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1Impacts of thermodynamic processes over the Tibetan Plateau on the Northern Hemispheric climate显示文摘We here report our recent research results on the climatic features of Tibetan thermodynamic functions and their impacts on the regional climates of the Northern Hemisphere. The results show that the thermodynamic processes over the Tibetan Plateau not only strongly influence the Asian monsoon and precipitation, but also modulate the atmospheric circulation and climate over North America and Europe through stimulating the large-scale teleconnections such as the Asian-Pacific oscillation and affect the atmospheric circulation over the southern Indian Ocean. The Tibetan climate may be affected by sea surface temperatures over the tropical Pacific. On the other hand, the Tibetan climate also affects the atmosphere-ocean interactions in the tropics and mid-latitudes of the Pacific by the atmospheric circulation over the North Pacific. In spring and summer, the thermodynamic anomalies on the plateau affect the subtropical high pressure, the Hadley circulation, and the intertropical convergence zone over the Pacific, and then modulate the development of the El Ni-o/Southern Oscillation (ENSO). It is necessary to study the forecasting methods for the development of ENSO from the Tibetan climate anomaly. This result also embodies the essence of interactions among land, atmosphere, and ocean over the Northern Hemisphere. Since the previous studies focused on impacts of the plateau on climates in the Asian monsoon regions, it is essential to pay more attention to studying the roles of the plateau in the Northern Hemispheric and even global climates.ZHOU XiuJi ZHAO Ping CHEN JunMing CHEN LongXun LI WeiLiang 2009Science China Earth Sciences2009,52,11:42
2Review of Key Problems Related to Integrated Energy Distribution Systems显示文摘Integrated energy distribution system(IEDS)is one of the integrated energy and power system forms,which involves electricity/gas/cold/heat and other various energy forms.The energy coupling relationship is close and complex.IEDS is the focus of regional energy internet research and development at home and abroad.Compared with the traditional power distribution system,IEDS through the multi-energy coupling link comprehensive utilization,effectively improve the distribution system economy,safety,reliability,flexibility and toughness,but also to ease the regional energy system environmental pressure.IEDS is an important direction for the future development of energy systems,and its related research and practice on China’s energy system development also has important practical and strategic significance.This paper summarizes the related researches of the IEDS and explores the energy operation characteristics and coupling mechanisms.What’s more,the integrated model of IEDS is summarized.On these bases,this paper discusses and prospects some key issues such as joint planning,optimization control and security analysis,state estimation and situational awareness and generalized demand side management.Dan Wang Liu Liu Hongjie Jia Weiliang Wang Yunqiang Zhi Zhengji Meng Bingyu Zhou 2018CSEE Journal of Power and Energy Systems2018,4,2:43
3Expression of vascular endothelial growth factor-C and the relationship between lymphangiogenesis and lymphatic metastasis in colorectal cancer显示文摘AIM: To investigate the expression of vascular endothelial growth factor-C (VEGF-C) and the relationship between VEGF-C and lymphangiogenesis, lymph node metastasis in colorectal cancer. METHODS: Fifty six cases of colorectal cancer were selected randomly. Expression of VEGF-C was detected by immunohistochemistry, and lymphatic vessels were stained by enzyme histochemical method. RESULTS: VEGF-C expression was found in 66.7% (37/56) patients. In VEGF-C positive and negative patients, the lymphatic vessel density was 25.16±7.52 and 17.14±7.22, respectively (P<0.05). The rate of lymph node metastasis in VEGF-C positive patients (81.1%) was significantly higher than that in the negative group (42.1%). CONCLUSION: VEGF-C expression may induce lymphangiogenesis in colorectal cancer, as a result, tumor cells can entry the lymphatic vessels easily. VEGF-C may serve as a useful prognotic factor in colorectal carcinoma.Yi-TaoJia Zhong-XinLi Yu-TongHe WeiLiang Hui-ChaiYang Hong-JunMa 2004World Journal of Gastroenterology2004,10,22:28
4Inhibition of SIRT6 in prostate cancer reduces cell viability and increases sensitivity to chemotherapeutics显示文摘SI RT6 is an important histone modifying protein that regulates DNA repair,telomere maintenance,energy me-tabolism,and target gene expression.Recently SIRT6 has been identifi ed as a tumor suppressor and is down-regulated in certain cancer types,but not in other can-cers.From deposited gene profi ling studies we found that SIRT6 was overexpressed in prostate tumors,compared with normal or paratumor prostate tissues.Tissue micro-array studies confi rmed the higher levels of SIRT6 in both prostate tumor tissues and prostate cancer cells than in their normal counterparts.Knockdown of SIRT6 in human prostate cancer cells led to sub-G1 phase arrest of cell cy-cle,increased apoptosis,elevated DNA damage level and decrease in BCL2 gene expression.Moreover,SIRT6-de-fi ciency reduced cell viability and enhanced chemothera-peutics sensitivity.Taken together,this study provides the fi rst evidence of SIRT6 overexpression in human prostate cancer,and SIRT6 regulation could be exploited for pros-tate cancer therapy.Yewei Liu Qian Reuben Xie Boshi Wang Jiaxiang Shao Tingting Zhang Tengyuan Liu Gang Huang Weiliang Xia 2013Protein & Cell2013,4,9:17
5Reliability-Based Design for Jacket Platform Under Extreme Loads显示文摘In this paper, reliability analysis for the offshore jacket platform with the interaction of structure- pile- soil under extreme environmental loads is carried out. The inherent uncertainties of the environmental load, foundation soil, platform itself, and calculating models are evaluated. The action of extreme loads on the offshore platform is modeled as a function of extreme wave height. The system capacity of the whole platform is determined by nonlinear pushover analysis, and the relevant probability property is obtained by the simulation method. The reliability model for the whole jacket platform is described as the relationship between the load and resistance based on the offshore design codes. The reliability of whole platform is calculated by the analytical method and the importance sampling method on the basis of a case study for a tripod jacket platform.Jin Weiliang Associate Professor, Dr. -Eng., Zhejiang University, Hangzhou 310027 1996China Ocean Engineering1996,11,2:17
6Tectonic Evolution of the Meso-Tethys in the Western Segment of Bangonghu-Nujiang Suture Zone: Insights from Geochemistry and Geochronology of the Lagkor Tso Ophiolite显示文摘The subduction of the Bangonghu-Nujiang Meso-Tethys and the collision between the Lhasa and Qiangtang blocks were important events in the growth of the Tibetan crust. However,the timing of collision initiation and closure timing,as well as nature and structure of the Bangonghu ocean basin,are still poorly constrained. The Lagkor Tso ophiolite,located in the south of Gerze County,Tibet,is one of the most completed ophiolites preserved in the southern side of the BangonghuNujiang suture zone. This study discussed the tectonic evolution of the Bangonghu-Nujiang suture zone as revealed by the Lagkor Tso ophiolite investigated by field investigations,petrology,geochemistry,geochronology and tectonic analysis methods. We present new LA-ICP-MS zircon U-Pb and 39Ar/40 Ar ages for the Lagkor Tso ophiolite,in addition to geochemical and platinum-group element(PGE) data presented for the Lagkor Tso ophiolite in Tibet. It is suggested that the ancient Lagkor Tso oceanic basin split in Middle Jurassic(161.2 ± 2.7 Ma – 165.4 ± 3.5 Ma),and experienced a second tectonic emplacement during the Early Cretaceous(137.90 ± 6.39 Ma). The Lagkor Tso ophiolite likely developed in an independent suture zone. The Bangonghu-Nujiang ocean subducted southwards,and the dehydration of the subducting oceanic crust materials caused partial melting of the continental mantle wedge,which formed the second-order expanding center of the obduction dish. This led to inter-arc expansion,followed by the formation of inter-arc and back-arc basins with island arc features,which are represented by ophiolites around the Shiquanhe-Lagkor Tso-Yongzhu region. The tectonic environment presently can be considered to be similar to that of the current Western Pacific,in which a large number of island arc-ocean basin systems are developed.YUAN Yajuan YIN Zhengxin LIU Weiliang HUANG Qiangtai LI Jianfeng LIU Hongfei WAN Zhifeng CAI Zhourong XIA Bin 2015Acta Geologica Sinica(English Edition)2015,89,2:17
7Myocardial infarction secondary prevention study (MISPS)显示文摘Background Traditional Chinese medicine (TCM), especially herbal medicine, has been widely used in China and now is also being increasingly used in other countries for the treatment of cardiovascular diseases. Although many studies have demonstrated that certain Chinese herbal products are effective and safe for the treatment of cardiovascular diseases, most of these lack sufficient quality. Therefore, large randomized clinical trials and further scientific research to determine its safety, effectiveness are necessary.QiShen YiQi Dripping Pills (QSYQDP) is a herbal preparation clinically used in the treatment and prevention of coronary artery disease. Preliminary observations have shown its safety and effectiveness. Methods/Design This randomized, controlled trial will recruit 3600 patients with a history of myocardial infarction. Patients will be randomized into two groups by a Centr-Randomized System. One group receives QSYQDP, the other group receive aspirin. This trial protocol will describe eligibility criteria, detailed information on the treatment definition, blinding, endpoints, statistical methods, sample size determination, data management, legal aspects, and the current status of the trial. Discussion This trial is one of the first randomized, controlled clinical trial to evaluate the efficacy and safety of traditional Chinese herbal medicine in the treatment and secondary prevention of coronary artery disease. The results of this study should help to define the role of TCM in modern medical care, as well as to provide the management strategy for CAD patients in China and other countries.Hongcai SHANG Guohua DAI Junhua HANG Yaozu XIANG Yang WANG Junping ZHANG Wuxun DU Jingyuan MAO Chen YAO Weiliang WENG Tiancai WEN Boli ZHANG 2006Journal of Geriatric Cardiology2006,3,2:14
8An Atypical Thioredoxin Imparts Early Resistance to Sugarcane Mosaic Virus in Maize显示文摘Qingqing Liu Huanhuan Liu Yangqing Gong Yongfu Tao Lu Jiang Weiliang Zuo Qin Yang Jianrong Ye Jinsheng Lai Jianyu Wu Thomas Lubberstedt Mingliang Xu 2017Molecular Plant2017,10,3:14
9Comparison of Clinical Efficacy of Three Surgical Methods in the Treatment of Pterygium显示文摘Purpose:To investigate and compare the efficacy of amniotic membrane transplantation,corneal limbus stem cell conjunctival transplantation and pedicle conjunctival flap transposition in the treatment of pterygium.Methods:.A total of 155 patients with pterygium were retrospectively analyted:.53 cases who received amniotic membrane transplantation,.41 who underwent corneal limbus stem cells conjunctival transplantation,and 61 patients who had pedicle conjunctival flap transposition.Results:Patients in the three groups had no significant differences in terms of age,times since surgery,or extent of pterygium extension onto the cornea (F:1.194,0.639,0.140 respectively;all P>0.05)..A total of 137 out of 155 patients (88.4%) completed 6 months of follow up.The recurrence rates of pterygium for the three surgeries (amniotic membrane transplantation,.corneal limbus stem cells conjunctival transplantation and pedicle conjunctival flap transposition) were 14.6%,13.9% and 7.7%,respectively.No significant difference was identified when comparing the recurrence rate between any two groups(X2:.0.008,1.211 and 0.890;P:0.593,0.218 and 0.276)..Five patients presented with postoperative complications,.including 3 cases of sub-conjunctival hemorrhage,1 case of amniotic membrane dissolution,and 1 case of conjunctival cyst,accounting for 3.64% of all participants.Conclusion:These three surgical methods are equally effective in preventing the recurrence of pterygium after excision.Chaoming Yu Weiliang Liang Yongyu Huang Weiwen Guan 2011Eye Science2011,26,4:14
10Evaluation of the Trend Uncertainty in Summer Ozone Valley over the Tibetan Plateau in Three Reanalysis Datasets显示文摘Trend uncertainty in the ozone valley over the Tibetan Plateau(OVTP)and the South Asian high(SAH)during1979–2009 in ERA-Interim(interim reanalysis data from the ECMWF),JRA-55(55-yr reanalysis data from the Japan Meteorological Agency),and NCEP-CFSR(Climate Forecast System Reanalysis)datasets was evaluated.The results showed that the NCEP-CFSR OVTP became strong in the summers of 1979–2009,whereas it became weak according to ERA-Interim and JRA-55.Satellite data merged with TOMS(Total Ozone Mapping Spectrometer)and OMI(Ozone Monitoring Instrument)agreed with the OVTP trend of NCEP-CFSR.The OVTP strengthening in NCEP-CFSR may have been caused by SAH intensification,a rising tropopause,and increasing ozone over non-TP(non-Tibetan Plateau)areas(27°–37°N,<75°E and>105°E).Analogously,the OVTP weakening in ERA-Interim and JRA-55 may have been affected by weakening SAH,descending tropopause,and decreasing non-TP ozone.Dong GUO Yucheng SU Xiuji ZHOU Jianjun XU Chunhua SHI Yu LIU Weiliang LI Zhenkun LI 2017Journal of Meteorological Research2017,31,2:13
11Humoral immune response to circulating SARS-CoV-2 variants elicited by inactivated and RBD-subunit vaccines显示文摘SARS-CoV-2 variants could induce immune escape by mutations on the receptor-binding domain(RBD)and N-terminal domain(NTD).Here we report the humoral immune response to circulating SARS-CoV-2 variants,such as 501Y.V2(B.1.351),of the plasma and neutralizing antibodies(NAbs)elicited by CoronaVac(inactivated vaccine),ZF2001(RBD-subunit vaccine)and natural infection.Among 86 potent NAbs identified by high-throughput single-cell VDJ sequencing of peripheral blood mononuclear cells from vaccinees and convalescents,near half anti-RBD NAbs showed major neutralization reductions against the K417N/E484K/N501Y mutation combination,with E484K being the dominant cause.VH3-53/VH3-66 recurrent antibodies respond differently to RBD variants,and K417N compromises the majority of neutralizing activity through reduced polar contacts with complementarity determining regions.In contrast,the 242–244 deletion(242–244Δ)would abolish most neutralization activity of anti-NTD NAbs by interrupting the conformation of NTD antigenic supersite,indicating a much less diversity of anti-NTD NAbs than anti-RBD NAbs.Plasma of convalescents and CoronaVac vaccinees displayed comparable neutralization reductions against pseudo-and authentic 501Y.V2 variants,mainly caused by E484K/N501Y and 242–244Δ,with the effects being additive.Importantly,RBD-subunit vaccinees exhibit markedly higher tolerance to 501Y.V2 than convalescents,since the elicited anti-RBD NAbs display a high diversity and are unaffected by NTD mutations.Moreover,an extended gap between the third and second doses of ZF2001 leads to better neutralizing activity and tolerance to 501Y.V2 than the standard three-dose administration.Together,these results suggest that the deployment of RBD-vaccines,through a third-dose boost,may be ideal for combating SARS-CoV-2 variants when necessary,especially for those carrying mutations that disrupt the NTD supersite.Yunlong Cao Ayijiang Yisimayi Yali Bai Weijin Huang Xiaofeng Li Zhiying Zhang Tianjiao Yuan Ran An Jing Wang Tianhe Xiao Shuo Du Wenping Ma Liyang Song Yongzheng Li Xiang Li Weiliang Song Jiajing Wu Shuo Liu Xuemei Li Yonghong Zhang Bin Su Xianghua Guo Yangyang Wei Chuanping Gao Nana Zhang Yifei Zhang Yang Dou Xiaoyu Xu Rui Shi Bai Lu Ronghua Jin Yingmin Ma Chengfeng Qin Youchun Wang Yingmei Feng Junyu Xiao Xiaoliang Sunney Xie 2021Cell Research2021,31,7:12
12Disease profile and plasma neutralizing activity of postvaccination Omicron BA.1 infection in Tianjin,China:a retrospective study显示文摘Dear Editor,SARS-CoV-2 Omicron variant BA.1 first emerged on the Chinese mainland on January 8,2022,in Tianjin and caused a large wave of infections.1 Four rounds of mass testing of its~14 million residents were launched on January 9,12,15,and 20,respectively.As of February 7,2022,a total of 430 individuals were tested positive for Omicron BA.1,with no new infections detected for the following 16 days.In the Chinese mainland,the most delivered vaccines are inactivated vaccines.As of January 8,2022,up to 93.2%of Tianjin’s residents had been vaccinated with at least one dose.2 We investigated the protection conferred by vaccination against Omicron BA.1 by examining the breakthrough infections among vaccinees as compared with unvaccinated cases.Our study population comprised all 430 cases during the outbreak of Omicron BA.1 in Tianjin.Hong Zheng Yunlong Cao Xiaosu Chen Fengmei Wang Ye Hu Weiliang Song Yangyang Chai Qingqing Gu Yansong Shi Yingmei Feng Shuxun Liu Yan Xie Xiaoliang Sunney Xie Wentao Jiang Zhongyang Shen 2022Cell Research2022,32,8:12
13Simulation of Airblast Load and Its Effect on RC Structures显示文摘In the analysis of a structure subjected to an explosion event, the determination of the blast load constitutes a crucial step. The effect of the blast load on the structure depends not only on the peak shock overpressure, but also the impulse (hence the duration). For structures with a regular geometry, the blast load may be fairly well estimated using appropriate empirical formulae; however, for more complex situations, a direct simulation using appropriate computational techniques is necessary. This paper presents a numerical simulation study on the prediction of the blast load in free air using a hydrocode, with focus on the sensitivity of the simulated blast load to the mesh grid size. The simulation results are compared with empirical predictions. It is found that the simulated blast load is sensitive to the mesh size, especially in the close-in range, and with a practically affordable mesh grid density, the blast load tends to be systematically underestimated. The study is extended to internal blast cases. An example concrete slab under internal explosion is analyzed using a coupled analysis scheme. The internal blast load from the simulation is examined and the response of the RC slab is commented.GONG Shunfeng LU Yong JIN Weiliang 2006Transactions of Tianjin University2006,12,B09:12
14Application of autologous tumor cell vaccine and NDV vaccine in treatment of tumors of digestive traet显示文摘AIM. TO treat patients with stage I-IV malignant tumors of digestive tract using autologous tumor cell vaccine and NDV(Newcastle disease virus) vaccine, and observe the survival period and curative effect.METHODS: 335 patients with malignant tumors of digestive tract were treated with autologous tumor cell vaccine and NDV vaccine. The autologous tumor cell vaccine received were assigned for long-term survival observation. While these failed to obtain the autologous tumor tissue were given with NDV vaccine for a received short-term observation on curative effect.RESULTS: The colorectal cancer patients treated with autologous tumor cell vaccine were divided into two groups:the controlled group (subjected to resection alone) (n=257),the vaccine group (subjected to both resection and immunotherapy) (n=310). 25 patients treated with NDV immunotherapy were all at stage IV without having resection.In postoperation adjuvant therapy patients, the 5, 6 and 7-year survival rates were 66.51%, 60.52 %, 56.50 %respectively; whereas in patients with resection alone, only 45.57 %, 44.76 % and 43.42 % respectively. The average survival period was 5.13 years (resection alone group 4.15 years), the median survival period was over 7 years (resection alone group 4.46 years). There were significant differences between the two groups. The patients treated with resection plus vaccine were measured delayed-type hypersensitivity (DTH) reactions after vaccination, (indurative scope >5 mm).The magnitude of DTH was related to the prognosis. The 5-year survival rate was 80 % for those with indurations greater than 5 mm, compared with 30 % for those with indurations less than 5 ram. The 1-year survival rate was 96 % for 25 patients treated with NDV immunotherapy. The total effective rate (CR+PR) was 24.00 % in NDV immunotherapy; complete remission (CR) in 1 case (4.00 %), partial remission (PR) in 5 cases (20.00 %), stabilizedin in 16 cases (64.00 %),progression (PD) in 1 case (4.00 %). After NDV vaccine immunotherapy, the number of NK cell increased and immune function imporved obviously.CONCLUSION: The autologous tumor cell vaccine and NDV vaccine can prolong the patients' life. NDV vaccine is notably effective for short-term with promotion of quality of life and can be used whenever necessary with good prospects.WeiLiang HuiWang Tie-MieSun Wen-QingYao Li-LiChen YuJin Chun-LingLi Fan-JuanMeng 2003World Journal of Gastroenterology2003,9,3:12
15Anomaly Detection of Industrial Control Systems Based on Transfer Learning显示文摘Industrial Control Systems(ICSs)are the lifeline of a country.Therefore,the anomaly detection of ICS traffic is an important endeavor.This paper proposes a model based on a deep residual Convolution Neural Network(CNN)to prevent gradient explosion or gradient disappearance and guarantee accuracy.The developed methodology addresses two limitations:most traditional machine learning methods can only detect known network attacks and deep learning algorithms require a long time to train.The utilization of transfer learning under the modification of the existing residual CNN structure guarantees the detection of unknown attacks.One-dimensional ICS flow data are converted into two-dimensional grayscale images to take full advantage of the features of CNN.Results show that the proposed method achieves a high score and solves the time problem associated with deep learning model training.The model can give reliable predictions for unknown or differently distributed abnormal data through short-term training.Thus,the proposed model ensures the safety of ICSs and verifies the feasibility of transfer learning for ICS anomaly detection.Weiping Wang Zhaorong Wang Zhanfan Zhou Haixia Deng Weiliang Zhao Chunyang Wang Yongzhen Guo 2021Tsinghua Science and Technology2021,26,6:11
16MVS-Pheno:A Portable and Low-Cost Phenotyping Platform for Maize Shoots Using Multiview Stereo 3D Reconstruction显示文摘Plant phenotyping technologies play important roles in plant research and agriculture.Detailed phenotypes of individual plants can guide the optimization of shoot architecture for plant breeding and are useful to analyze the morphological differences in response to environments for crop cultivation.Accordingly,high-throughput phenotyping technologies for individual plants grown in field conditions are urgently needed,and MVS-Pheno,a portable and low-cost phenotyping platform for individual plants,was developed.The platform is composed of four major components:a semiautomatic multiview stereo(MVS)image acquisition device,a data acquisition console,data processing and phenotype extraction software for maize shoots,and a data management system.The platform’s device is detachable and adjustable according to the size of the target shoot.Image sequences for each maize shoot can be captured within 60-120 seconds,yielding 3D point clouds of shoots are reconstructed using MVS-based commercial software,and the phenotypic traits at the organ and individual plant levels are then extracted by the software.The correlation coefficient(R^(2))between the extracted and manually measured plant height,leaf width,and leaf area values are 0.99,0.87,and 0.93,respectively.A data management system has also been developed to store and manage the acquired raw data,reconstructed point clouds,agronomic information,and resulting phenotypic traits.The platform offers an optional solution for high-throughput phenotyping of field-grown plants,which is especially useful for large populations or experiments across many different ecological regions.Sheng Wu Weiliang Wen Yongjian Wang Jiangchuan Fan Chuanyu Wang Wenbo Gou Xinyu Guo 2020Plant Phenomics2020,2,1:11
17Optimal Energy-Efficient Transmission for Hybrid Spectrum Sharing in Cooperative Cognitive Radio Networks显示文摘In order to improve the energy efficiency(EE)in cognitive radio(CR),this paper investigates the joint design of cooperative spectrum sensing time and the power control optimization problem for the secondary user systems to achieve the maximum energy efficiency in a cognitive network based on hybrid spectrum sharing,meanwhile considering the maximum transmit power,user quality of service(QoS)requirements,interference limitations,and primary user protection.The optimization of energy efficient sensing time and power allocation is formulated as a non-convex optimization problem.The Dinkelbach’s method is adopted to solve this problem and to transform the non-convex optimization problem in fractional form into an equivalent optimization problem in the form of subtraction.Then,an iterative power allocation algorithm is proposed to solve the optimization problem.The simulation results show the effectiveness of the proposed algorithms for energy-efficient resource allocation in the cognitive network.Linna Hu Rui Shi Minghe Mao Zhiyu Chen Hongxi Zhou Weiliang Li 2019China Communications2019,16,6:9
18Humoral immunogenicity and reactogenicity of CoronaVac or ZF2001 booster after two doses of inactivated vaccine显示文摘Dear Editor,COVID-19 vaccination campaigns are being conducted in countries worldwide,and 47.4% of the world population has received at least one dose of a COVID-19 vaccine.1 Although vaccination has shaped COVID-19 epidemic curves,waning antibody levels and relatively short-duration protection provided by current COVID-19 vaccines have been observed,especially against SARS-CoV-2 variants of concern(VOCs)and among older individuals.Yunlong Cao Xiaohua Hao Xi Wang Qianhui Wu Rui Song Dong Zhao Weiliang Song Yao Wang Ayijiang Yisimayi Wei Wang Juan Du Hongjie Yu Xiaoliang Sunney Xie Ronghua Jin 2022Cell Research2022,32,1:8
19Study on the deactivation and regeneration of the ZSM-5 catalyst used in methanol to olefins显示文摘ZSM-5 zeolite catalyst modified by a trace of metal cations shows high activity and high selectivity for the reaction of methanol to olefins (MTO), but it inclines to deactivate during the reaction. In this paper, the mechanism of the catalyst deactivation and the regeneration method were studied by X-ray diffraction (XRD), N2 adsorption-desorption, infrared spectra (IR), and infrared spectra coupled with NH3 molecular probes (IR-NH3). These characterizations indicated that coke formation was the main reason for the catalyst deactivation. To regenerate the deactivated catalyst, two methods, i.e., calcination and methanol leaching, were used. N2 adsorption-desorption, IR and IR-NH3 characteriza-tions showed that both methods can eliminate coke deposited on the catalyst and make the catalyst reactivated. XRD showed that the structure of the catalyst did not change after regeneration. Interestingly, the regenerated catalyst even showed better catalytic performance of the MTO reaction than the fresh one. Besides, the calcination regeneration can eliminate coke more completely, however, the methanol leaching method can be more easily carried out in situ in the reactor.Jingchang Zhang Haibin Zhang Xiuying Yang Zhong Huang Weiliang Cao 2011Journal of Natural Gas Chemistry2011,20,3:8
20Simulation of secondary aerosols over North China in summer显示文摘The comparisons of observed and simulated NOx, CO, O3, NH3, HNO3, SO2 and PM2.5 indicate that CMAQ model can simulate variations of pollutants over North China well.Moreover, the model results show that high NH3 is in Hebei, Henan and Shandong provinces,with average concentration of (30-35)×10-9. The results of the sensitive experiment indicate that high concentration of NH3 has the efficiency of the production of secondary sulfate aerosol increase by more than 30%, especially at the juncture of Handan, Anyang and Changzhi that increased by 50%. In addition, NH3 also produces secondary ammonia and nitrate aerosol, and the sum of them is approximately equal to sulfate aerosol. The height of planetary boundary layer (PBL) in Beijing is higher in daytime, with average height of 1500 m at noon. This makes SO2,NH3 and HNO3 transported into upper PBL of 850 hPa. The high secondary sulfate, and ammonia and nitrate aerosol happen in the upper and lower PBL, respectively. Because PM2.5 lifetime is relatively long, it can be transported into the middle troposphere to form a thick aerosol layer,which is the arched roof of aerosol. The model result suggests that if the aerosol concentration in North China would be controlled, the reduction of NH3 emission is one of efficient ways besides the reduction of primary SO2, NOx and aerosol emission.LIU Yu LI Weiliang ZHOU Xiuji 2005Science China Earth Sciences2005,48,z2:8
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