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Future forestation in China should aim to align the temporal service window of the forest carbon sink with the“carbon neutrality”strategy

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Science China Earth Sciences 2023年第12期66卷 2971-2976页

作者： Hao xu Chao YUE Shilong piao College of Urban and Environmental Sciences Peking UniversityBeijing 100871China Institute of Soil and Water Conservation Northwest A&F UniversityYangling 712100China Institute of Tibetan Plateau Research Chinese Academy of SciencesBeijing 100101China

*** Carbon sequestration in forest ecosystems worldwide dominates the current global terrestrial carbon sink,offsetting approximately 26% of global anthropogenic carbon emissions annually(Pan et al.,2011).

关键词： service annually forest

A one-year trial of entecavir treatment in patients with HBeAg-positive chronic hepatitis B

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World Journal of Gastroenterology 2007年第31期13卷 4264-4267页

作者： Fen-Yu Ren Dong-Ming piao Xi-xu piao Department ofGastroenterology and Hepatology Yanbian University HospitalYanji 133000 Jilin Province China

To evaluate the efficacy and safety of entecavir （ETV） in hepatitis Be antigen （HBeAg）-positive chronic hepatitis B （CriB） patients who had not received a nucleoside analogue and who had failed in lamivudine （LVD） therapy. METHODS： Sixty-one patients were divided into three groups. Forty-two patients who had not received a nucleoside analogue were randomized into two groups： group A （n = 21） received LVD 100 mg/d and group B （n -- 21） received ETV 0.5 mg/d. The remaing 19 patients treated with LVD （n = 19）, who switched to ETV 1.0 mg/d served as group C. All patients were treated for 48 wk. HBV DNA levels were measured with polimerase- chain-reaction （PCR） analysis. Liver function tests, HBV serology and safety assessments were also conducted. RESULTS： Significantly more patients in group B （52.1% and 71.4%） had undetectable HBV DNA levels than in groups A （35.8% and 38%; P 〈 0.0001） and C （10.6% and 21.1%, P 〈 0.0001） at wk 24 and 48, respectively. At wk 48, ALT levels were normalized in more patients in group B （85.7%） than in groups A （76.2%） and C （74%）. CONCLUSION： ETV had a significantly higher response rate than LVD in patients with HBeAg-positive CriB who had not previously received a nucleoside analogue; ETV can effectively inhibit the replication of HBV DNA and normalize the levels of ALT in refractory CriB patients treated with LVD; and ETV is safe in clinical application.

关键词： Entecavir Lamivudine Lamivudinerefractory Chronic hepatitis B, HBV DNA

Perfectly Matched Layer for an Elastic Parabolic Equation Model in Ocean Acoustics

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Journal of Ocean University of China 2017年第1期16卷 57-64页

作者： xu Chuanxiu ZHANG Haigang piao Shengchun yang Shi’e SUN Sipeng TANG Jun Acoustic Science and Technology Laboratory Harbin Engineering UniversityHarbin 150001P.R.China College of Underwater Acoustic Engineering Harbin Engineering UniversityHarbin 150001P.R.China

The perfectly matched layer(PML) is an effective technique for truncating unbounded domains with minimal spurious reflections. A fluid parabolic equation(PE) model applying PML technique was previously used to analyze the sound propagation problem in a range-dependent waveguide(Lu and Zhu, 2007). However, Lu and Zhu only considered a standard fluid PE to demonstrate the capability of the PML and did not take improved one-way models into consideration. They applied a [1/1] Padé approximant to the parabolic equation. The higher-order PEs are more accurate than standard ones when a very large angle propagation is considered. As for range-dependent problems, the techniques to handle the vertical interface between adjacent regions are mainly energy conserving and single-scattering. In this paper, the PML technique is generalized to the higher order elastic PE, as is to the higher order fluid PE. The correction of energy conserving is used in range-dependent waveguides. Simulation is made in both acoustic cases and seismo-acoustic cases. Range-independent and range-dependent waveguides are both adopted to test the accuracy and efficiency of this method. The numerical results illustrate that a PML is much more effective than an artificial absorbing layer(ABL) both in acoustic and seismo-acoustic sound propagation modeling.

关键词： elastic parabolic equation perfectly matched layer artificial absorbing layer

Micro-encapsulated essential oils and organic acids combination improves intestinal barrier function,inflammatory responses and microbiota of weaned piglets challenged with enterotoxigenic Escherichia coli F4(K88^+)

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Animal Nutrition 2020年第3期6卷 269-277页

作者： Yetong xu Ludovic Lahaye Zhengxiao He Jinxiao Zhang Chengbo yang Xiangshu piao State Key Laboratory of Animal Nutrition Ministry of Agriculture Feed Industry CentreChina Agricultural UniversityBeijing100193china Jefo Nutrition Inc QuebecJ2S7B6Canada Department of Animal Science University of ManitobaWinnipegMBR3T 2N2Canada

This study evaluated the effects of micro-encapsulated(protected)organic acids(OA)and essential oils(EO)combination,P(OA+EO),and effects of a regular blend of free acids(FA)on the growth,immune responses,intestinal barrier and microbiota of weaned piglets challenged with enterotoxigenic Escherichia coli(ETEC)F4(K88^+).A total of 30 crossbred(Duroc×Landrace×Large White)weaned barrows(7.41±0.06 kg,28 d old)were assigned randomly to 5 treatments:1)non-challenged positive control(PC),2)ETEC F4(K88^+)-challenged negative control(NC),3)NC+kitasamycin at 50 mg/kg+olaquindox at 100 mg/kg+free acidifier(FA)at 5 g/kg,4)NC+kitasamycin at 50 mg/kg+olaquindox at 100 mg/kg+P(OA+EO)at 1 g/kg(P1),5)NC+kitasamycin at 50 mg/kg+olaquindox at 100 mg/kg+P(OA+EO)at 2 g/kg(P2).Each dietary treatment had 6 replicates of one piglet each and the study lasted for 3 *** d 7,pigs in NC,FA,P1 and P2 were orally dosed with 10 mL of ETEC F4(K88^+)culture(1×10^9 CFU/mL).From d 7 to 14 after the ETEC F4(K88^+)challenge,P1 increased gain-to-feed ratio(G:F)significantly(P<0.05)compared with NC and FA *** d 14 to 21,P2 increased the average daily gain of pigs(P<0.05)compared with NC and FA *** with NC,P2 reduced tumor necrosis factor-α(TNF-α),interleukin(IL)-6 and IL-10 concentrations(P<0.05)in sera collected at 4 h later after ETEC F4(K88^+)*** d 21,P1 increased occludin and zonula occludens-1 protein expression in ileum compared with NC(P<0.05).After this 3-wk experiment,alpha diversity of gut microbiota was decreased by P2 compared with PC,and P1 increased the relative abundance of Lactobacillus in ileum,cecum and colon(P<0.05).In co nclusio n,dietary P(OA+EO)additive at 2 g/kg combined with antibiotics could improve piglet performance and attenuate inflammation,and P(OA+EO)additive at 1 g/kg combined with antibiotics improved intestinal barrier and increased beneficial microbiota composition after an F4(K88^+)challenge.

关键词： Essential oil Organic acid Enterotoxigenic Escherichia coli F4(K88^+) Gut health Weaned piglet

Ribavirin and IFN-α combination therapy induces CD4+ T-cell proliferation and Th1 cytokine secretion in patients with chronic hepatitis B

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World Journal of Gastroenterology 2007年第41期13卷 5440-5445页

作者： Fen-Yu Ren Hai Jin Xi-xu piao Feng-Shun piao Department of Gastroenterology and Hepatology Yanbian University Hospital Yanji 133000 Jilin Province China

AIM: To investigate the anti-viral mechanism of combination therapy of interferon (IFN)-α and ribavirin in patients with chronic hepatitis B. METHODS: Twenty patients were assigned to receive either IFN-α plus ribavirin (group A,n = 14) or no treatment as a control (group B,n = 6). Patients were analyzed for T-cell proliferative responses specific for hepatitis B virus (HBV)-antigen and cytokine production by peripheral blood mononuclear cells (PBMCs). RESULTS: Combination therapy induced HBV-antigen specific CD4+ T-cell proliferative responses in four patients (28.6%). Production of high levels of HBV-specific IFN-γ,tumor necrosis factor (TNF)-α,interleukin (IL)-12 by PBMCs was found in five patients (35.7%),who showed significantly lower HBV DNA levels in serum at 12 mo after treatment ended (P = 0.038) and at 24 mo of follow-up (P = 0.004) than those without high levels of cytokine production. CONCLUSION: HBV-antigen specific CD4+ T cells may directly control HBV replication and secretion of anti-viral T helper 1 (Th1) cytokines by PBMCs during combination therapy of chronic hepatitis B with ribavirin and IFN-α.

关键词： Hepatitis B Interferon-alpha Ribavirin CD4+ T cells Th1

The effect of the density difference between supercritical CO_(2) and supercritical CH_(4) on their adsorption capacities: An experimental study on anthracite in the Qinshui Basin

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Petroleum Science 2022年第4期19卷 1516-1526页

作者： Si-Jie Han Shu-xun Sang piao-piao Duan Jin-Chao Zhang Wen-Xin Xiang Ang xu Jiangsu Key Laboratory of Coal-based Greenhouse Gas Control and Utilization China University of Mining and TechnologyXuzhouJiangsu221008China Carbon Neutrality Institute China University of Mining and Technology XuzhouJiangsu221008China School of Resources and Geosciences China University of Mining and TechnologyXuzhouJiangsu221116China

Deep unmineable coals are considered as economic and effective geological media for CO_(2) storage and CO_(2) enhanced coalbed methane(CO_(2)-ECBM) recovery is the key technology to realize CO_(2) geological sequestration in coals. Anthracite samples were collected from the Qinshui Basin and subjected to mercury intrusion porosimetry, low-pressure CO_(2) adsorption, and high-pressure CH_(4)/CO_(2) isothermal adsorption experiments. The average number of layers of adsorbed molecules(ANLAM) and the CH_(4)/CO_(2) absolute adsorption amounts and their ratio at experimental temperatures and pressures were calculated. Based on a comparison of the density of supercritical CO_(2) and supercritical CH_(4), it is proposed that the higher adsorption capacity of supercritical CO_(2) over supercritical CH_(4) is the result of their density differences at the same temperature. Lastly, the optimal depth for CO_(2)-ECBM in the Qinshui Basin is recommended. The results show that:(1) the adsorption capacity and the ANLAM of CO_(2) are about twice that of CH_(4) on SH-3 anthracite. The effect of pressure on the CO_(2)/CH_(4) absolute adsorption ratio decreases with the increase of pressure and tends to be consistent.(2) A parameter(the density ratio between gas free and adsorbed phase(DRFA)) is proposed to assess the absolute adsorption amount according to the supercritical CO_(2)/CH_(4) attributes. The DRFA of CO_(2) and CH_(4) both show a highly positive correlation with their absolute adsorption amounts, and therefore, the higher DRFA of CO_(2) is the significant cause of its higher adsorption capacity over CH_(4) under the same temperature and pressure.(3) CO_(2) adsorption on coal shows micropore filling with multilayer adsorption in the macro-mesopore, while methane exhibits monolayer surface coverage.(4) Based on the ideal CO_(2)/CH_(4) competitive adsorption ratio, CO_(2) storage capacity, and permeability variation with depth, it is recommended that the optimal depth for CO_(

关键词： CO_(2)geological storage Competitive adsorption Deep unmineable coal Average number of layers of adsorbed molecules Density ratio between free phase and adsorbed phase Micropore filling

Strong direct and indirect influences of climate change on water yield confirmed by the Budyko framework

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Geography and Sustainability 2021年第4期2卷 281-287页

作者： Hui yang Hao xu Chris Huntingford Philippe Ciais Shilong piao Sino-French Institute for Earth System Science College of Urban and Environmental SciencesPeking UniversityBeijing 100871China Laboratoire des Sciences du Climat et de l’Environnement CEA CNRS UVSQ91191France Centre for Ecology and Hydrology WallingfordOxfordshireOX108BBUK Key Laboratory of Alpine Ecology Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China Center for Excellence in Tibetan Earth Science Chinese Academy of SciencesBeijing 100085China

Research findings concerning the main processes influencing water resources differ substantially,and so the topic remains *** studies indicate that the changes in water yield,expressed through the n-parameter of Budyko framework,are associated with vegetation coverage ***,we use runoffmeasurements and outputs from 13 dynamic global vegetation models,to investigate the underlying drivers of the n-parameter *** previous studies,we instead find that climate change is the primary driver of adjustments on water *** climatic characteristics,particularly the intensity and seasonality of rainfall,modulates the runoffgeneration *** effects of climate change occur through altering vegetation properties,which in turn also impact river *** also find that in the arid and sparse vegetation regions,water yield is more sensitive to changes in ***,the Budyko framework provides a reliable parameter-sparse representation of runoffchanges,and reveals that terrestrial water cycle is changing substantially under climate *** climate forcing requires on-going investigation to generate more refined and reliable projections of future water availability.

关键词： Water cycle Climate change Atmospheric CO_(2) Land cover change Runoff

Accumulated damage process of thermal sprayed coating under rolling contact by acoustic emission technique

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Frontiers of Mechanical Engineering 2016年第3期11卷 227-232页

作者： Jia xu Zhen-yu ZHOU Zhong-yu piao Key Laboratory of Special Purpose Equipment and Advanced Processing Technology (Zhejiang University of Technology) Ministry ofEducation and Zhejiang Province Hangzhou 310014 China Key Laboratory of Special Purpose Equipment and Advanced Processing Technology (Zhejiang University of Technology) Ministry ofEducation and Zhejiang Province Hangzhou 310014 China The StateKey Laboratory of Fluid Power Transmission and Control Hangzhou310027 China

The accumulated damage process of rolling contact fatigue （RCF） of plasma-sprayed coatings was investigated. The influences of surface roughness, loading condition, and stress cycle frequency on the accumulated damage status of the coatings were discussed. A ball-on- disc machine was employed to conduct RCF experiments. Acoustic emission （AE） technique was introduced to monitor thc RCF process of the coatings. AE signal characteristics were investigated to reveal the accumulated damage process. Result showed that the polished coating would resist the asperity contact and remit accumulated damage. The RCF lifetime would then extend. Heavy load would aggravate the accumulated damage status and induce surface fracture. Wear became the main failure mode that reduced the RCF lifetime. Frequent stress cycle would aggravate the accumulated damage status and induce interface fracture. Fatigue then became the main failure mode that also reduced the RCF lifetime.

关键词： accumulated damage spray coating rolling contact fatigue acoustic emission

One-pot synthesis of tetrahydroindoles via a copper catalyzed N-alkynation/[4+2] cycloaddition cascade

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Chinese Chemical Letters 2019年第1期30卷 266-268页

作者： Chun Jiang piao-piao Yu Qing Zhang Hua-Dong xu Mei-Hua Shen School of Pharmaceutical Engineering & Life Science Changzhou University

A CuSO_4 catalyzed ynamide formation/[4+2] cycloaddition relay reaction was achieved in *** 4,7-cis-dihydroindolines were produced in good to high yields. The one-pot operation in conjunction with the cheap and benign... 详细信息

关键词： Tetrahydroindole N-Alkynation Intramolecular [4+2]cycloaddition Copper catalysis Ynamide Relay reaction