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| 1 | Starch grain analysis reveals function of grinding stone tools at Shangzhai site, Beijing显示文摘Prehistoric groundstone tools including slabs (metate, mo-pan) and mullers (mano, mo-bang) are often considered to be tools that were used to process cereals in ancient China. Most archaeologists believe that groundstone tools are indicators of an agrarian economy. This study employed starch grain analysis to examine a slab and a muller excavated from the Shangzhai Site (7500-7000 cal a BP), Beijing. Identifiable starch grains recovered from the stone tools were classified into 9 genera and 12 species, most of which were from acorns and foxtail millets. Remains from the oak species Q. mongolicus, Q. acuttssima, and Q. dentate were identified as well as a few starch grains from broomcorn (Panicum miliaseum) and bean (Vigna sp.). Other starch grains were from unidentifiable roots and grasses. A variety of starch grains indicates that the grinding stone tools were used to process not only cereals, but also other seeds or roots that had to be ground or husked, thus bringing into question the aforementioned cereal hypothesis. Because the numbers of starch grains from nuts and millets were so large, both gathering and cultivation might have been important economic patterns before 7000 years ago in Beijing area. Moreover, the starch remains are derived from plants that indicate that the paleoclimate of Beijing was wetter and warmer than today’s. | YANG XiaoYan YU JinCheng Lü HouYuan CUI TianXing GUO JingNing GE QuanSheng | 2009 | Science China Earth Sciences2009，52，8： | 32 |
| 2 | Clinical research linking Traditional Chinese Medicine constitution types with diseases:a literature review of 1639 observational studies显示文摘OBJECTIVE:To analyze clinical studies on correlations between Traditional Chinese Medicine(TCM)body constitution types and diseases published in the past 10 years,and to provide an evidence base to support the use of such correlations for health maintenance and disease prevention.METHODS:We searched five databases for the period April 2009 to December 2019:China National Knowledge Infrastructure Database,Wanfang Database,China Science and Technology Journal Database,PubMed and Embase.Three types of observational studies on correlation between constitution types and diseases were included:cross-sectional,case-control and cohort studies.Descriptive statistical methods were employed for data analysis.RESULTS:A total of 1639 clinical studies were identified:1452(88.59%)cross-sectional studies,115(7.02%)case-control studies and 72(4.39%)cohort studies covering 30 regions of China and five other countries(Malaysia,South Korea,Singapore,Thailand and France).The collection of studies comprised 19 disease categories and 333 different diseases.The 10 most commonly studied diseases were hypertension,diabetes,stroke,coronary atherosclerotic heart disease(CAHD),sleep disorders,neoplasm of the breast,dysmenorrhea,fatty liver disease,chronic viral hepatitis B and dyslipidemia.We found high distributions for each biased constitution type in different patient populations as follows:Qi-deficiency constitution in stroke,diabetes,chronic obstructive pulmonary disease,acquired immunodeficiency syndrome and hypertension;Yang-deficiency constitution in female infertility,osteoporosis,irritable bowel syndrome,gonarthrosis and dysmenorrhea;Yin-deficiency constitution in hypertension,diabetes,constipation,female climacteric states and osteoporosis;phlegm-dampness constitution in hypertension,stroke,fatty liver disease,diabetes and metabolic syndrome;damp-heat constitution in acne,chronic gastritis,chronic viral hepatitis B,human papillomavirus infection and hyperuricemia;blood-stasis constitution in CAHD,endometriosis and stroke;Qi-stagnation constitution in hyperplasia and neoplasms of the breast,insomnia,depression and thyroid nodules;and inherited-special constitution in asthma and allergic rhinitis.CONCLUSION:Eight biased TCM constitutions were closely related to specific diseases,and could be used to guide individualized prevention and treatment.More rigorously designed studies are recommended to further verify the constitution-disease relationship. | Liang Xue Wang Qi Jiang Zeqiang Li Zhuqing Zhang Mengxing Yang Peiying Wang Xin Wang Yanqiu Qin Yuehua Li Tianxing Zhang Tianyi Wang Yi Sun Jianxiang Li Yusi Luo Hui Li Lingru | 2020 | Journal of Traditional Chinese Medicine2020，40，4： | 29 |
| 3 | A review of the estimation of downward surface shortwave radiation based on satellite data:Methods, progress and problems显示文摘The estimation of downward surface shortwave radiation(DSSR)is important for the Earth’s energy budget and climate change studies.This review was organised from the perspectives of satellite sensors,algorithms and future trends,retrospects and summaries of the satellite-based retrieval methods of DSSR that have been developed over the past 10 years.The shortwave radiation reaching the Earth’s surface is affected by both atmospheric and land surface parameters.In recent years,studies have given detailed considerations to the factors which affect DSSR.It is important to improve the retrieval accuracy of cloud microphysical parameters and aerosols and to reduce the uncertainties caused by complex topographies and high-albedo surfaces(such as snow-covered areas)on DSSR estimation.This review classified DSSR retrieval methods into four categories:empirical,parameterisation,look-up table and machine-learning methods,and evaluated their advantages,disadvantages and accuracy.Further efforts are needed to improve the calculation accuracy of atmospheric parameters such as cloud,haze,water vapor and other land surface parameters such as albedo of complex terrain and bright surface,organically combine machine learning and other methods,use the new-generation geostationary satellite and polar orbit satellite data to produce highresolution DSSR products,and promote the application of radiation products in hydrological and climate models. | Husi LETU Jiancheng SHI Ming LI Tianxing WANG Huazhe SHANG Yonghui LEI Dabin JI Jianguang WEN Kun YANG Liangfu CHEN | 2020 | Science China Earth Sciences2020，63，6： | 8 |
| 4 | A Virulent PEDV Strain FJzz1 with Genomic Mutations and Deletions at the High Passage Level Was Attenuated in Piglets via Serial Passage In Vitro显示文摘Highly virulent porcine epidemic diarrhea virus(PEDV)strains re-emerged and circulated in China at the end of 2010,causing significant economic losses in the pork industry worldwide.To understand the genetic dynamics of PEDV during its passage in vitro,the PEDV G2 strain FJzzl was serially propagated in Vero cells for up to 200 passages.The susceptibility and adaptability of the FJzzl strain increased gradually as it was serially passaged in vitro.Sequence analysis revealed that amino acid(aa)changes were mainly concentrated in the S glycoprotein,which accounted for 72.22%-85.71%of all aa changes.A continuous aa deletion(^(55)I^(56)G^(57)E→^(55)K^(56)Δ^(57)Δ)occurred in the N-terminal domain of S1(Sl-NTD).To examine how the aa changes affected its virulence,FJzzl-F20 and FJzzl-F200 were selected to simultaneously evaluate their pathogenicity in suckling piglets.All the piglets in the FJzzl-F20-infected group showed typical diarrhea at 24 h postinfection,and the piglets died successively by 48 h postinfection.However,the clinical signs of the piglets in the FJzzl-F200-infected group were significantly weaker,and no deaths occurred.The FJzzl-F200-infected group also showed a lower level of fecal viral shedding and lower viral loads in the intestinal tissues,and no obvious histopathological lesions.TypeⅠandⅢinterferon were induced in the FJzzl-F200 infection group,together with pro-inflammatory cytokines,such as TNF-α,IL-1βand IL-8.These results indicate that the identified genetic changes may contribute to the attenuation of FJzzl strain,and the attenuated FJzzl-F200 may have the potential for developing PEDV live-attenuated vaccines. | Pengfei Chen Xiongwei Zhao Shuting Zhou Tianxing Zhou Xiangmei Tan Xia Wu Wu Tong Fei Gao Lingxue Yu Yifeng Jiang Hai Yu Zhibiao Yang Guangzhi Tong Yanjun Zhou | 2021 | Virologica Sinica2021，36，5： | 4 |
| 5 | Non-contact cylindrical rotating triboelectric nanogenerator for harvesting kinetic energy from hydraulics显示文摘Hydraulics provide a unique and widely existed mechanical energy source around us,such as in water or oil pipes,and sewers.Here,a non-contact cylindrical rotating triboelectric nanogenerator(TENG)was developed to harvest the mechanical energy from water flows.Operation of the TENG was based on the non-contact free-rotating between a curved Cu foil and a flexible nanostructured fluorinated ethylene propylene(FEP)polymer film.The free-standing distance between two rotating interfaces avoided abrading of electrode materials.The TENG was able to effectively convert mechanical energy of the water flow into electricity.When driven by water flow,the output voltage and current of the TENG reached 1,670 V and 13.4 uA,respectively.Without any energy storage component,the produced electricity could instantaneously power 12 white light emitting diodes(LEDs)bulbs and a digital timer.This non-contact rotating TENG would provide new opportunities for harvesting energy from many types of hydraulics as a self-sustainable power source for sensing,detection,and protection. | Nan Zhang Cheng Qin Tianxing Feng Jun Li Zhirui Yang Xiupeng Sun Erjun Liang Yanchao Mao Xudong Wang | 2020 | Nano Research2020，13，7： | 4 |
| 6 | In-situ study on hydrogen bubble evolution in the liquid Al/solid Ni interconnection by synchrotron radiation X-ray radiography显示文摘Synchrotron X-ray radiography was used to carry out an in-situ observation of the hydrogen bubble evolution in the liquid Al/solid Ni interconnection. The individual bubble mainly grows in a stochastic way during heating. The size distribution for groups of bubbles follows a Gaussian distribution in the early stage and Lifshitz-Slyozov-Wagner(LSW) diffusion controlled distribution in the final stage. The intermetallic compounds(IMCs) first form during solidification, following by the hydrogen bubbles. The bubbles between two adjacent Al3Ni grains grow unidirectionally along the liquid channel, with the bottom being impeded by the Al3Ni phase and the radius of the growth front being smaller. For the bubbles at triple junctions, they grow along the liquid channel and the crack with morphology transition. | Zongye Ding Qiaodan Hu Wenquan Lu Xuan Ge Sheng Cao Siyu Sun Tianxing Yang Mingxu Xia Jianguo Li | 2019 | Journal of Materials Science & Technology2019，35，7： | 3 |
| 7 | Prognostic Role and Potential Mechanisms of N6-methyladenosine-related Long Noncoding RNAs in Hepatocellular Carcinoma显示文摘Background and Aims:Numerous studies have explored the important role of N6-methyladenosine(m^(6)A)in cancer.Nonetheless,the interaction between m^(6)A and long noncoding RNAs(lncRNAs)is poorly investigated.Herein,we systematically analyzed the role and prognostic value of m^(6)A-related lncRNAs in hepatocellular carcinoma(HCC).Methods:The m^(6)A-related lncRNAs were identified based on the correlation coefficients with m^(6)A-related genes in HCC from The Cancer Genome Atlas.Subsequently,a novel risk score model was determined using the least absolute shrinkage and selection operator Cox regression analyses.Univariate and multivariate Cox analyses were used to identify independent prog-nostic factors for overall survival(OS)of HCC;thereafter,a prognostic nomogram was constructed.Results:A total of 259 lncRNAs showed significant correlations with m^(6)A in HCC,while 29 lncRNAs had prognostic significance.Further,six critical m^(6)A-related lncRNAs(NRAV,SNHG3,KDM4A-AS1,AC074117.1,AC025176.1,and AL031985.3)were screened out to construct a novel risk score model which classified HCC patients into high-and low-risk groups.Survival analy-ses revealed that patients in the high-risk group exhibited worse OS,both in the training and validation groups.The risk score was also identified as an independent prognostic factor of OS,and a nomogram was established and verified with superior prediction capacity.Besides,the risk score signifi-cantly correlated with the expression of immune checkpoint genes and immune subtypes.Conclusions:These findings indicated the significant role of m^(6)A-related lncRNAs in HCC and the potential application of the novel risk score model for prognostic prediction. | Tianxing Dai Jing Li Linsen Ye Haoyuan Yu Mingbin Deng Wei Liu Hua Li Yang Yang Guoying Wang | 2022 | Journal of Clinical and Translational Hepatology2022，10，2： | 1 |
| 8 | Preparation, characterization, release kinetics, and in vitro cytotoxicity of calcium silicate cement as a risedronate delivery system显示文摘 | Tianxing Gong Zhiqin Wang Yubiao Zhang Changshan Sun Quanzu Yang Tom Troczynski Urs O. H?feli | 2014 | J Biomed Mater Res2014，，7： | 1 |
| 9 | Potential of endophytic bacteria isolated from Sophora alopecuroides nodule in biological control against Verticillium wilt disease显示文摘 | Lin Tianxing Zhao Longfei Yang Yazhen | 2013 | Australian Journal of Crop Science2013，7，1： | 1 |
| 10 | 显示文摘 | TianX B Wei C B Yang S Q | 2005 | Surface and Coating Technology2005，198，13： | 1 |
| 11 | Distribution and transportation of nitrogen in Miyun reservoir waters显示文摘The Miyun reservoir is an important water supply for Beijing city. The distribution laws of nitrogen in the Miyun reservoir waters and the transportation factors have been systematically analyzed in space and time by using water monitoring data sampled in the high-water and low-flow periods in 2001 and 2002. The nitrogen in east and west reservoir waters is distributed differently in space. It shows the change characteristics in high-water and low-flow periods and is affected by the source of nitrogen, runoff conditions, hydrodynamic conditions, precipitation and the control of bed mud, of which the source of nitrogen controls the change of concentration of nitrogen, the peripheral runoff controls the distribution law of nitrogen, bed mud controls the vertical distribution of nitrogen, and the contents of nitrogen and its change in the surrounding environment directly cause the change of concentration of total nitrogen in the waters. The improvement and protection of the waters in the Miyun reservoir basically rests with the amelioration of the peripheral environment. | LIANG Xiujuan, XIAO Changlai, YANG Tianxing, WANG Jing & LIU Xiaoduan College of Environment and Resources, Jilin University, Changchun 130026, China College of Geo-exploration Science and Technology, Jilin University, Changchun 130026, China National Research Center for Geoanalysis, Beijing 100037, China | 2005 | Science China Earth Sciences2005，48，z2： | 1 |
| 12 | Omicron variants breakthrough infection elicited higher specific memory immunity than third dose booster in healthy vaccinees显示文摘Homologous booster,heterologous booster,and Omicron variants breakthrough infection(OBI)could improve the humoral immunity against Omicron variants.Questions concerning about memory B cells(MBCs)and T cells immunity against Omicron variants,features of long-term immunity,after booster and OBI,needs to be explored.Here,comparative analysis demonstrate antibody and T cell immunity against ancestral strain,Delta and Omicron variants in Omicron breakthrough infected patients(OBIPs)are comparable to that in Ad5-nCoV boosted healthy volunteers(HVs),higher than that in inactivated vaccine(InV)boosted HVs.However,memory B cells(MBCs)immunity against Omicron variants was highest in OBIPs,followed by Ad5-nCoV boosted and InV boosted HVs.OBIPs and Ad5-nCoV boosted HVs have higher classical MBCs and activated MBCs,and lower naïve MBCs and atypical MBCs relative to both vaccine boosted HVs.Collectively,these data indicate Omicron breakthrough infection elicit higher MBCs and T cells against SARS-CoV-2 especially Omicron variants relative to homologous InV booster and heterologous Ad5-nCoV booster. | Pei Yu Zijian Liu Zhuoqi Zhu Jiaqing Yang Min Deng Mingxiao Chen Changchun Lai Weiya Kong Shilong Xiong Li Wan Weikang Mai Lu Chen Yu Lei Shahzad Akbar Khan Jianfeng Ruan An Kang Xuguang Guo Qiang Zhou Wenrui Li Zheng Chen Yuemei Liang Pingchao Li Lei Zhang Tianxing Ji | 2023 | Virologica Sinica2023，38，2： | 0 |
| 13 | A biosensing system employing nanowell microelectrode arrays to record the intracellular potential of a single cardiomyocyte显示文摘Electrophysiological recording is a widely used method to investigate cardiovascular pathology,pharmacology and developmental biology.Microelectrode arrays record the electrical potential of cells in a minimally invasive and highthroughput way.However,commonly used microelectrode arays primarily employ planar microelectrodes and cannot work in applications that require a recording of the intracellular action potential of a single cell.In this study,we proposed a novel measuring method that is able to record the intracellular action potential of a single cardiomyocyte by using a nanowell patterned microelectrode array(NWMEA).The NWMEA consists of five nanoscale wells at the center of each circular planar microelectrode.Biphasic pulse electroporation was applied to the NWMEA to penetrate the cardiomyocyte membrane,and the intracellular action potential was continuously recorded.The intracellular potential recording of cardiomyocytes by the NWMEA measured a potential signal with a higher quality(213.76±25.85%),reduced noise root-mean-square(~33%),and higher signal-to-noise ratio(254.36±12.61%)when compared to those of the extracellular recording.Compared to previously reported nanopillar microelectrodes,the NWMEA could ensure single cell electroporation and acquire high-quality action potential of cardiomyocytes with reduced fabrication processes.This NWMEA-based biosensing system is a promising tool to record the intracellular action potential of a single cell to broaden the usage of microelectrode arrays in electrophysiological investigation. | Yuting Xiang Haitao Liu Wenjian Yang Zhongyuan xu Yue Wu Zhajian Tang Zhjing Zhu Zhiyong Zeng Depeng Wang Tianxing Wang Ning Hu Diming Zhang | 2022 | Microsystems & Nanoengineering2022，8，3： | 0 |
| 14 | Unveiling the Growth Mechanism of Faceted Primary Al_(2)Cu with Complex Morphologies During Solidification显示文摘The growth characteristic of primary faceted Al_(2)Cu intermetallic compounds(IMCs)during solidification was observed directly by synchrotron radiography.The formation and transition mechanisms of Al_(2)Cu IMCs with diverse morphologies were elucidated by first-principle calculations combined with electron backscatter diffraction analysis.The Al_(2)Cu crystals preferred to grow along the[001]direction and were bounded by{110}planes with the lowest surface energy.The faceted Al_(2)Cu rod-like clusters consisted of multiple crystals with complete rod,hollowness and partial sides,which was attributed to the increase in strain energy and solute redistribution during solidification.The faceted Al_(2)Cu with branches was characteristic with the perpendicular relationship between the main branches and side steps and partial coalescence at the junction,which was ascribed to the continuous propagation and growth of newly formed crystals along the diagonal direction. | Zongye Ding Qiaodan Hu Fan Yang Liao Yu Tianxing Yang Naifang Zhang Wenquan Lu Jingwei Yang Jian Qiao Jianguo Li | 2022 | Acta Metallurgica Sinica(English Letters)2022，35，1： | 0 |
| 15 | Homogeneous distributed natural pyrite-derived composite induced by modified graphite as high-performance lithium-ion batteries anode显示文摘Natural minerals-based energy materials have attracted enormous attention because of the advantages of good materials consistency,high production,environmental friendliness,and low cost.The uniform distribution of grains can effectively inhibit the aggregation of active materials,improving lithium storage performance.In this work,natural graphite is modified by polyvinylpyrrolidone to obtain modified graphite with reduced size and better dispersion.Natural pyrite composite polyvinylpyrrolidone-modified graphite(pyrite/PG)material with uniform particle distribution is obtained by the ball milling process.The subsequent calcination process converts pyrite/PG into Fe_(1-x)Scompounded with polyvinylpyrrolidone-modified graphite(Fe_(1-x)S/PG).The homogeneous grain distributions of active material can facilitate the faster transfer of electrons and promote the efficient utilization of active materials.The as-prepared Fe_(1-x)S/PG electrode exhibits a remarkably reversible specific capacity of 613.0 mAh·g^(-1)at 0.2 A·g^(-1)after 80 cycles and an excellent rate capability of 523.0 mAh·g^(-1)at 5 A·g^(-1).Even at a higher current density of 10 A·g^(-1),it can deliver a specific capacity of 348.0 mAh·g^(-1).Moreover,the dominant pseudocapacitance in redox reactions accounts for the impressive rate and cycling stability.This work provides a low-cost and facile method to fabricate natural mineral-based anode materials and apprise readers about the impact of uniform particle distribution on lithium storage performance. | Juan Yu Yinbo Wei Bicheng Meng Jiaxin Peng Kai Yang Tianxing Chen Naixing Yang Xiuyun Chuan | 2023 | International Journal of Minerals,Metallurgy and Materials2023，30，7： | 0 |
| 16 | Detection of scene-irrelevant head movements via eye-head coordination information显示文摘Background Accurate motion tracking in head-mounted displays(HMDs)has been widely used in immersive VR interaction technologies.However,tracking the head motion of users at all times is not always desirable.During a session of HMD usage,users may make scene-irrelevant head rotations,such as adjusting the head position to avoid neck pain or responding to distractions from the physical world.To the best of our knowledge,this is the first study that addresses the problem of scene-irrelevant head movements.Methods We trained a classifier to detect scene-irrelevant motions using temporal eye head-coordinated information sequences.To investigate the usefulness of the detection results,we propose a technique to suspend motion tracking in HMDs where scene-irrelevant motions are detected.Results/Conclusions Experimental results demonstrate that the scene-relevancy of movements can be detected using eye-head coordination information,and that ignoring scene-irrelevant head motions in HMDs improves user continuity without increasing sickness or breaking immersion. | Xiaoxiong FAN Yun CAI Yufei YANG Tianxing XU Yike Li Songhai ZHANG Fanglue ZHANG | 2021 | Virtual Reality & Intelligent Hardware2021，3，6： | 0 |
| 17 | Microwear analysis of a bone-handled microblade excavated at Shangzhai site in Beijing: Evidences from ESEM显示文摘The conventional wisdom has been challenged recently that microblades with handles are only tools for hunting and gathering in the Neolithic Age. Some scholars argued that microblades actually played an important part in the early agricultural development in the Neolithic. However, both of these opinions lacked direct evidence. Environmental scanning electron microscopy (ESEM) is used to analyze the residues of the bone-handled microblade excavated at the Shangzhai site in Pinggu, Beijing. The ESEM observation and EDX analysis show that at the edge of this bone-handled microblade are Ca, P, C, O or C, N, O, etc, which provide direct evidence for determining its function, namely that this microblade may have been dealt with animals. In addition, there was a layer of glue at the back of the microblade with barium and zinc salt distributed evenly in it, this new discovery sheds new light on adhesive technology in ancient China. | CUI TianXing YANG Qin YU JinCheng ZHOU ShuangLin ZHAO ChaoHong | 2010 | Science China Earth Sciences2010，53，9： | 0 |
| 18 | Application of Element-Free Method to water quality analysis of Miyun reservoir显示文摘This paper presents a 3D mathematical model for transfer and transform of water contaminants in reservoir, describes the discrete methods and the compute process of using an element-free collocation method. By these models and methods, the water quality conditions of Miyun reservoir area, the quantified description of three dimensions concerning the distribution and change of diversified contaminants are obtained within the assigned time. The distributions of total nitrogen and total phosphorus of the reservoir area in 2003, 2004 and 2005 are simulated and forecasted by the boundary conditions in 2003, so the main development trend is shown. It is found through calculation that: The contribution of the bed mud with regard to total phosphorus is comparatively marked. On the whole, the influence factor of the bed mud in the reservoir area and other comprehensive factors to total phosphorus are quite great. The influence of the living things or other function in the surface water of the Chaohe River valley in the east of the reservoir on the total phosphorus is comparatively conspicuous. Within the reservoir area in spring, summer and autumn, the concentration distribution of total nitrogen is basically in the trend of a slow progressive decrease, but the concentration of total phosphorus increases progressively. It is just contrary in autumn, winter and spring, the concentration of total nitrogen increases and the concentration of total phosphorus decreases. On the whole of the year's development, the total nitrogen is basically in a steady state, and the total phosphorus is in the increasing trend with years, but the kind of the trend is not conspicuous. | GU Zhaosheng, YANG Tianxing & XU Qing Changchun Institute of Technology, Changchun 130012, China College of Geo-Exploration Science and Technology, Jilin University, Changchun 130026, China National Research Center of Geoanalysis, Beijing 100037, China | 2005 | Science China Earth Sciences2005，48，z2： | 0 |
| 19 | Study on the Variation Characteristics of Haze Weather in Hubei Province during 1980-2012显示文摘This paper, using the method of 'the combination of 14 o'clock relative humidity, visibility and weather phenomena', selected haze days during 1980-2012 from 13 stations of Hubei Province, and studied years of variation characteristics of haze weather in Hubei Province. The results showed that the average annual haze days showed a fluctuant rising trend in whole from 1980 to 2012, but there were many peak value and valley value during the whole changing process; haze days of most stations showed an increasing trend, among which the stations with less than50 d haze days had a more obvious increasing trend, and the spatial distribution of annual mean haze days had distinct inhomogeneity. Haze days of Hubei Province presented the distribution characteristics of more in autumn and winter, and less in spring and summer, in which haze days during December-January were the most,and haze days during July-August were the least. Terrain had a big impact on local haze days, piedmont leeward zones were prone to haze days, mountainous regions were just the opposite. The research suggested that we should combine different situations with different stations instead of exclusively from the mean value of multiple stations when we analyze the mean change of haze days in a broader area, to investigate the overall changing trend and the reasons. | Tianxing SU Mingfang XU Xiang ZHOU Zaiqiang YANG Jijian YUAN Haiyan ZHANG | 2015 | Agricultural Science & Technology2015，16，1： | 0 |
| 20 | Engineering of Ag@Pd/Al_(2)O_(3)with varied Pd-shell thickness:Dynamic evolution of ligand and strain effects on acetylene selective hydrogenation显示文摘Bimetallic nanoparticles exhibit a synergistic effect that critically depends on their surface composition,but such promotion mechanisms become vague with varying surface compositions.Here,alumina supported Ag@Pd core–shell and PdAg alloy structure with controlled size and surface compositions were prepared to demonstrate synergetic mechanisms,particularly,ligand and strain effects on activity and ethylene selectivity for acetylene hydrogenation.The performance evaluation indicates that Ag@Pd catalysts with well-controlled Pd-shell thickness can effectively lower apparent activation energy and improve ethylene selectivity.Hydrogenation activity increases from 0.019 to 0.062 s^(-1) with decreasing Pd-shell thickness under mild conditions,which is 3–6 times higher than their alloyed and monometallic counterparts.Combined characterizations and density functional theory are conducted to reveal such shell-thickness-dependent performance.The ligand effect arising from Ag alloying in the interface of Ag@Pd2ML observes the strongest binding of acetylene,but it diminished sharply and the strain effect gets more prevailing with increasing shell thickness.The competition of ethylene desorption and deephydrogenation were also investigated to understand the selectivity governing factors,and the selectivity descriptor(0.5BE(C_(2)H_(4))–BE(H))was built to match the contribution of ligand and strain effect on the different surfaces of Pd-Ag bimetallic NPs.The exploration of synergetic mechanisms among bimetallic NPs with varied structure and surface compositions in this work can help us to deepen the understanding catalyst structure–activity relationship and provide a feasible way to optimize the overall catalytic performance. | Mingbo Yang Tianxing Yang Rui Ma Sha Li Yufei He Dianqing Li | 2023 | Chinese Journal of Chemical Engineering2023，64，12： | 0 |
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