Chem Guangzhou 510632 Peoples R China

The surface pressure-area isotherms of bilirubin (BR) monolayers at an air-water interface on subphases with and without metal ions were investigated. The formation of BR-metal complexes leads to changes in the shape of isotherms of BR and changes in UV-visible absorption spectra of the monolayer assemblies. In XPS spectra new XPS peaks assigned to the metal ions containing subphases appeared. Low-angle X-ray diffraction indicates this Y-type LB films of MBR were formed with bilayer spacing of ca. 2.1 nm.

关键词： monolayer bilirubin complexation

Tailoring the photophysical and photovoltaic properties of boron-difluorodipyrromethene dimers

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Chinese Chemical Letters 2017年第4期28卷 875-880页

作者： Wen-Xu Liu jian-Nian Yao chuan-Lang Zhan Beijing National Laboratory of Molecular Science CAS Key Laboratory of PhotochemistryInstitute of ChemistryChinese Academy of SdencesBeijing 100190China

Five boron-difluorodipyrromethene（BODIPY） dimers have been designed and synthesized successfully via acid-catalysed condensation and Pd-catalysed cross-coupling *** structural modification,including verifying the structures of the π-bridges,altering the positions the bridges link（meso-or β-positions）,and regulating the molecular planarity,can modulate the photophysical properties and the aggregation behaviors of the five dimers ***-processed organic solar cells were fabricated to evaluate the photovoltaic properties of these molecules further either as acceptors or *** using as nonfullerene acceptor and blended with the polymer donor of PTB7,an opencircuit voltaic（V_（oc）） of 1.12 and 1.08 V was achieved from the thiophene and benzodithiophene bridged BODIPY dimers,*** V_（oc） is among the top values achieved from the non-fullerene organic solar cells so far.

关键词： BODIPY Nonfullerene acceptor Small molecule donor Photovoltaic cell Solution-processed

Grid authentication from identity-based cryptography without random oracles

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The Journal of China Universities of Posts and Telecommunications 2008年第4期15卷 55-59页

作者： zheng Yan WANG Hai-yan WANG Ru-chuan College of Computer Science Nanjing University of Posts and Telecommunications Nanjing 210003 China

As a critical component of grid security, secure and efficient grid authentication needs to be well addressed. However, the most widely accepted and applied grid authentication is based on public key infrastructure （PKI） and X.509 certificates, which make the system have low processing efficiency and poor anti-attack capability. To accommodate the challenge of grid authentication, this article aims at designing a secure and efficient method for grid authentication by employing identity-based cryptography （IBC）. Motivated by a recently proposed secure and efficient identity-based encryption （IBE） scheme without random oracles, an identity-based signature （IBS） scheme is first proposed for the generation of private key during grid authentication. Based on the proposed IBS and the former IBE schemes, the structure of a novel grid authentication model is given, followed by a grid authentication protocol described in detail. According to the theoretical analysis of the model and the protocol, it can be argued that the new system has improved both the security and efficiency of the grid authentication when compared with the traditional PKI-based and some current IBC-based models.

关键词： grid authentication security IBC scheme

Density Functional Studies on Isonicotinato Lead(II) Complex [Pb(C_5H_4NCOO)_2]

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Chinese Journal of Structural Chemistry 2006年第6期25卷 657-662页

作者： ZHAO Pu-Su jian Fang-Fang LI Chun-Lei zheng jian Department of Chemistry Huaiyin Teachers＇College Huaian Jiangsu 223001 China New Materials ＆ Function Coordination Chemistry Laboratory Qingdao University of Science and Technology Qingdao Shandong 266042 China

The title compound of isonicotinato lead（Ⅱ） [Pb（C5H4NCOO）2] has been optimized at B3LYP/LANL2DZ level of theory and calculated results show that the lead（Ⅱ） ion adopts 4-coordinate geometry. Atomic charge distributions indicate that during forming the title compound, each isonicotinic acid ion transfers -0.452 e to lead（Ⅱ） ion. The electronic spectra calculations show that there exist two absorption bands and the electronic transitions are mainly derived from the contribution of intraligand π→π^＊ transition and ligand-to-metal charge transfer （LMCT） transition. The thermodynamic properties of the title compound at different temperatures have been calculated and corresponding relations between property and temperature have also been obtained. The calculation of the second order optical nonlinearity was carried out, and the molecular hyperpolarizability was 3.62365^＊10^-30 esu.

关键词： isonicotinato lead(Ⅱ) complex density functional theory electronic spectra thermal property analysis the second order optical nonlinearity

A novel MAC mechanism to resolve 802.11 performance anomaly

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第10期8卷 1573-1583页

作者： CHENG Yan-hong LI Zhi-shu XING jian-chuan ZHU Li School of Computer Science Sichuan University Chengdu 610065 China

In the 802.11b networks, the guarantee of an equal long-run channel access probability causes performance anomaly in a multi-rate wireless cell. Much interest has been involved in this issue and many effective mechanisms have been proposed. The usual MAC layer solutions include the initial contention window adaptation, the maximum transfer unit size adaptation and the packet bursting. In this paper, we propose a novel approach which introduces a new parameter called the transmission prob- ability pt to the legacy protocol. By adjusting pt according to the transmission rate, the proposed scheme can solve the performance anomaly problem cleanly. Throughput analysis and performance evaluation show that our scheme achieves significant im- provement in the aggregate throughput and the fairness.

关键词： IEEE 802.11 WLAN Transmission probability Performance anomaly

Storage life prediction under pre-strained thermally-accelerated aging of HTPB coating using the change of crosslinking density

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Defence Technology（防务技术） 2021年第4期17卷 1387-1394页

作者： Yong-qiang Du jian zheng Gui-bo Yu Shijiazhuang Campus Army Engineering UniversityShijiazhuang050003China

In order to predict the storage life of a certain type of HTPB(hydroyl-terminated polybutadiene)coating at 25℃ and analyze the influence of pre-strain on the storage life,the accelerated aging tests of HTPB coating at 40℃,50℃,60℃,70℃ with the pre-strain of 0%,3%,6%,9%,respectively were carried *** variation regularity of the change of crosslinking density was analyzed and the aging model of HTPB coating under pre-strained thermally-accelerated aging was *** storage life of HTPB coating at 25℃ was estimated by using the Berthelot equation as the end point of the aging life with a 30% decrease in maximum *** results showed that the change of crosslinking density of HTPB coating increased with the increase of aging temperature and aging time,and decreased with the increase of *** 0% prestrain,the relationship between the change of crosslinking density of HTPB coating and the aging time can be described by the logarithmic model with the confidence probability greater than 99%.The stress relaxation phenomenon existed under 3%,6%and 9%pre-strained *** aging model considering chemical aging and pre-strain was established with the confidence probability greater than 90%.The storage life of HTPB coating was 15.2935 years at 25C under 0% prestrain,which was reduced by 13.9007%,75.6949% and 89.7859% under 3%,6% and 9% pre-strain,*** existence of pre-strain has a serious impact on the storage life of HTPB coating,therefore,the pre-strain should be avoided as much as possible during the actual storage.

关键词： HTPB coating Crosslinking density Aging model Storage life prediction Berthelot

The dominant driving force for supercontinent breakup: Plume push or subduction retreat?

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Geoscience Frontiers 2018年第4期9卷 997-1007页

作者： Nan Zhang Zhuo Dang chuan Huang zheng-Xiang Li Key Laboratory of Orogenic Belts and Crustal Evolution School of Earth and Space SciencesPeking University Earth Dynamics Research Group ARC Center of Excellence for Core to Crust Fluid Systems(CCFS)and The Institute for Geoscience Research(TIGeR)School of Earth and Planetary SciencesCurtin University

Understanding the dominant force responsible for supercontinent breakup is crucial for establishing Earth＇s geodynamic evolution that includes supercontinent cycles and plate tectonics. Conventionally,two forces have been considered： the push by mantle plumes from the sub-continental mantle which is called the active force for breakup, and the dragging force from oceanic subduction retreat which is called the passive force for breakup. However, the relative importance of these two forces is unclear. Here we model the supercontinent breakup coupled with global mantle convection in order to address this question. Our global model features a spherical harmonic degree-2 structure, which includes a major subduction girdle and two large upwelling（superplume） systems. Based on this global mantle structure,we examine the distribution of extensional stress applied to the supercontinent by both subsupercontinent mantle upwellings and subduction retreat at the supercontinent peripheral. Our results show that：（1） at the center half of the supercontinent, plume push stress is ～3 times larger than the stress induced by subduction retreat;（2） an average hot anomaly of no higher than 50 K beneath the supercontinent can produce a push force strong enough to cause the initialization of supercontinent breakup;（3） the extensional stress induced by subduction retreat concentrates on a ～600 km wide zone on the boundary of the supercontinent, but has far less impact to the interior of the supercontinent. We therefore conclude that although circum-supercontinent subduction retreat assists supercontinent breakup, sub-supercontinent mantle upwelling is the essential force.

关键词： Supercontinent breakup Plume push Subduction retreat

Fork-Join program response time on multiprocessors with exchangeable join

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2006年第6期7卷 927-936页

作者： WANG Yong-cai ZHAO Qian-chuan zheng Da-zhong Center for Intelligent and Networked Systems Department of Automation Tsinghua University Beijing 100084 China

The Fork-Join program consisting of K parallel tasks is a useful model for a large number of computing applications. When the parallel processor has multi-channels, later tasks may finish execution earlier than their earlier tasks and may join with tasks from other programs. This phenomenon is called exchangeable join (EJ), which introduces correlation to the task’s service time. In this work, we investigate the response time of multiprocessor systems with EJ with a new approach. We analyze two aspects of this kind of systems: exchangeable join (EJ) and the capacity constraint (CC). We prove that the system response time can be effectively reduced by EJ, while the reduced amount is constrained by the capacity of the multiprocessor. An upper bound model is constructed based on this analysis and a quick estimation algorithm is proposed. The approximation formula is verified by extensive simulation results, which show that the relative error of approximation is less than 5%.

关键词： Exchangeable join First come first served (FCFS) Fork-Join Multiprocessor Response time

A graph deep learning method for landslide displacement prediction based on global navigation satellite system positioning

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Geoscience Frontiers 2024年第1期15卷 29-38页

作者： chuan Yang Yue Yin jiantong Zhang Penghui Ding jian Liu China Transport Telecommunications and Information Center Beijing 100011PR China China Nuclear Power Engineering Co. LtdBeijing 100011PR China

The accurate prediction of displacement is crucial for landslide deformation monitoring and early *** study focuses on a landslide in Wenzhou Belt Highway and proposes a novel multivariate landslide displacement prediction method that relies on graph deep learning and Global Navigation Satellite System(GNSS)*** model the graph structure of the monitoring system based on the engineering positions of the GNSS monitoring points and build the adjacent matrix of graph *** construct the historical and predicted time series feature matrixes using the processed temporal data including GNSS displacement,rainfall,groundwater table and soil moisture content and the graph *** introduce the state-of-the-art graph deep learning GTS(Graph for Time Series)model to improve the accuracy and reliability of landslide displacement prediction which utilizes the temporal-spatial dependency of the monitoring *** approach outperforms previous studies that only learned temporal features from a single monitoring point and maximally weighs the prediction performance and the priori graph of the monitoring *** proposed method performs better than SVM,XGBoost,LSTM and DCRNN models in terms of RMSE(1.35 mm),MAE(1.14 mm)and MAPE(0.25)evaluation metrics,which is provided to be effective in future landslide failure early warning.

关键词： Landslide displacement prediction GNSS positioning Graph deep learning