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A relaxation scheme for a multi-class Lighthill-Whitham-Richards traffic flow model

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第12期10卷 1835-1844页

作者： Jian-zhong CHEN Zhong-ke SHI Yan-mei hu College of Automation Northwestern Polytechnical University Xi 'an 710072 China College of Science Chang 'an University Xi 'an 710064 China

We present a high-resolution relaxation scheme for a multi-class Lighthill-Whitham-Richards (MCLWR) traffic flow model. This scheme is based on high-order reconstruction for spatial discretization and an implicit-explicit Runge-Kutta method for time integration. The resulting method retains the simplicity of the relaxation schemes. There is no need to involve Riemann solvers and characteristic decomposition. Even the computation of the eigenvalues is not required. This makes the scheme particularly well suited for the MCLWR model in which the analytical expressions of the eigenvalues are difficult to obtain for more than four classes of road users. The numerical results illustrate the effectiveness of the presented method.

关键词： Relaxation scheme Multi-class LWR model Traffic flow CWENO reconstruction Implicit-explicit Runge-Kutta

Preparation of TiO_(2) Supported Mxene Catalyst for High Efficiency Hydrogen Production

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Journal of Wuhan University of Technology(Materials Science) 2023年第2期38卷 286-291页

作者： hu mei XIN Jin LIU Zhenyu ZENG hui WANG Yanze Wuhan Institute of Marine Electric Propulsion Wuhan430064China State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhan430070China

We studied a method to prepare a novel titanium dioxide(TiO_(2))composite photocatalyst,starting from improving the separation efficiency of photogenerated electrons and *** TiO_(2)microspheres were prepared by sol-gel method and loaded onto Ti3C2Tx(Mxene).The high electrical conductivity of Mxene was utilized to transfer photogenerated electrons quickly and effectively prevent their *** adjusting the addition amount of Mxene,the hydrogen production efficiency of the sample was greatly improved,and the maximum efficiency reached 135.2μmol·g^(-1)·h^(-1),which was twice that of pure TiO_(2).The nanocomposites were characterized by XRD,PL,TEM and SEM analysis and electrochemical methods,and the test proved that the improvement of hydrogen production efficiency was caused by the improvement of the separation efficiency of photogenerated electrons and *** work demonstrates the application of Mxene as a catalyst to improve efficiency and broadens the application prospects of Mxene.

关键词： TiO_(2) Mxene hydrogen production photocatalysis

Synthesis and Crystal Structure of an Indenylnickel(II) NHC Complex (Ind)NiBr(1,3-bisbenzylimidazol-2-ylidene)

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Chinese Journal of Structural Chemistry 2006年第10期25卷 1255-1259页

作者： hu Dong-mei SUN Hong-mei WANG Yong-Sheng SHEN Qi XUE Feng The Key Lab of Organic Synthesis of Jiangsu Province College of Chemistry and Chemical Engineering Suzhou University Suzhou 215123 China Department of Chemistry The National University of Singapore Singapore 117543 Republic of Sinapore

The complex （Ind）NiBr（1,3-bisbenzylimidazol-2-ylidene）（Ind = indenyl） 1 has been prepared in ca. 65% yield via the reaction of （Ind）2Ni with an equivalent of 1,3-bis-benzylimidazolium bromide in THF/CH2Cl2 at 45℃, supported by elemental analysis, NMR spectroscopy and X-ray crystal determination. The crystal belongs to the triclinic system, space group Pi with a = 7.072（1）, b = 11.264（2）, c = 14.541（3）°A, α = 102.21（3）,β = 93.44（3）,γ = 90.81（3）°, V = 1129.7（4）°A^3, Z = 2, Mr = 502.08, Dc = 1.476 g/cm^3, F（000） = 512, μ= 2.642 mm^-1, R = 0.0490 and wR = 0.1137 for 3913 observed reflections （I〉 2σ（I））. The center nickel atom is coordinated by a bromide ligand, a carbene carbon and three carbon atoms of the five-membered indenyl group to form either a highly distorted square pyramid or a highly distorted square plane.

关键词： nickel complex indenyl ligand N-heterocyclic carbene

华北平原地区HCFC-142b排放清单建立及环境影响分析

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中国环境科学 2024年第5期44卷 2847-2852页

作者：张大宇吴婧王彤刘泽华胡冬梅彭林华北电力大学环境科学与工程学院资源环境系统优化教育部重点实验室北京102206 北京交通大学环境学院智能交通绿色低碳技术教育部工程研究中心北京100044 北京交通大学交通能源与环境研究院北京100044

选择华北平原地区作为研究对象,采用排放因子法建立该区域2000~2060年HCFC-142b排放清单,探讨了其空间分布特征,并对不同行业开展了排放结果的敏感性分析.结果显示,该地区2000~2019年HCFC-142b累计排放量为34.0kt.其中,江苏、山东和河... 详细信息

选择华北平原地区作为研究对象,采用排放因子法建立该区域2000~2060年HCFC-142b排放清单,探讨了其空间分布特征,并对不同行业开展了排放结果的敏感性分析.结果显示,该地区2000~2019年HCFC-142b累计排放量为34.0kt.其中,江苏、山东和河南是排放量最大省份,累计排放量分别为595.1t、267.6t和***泡沫排放最大,其次是ICR行业,两个行业对排放结果最敏感的因子分别是初始排放因子和设备废弃率.排放预测显示,在《蒙特利尔议定书》管控下,该地区2020~2060年的累计减排潜力为151.9kt(9.9kt CFC-11-eq;350.9mt CO_(2)-eq).

关键词：臭氧类消耗全球变暖华北平原地区排放清单减排潜力

Testing Serial Correlation in Semiparametric Varying-Coefficient Partially Linear EV Models

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Acta Mathematicae Applicatae Sinica 2008年第1期24卷 99-116页

作者： Xue-mei hu Zhi-zhong Wang Feng Liu School of Mathematics and Computing Technology Central South University Changsha 410075 China School of Mathematics and Physics Chongqing Institute of Technology Chongqing 400050 China

This paper studies estimation and serial correlation test of a semiparametric varying-coefficient partially linear EV model of the form Y = X^Tβ ＋Z^Tα（T）＋ε,ξ = X ＋ η with the identifying condition E[（ε,η^T）^T] =0, Cov[（ε,η^T）^T] = σ^2Ip＋1. The estimators of interested regression parameters /3 , and the model error variance σ2, as well as the nonparametric components α（T）, are constructed. Under some regular conditions, we show that the estimators of the unknown vector β and the unknown parameter σ2 are strongly consistent and asymptotically normal and that the estimator of α（T） achieves the optimal strong convergence rate of the usual nonparametric regression. Based on these estimators and asymptotic properties, we propose the VN,p test statistic and empirical log-likelihood ratio statistic for testing serial correlation in the model. The proposed statistics are shown to have asymptotic normal or chi-square distributions under the null hypothesis of no serial correlation. Some simulation studies are conducted to illustrate the finite sample performance of the proposed tests.

关键词： Varying-coefficient model partial linear EV model the generalized least squares estimation serial correlation empirical likelihood

Numerical solutions of a multi-class traffic flow model on an inhomogeneous highway using a high-resolution relaxed scheme

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Journal of Zhejiang University-Science C(Computers and Electronics) 2012年第1期13卷 29-36页

作者： Jian-zhong CHEN Zhong-ke SHI Yan-mei hu College of Automation Northwestern Polytechnical University Xi＇an 710072 China College of Science Chang ＇an University Xi ＇an 710064 China

A high-resolution relaxed scheme which requires little information of the eigenstructure is presented for the multiclass Lighthill-Whitham-Richards （LWR） model on an inhomogeneous highway. The scheme needs only an estimate of the upper boundary of the maximum of absolute eigenvalues. It is based on incorporating an improved fifth-order weighted essentially non-oscillatory （WENO） reconstruction with relaxation approximation. The scheme benefits from the simplicity of relaxed schemes in that it requires no exact or approximate Riemann solvers and no projection along characteristic directions. The effectiveness of our method is demonstrated in several numerical examples.

关键词： Relaxed scheme Multi-class model Weighted essentially non-oscillatory (WENO) reconstruction

Polyaspartic acid mediates the absorption and translocation of mineral elements in tomato seedlings under combined copper and cadmium stress

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Journal of Integrative Agriculture 2019年第5期18卷 1130-1137页

作者： hu mei-mei DOU Qiao-hui CUI Xiu-min LOU Yan-hong ZhuGE Yu-ping National Engineering Laboratory for Efficient Utilization of Soil and Fertilizer Resources/College of Resource and Environment Shandong Agricultural University

Polyaspartic acid(PASP)is a nontoxic,biodegradable,environmentally friendly polymer and is widely used as a fertilizer synergist in agricultural *** many old orchards and vegetable gardens,highly fertile soil is often accompanied by severe heavy metal *** present study was designed to investigate mineral element interactions mediated by PASP under copper(Cu)+cadmium(Cd)combined stress to provide reasonable suggestions for scientific fertilization.A pot experiment was conducted in which tomato seedlings served as plant materials.A concentration of 700 mgPASP and foliar spraying application methods were selected based on previous *** treatments were applied:normal soil(control(CK)),Cu+Cd(combined stress),Cu+Cd+PASP,and normal soil+*** plant biomass,root activity,and mineral elements were measured,and these data were analyzed by Data Processing System(DPS)statistical *** results showed that,under Cu+Cd combined stress,PASP promoted stem diameter growth,root activity and chlorophyll content and ultimately increased the biomass of tomato seedlings to different ***,the content of both Cu and Cd and their individual accumulation in plants *** increased the distribution of Cu and Cd in the roots under Cu+Cd combined stress,and the translocation ability from the roots to shoots was significantly *** respect to essential elements,PASP promoted mainly the absorption and translocation of potassium(K),calcium(Ca),and magnesium(Mg),which greatly exerted physiological ***,the variation trends of Cu and Cd under normal soil conditions contrasted with those under stress *** respect to essential elements other than K,Ca,and Mg,PASP mostly restrained their absorption but promoted their *** regulatory mechanism of PASP differed between the combined stress conditions and normal soil *** the combined stress conditions,PASP seemed to mainly promote these

关键词： tomato seedlings polyaspartic acid Cu+Cd combined stress

Intrinsic Decoherence on Two-Qubit Heisenberg XX Chain

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Communications in Theoretical Physics 2007年第5期47卷 811-815页

作者： HE Zheng-Hong XIONG Zu-Hong hu Dong-mei School of Physics Southwest University Chongqing 400715 China

Quantum teleportation is investigated by using the entangled states of two-qubit Heisenberg XX chain in an external uniform magnetic field as resources in the model of Milburn＇s intrinsic decoherence. Though intrinsic decoherence on quantum entanglement and quantum teleportation exerts different effects in different initial systems, proper magnetic fields and probabilities of different eigenstates in the initial states can weaken the effects.

关键词： Heisenberg chain fidelity intrinsic decoherence entanglement

三种不同神经阻滞方法对乳腺良性肿瘤切除手术患者术后疼痛及应激反应的影响比较

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临床和实验医学杂志 2024年第17期23卷 1898-1902页

作者：胡剑梅刘印华全燕秦皇岛市妇幼保健院麻醉科河北秦皇岛066000

目的探究Ⅰ型胸神经胸壁神经阻滞(PECSⅠ)、Ⅱ型胸神经PECS(PECSⅡ)、前锯肌平面阻滞对乳腺良性肿瘤切除手术患者术后疼痛及应激反应的影响。方法选取研究对象为2021年11月至2023年11月在秦皇岛市妇幼保健院接受乳腺良性肿瘤切除手术... 详细信息

目的探究Ⅰ型胸神经胸壁神经阻滞(PECSⅠ)、Ⅱ型胸神经PECS(PECSⅡ)、前锯肌平面阻滞对乳腺良性肿瘤切除手术患者术后疼痛及应激反应的影响。方法选取研究对象为2021年11月至2023年11月在秦皇岛市妇幼保健院接受乳腺良性肿瘤切除手术的患者,共120例,患者均进行全身麻醉,采用信封法对患者进行分组:观察1组(n=42)接受PECSⅠ,观察2组(n=41)接受前锯肌平面阻滞;观察3组(n=37)接受PECSⅡ,术后均采用舒芬太尼行静脉自控镇痛,比较各组患者的舒芬太尼使用量、拔管时间、苏醒时间,比较各组患者皮肤痛觉阻滞总节段范围,并对患者术后不同时间的VAS评分、应激指标水平进行比较,记录并比较各组的不良反应情况。结果观察2组患者的舒芬太尼使用量高于观察1组、观察3组,差异有统计学意义(P0.05);观察2组、观察3组患者的拔管时间长于观察1组,差异有统计学意义(P0.05);观察2组苏醒时间长于观察1组,差异有统计学意义(P0.05)。观察2组在锁骨中线、腋前线的皮肤痛觉阻滞总节段均大于观察1组、观察3组,差异有统计学意义(P0.05);观察1组、观察2组、观察3组在腋中线及腋后线的皮肤痛觉阻滞总节段组间比较差异无统计学意义(P>0.05)。出复苏室时,3组间VAS评分差异无统计学意义(P>0.05),在术后4、12、24 h时,观察2组、观察3组的VAS评分低于观察1组,差异有统计学意义(P0.05)。3组患者的术前及术后2 h的去甲肾上腺素、肾上腺素及血管紧张素Ⅱ水平比较,组间差异均无统计学意义(P>0.05)。3组患者的不良反应比较,组间差异无统计学意义(P>0.05)。结论在乳腺良性肿瘤切除手术中,前锯肌平面阻滞在术后恢复、阻滞节段方面显示出优势,其镇痛效果、麻醉效果与胸椎旁神经阻滞相当。PECSⅠ、前锯肌平面阻滞、PECSⅡ均能够改善患者的术后疼痛情况,麻醉效果较好,可根据临床实际灵活选择。

关键词：胸壁神经阻滞前锯肌平面阻滞胸椎旁神经阻滞疼痛应激反应