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| 1 | Influence of tribofilm on superlubricity of highly-hydrogenated amorphous carbon films in inert gaseous environments显示文摘In this study,we mainly focus on the structural morphology and inter-atomic bonding state of tribofilms resulting from a highly-hydrogenated amorphous carbon(a-C:H) film in order to ascertain the underlying mechanisms for its superlubric behavior(i.e.,less than 0.01 friction coefficient).Specifically,we achieved superlubricity(i.e.,friction coefficients of down to 0.003) with this film in dry nitrogen and argon atmospheres especially when the tribo-pair is made of an a-C:H coated Si disk sliding against an a-C:H coated steel ball,while the a-C:H coated disk against uncoated ball does not provide superlubricity.We also found that the state of superlubricity is more stable in argon than in nitrogen and the formation of a smooth and uniformly-thick carbonaceous tribofilm appears to be one of the key factors for the realization of such superlubricity.Besides,the interfacial morphology of sliding test pairs and the atomic-scale bond structure of the carbon-based tribofilms also play an important role in the observed superlubric behavior of a-C:H films.Using Raman spectroscopy and high resolution transmission electron microscopy,we have compared the structural differences of the tribofilms produced on bare and a-C:H coated steel balls.For the a-C:H coated ball as mating material which provided superlow friction in argon,structural morphology of the tribofilm was similar or comparable to that of the original a-C:H coating;while for the bare steel ball,the sp^2-bonded C fraction in the tribofilm increased and a fingerprint-like nanocrystalline structure was detected by high resolution transmission electron microscopy(HRTEM).We also calculated the shear stresses for different tribofilms,and established a relationship between the magnitude of the shear stresses and the extent of sp^3-sp^2 phase transformation. | LIU ShuWei ZHANG ChenHui OSMAN Eryilmaz CHEN XinChun MA TianBao HU YanZhong LUO JianBin ALI Erdemir | 2016 | Science China(Technological Sciences)2016，59，12： | 2 |
| 2 | New β-delayed Proton Precursor ^(135)Gd显示文摘Newβ-delayedProtonPrecursor^(135)Gd￥XuShuwei;XieYuanxiang;LiZhankui;MaRuichang;GeYuanxiu;WangChunfang;GuoBing;XingJianping;Hu?.. | Xu Shuwei Xie Yuanxiang Li Zhankui Ma Ruichang Ge Yuanxiu Wang Chunfang Guo Bing Xing Jianping Huang Wenxue Zhang Tianmei Liu Zhong Zhu Shaofei Jin Genming and Luo Yixiao | 1996 | IMP & HIRFL Annual Report1996，，1： | 2 |
| 3 | Alphanumeric charac- ter recognition based on BP neural network classification and combined features 显示文摘 | Luo Yong Chen Shuwei He Xiaojuan | 2013 | International Journal of Computational Intelligence Systems2013，6，6： | 1 |
| 4 | Optimization of core-shell structure distribution in sintered Nd-Fe-B magnets by titanium addition显示文摘In view of the uneven distribution of the core-shell structure of sintered Nd-Fe-B magnets after grain boundary diffusion,this study proposes to use high-melting-point and reactive element titanium(Ti)as an additive to increase the diffusion channels and to enhance the diffusion of heavy rare earth elements along the grain boundary phase.By adding Ti element,the diffusion depth and hence the intrinsic coercivity of magnets are increased significantly.The addition of Ti increases the coercivity at two stages:initially from 16.07 to 16.29 kOe by addition effect,and then from 16.29 to 25.16 kOe by facilitating the diffusion of Tb element.The formation of TiB_(2) phase improves the periodic arrangement of the crystal structure in the surroundings of the grain boundary phase and enhances its activity.The improved grain boundary diffusion and better core-shell structure distribution provide a theoretical guidance fo r solving the problem of diffusion depth in bulk magnets. | Shuwei Zhong Munan Yang Sajjad Ur Rehman Sangen Luo Longgui Li Chao Li Jiajie Li Shuhua Xiong Ihor Bulyk Bin Yang | 2023 | Journal of Rare Earths2023，41，7： | 1 |
| 5 | Growth of SiC as Binder to Adhere Diamond Particle and Tribological Properties of Diamond Particles Coated SiC显示文摘The purpose of this work was to grow SiC as binder to adhere diamond particles to graphite substrate by low pressure chemical vapor deposition(LPCVD) at 1100 °C and 100 Pa using methyltrichlorosilane(MTS: CH3 SiCl3) as precursor. The composite coatings on graphite substrates were analyzed by various techniques. Results show that a dense SiC coating with a cloud-cluster shape was formed both on the diamond particles and the substrate after deposition. The thermal stress(290.6 MPa) strengthened the interfacial bonding between the diamond particle and the SiC coating, which is advantageous for the purpose of adhering diamond particles to graphite substrate. The applied load of sliding wear test was found to affect not only the friction coefficient, but also the wear surface morphology. With increasing loads, the asperity penetration was high and the friction coefficient decreased. | Shengjie Yu Zhaofeng Chen Yang Wang Shuwei Hu Ruiying Luo Sheng Cui | 2015 | Journal of Materials Science & Technology2015，31，11： | 1 |
| 6 | Effect of sodium alginate-based hydrogel loaded with lutein on gut microbiota and inflammatory response in DSS-induced colitis mice显示文摘In order to effectively deliver lutein to the inflamed colon and better exert its pharmacological activity,this paper constructed a sodium alginate hydrogel-based delivery system loaded with lutein nanoparticles,evaluated the regulation on the expression and secretion of related inflammatory factors in mice with colitis,and its impact on intestinal microbial environment.The results showed that comparing lutein crystal and its nanoparticle,lutein hydrogel alleviated dextran sodium sulfate(DSS)-induced colitis in mice more effectively by adjusting fecal heme content,colon tissue damage,and inflammatory factor levels.Moreover,lutein hydrogel increased the expression of intestinal tight junction proteins zonula occluden-1(ZO-1),claudin-1 and occludin to maintain the integrity of the intestinal-barrier,inhibited the nuclear factor-κB(NF-κB)pathway and reduced expression and secretion of inflammatory factors including tumour necrosis factor-α(TNF-α),inducible nitric oxide synthase(iNOS),NOD-like receptors 3(NLRP3)and interleukin(IL)-1β.In addition,the intestinal microbial environment of mice with colitis was improved by down-regulating the relative abundance of Desulfovibrionaceae and up-regulating the relative abundance of Erysipelotrichaceae and Rikenellaceae.As a slow-release carrier to load lutein nanoparticles,sodium alginate-based hydrogel has potential application prospect. | Pengxiang Xu Shuwei Luo Jiangfeng Song Zhuqing Dai Dajing Li Cai’e Wu | 2023 | Food Science and Human Wellness2023，12，6： | 0 |
| 7 | HYDROFORMYLATION OF OLEFINS CATALYZED BY HOMOGENEOUS HETERONUCLEAR METAL CLUSTER [PhCH_2Me_3N][FeCo_3(CO)_(12)]显示文摘Hydroformylation of olefins catalyzed by heteronuclear metal cluster [PhCH2Me3N]-[FeCo3(CO)12] was studied. The effect of temperature, pressure, and solvent ect. on olefin hydroformylation was examined. The results show that for the hydroformylation of various olefins, e.g. 1-hexene, isobutene, 2-octene, cyclohexene, diisobutene, and styrene, the Fe-Co cluster exhibits rather high activity under mild conditions. For example, under the pressure such of 4 MPa, H2/CO ratio of 1: 1, at 120℃, 1-hexene was hydroformylated to heptanal with the conversion of > 80% and the selectivity of > 95% in 1 hr. | Luo Yuzhong, Fu Hongxiang, Zhang Shuwei(Lanzhou Institute of Chemical Physics, Chinese Academy of Science, Lanzhou, China) Wang Yunpu, Wu Nan, Zhang Aimi(Northwestern Teachers College, Lanzhou, China) | 1990 | 分子催化1990，4，S1： | 0 |
| 8 | Ultrafast metal oxide reduction at Pd/PdO_(2) interface enables onesecond hydrogen gas detection under ambient conditions显示文摘Here,we report a Pd/PdO_(x) sensing material that achieves 1-s detection of 4% H_(2) gas(i.e.,the lower explosive limit concentration for H_(2))at room temperature in air.The Pd/PdO_(x) material is a network of interconnected nanoscopic domains of Pd,PdO,and PdO_(2).Upon exposure to 4% H_(2),PdO and PdO_(2) in the Pd/PdO_(x) are immediately reduced to metallic Pd,generating over a>90% drop in electrical resistance.The mechanistic study reveals that the Pd/PdO_(2) interface in Pd/PdOx is responsible for the ultrafast PdO_(x) reduction.Metallic Pd at the Pd/PdO_(2) interface enables fast H_(2) dissociation to adsorbed H atoms,significantly lowering the PdO2 reduction barrier.In addition,control experiments suggest that the interconnectivity of Pd,PdO,and PdO2 in our Pd/PdO_(x) sensing material further facilitates the reduction of PdO,which would otherwise not occur.The 1-s response time of Pd/PdO_(x) under ambient conditions makes it an excellent alarm for the timely detection of hydrogen gas leaks. | Xin Geng Shuwei Li Zhi Mei Dongsheng Li Liang Zhang Long Luo | 2023 | Nano Research2023，16，1： | 0 |
| 9 | Feature based problem hardness understanding for requirements engineering显示文摘Heuristics and metaheuristics have achieved great accomplishments in various fields, and the investigation of the relationship between these algorithms and the problem hardness has been a hot topic in the research field. Related research work has contributed much to the understanding of the underlying mechanisms of the algorithms for problem solving. However, most existing studies consider traditional combinatorial problems as their case studies. In this study, taking the Next Release Problem(NRP) from the requirements engineering as a case study, we investigate the relationship between software engineering problem instances and heuristics. We employ an evolutionary algorithm to evolve NRP instances, which are uniquely hard or easy for the target heuristic(Greedy Randomized Adaptive Search Procedure and Randomized Hill Climbing in this paper). Then, we use a feature-based method to estimate the hardness of the evolved instances, with respect to the target heuristic. Experimental results demonstrate that, evolutionary algorithm can be used to evolve NRP instances that are uniquely hard or easy to solve. Moreover, the features enable the estimation of the target heuristics' performance. | Zhilei REN He JIANG Jifeng XUAN Shuwei ZHANG Zhongxuan LUO | 2017 | Science China(Information Sciences)2017，60，3： | 0 |
| 10 | Sediment budget and riverbed deformation in the uppermost part of the lower Yangtze River, China显示文摘The Yangtze River(YR), similar to most large rivers in the world, has experienced significant changes in its depositional environment due to anthropogenic disturbances and climatic influences in recent decades. However, knowledge of how the river channel and bed deformation respond to these changes in the uppermost part of the lower YR, a 200-km-long branched channel, is limited. In the current study,historical bathymetric data collected from 1992 to 2013 and high-resolution multibeam echo sounder(MBES) data obtained from 2015 to 2016 were analyzed to address the changes in the depositional environment. The results indicate that the whole riverbed in the Hukou to Datong reach(HDR) has been scouring over the past two decades and this trend is expected to continue in the future due to decreasing sediment supply from the upper watershed. The amount of net erosion from the HDR during 1992-2013approximately accounted for 7.2% of total sediment load in the Yangtze River(5.02 billion metric tons at Datong). The evolution of the riverbed is trending towards stabilization even though the patterns of erosion and/or deposition in the HDR have dramatically changed in the last two decades. The part of the channel from the upper 100 km to Datong was found to be a sensitive reach that first showed erosion from 1992 to 2003 and showed deposition during 2003-2008, and then mild erosion during 2008-2013in response to environmental changes. Thus, the findings indicate that riverine channel deformation in response to anthropogenic disturbance and climate influence is dynamic in different reaches, and this finding has both scientific and practical significance in terms of understanding channel stability and its response to external stressors. | Shuwei Zheng Huanlong Luo Jiayue Zhang Heqin Cheng Zijun Li Yugai Ma Shuaihu Wu Enfeng Liu | 2022 | International Journal of Sediment Research2022，37，4： | 0 |
| 11 | HYDROFORMYLATION OF ETHYLENE CATALYZED BY HOMOGENEOUS METAL CLUSTERS显示文摘This paper deals with a study of hydroformylation of ethylene catalyzed by homoge-neous metal clusters.〔PhCH2Me3N〕〔FeCo3(CO)12〕and〔PhCH2Me3N〕〔RuCO3(CO)12〕show high catalytic activity for the hydroform ylation of ethylene compared with YCCo3(CO)9,CO4(CO)10(PPh)2,Co2(CO)6(PBu3)2,and Fe2(CO)4(C5H5)2.The reacton rate ofheteronuclear clusters is faster than that with homonuclear clusters.The effect of tempera-ture and pressure on hydroformylation of ethylene with〔PhCH2Me3〕〔FeCo3(CO)12〕ascatalyst was studied.The experimental results.show that the conversion of ethylene exceeds90% with a selectivity up to 95% at temperature 130℃ and pressure 3.9 MPa.When studiedwith high pressure in situ infrared spectroscopic method,PhCCo3(CO)9 was found to havehigher thermostability than 〔PhCH2Me3N〕〔FeCo3(CO)12〕. | Fu Hongxiang, Luo Yuzong , Zhang Shuwei, Ren Xu (Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, China) | 1989 | 分子催化1989，3，S1： | 0 |
| 12 | Groundwater contaminant source identification considering unknown boundary condition based on an automated machine learning surrogate显示文摘Groundwater contamination source identification(GCSI)is a prerequisite for contamination risk evaluation and efficient groundwater contamination remediation programs.The boundary condition generally is set as known variables in previous GCSI studies.However,in many practical cases,the boundary condition is complicated and cannot be estimated accurately in advance.Setting the boundary condition as known variables may seriously deviate from the actual situation and lead to distorted identification results.And the results of GCSI are affected by multiple factors,including contaminant source information,model parameters,boundary condition,etc.Therefore,if the boundary condition is not estimated accurately,other factors will also be estimated inaccurately.This study focuses on the unknown boundary condition and proposed to identify three types of unknown variables(contaminant source information,model parameters and boundary condition)innovatively.When simulation-optimization(S-O)method is applied to GCSI,the huge computational load is usually reduced by building surrogate models.However,when building surrogate models,the researchers need to select the models and optimize the hyperparameters to make the model powerful,which can be a lengthy process.The automated machine learning(AutoML)method was used to build surrogate model,which automates the model selection and hyperparameter optimization in machine learning engineering,largely reducing human operations and saving time.The accuracy of AutoML surrogate model is compared with the surrogate model used in eXtreme Gradient Boosting method(XGBoost),random forest method(RF),extra trees regressor method(ETR)and elasticnet method(EN)respectively,which are automatically selected in AutoML engineering.The results show that the surrogate model constructed by AutoML method has the best accuracy compared with the other four methods.This study provides reliable and strong support for GCSI. | Yaning Xu Wenxi Lu Zidong Pan Chengming Luo Yukun Bai Shuwei Qiu | 2024 | Geoscience Frontiers2024，15，1： | 0 |
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