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| 1 | Three-dimensional-printed individualized porous implants:A new“implant-bone”interface fusion concept for large bone defect treatment显示文摘Bone defect repairs are based on bone graft fusion or replacement.Current large bone defect treatments are inadequate and lack of reliable technology.Therefore,we aimed to investigate a simple technique using three-dimensional(3D)-printed individualized porous implants without any bone grafts,osteoinductive agents,or surface biofunctionalization to treat large bone defects,and systematically study its long-term therapeutic effects and osseointegration characteristics.Twenty-six patients with large bone defects caused by tumor,infection,or trauma received treatment with individualized porous implants;among them,three typical cases underwent a detailed study.Additionally,a large segmental femur defect sheep model was used to study the osseointegration characteristics.Immediate and long-term biomechanical stability was achieved,and the animal study revealed that the bone grew into the pores with gradual remodeling,resulting in a long-term mechanically stable implant-bone complex.Advantages of 3D-printed microporous implants for the repair of bone defects included 1)that the stabilization devices were immediately designed and constructed to achieve early postoperative mobility,and 2)that osseointegration between the host bone and implants was achieved without bone grafting.Our osseointegration method,in which the“implant-bone”interface fusion concept was used instead of“bone-bone”fusion,subverts the traditional idea of osseointegration. | Teng Zhang Qingguang Wei Hua Zhou Zehao Jing Xiaoguang Liu Yufeng Zheng Hong Cai Feng Wei Liang Jiang Miao Yu Yan Cheng Daoyang Fan Wenhao Zhou Xinhong Lin Huijie Leng Jian Li Xinyu Li Caimei Wang Yun Tian Zhongjun Liu | 2021 | Bioactive Materials2021，6，11： | 9 |
| 2 | Road Impacts on Spatial Patterns of Land Use and Landscape Fragmentation in Three Parallel Rivers Region,Yunnan Province,China显示文摘The structure and function of network is a central issue in landscape ecology.Road networks with hierarchical structure are crucial for understanding landscape dynamics.In this study,we compared the distribution of national road,provincial road,county road and rural road in the Three Parallel Rivers Region(TPRR)in Yunnan Province of China,and estimated the effect of roads(and other factors)on the spatial patterns of land use and land cover with logistic regression.In addition,we analyzed the land use and land cover change(LUCC)and landscape fragmentation in 1989–2005 along a buffer zone of the primary traffic corridor,national road G214.The results showed that,county and rural roads had much higher percentage of length extending into more natural habitats at higher elevation and steeper slope,compared with the higher level roads in this region.While the distributions of natural land cover types were dominated by environmental factors,human land use types i.e.,building land and farmland types were significantly related with roads,linking more closely with lower level roads.The LUCC dynamics(1989–2005)of the G214 buffer zone showed a general trend of land transformation from conifer forests and valley arid shrubs to building land and farmland,and from ice and snow to alpine shrubs and forests.With the length of G214 unchanged during the time,the overall landscape pattern changed little in the buffer zone,but habitat fragmentation and area decrease had occurred for the natural vegetation types,in contrast to patch mergence and expansion of human land use types,and landscape fragmentation was intensified above 2500 m a.s.l.but declined below the elevation.The results indicated the dynamics of landscape composition and patch type level distribution in spite of the stability of the overall landscape pattern,and implied the potential role of roads,especially the low level roads on landscape changes. | LIANG Jun LIU Ye YING Lingxiao LI Peng XU Yue SHEN Zehao | 2014 | Chinese Geographical Science2014，24，1： | 8 |
| 3 | Community assemblage of free-living diazotrophs along the elevational gradient of Mount Gongga显示文摘Mountain systems are unique for studying the responses of species distribution and diversity to environmental changes along elevational gradients.It is well known that free-living diazotrophic microorganisms are important to nitrogen cycling in mountain systems.However,the elevational patterns of free-living diazotrophs and the underlying ecological processes in controlling their turnover along broader gradients are less well documented.Here,we investigated the pattern of diazotrophic diversity along the elevational gradient(1800 m-4100 m)in Mount Gongga of China.The results showed that the α-diversity of diazotrophs did not change with the elevation from 1800 m to 2800 m,but decreased at elevations above 3000 m.Such diversity pattern was driven mainly by soil total carbon,nitrogen,and plant richness.Various diazotrophic taxa showed differential abundance-elevation relationships.Ecological processes determining diazotrophic community assemblage shift along the elevations.Deterministic processes were relatively stronger at both low and high elevations,whereas stochastic processes were stronger at the middle elevation.This study also suggested a strong relationship among aboveground plants and diazotrophs,highlighting their potential interactions,even for free-living diazotrophs. | Yansu Wang Chaonan Li Zehao Shen Junpeng Rui Decai Jin Jiabao Li Xiangzhen Li | 2019 | Soil Ecology Letters2019，1，3： | 8 |
| 4 | Corridors and Networks in Landscape:Structure,Functions and Ecological Effects显示文摘 | SHEN Zehao WANG Yanglin FU Bojie | 2014 | Chinese Geographical Science2014，24，1： | 7 |
| 5 | Spatiotemporal Patterns of Road Network and Road Development Pri-ority in Three Parallel Rivers Region in Yunnan,China:An Evaluation Based on Modified Kernel Distance Estimate显示文摘Road network is a critical component of public infrastructure,and the supporting system of social and economic development.Based on a modified kernel density estimate(KDE)algorithm,this study evaluated the road service capacity provided by a road network composed of multi-level roads(i.e.national,provincial,county and rural roads),by taking account of the differences of effect extent and intensity for roads of different levels.Summarized at town scale,the population burden and the annual rural economic income of unit road service capacity were used as the surrogates of social and economic demands for road service.This method was applied to the road network of the Three Parallel River Region,the northwestern Yunnan Province,China to evaluate the development of road network in this region.In results,the total road length of this region in 2005 was 3.70×104km,and the length ratio between national,provincial,county and rural roads was 1∶2∶8∶47.From 1989 to 2005,the regional road service capacity increased by 13.1%,of which the contributions from the national,provincial,county and rural roads were 11.1%,19.4%,22.6%,and 67.8%,respectively,revealing the effect of′All Village Accessible′policy of road development in the mountainous regions in the last decade.The spatial patterns of population burden and economic requirement of unit road service suggested that the areas farther away from the national and provincial roads have higher road development priority(RDP).Based on the modified KDE model and the framework of RDP evaluation,this study provided a useful approach for developing an optimal plan of road development at regional scale. | YING Lingxiao SHEN Zehao CHEN Jiding FANG Rui CHEN Xueping JIANG Rui | 2014 | Chinese Geographical Science2014，24，1： | 7 |
| 6 | High-performance microwave absorption enabled by Co_(3)O_(4) modified VB-group laminated VS_(2) with frequency modulation from S-band to Ku-band显示文摘High performance microwave absorption(MA)materials especially those with tunable frequency are highly desirable for telecommunication industries and military camouflage in the information era.Herein,we constructed hierarchical heterostructures based on VB-group laminated vanadium disulfide(VS_(2))nanosheets embedded with cobalt tetroxide(Co_(3)O_(4))nanoparticles.The highly dispersed Co_(3)O_(4)nanoparticles generate strong electromagnetic coupling networks that could enhance the loss properties of MA materials.Moreover,the interconnected VS_(2)layered network results in dipolar/interfacial polarization,multiple reflection and scattering favorable for the enhanced MA performance.Impressively,the maximum reflection loss of the VS_(2)/Co_(3)O_(4)hybrids containing 10%Co_(3)O_(4)can reach 57.96 dB at a thin thickness of 1.57 mm,and the bandwidth with an RL value less than-10 dB is as large as 3.5 GHz.The effective MA band could be adjusted in a range of 15.1 GHz(2.9-18 GHz)from S to Ku bands by the increase in thickness from 1.2 mm to 5.5 mm.The results show that the synergistic effect of multiple loss mechanisms and good impedance matching could be the reasons for strong MA capability in nearly all frequency bands,and thus,the high-performance and lightweight MA materials could be developed by the VS_(2)/Co_(3)O_(4)hybrids. | Zehao Huang Junye Cheng Huibin Zhang Yingfei Xiong Zhanxin Zhou Qingbin Zheng Guangping Zheng Deqing Zhang Maosheng Cao | 2022 | Journal of Materials Science & Technology2022，，12： | 6 |
| 7 | The Medium Energy X-ray telescope (ME) onboard the Insight-HXMT astronomy satellite显示文摘The Medium Energy X-ray telescope(ME) is one of the three main telescopes on board the Insight hard X-ray modulation telescope(Insight-HXMT) astronomy satellite. ME contains 1728 pixels of Si-PIN detectors sensitive in 5-30 ke V with a total geometrical area of 952 cm^2. The application specific integrated circuit(ASIC) chip, VA32TA6, is used to achieve low power consumption and low readout noise. The collimators define three kinds of field of views(FOVs) for the telescope, 1°×4°, 4°×4°,and blocked ones. Combination of such FOVs can be used to estimate the in-orbit X-ray and particle background components.The energy resolution of ME is ~3 ke V at 17.8 ke V(FWHM) and the time resolution is 255 μs. In this paper, we introduce the design and performance of ME. | XueLei Cao WeiChun Jiang Bin Meng WanChang Zhang Tao Luo Sheng Yang ChunLei Zhang YuDong Gu Liang Sun XiaoJing Liu JiaWei Yang Xian Li Ying Tan ShaoZhen Liu YuanYuan Du FangJun Lu YuPeng Xu Ju Guan ShuangNan Zhang HuanYu Wang TiPei Li ChengMo Zhang XiangYang Wen JinLu Qu LiMing Song XiaoBo Li MingYu Ge YuPeng Zhou ShaoLin Xiong Shu Zhang YongJie Zhang ZeHao Cheng Fei Zhang MaoShun Li XiaoHua Liang Min Gao EnBo Yang XiaoHang Liu HongWei Liu YiJung Yang Fan Zhang | 2020 | Science China(Physics,Mechanics & Astronomy)2020，63，4： | 5 |
| 8 | How does contemporary climate versus climate change velocity affect endemic plant species richness in China?显示文摘Climate change is considered a top threat to biodiversity, but the relative roles of contemporary climate versus the rate of climate change in determining spatial patterns of biodiversity are far from clear. China has a very diverse flora and harbors a high percentage of endemic species, but the mechanisms underlying spatial patterns of plant endemism are poorly understood. This study explores the geographical patterns of a representative sample of 555 endemic seed plant species at the scale of 0.5° latitude 9 0.5° longitude. Ordinary least squares and spatial autoregressive models were compared to assess the relationship between richness of endemics and the rate of climate change in the past century, as well as a group of contemporary climate variables. In China, a high level of endemism was associated with high elevation and low rate of climate change. However, contemporary climate had a stronger impact than climate change velocity in the past century on endemic species richness patterns. Specifically,mean annual precipitation and annual range of temperature were important contemporary climatic factors. The rate of change of annual mean temperature, but not that of annual precipitation, also significantly contributed to the spatial pattern of plant endemic species richness. We found no significant relationship between topographic variation and endemic species richness, while temperature variability at multiple time scales was strongly correlated with the species richness pattern. Future work should consider the direction of climate change and incorporate higher-resolution data. | Chunjing Qiu Zehao Shen Peihao Peng Lingfeng Mao Xinshi Zhang | 2014 | Chinese Science Bulletin2014，59，34： | 4 |
| 9 | Extended state observer for uncertain lower triangular nonlinear systems subject to stochastic disturbance显示文摘扩大州的观察员(ESO ) 是为这天作为活跃骚乱拒绝控制所知的一种新兴的控制技术的最重要的部分,瞄准估计从看得见的测量输出的全部的骚乱。在这份报纸,我们与随机的骚乱为不明确的更低的三角形的非线性的系统的一个班构造非线性的 ESO 并且显示出它的集中,在全部的骚乱包括内部不明确的非线性的部分和外部随机的骚乱的地方。数字实验被执行说明建议途径的有效性。 | Zehao WU Baozhu GUO | 2016 | Control Theory and Technology2016，14，3： | 3 |
| 10 | Geographical Patterns of Chinese Ethnic Minority Population Composition and Ethnic Diversity显示文摘Ethnicity is a carrier of language and culture.Spatial distribution of ethnic diversity is fundamental for identifying and reconstructing the migration patterns and evolution histories of cultures and languages.Utilizing the Chinese 4th National Census (1990) data,we investigated the specific time geographical patterns of population and diversity of Chinese ethnicminorities.As anticipated,results show that Chineseminorities are chiefly concentrated in dis-tant plateaus and mountains in the southwest,northwest and northeast of China.Further,population density centers of the 10 majorminorities are rather scattered,alternatively dominating at different parts of the country.This study pro-vides a first comprehensive quantitative test on a prevailing notion of 'six plates and three corridors' on the empirical clustering patterns of Chinese ethnicminorities.There are more consistent evidences supporting this notion in the north of China,with the central and southern regions showing more complex patterns,potentially transformed by processes such as migration,fragmentation,and percolation.The results of this study suggest that a geographical ap-proach can provide heuristic and complementary information for better understanding of historical social processes. | SHEN Zehao LI Peng SUN Hongkai PANG Lihua | 2011 | Chinese Geographical Science2011，21，4： | 3 |
| 11 | Auxin response factor 6A regulates photosynthesis,sugar accumulation,and fruit development in tomato显示文摘Auxin response factors(ARFs)are involved in auxin-mediated transcriptional regulation in plants.In this study,we performed functional characterization of SlARF6A in tomato.SlARF6A is located in the nucleus and exhibits transcriptional activator activity.Overexpression of SlARF6A increased chlorophyll contents in the fruits and leaves of tomato plants,whereas downregulation of SlARF6A decreased chlorophyll contents compared with those of wild-type(WT)plants.Analysis of chloroplasts using transmission electron microscopy indicated increased sizes of chloroplasts in SlARF6A-overexpressing plants and decreased numbers of chloroplasts in SlARF6A-downregulated plants.Overexpression of SlARF6A increased the photosynthesis rate and accumulation of starch and soluble sugars,whereas knockdown of SlARF6A resulted in opposite phenotypes in tomato leaves and fruits.RNA-sequence analysis showed that regulation of SlARF6A expression altered the expression of genes involved in chlorophyll metabolism,photosynthesis and sugar metabolism.SlARF6A directly bound to the promoters of SlGLK1,CAB,and RbcS genes and positively regulated the expression of these genes.Overexpression of SlARF6A also inhibited fruit ripening and ethylene production,whereas downregulation of SlARF6A increased fruit ripening and ethylene production.SlARF6A directly bound to the SAMS1 promoter and negatively regulated SAMS1 expression.Taken together,these results expand our understanding of ARFs with regard to photosynthesis,sugar accumulation and fruit development and provide a potential target for genetic engineering to improve fruit nutrition in horticulture crops. | Yujin Yuan Xin Xu Zehao Gong Yuwei Tang Mengbo Wu Fang Yan Xiaolan Zhang Qian Zhang Fengqing Yang Xiaowei Hu Qichen Yang Yingqing Luo Lihua Mei Wenfa Zhang Cai-Zhong Jiang Wangjin Lu Zhengguo Li Wei Deng | 2019 | Horticulture Research2019，6，1： | 3 |
| 12 | Design principles in MOF-derived electromagnetic wave absorption materials:Review and perspective显示文摘At present,metal-organic framework(MOF)-derived nano-micro architectures are actively explored for electromagnetic(EM)wave absorption owing to their flexible composition and structural manipulation that enhance dielectric and magnetic attenuations.However,the basic design principles in MOF-derived microwave absorption materials have not been summarized.This review is devoted to analyzing design principles in MOF-derived microwave absorption materials from the following perspectives:diverse monomers(ligands and ions of MOFs),topologies,chemical states,and physical properties.The derived essential information regarding the EM wave absorption mechanism and the structural-functional dependency is also comprehensively summarized.Finally,a clear insight into the challenges and perspectives of the industrial revolution upgrading in this promising field is proposed. | Zhenguo Gao Kai Yang Zehao Zhao Di Lan Qian Zhou Jiaoqiang Zhang Hongjing Wu | 2023 | International Journal of Minerals,Metallurgy and Materials2023，30，3： | 3 |
| 13 | 3D-printed models improve surgical planning for correction of severe postburn ankle contracture with an external fixator显示文摘Gradual distraction with an external fixator is a widely used treatment for severe postburn ankle contracture(SPAC).However,application of external fixators is complex,and conventional two-dimensional(2D)imaging-based surgical planning is not particularly helpful due to a lack of spatial geometry.The purpose of this study was to evaluate the surgical planning process for this procedure with patient-specific three-dimension-printed models(3DPMs).In this study,patients coming from two centers were divided into two cohorts(3DPM group vs.control group)depending on whether a 3DPM was used for preoperative surgical planning.Operation duration,improvement in metatarsal-tibial angle(MTA),range of motion(ROM),the American Orthopedic Foot and Ankle Society(AOFAS)scores,complications,and patient-reported satisfaction were compared between two groups.The 3DPM group had significantly shorter operation duration than the control group((2.0±0.3)h vs.(3.2±0.3)h,P<0.01).MTA,ROM,and AOFAS scores between the two groups showed no significant differences pre-operation,after the removal of the external fixator,or at follow-up.Plantigrade feet were achieved and gait was substantially improved in all patients at the final follow-up.Pin-tract infections occurred in two patients(one in each group)during distraction and were treated with wound care and oral antibiotics.Patients in the 3DPM group reported higher satisfaction than those in the control group,owing to better patient-surgeon communication.Surgical planning using patient-specific 3DPMs significantly reduced operation duration and increased patient satisfaction,while providing similar improvements in ankle movement and function compared to traditional surgical planning for the correction of SPAC with external fixators. | Youbai CHEN Zehao NIU Weiqian JIANG Ran TAO Yonghong LEI Lingli GUO Kexue ZHANG Wensen XIA Baoqiang SONG Luyu HUANG Qixu ZHANG Yan HAN | 2021 | Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)2021，22，10： | 3 |
| 14 | Practical strategy to construct anti-osteosarcoma bone substitutes by loading cisplatin into 3D-printed titanium alloy implants using a thermosensitive hydrogel显示文摘Surgical resection and perioperative adjuvant chemotherapy-based therapies have improved the prognosis of patients with osteosarcoma;however,intraoperative bone defects,local tumour recurrence,and chemotherapy-induced adverse effects still affect the quality of life of patients.Emerging 3D-printed titanium alloy(Ti6Al4V)implants have advantages over traditional implants in bone repair,including lower elastic modulus,lower stiffness,better bone conduction,more bone in-growth,stronger mechanical interlocking,and lager drug-loading capacity by their inherent porous structure.Here,cisplatin,a clinical first-line anti-osteosarcoma drug,was loaded into Ti6Al4V implants,within a PLGA-PEG-PLGA thermo-sensitive hydrogel,to construct bone substitutes with both anti-osteosarcoma and bone-repair functions.The optimal concentrations of cisplatin(0.8 and 1.6 mg/mL)were first determined in vitro.Thereafter,the anti-tumour effect and biosafety of the cisplatin/hydrogel-loaded implants,as well as their bone-repair potential were evaluated in vivo in tumour-bearing mouse,and bone defect rabbit models,respectively.The loading of cisplatin reduced tumour volume by more than two-thirds(from 641.1 to 201.4 mm3)with negligible organ damage,achieving better anti-tumour effects while avoiding the adverse effects of systemic cisplatin delivery.Although bone repair was hindered by cisplatin loading at 4 weeks,no difference was observed at 8 weeks in the context of implants with versus without cisplatin,indicating acceptable long-term stability of all implants(with 8.48%-10.04%bone in-growth and 16.94%-20.53%osseointegration).Overall,cisplatin/hydrogel-loaded 3D-printed Ti6Al4V implants are safe and effective for treating osteosarcoma-caused bone defects,and should be considered for clinical use. | Zehao Jing Renhua Ni Jiedong Wang Xinhong Lin Daoyang Fan Qingguang Wei Teng Zhang Yufeng Zheng Hong Cai Zhongjun Liu | 2021 | Bioactive Materials2021，6，12： | 3 |
| 15 | A new measurement method for radial permeability and porosity of shale显示文摘To more conveniently and accurately obtain the radial permeability of shale,a new measurement method was proposed for the pressure attenuation of radial permeability and porosity in shale.Through experiments,this method could be used to get the pressure attenuation curve in annular space between the core and inner wall of PVT vessel under the helium along shale radial flow.Accordingly,a mathematical model was established to obtain the semi-analytical solution between pressure and time in the radial model.Meanwhile,through fitting the experimental results,the concentration conductivity and porosity of shale were obtained,and their relationship was used to derive the radial permeability of shale.This method was adopted to measure the permeability and porosity of two cores under three sets of different initial pressures in the annular space.The permeability test results were compared with those obtained by the conventional Dicker method and Smits pressure-attenuation method,and the porosity test results were also compared with those obtained by the conventional porosimeter,thus the feasibility and superiority of this method were confirmed.In contrast to the conventional pressureattenuation methods,this new model had advantages of simpler instruments and more convenient operation,and was also easy to measure the radial permeability and porosity of shale. | Zehao Yang Mingzhe Dong | 2017 | Petroleum Research2017，2，2： | 2 |
| 16 | Effects of climate change on biodiversity显示文摘直到 1980 年代,气候变化和生物多样性为超过一个世纪作为二个独立学科被学习。在 1992,美洲年度报告的生态的社会作为第二十一个世纪的三个主要全球环境问题说出气候变化,生物多样性,和持续生态的系统[1 ] 。 | Zehao Shen Keping Ma | 2014 | Chinese Science Bulletin2014，59，34： | 2 |
| 17 | The impact of biofuel plantation on biodiversity: a review显示文摘Because plants convert solar energy into chemical energy stored in organisms, biomass production as an energy source can help to reduce the world's reliance on fossil energy and mitigate global warming. Biofuel production is a fast-growing industry that represents a new type of large-scale human disturbance on ecosystems. Thus, the benefits of biofuel production bring environmental risks that include its potential impact on biodiversity, which is still an open question. In this review, we start first with a brief overview of the evolution of biofuel concept; second, we review the state of biofuel production across the continents,with a major emphasis on the main species used and their major feedstock. For which, we found significant differences for land use and environmental cultural management of biofuel plantation between tropical and temperate regions.Third, we summarize the impacts of biofuel plantation on biodiversity at multiple scales, based on the case studied with respect to the corresponding issues. At the genetic level,introgression and contamination by aggressive genotypes are a primary risk. At the species level, habitat pollution, degradation, and disturbance caused by intensive managementof biofuel plantation significantly raise the risk of habitat fragmentation, native extinction, and bio-invasion. At the ecosystem level, the large-scale homogeneous landscape of biofuel plantation results in simplified community and food web that severely damage ecosystem services, including ecosystem diversity. Finally, we compare the current and potential benefits and risks of biofuel plantations for the practical application of a biofuel industry of China. We emphasize the land use constraint from food security and biodiversity conservation, and the need for scientific research and systematic monitoring as a critical support for the sustainable development of biofuel production in China. | Ye Liu Yue Xu Fengchun Zhang Jinqi Yun Zehao Shen | 2014 | Chinese Science Bulletin2014，59，34： | 2 |
| 18 | Effects of wildfire on soil respiration and its heterotrophic and autotrophic components in a montane coniferous forest显示文摘Aims Episodic wildfires are expected to occur more frequently under future climate change scenarios,with substantial effects on CO_(2) exchange between terrestrial ecosystems and the atmosphere.This study examined the effects of wildfire on soil respiration(R_(S))and its heterotrophic(R_(H))and autotrophic(R_(A))components,as well as their temperature responses(temperature sensitivity,Q_(10)).Methods We began this study in January 2014,8 months after a wildfire,in a montane coniferous forest in southwestern China.A trenching method was used to exclude plant roots and quantify R_(H).R_(A) was calculated by subtracting R_(H) from R_(S).Important findings From 2014 to 2015,the wildfire significantly reduced R_(S),R_(H) and R_(A) by 61.3%,42.5%and 84.0%,respectively,leading to increases in the ratio of R_(H) to R_(S),from 0.63 in the unburned stand to 0.85 in the burned stand.Ignoring diurnal differences,the wildfire did not affect the Q_(10) of R_(S) or R_(H),but substantially decreased the Q_(10) of R_(A),from 2.62 in the unburned stand to 2.08 in the burned stand.However,the daytime Q_(10) of R_(S) and R_(H) was suppressed follow-ing the wildfire by 25.1%and 28.8%,respectively,primarily due to increased daytime soil temperature.In the montane coniferous for-est,monthly precipitation but not soil temperature drove seasonal dynamics of soil CO_(2) release.Our findings help to clarify the mech-anisms underlying carbon cycling responses to natural disturbance,especially under a warmer future climate. | Jian Song Zhen Liu Yuan Zhang Tao Yan Zehao Shen Shilong Piao | 2019 | Journal of Plant Ecology2019，12，2： | 2 |
| 19 | Accuracy assessment and error analysis for diameter at breast height measurement of trees obtained using a novel backpack LiDAR system显示文摘Background: The LiBackpack is a recently developed backpack light detection and ranging(LiDAR) system that combines the flexibility of human walking with the nearby measurement in all directions to provide a novel and efficient approach to LiDAR remote sensing, especially useful for forest structure inventory. However, the measurement accuracy and error sources have not been systematically explored for this system.Method: In this study, we used the LiBackpack D-50 system to measure the diameter at breast height(DBH) for a Pinus sylvestris tree population in the Saihanba National Forest Park of China, and estimated the accuracy of LiBackpack measurements of DBH based on comparisons with manually measured DBH values in the field. We determined the optimal vertical slice thickness of the point cloud sample for achieving the most stable and accurate LiBackpack measurements of DBH for this tree species, and explored the effects of different factors on the measurement error.Result: 1) A vertical thickness of 30 cm for the point cloud sample slice provided the highest fitting accuracy(adjusted R2= 0.89, Root Mean Squared Error(RMSE) = 20.85 mm);2) the point cloud density had a significant negative, logarithmic relationship with measurement error of DBH and it explained 35.1% of the measurement error;3) the LiBackpack measurements of DBH were generally smaller than the manually measured values, and the corresponding measurement errors increased for larger trees;and 4) by considering the effect of the point cloud density correction, a transitional model can be fitted to approximate field measured DBH using LiBackpackscanned value with satisfactory accuracy(adjusted R2= 0.920;RMSE = 14.77 mm), and decrease the predicting error by 29.2%. Our study confirmed the reliability of the novel LiBackpack system in accurate forestry inventory, set up a useful transitional model between scanning data and the traditional manual-measured data specifically for P.sylvestris, and implied the applicable substitution of this new approach for more species, with necessary parameter calibration. | Yuyang Xie Jie Zhang Xiangwu Chen Shuxin Pang Hui Zeng Zehao Shen | 2020 | Forest Ecosystems2020，7，3： | 2 |
| 20 | Laser powder bed fusion of high-strength Sc/Zr-modified Al–Mg alloy:phase selection,microstructural/mechanical heterogeneity,and tensile deformation behavior显示文摘Laser powder bed fusion(L-PBF)of Sc/Zr-modified Al-based alloys has recently become a promising method for developing a new generation of high-performance Al alloys.To clarify the modification roles of Sc/Zr elements,an Al–4.66Mg–0.48Mn–0.72Sc–0.33Zr(wt.%)alloy was processed using L-PBF.The effect of the local solidification condition of the molten pool on the precipitation behavior of primary Al_(3)(Sc,Zr)was analyzed based on time-dependent nucleation theory.It was found that primary Al_(3)(Sc,Zr)inevitably precipitated at the fusion boundary,while its precipitation could be effectively suppressed in the inner region of the molten pool.This subsequently induced the formation of a heterogeneousα-Al matrix.After direct aging,the heredity of solidification microstructure introduced heterogeneous secondary Al_(3)(Sc,Zr)precipitates withinα-Al matrix.Owing to the inverse relationship between grain boundary strengthening and precipitation strengthening,the direct-aged sample with dual heterogeneous structures exhibited reduced mechanical heterogeneity,resulting in lowered hetero-deformation-induced hardening.The low strain-hardening capability in the direct-aged sample promoted necking instability while inducing a large Lüders elongation,which effectively improved the tensile ductility. | Zihong Wang Xin Lin Nan Kang Jing Chen Hua Tan Zhe Feng Zehao Qin Haiou Yang Weidong Huang | 2021 | Journal of Materials Science & Technology2021，，36： | 2 |
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