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| 1 | Numerical simulation of powder transport behavior in laser cladding with coaxial powder feeding显示文摘Laser cladding with coaxial powder feeding is one of the new processes applied to produce well bonding coating on the component to improve performance of its surface. In the process, the clad material is transported by the carrying gas through the coaxial nozzle, generating gas-powder flow. The powder feeding process in the coaxial laser cladding has important influence on the clad qualities. A 3D numerical model was developed to study the powder stream structure of a coaxial feeding nozzle. The predicted powder stream structure was well agreed with the experimental one. The validated model was used to explore the collision behavior of particles in the coaxial nozzle, as well as powder concentration distribution. It was found that the particle diameter and restitution coefficient greatly affect the velocity vector at outlet of nozzle due to the collisions, as well as the powder stream convergence characteristics below the nozzle. The results indicated a practical approach to optimize the powder stream for the coaxial laser cladding. | LIU Hao HE XiuLi YU Gang WANG Zhong Bin LI ShaoXia ZHENG CaiYun NING WeiJian | 2015 | Science China(Physics,Mechanics & Astronomy)2015，58，10： | 17 |
| 2 | The impacts of conservation agriculture on crop yield in China depend on specific practices, crops and cropping regions显示文摘For smooth and wide application of conservation agriculture(CA), remaining uncertainties about its impacts on crop yield need to be reduced. Based on previous field experiments in China, a meta-analysis was performed to quantify the actual impacts of CA practices(NT: no/reduced-tillage only, CTSR: conventional tillage with straw retention, NTSR: NT with straw retention) on crop yields as compared to conventional tillage without straw retention(CT).Although CA practices increased crop yield by 4.6% on average, there were large variations in their impacts. For each CA practice, CTSR and NTSR significantly increased crop yield by 4.9%and 6.3%, respectively, compared to CT. However, no significant effect was found for NT. Among ecological areas, significant positive effects of CA practices were found in areas with an annual precipitation below 600 mm. Similar effects were found in areas with annual mean air temperature above 5 °C. For cropping regions, CA increased crop yield by 6.4% and 5.5%compared to CT in Northwest and South China, respectively, whereas no significant effects were found in the North China and Northeast China regions. Among crops, the positive effects of CA practices were significantly higher in maize(7.5%) and rice(4.1%) than in wheat(2.9%). NT likely decreased wheat yield. Our results indicate that there are great differences in the impacts of CA practices on crop yield, owing to regional variation in climate and crop types. CA will most likely increase maize yield but reduce wheat yield. It is strongly recommended to apply CA with crop straw retention in maize cropping areas and seasons with a warm and dry climate pattern. | Chengyan Zheng Yu Jiang Changqing Chen Yanni Sun Jinfei Feng Aixing Deng Zhenwei Song Weijian Zhang | 2014 | The Crop Journal2014，2，5： | 15 |
| 3 | Response of grain yield to plant density and nitrogen rate in spring maize hybrids released from 1970 to 2010 in Northeast China显示文摘The objective of this study was to identify the response of grain yield to plant density and nitrogen rate in spring maize hybrids released from 1970 to 2010 and grown extensively in Northeast China.Twenty-one hybrids were grown for 2 years in Northeast China at densities of 30,000,52,500,75,000,and 97,500 plants ha^(-1)and N application levels of 0,150,300,and 450 kg N ha^(-1).Irrespective of density or nitrogen application rate,grain yields both per plant and per unit area were significantly higher for newer than older hybrids.As plant density increased from 30,000 to 97,500 plant ha^(-1),yield per plant of 1970 s,1980 s,1990 s,and 2000 s hybrids decreased by 50%,45%,46%,and 52%,respectively.The response of grain yield per unit area to plant density was curvilinear.The estimated optimum plant densities were about 58,000,49,000,65,000,and 65,000 plants ha^(-1)for hybrids released in the 1970 s,1980s,1990 s,and 2000 s,respectively.The theoretical optimum densities for the hybrids released from the 1970 s to the 2000 s increased by 1750 plants ha^(-1)decade^(-1).Nitrogen fertilization significantly increased grain yields per plant and per unit area for all hybrids.The theoretical optimum N application rates for high yield for hybrids released in the 1970 s and 1980 s were about 280 and 360 kg ha^(-1),and the hybrids from the 1990 s and 2000 s showed highest yield at 330 kg ha^(-1)N.No significant difference in the grain yields of 2000 s hybrids between the N levels of 150 to 450 kg ha^(-1)was found.Significant yield gains per plant and per unit area were found,with average increases of 17.9 g plant^(-1)decade^(-1)and936 kg ha^(-1)decade^(-1)over the period 1970–2010,respectively.Yield gains were attributed mainly to increased yield per plant,contributed by increases in kernel number per ear and1000-kernel weight.The rates of lodging and barren plants of newer hybrids were significantly lower than those of older ones,especially at high plant density. | Chunrong Qian Yang Yu Xiujie Gong Yubo Jiang Yang Zhao Zhongliang Yang Yubo Hao Liang Li Zhenwei Song Weijian Zhang | 2016 | The Crop Journal2016，4，6： | 15 |
| 4 | Field investigations of high stress soft surrounding rocks and deformation control显示文摘Field investigations of high stress soft rock deformations show that the high stress soft rock roadway can slide with large deformation. Severe extrusion and floor heave can also be subsequently observed. The supported roadway can be locally damaged or completely fail, where the floor has a large deformation and/or is seriously damaged. The factors inducing large deformation of surrounding rocks in deep roadway are rock strengths, structure face cutting types, stress states, stress release, support patterns,and construction methods. Based on the deformation characteristics of high stress soft rock roadway, a comprehensive support scheme is proposed. The overall support technology of 'step-by-step and joint,hierarchical reinforcement' for roadway is presented, and the anchor cable and bolt parameters to check the design methods are also given. Finally, the proposed comprehensive support method 'bolt t metal mesh t U-steel arch t shortcrete t grouting and cable' is used in the extension section of east main haulage roadway at 850 m level of Qujiang coal mine. The 173-day monitoring results show that the average convergence of sidewalls reaches 208 mm, and the average relative convergence of roof and floor reaches 448 mm, suggesting that this kind of support technology for controlling large deformation of high stress soft surrounding rock roadway is effective. | Weijian Yu Weijun Wang Xinyuan Chen Shaohua Du | 2015 | Journal of Rock Mechanics and Geotechnical Engineering2015，7，4： | 12 |
| 5 | Research on characters of surrounding rock in complex geology conditions and supporting time显示文摘The methods combined by test, field monitoring and theoretical analysis were adopted to do the systemic research on the rock mass from micro-structure to macro-deformation, and rheological model of Jinchuan rock mass was established to discuss the reasonable supporting time. Results show that supporting after suitable stress and displacement release can benefit for the long-term stability of surrounding rock. | Yu Weijian Gao Qian Zhai Shuhua Zhang Meihua | 2008 | Engineering Sciences2008，6，2： | 9 |
| 6 | Estimation of the Type of Low Energy Discharge in GIS Adopting Characteristic Gas显示文摘In order to guarantee safe operations, low energy discharge within gas insulated switchgear (GIS) should be detected as soon as possible before they develop severely and cause final breakdown failures. This paper aims to present a GIS discharge diagnosis technique adopting gaseous decompositions. To reach this aim, needle-plate electrode and the sphere-plate electrode with metallic particles on the plate are designed to simulate two kinds of low energy discharge, namely, corona discharge and spark discharge, respectively. After sampling and analyzing the gases, different yields of gaseous by-products under different types of low energy discharge are obtained. Based on the decomposition mechanisms reported by previous researches and the experiment results, it can be concluded that S2OF10, SO2F2 , and SO2 can be used as the characteristic gas to identify low energy discharge; the increment of S2OF10 can indicate the occurrence of low energy discharges while the volume ratio between SO2F2 and SO2 can define the type of low energy discharge. | CHEN Jun LI Li YAO Weijian TANG Yang ZHENG Xiaoguang YU Jianhui LUO Yunbai ZHOU Wenjun | 2011 | Wuhan University Journal of Natural Sciences2011，16，4： | 7 |
| 7 | Failure mechanism of Mesozoic soft rock roadway in Shajihai coal mine and its surrounding rock control显示文摘In view of the buckling failure caused by large deformation of Mesozoic soft rock roadway in Shajihai mining area, such as serious roof fall, rib spalling, floor heave, etc., based on the detail site investigation,theoretical analysis, mineral composition test, microstructure test, water-physical property test and field experiments were carried out. And we revealed the compound failure mechanism of Mesozoic soft rock roadway in Shajihai mining area, namely the molecule expansion-shear slip of weak structural plane-construction disturbance. On this basis, the coupling support technology whose core is constant resistance with large deformation bolt was proposed. The feature of this supporting technology is that a new type of structural composite material was used, which makes the supporting system not only has the ideal deformation characteristics, but also has high supporting resistance. Thus the fully release of plastic energy within surrounding rock and reasonable control of the thickness of the plastic ring were realized. Then the differential deformation between the surrounding rock and support was eliminated by the secondary coupling support of bolt–mesh–cable, and the bolt with high strength was applied in the base angle to control floor. Eventually the collaborative bearing system of surrounding rock–support was formed. Through field tests the validity and rationality of support was also verified. | Yuan Yue Zhu Yongjian Wang Weijun Yu Weijian | 2014 | International Journal of Mining Science and Technology2014，24，6： | 7 |
| 8 | Experimental and theoretical investigation on mechanisms performance of the rock-coal-bolt(RCB)composite system显示文摘For coal mines,rock,coal,and rock bolt are the critical constituent materials for surrounding rock in the underground engineering.The stability of the“rock-coal-bolt”(RCB)composite system is affected by the structure and fracture of the coal-rock mass.More rock bolts installed on the rock,more complex condition of the engineering stress environment will be(tensile-shear composite stress is principal).In this paper,experimental analysis and theoretical verification were performed on the RCB composite system with different angles.The results revealed that the failure of the rock-coal(RC)composite specimen was caused by tensile and shear cracks.After anchoring,the reinforcement body formed inside the composite system limits the area where the crack could occur in the specimen.Specifically,shearing damage occurred only around the bolt,and the stress-strain curve presented a better post-peak mechanical property.The mechanical mechanism of the bolt under the combined action of tension and shear stress was analyzed.Additionally,a rock-coal-bolt tensile-shear mechanical(RCBTSM)model was established.The relationship(similar to the exponential function)between the bolt tensile-shear stress and the angle was obtained.Moreover,the influences of the dilatancy angle and bolt diameter of the RCB composite system were also considered and analyzed.Most of the bolts are subjected to the tensile-shearing action in the post-peak stage.The implications of these results for engineering practice indicated that the bolts of the RCB composite system should be prevented from entering the limit shearing state early. | Genshui Wu Weijian Yu Jianping Zuo Shaohua Du | 2020 | International Journal of Mining Science and Technology2020，30，6： | 5 |
| 9 | Compositions of aliphatic des-A-triterpenes in the Hani peat deposit,Northeast China and its biological significance显示文摘Aliphatic des-A-triterpenes,the degradation products of pentacyclic triterpenes have been tentatively assigned in samples taken from a 963-cm-thick peat sequence from the Hani region of Northeast China using gas chromatography-mass spectrometry(GC-MS)in order to understand and identify these des-A-triterpenes response to climate and ecology.The study indicates that aliphatic des-A-triterpenes are abundant in the Hani peat bog.The high relative abundance of the total des-A-triterpenes mainly occurs at the Holocene periods and is corresponding to the low sedimentation rate.The mechanism of des-A-triterpenes accumulation is not consistent with the previous studies.It is proposed that the biological community is also one influence factor.The obvious stage variations of the total des-A-triterpenes in the whole sequence reveal the different biological(microbes and plants) processes and responses,possibly revealing the four large replacements of biological community and functional composition in the swamp environment over the 16000 cal a BP.The low total des-A-triterpenes values occur at about 10200,8700,7700,6600,4480-3940 and 3040 cal a BP,reflecting the multiple millennial micro-environment oscillations under the macro-environment of the swamp during the Holocene.The ratios of diene and monoene des-A-triterpenes(DT/MT),des-A-lupane and diene and monoene des-A-triterpenes(DL/(DT+MT)),ratios ofindividual compounds exhibit vertical opposite to the total des-A-triterpenes. Namely,these ratios are high during the last deglaciation and late Holocene whereas they are low at other periods,indicating different compounds have different responses to micro-environment and microbial activities.This study discusses the diversity of biological community and biological functional composition response to micro-environment,which not only provides the complement in Northeast China,but also bears important fundamental information for the implication to ecological environment in the future. | ZHENG YanHong ZHOU WeiJian LIU Zhao CHEN QingMin YU XueFeng LIU XiaoMin | 2010 | Chinese Science Bulletin2010，55，21： | 5 |
| 10 | Meta analysis of olfactory ensheathing cell transplantation promoting functional recovery of motor nerves in rats with complete spinal cord transection显示文摘OBJECTIVE:To evaluate the effects of olfactory ensheathing cell transplantation on functional recovery of rats with complete spinal cord transection.DATA SOURCES: A computer-based online search of Medline(1989–2013),Embase(1989–2013),Cochrane library(1989–2013),Chinese Biomedical Literature Database(1989–2013),China National Knowledge Infrastructure(1989–2013),VIP(1989–2013),Wanfang databases(1989–2013) and Chinese Clinical Trial Register was conducted to collect randomized controlled trial data regarding olfactory ensheathing cell transplantation for the treatment of complete spinal cord transection in rats.SELECTION CRITERIA: Randomized controlled trials investigating olfactory ensheathing cell transplantation and other transplantation methods for promoting neurological functional recovery of rats with complete spinal cord transection were included in the analysis.Meta analysis was conducted using Rev Man 4.2.2 software.MAIN OUTCOME MEASURES: Basso,Beattie and Bresnahan scores of rats with complete spinal cord transection were evaluated in this study.RESULTS: Six randomized controlled trials with high quality methodology were included.Meta analysis showed that Basso,Beattie and Bresnahan scores were significantly higher in the olfactory ensheathing cell transplantation group compared with the control group(WMD = 3.16,95% CI(1.68,4.65); P < 0.00001).CONCLUSION: Experimental studies have shown that olfactory ensheathing cell transplantation can promote the functional recovery of motor nerves in rats with complete spinal cord transection. | Jun Liu Ping Chen Qi Wang Yu Chen Hailong Yu Junxiong Ma Mingming Guo Meihui Piao Weijian Ren Liangbi Xiang | 2014 | Neural Regeneration Research2014，9，20： | 4 |
| 11 | Responsive and self-healing structural color supramolecular hydrogel patch for diabetic wound treatment显示文摘The treatment of diabetic wounds remains a great challenge for medical community.Here,we present a novel structural color supramolecular hydrogel patch for diabetic wound treatment.This hydrogel patch was created by using N-acryloyl glycinamide(NAGA)and 1-vinyl-1,2,4-triazole(VTZ)mixed supramolecular hydrogel as the inverse opal scaffold,and temperature responsive poly(N-isopropylacrylamide)(PNIPAM)hydrogel loaded with vascular endothelial cell growth factor(VEGF)as a filler.Supramolecular hydrogel renders hydrogel patch with superior mechanical properties,in which NAGA and VTZ also provide self-healing and antibacterial properties,respectively.Besides,as the existence of PNIPAM,the hydrogel patch was endowed with thermal-responsiveness property,which could release actives in response to temperature stimulus.Given these excellent performances,we have demonstrated that the supramolecular hydrogel patch could significantly enhance the wound healing process in diabetes rats by downregulating the expression of inflammatory factors,promoting collagen deposition and angiogenesis.Attractively,due to responsive optical property of inverse opal scaffold,the hydrogel patch could display color-sensing behavior that was suitable for the wound monitoring and management as well as guidance of clinical treatment.These distinctive features indicate that the presented hydrogel patches have huge potential values in biomedical fields. | Canwen Chen Yu Wang Han Zhang Hui Zhang Weiliang Dong Weijian Sun Yuanjin Zhao | 2022 | Bioactive Materials2022，7，9： | 2 |
| 12 | Sterilization and disinfection methods for decellularized matrix materials:Review,consideration and proposal显示文摘Sterilization is the process of killing all microorganisms,while disinfection is the process of killing or removing all kinds of pathogenic microorganisms except bacterial spores.Biomaterials involved in cell experiments,animal experiments,and clinical applications need to be in the aseptic state,but their physical and chemical properties as well as biological activities can be affected by sterilization or disinfection.Decellularized matrix(dECM)is the low immunogenicity material obtained by removing cells from tissues,which retains many inherent components in tissues such as proteins and proteoglycans.But there are few studies concerning the effects of sterilization or disinfection on dECM,and the systematic introduction of sterilization or disinfection for dECM is even less.Therefore,this review systematically introduces and analyzes the mechanism,advantages,disadvantages,and applications of various sterilization and disinfection methods,discusses the factors influencing the selection of sterilization and disinfection methods,summarizes the sterilization and disinfection methods for various common dECM,and finally proposes a graphical route for selecting an appropriate sterilization or disinfection method for dECM and a technical route for validating the selected method,so as to provide the reference and basis for choosing more appropriate sterilization or disinfection methods of various dECM. | Meihan Tao Tianrang Ao Xiaoyan Mao Xinzhu Yan Rabia Javed Weijian Hou Yang Wang Cong Sun Shuang Lin Tianhao Yu Qiang Ao | 2021 | Bioactive Materials2021，6，9： | 2 |
| 13 | A facile solution processed ZnO@ZnS core–shell nanorods arrays for high-efficiency perovskite solar cells with boosted stability显示文摘Zinc Oxide(ZnO)has been extensively applied as electron transport material(ETM)in perovskite solar cells(PSCs)since the emergence of PSCs.However,some chemisorbed oxygen species on the surface of ZnO can cause the degradation of CH3NH3+(MA^(+))based perovskite.To avoid the destructive effect of ZnO,a facile solution strategy was proposed to produce a ZnS shell around the ZnO nanorods arrays(ZnO-NRs),i.e.ZnO@ZnS core-shell nanorods(ZnO-NRs@ZnS).The ZnO-NRs@ZnS cascade structure can not only facilitate carrier transport,but also enhance the stability of ZnO based PSCs.A power conversion efficiency(PCE)of 20.6%was finally yielded,which is the-state-of-the-art efficiency for PSCs with one-dimensional(1 D)ZnO electron transport materials(ETMs).Moreover,over 90%of the initial efficiency was retained for the unencapsulated device with ZnO-NRs@ZnS ETMs at 85℃for 500 h,demonstrating excellent stability.This work provides a simple and efficient avenue to simultaneously enhance the photovoltaic(PV)performance and stability of 1 D ZnO nanostructure-based PSCs. | Kun Chen Weijian Tang Yu Chen Ruihan Yuan Yinhua Lv Wenjuan Shan Wen-Hua Zhang | 2021 | Journal of Energy Chemistry2021，30，10： | 2 |
| 14 | Driving mechanism of keyhole evolution during multi-pulse drilling with a millisecond laser显示文摘To better understand the physical processes of multi-pulse laser drilling,this study investigates the keyhole evolution and its driving mechanism in a time-resolved observation system.The evolution characteristics suggested a two-phase process of rapid penetration followed by moderate penetration.As revealed in the ejection and vaporization behavior,the keyhole evolution was dominated by ejection and vaporization during the rapid and moderate penetration stages,respectively.In a single laser-pulsed drilling experiment,the driving mechanism itself was found to be affected by the dimensionless laser power density.The effect of dimensionless laser power density on depth increment was then discussed by comparing the experimental observations with numerical simulation results.The results further confirmed the driving mechanism of the keyhole evolution.The results in this paper are useful for understanding the driving mechanism of the keyhole evolution during multi-pulse laser drilling. | Yue Zhang Gang Yu XiuLi He ShaoXia Li WeiJian Ning | 2019 | Science China(Physics,Mechanics & Astronomy)2019，62，10： | 2 |
| 15 | Effects of long-term fertilization on corn productivity and its sustainability in an Ultisol of southern China显示文摘 | Shan Huang Weijian Zhang Xichu Yu Qianru Huang | 2010 | Agriculture Ecosystems and Environment2010，，1： | 2 |
| 16 | Cyclic-anion salt for high-voltage stable potassium-metal batteries显示文摘Electrolyte anions are critical for achieving high-voltage stable potassium-metal batteries(PMBs).However,the common anions cannot simultaneously prevent the formation of‘dead K’and the corrosion of Al current collector,resulting in poor cycling stability.Here,we demonstrate cyclic anion of hexafluoropropane-1,3-disulfonimide-based electrolytes that can mitigate the‘dead K’and remarkably enhance the high-voltage stability of PMBs.Particularly,even using low salt concentration(0.8 M)and additive-free carbonate-based electrolytes,the PMBs with a high-voltage polyanion cathode(4.4 V)also exhibit excellent cycling stability of 200 cycles with a good capacity retention of 83%.This noticeable electrochemical performance is due to the highly efficient passivation ability of the cyclic anions on both anode and cathode surfaces.This cyclic-anion-based electrolyte design strategy is also suitable for lithium and sodium-metal battery technologies. | Yanyao Hu Ling Fan Apparao M.Rao Weijian Yu Caixiang Zhuoma Yanhong Feng Zhihui Qin Jiang Zhou Bingan Lu | 2022 | National Science Review2022，9，10： | 1 |
| 17 | Finite Time Synchronization of Complex Network 显示文摘 | YU Di BA1 Xuefeng REN Weijian | 2014 | Journal of Jilin University: Information Science Edition2014，32，4： | 1 |
| 18 | Effects of long-term fertilization on corn productivity and its sustainability in an Ultisol of southern China显示文摘 | Shan Huang Weijian Zhang Xichu Yu Qianru Huang | 2010 | Agriculture, Ecosystems and Environment2010，，： | 1 |
| 19 | Tranexamic acid reduces postoperative blood loss of degenerative lumbar instability with stenosis in posterior approach lumbar surgery: a randomized controlled trial显示文摘 | Qi Wang Jun Liu Rong Fan Yu Chen Hailong Yu Yan Bi Zhengzhe Hua Meihui Piao Mingming Guo Weijian Ren Liangbi Xiang | 2013 | European Spine Journal2013，，9： | 1 |
| 20 | Heat and mass transfer in laser dissimilar welding of stainless steel and nickel显示文摘 | Yaowu Hu Xiuli He Gang Yu Zhifu Ge Caiyun Zheng Weijian Ning | 2012 | Applied Surface Science2012，，15： | 1 |
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