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| 1 | 2D DEM simulation of particle mixing in rotating drum: A parametric study显示文摘Mixing behaviors of equal-sized glass beads in a rotating drum were investigated by both DEM simulations and experiments. The experiments indicated that higher rotation speed can significantly enhance mixing. The particle profiles predicted by 2D DEM simulation were compared with the experimental results from a quasi-2D drum, showing inconsistency due to reduction of contacts in the single-layer 2D simulation which makes the driving friction weaker than that in the quasi-2D test, better results could be reached by specifying a higher frictional coefficient between the particles and the cylinder wall. In order to explore the influences of physical properties (density, size or friction) on mixing behavior, numerical 2D simulations were carried out systematically, in which one examined specific property being examined was exaggerated while the others were kept the same as that in the control group. The DEM simulations reveal that particle density and size are the dominating factors affecting mixing behaviors, while the effect of frictional coefficient is less significant. However, segregation due to any of the factors can be diminished by specifying a proper particle size distribution (multi-size with lower size ratio). | Yong Xu Chunhui Xu Zhe Zhou Jing Du Daping Hu | 2010 | Particuology2010，8，2： | 16 |
| 2 | Growth and nutrient dynamics of Betula alnoides seedlings under exponential fertilization显示文摘Betula alnoides is a fast-growing hardwood species grown in large plantations in Southeast Asia and South China.Nitrogen requirements for producing robus seedlings,growth and nutrient dynamics were investigated using exponential fertilization treatments.Root collar diameter,height,dry mass and nutrient contents of seedlings increased exponentially in all fertilization treatments as time progressed.Moreover,with water soluble fertilizer(Plant Products plus microelements N–P_2O_5–K_2O:20–20–20),300 mg N seedling^(-1)was adequate.Vector analysis revealed that P was the most responsive nutrient element followed by N and K.Dilutions of N and K were evident in the plants without N addition,which induced initial P sufficiency and then luxury consumption probably due to the antagonistic interaction between N and P.However deficiencies of N,P and K were mostly observed in al exponential regimes during the experiment because seedling growth rate exceeded nutrient uptake rate,inferring that further study on improving the nutrient uptake efficiency is needed.Analysis of relationships among nutrient supply,dry mass,N content and N concentration demonstrated that 100–400 mg N seedling^(-1)induced sufficiency to luxury consumption of nitrogen without significant change in dry mass,and 400 mg N seedling^(-1)is recommended to apply for nutrient loading of seedlings before outplanting.The findings will help improve seedling quality and enhance the production of robust seedlings for plantation forestry of this species. | Lin Chen Chunsheng Wang Bernard Dell Zhigang Zhao Junjie Guo Daping Xu Jie Zeng | 2018 | Journal of Forestry Research2018，29，1： | 14 |
| 3 | Study of the influences of rotary table speed on stick-slip vibration of the drilling system显示文摘Stick-slip vibration presents one of the major causes of drilling problems,such as premature tool failures,low drilling efficiency and poor wellbore quality.The objective of this work is to investigate the influences of rotary table speed(RTS)on stick-slip phenomenon of the drilling system.In this study,the drilling system is treated as a lumped torsional pendulum model of which the bit/rock interaction is regarded as Coulomb friction.By analyzing cases with different RTS,two types of vibrations on the bit are found:stick-slip vibration and uniform motion.With an increase in the RTS,the stick-slip vibration on the drill bit disappears once the RTS arrives at its critical value.For the cases that stick-slip vibrations occur,the phase trajectories converge toward a limit cycle.For the cases that stick-slip vibration does not appear,the drill bit tends to stabilize at a uniform motion and the phase trajectories correspond to contracting spirals observed in the phase plane. | Liping Tang Xiaohua Zhu Changshuai Shi Jian Tang Daping Xu | 2015 | Petroleum2015，1，4： | 5 |
| 4 | Polysaccharide,proline,and anti-oxidation enzyme activities of Thailand rosewood(Dalbergia cochinchinensis)seedlings exposed to exponential fertilization显示文摘Thailand rosewood(Dalbergia cochinchinensis)is a vulnerable high value tree species in subtropical and tropical Southeast Asia.The demand for the rehabilitation of the natural habitat of the species requires high-quality seedlings.However,current fertilizer regimes tend to deliver a coarse rate of fertilizers that result in a low uptake efficiency and a high risk of nutrient excess.Exponential fertilization is an effective approach to promote seedling quality through identifying an optimum dose out of a range of applications.In this study,Thailand rosewood seedlings were cultured in a mixed substrate of perlite,vermiculite,and peat(2:2:3,v/v/v)and received exponential fertilization from 0(control),through 100,200,300,400,and 600 mg nitrogen(N)per plant over a four-month cultural rotation.Height,diameter,and shoot biomass increased with fertilizer rate and were maximized at 300 mg N per plant.This application also reduced nutrient deficiencies and avoided excess supply compared to higher rates.Polysaccharide,proline,and anti-oxidation enzyme activities tended to be greater in unfertilized controls or in over-fertilized high dosages,with lower activities around 100–300 mg N plant(-1).Application of 300 mg N per plant was identified as the optimum dosage as it maximized nutrient reserves,polysaccharide and proline contents,and anti-oxidants without causing any symptoms from excess fertilizer toxicity.Future work is required to identify the effects of N-fixation on the formation of nutritional reserves in Thailand rosewood seedlings subjected to exponential fertilization. | Zhou Hong Junyu Guo Ningnan Zhang Zengjiang Yang Xiaojing Liu Zhiyi Cui Daping Xu | 2022 | Journal of Forestry Research2022，33，1： | 4 |
| 5 | Effects of weeding and fertilization on soil biology and biochemical processes and tree growth in a mixed stand of Dalbergia odorifera and Santalum album显示文摘In southern China,the eucalyptus plantation industry has been severely restricted by government policy over concerns on negative environmental impacts.In its place,large-scale plantations of high-value tropical tree species such as nitrogen-fixing Dalbergia odorifera and hemiparasite Santalum album have been widely cultivated including in mixed-species plantations.However,despite their poor growth,little information is available on suitable silvicultural practices of these plantations.Therefore,we subjected an 8-year-old mixed stand of D.odorifera and S.album to weeding,fertilization,weeding+fertilization,or no(CK)treatments and measured soil microbial biomass,respiration,nutrients,nitrogen mineralization and leaching and tree growth and litter production.Weeding and fertilization decreased microbial biomass but increased soil respiration,inhibited mineralization,had not effect on leaching of soil nitrogen,and improved the nutrient status of plantation soil.All practices improved the growth of D.odorifera.In the mixed plantation,fertilization increased litter production and nutrient content,but weeding and weeding+fertilization decreased growth of S.album and litter production in mixed plantation because weeding decreased the number of S.album haustoria in underground plant roots.In conclusion,fertilization is recommended;however,weeding-related practices are inappropriate for D.odorifera and S.album mixed plantations.These conclusions have important implications for managing other parasite or mixed-species plantations. | Peng Zhang Xiaofei Li Shiyu Xue Zhiyi Cui Daping Xu Zengjiang Yang | 2021 | Journal of Forestry Research2021，32，6： | 2 |
| 6 | Composite rock-breaking of high-pressure CO_(2)jet&polycrystallinediamond-compact(PDC)cutter using a coupled SPH/FEM model显示文摘CO_(2) drilling is a promising underbalance drilling technology with great advantages,such as lower cutting force,intense cooling and excellent lubrication.However,in the underbalance drilling,the mechanism of the coupling CO_(2) jet and polycrystalline-diamond-compact(PDC)cutter are still unclear.Whereby,we established a coupled smoothed particle hydrodynamics/finite element method(SPH/FEM)model to simulate the composite rock-breaking of high-pressure CO_(2) jet&PDC cutter.Combined with the experimental research results,the mechanism of composite rock-breaking is studied from the perspectives of rock stress field,cutting force and jet field.The results show that the composite rock-breaking can effectively relieve the influence of vibration and shock on PDC cutter.Meanwhile,the high-pressure CO_(2) jet has a positive effect on carrying rock debris,which can effectively reduce the temperature rising and the thermal wear of the PDC cutter.In addition,the effects of CO_(2) jet parameters on composite rock-breaking were studied,such as jet impact velocity,nozzle diameter,jet injection angle and impact distance.The studies show that when the impact velocity of the CO_(2) jet is greater than 250 m/s,the CO_(2) jet could quickly break the rock.It is found that the optimal range of nozzle diameter is 1.5–2.5 mm,the best injection angle of CO_(2) jet is 60,the optimal impact distance is 10 times the nozzle diameter.The above studies could provide theoretical supports and technical guidance for composite rock-breaking,which is useful for the CO_(2) underbalance drilling and drill bit design. | Can Cai Pei Zhang Daping Xu Xianpeng Yang Yingfang Zhou | 2022 | International Journal of Mining Science and Technology2022，32，5： | 2 |
| 7 | A novel non-precious metal catalyst synthesized via pyrolysis of polyaniline-coated tungsten carbide particles for oxygen reduction reaction显示文摘 | Kezhu Jiang Qingmin Jia Mingli Xu Daping Wu Lunquan Yang Guotao Yang Linyan Chen Guanghua Wang Xikun Yang | 2012 | Journal of Power Sources2012，，： | 1 |
| 8 | Bacterial Wilt and Boron Deficiency Stress:A New Disorder in Eucalypt Plantations in South China显示文摘This paper reports on a new disorder that first appeared in eucalypt plantations in south China in2003. The plantations were destructively sampled near Leizhou, Yanxi, Kaiping and Gaoyao in September toDecember 2003. Whilst some 5% of 0.5 to 1.5 year-old Eucalyptus urophylla trees declined rapidly andexhibited symptoms of wilting, the majority of the affected trees declined slowly and exhibited two foliarsymptoms. Young leaves initially developed an interveinal chlorosis extending from the leaf margin inwardsto the midrib. Most leaves then developed pockets of necrotic tissue that became bleached but typically hadbrown margins. The former symptoms have been recognised as being caused by limited boron supply in soil,but the latter symptoms have not been previously observed in eucalypts in China. Inorganic analysisshowed that the leaves with the latter symptoms had deficient B concentrations whereas the leaves fromhealthy trees had adequate B concentrations. Bacterial wilt, Ralstonia solanacearum, was present at all siteswhere foliar symptoms and tree death were present. The root system of all trees with foliar chlorosis andnecrosis had signs of infection in some roots and attrition of lateral roots. The trunk and branches of therecently died trees and the trees with advanced leaf drop had discoloured xylem, which on cutting, oozedbacterial slime. Possible relationships between root damage caused by abiotic (e.g. typhoons, root damagefrom hand weeding) and biotic factors and reduced B uptake are discussed. Recommendations are made forreducing bacterial wilt disease and improving B management in fast-growing short-rotation eucalypt plantations. | DELL Bernard XU Daping | 2006 | Chinese Forestry Science and Technology2006，5，1： | 1 |
| 9 | A novel non-precious metal catalyst synthesized via pyrolysis of polyaniline-coated tungsten carbide particles for oxygen reduction reaction显示文摘 | Kezhu Jiang Qingmin Jia Mingli Xu Daping Wu Lunquan Yang Guotao Yang Linyan Chen Guanghua Wang Xikun Yang | 2012 | Journal of Power Sources2012，，： | 1 |
| 10 | Application of Principal Components Analysis in Condenser Fault Diagnosis显示文摘 | HAN Xiaojuan XU Daping LIU Yibing | 2006 | Intelligent Control and Automation2006，，2： | 1 |
| 11 | Effects of calcium,boron and nitrogen fertilization on the growth of teak ( Tectona grandis) seedlings and chemical property of acidic soil substrate 显示文摘 | Zaizhi Zhou Kunnan Liang Daping Xu | 2012 | New Forests2012，43，2： | 1 |
| 12 | Evaluation of Surface Water Quality in Forest Catchment Based on Euclidean Distance Model with Varying Weights显示文摘The Euclidean distance model with varying weights was applied to evaluate the surface water quality based on the monitoring data derived from April 2010 to February 2011 in secondary forest catchment,eucalypt plantation catchment and rubber plantation catchment in Limu Mountain,Hainan Island.The results were compared with that of grey association analysis method,grey clustering model and fuzzy comprehensive evaluation method.The results indicated that the assessment results of surface water quality in the three types of forest catchments based on Euclidean distance model with varying weights and grey clustering model were GradeⅠ,the assessment results of surface water quality in secondary forest catchment based on grey association analysis method and fuzzy comprehensive evaluation method were also GradeⅠ,but besides that the assessment results of surface water quality in eucalypt plantation catchment in June 2010 and rubber plantation catchment in August 2010 based on the last two methods were GradeⅡ,those in the remain seven months were GradeⅠ,showing that the plantation in this area did not cause significantly negative effect on surface water. | Xiang Yangzhou Xu Daping Yang Zengjiang Zhang Ningnan Guo Junyu | 2012 | Chinese Forestry Science and Technology2012，11，3： | 0 |
| 13 | Ex vivo cartilage explant model for the evaluation of chondrocyte-targeted exosomes显示文摘There is no efficient tracking system available for the therapeutic molecules delivered to cartilage.The dense matrix covering the cartilage surface is the main biological barrier that the therapeutic molecules must overcome.In this study,we aimed to establish a system that can dynamically and effectively track the therapeutic molecules delivered to cartilage.To this aim,we adopted bovine and human cartilage explants as ex vivo models for chondrocyte-targeted exosome dispersion.The efficiency of drug delivery was evaluated using frozen sections.The results of this study showed that the penetration and distribution of chondrocyte-targeted exosomes in cartilage explants can be tracked dynamically.Thus,ex vivo cartilage explants provide an effective and economic system to evaluate therapeutic drugs encapsulated in chondrocyte-targeted exosomes in preclinical studies. | KAN OUYANG MEIQUAN XU YUJIE LIANG XIAO XU LIMEI XU CAINING WEN ZHUAN QIN YIXIN XIE HUAWEI ZHANG LI DUAN DAPING WANG | 2022 | BIOCELL2022，46，6： | 0 |
| 14 | Research and Development of the Profibus-dp Card Based onWin CE.net显示文摘This paper is to briefly introduce the Embedded Intelligent Monitoring System, which is based on the embedded operation system of Wince.net and ARM9. The practical application of PROFIBUS in this system is researched. The master station protocol chip- MDP card is discussed in details. The development of the hardware structure and the device driver of the DP protocol card are presented. | (Department of Automation, North China Electric Power U- niversity)Lü,Yuegang Wang,Yanyan Xu,Daping | 2006 | 微计算机信息2006，22，11S： | 0 |
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