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An analytical and numerical study of chaotic dynamics in a simple bouncing ball model

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Acta Mechanica Sinica 2011年第1期27卷 130-134页

作者： Andrzej Okninski Bogusaw Radziszewski Physics Division Politechnika Swietokrzyska Department of Mechatronics and Mechanical Engineering Politechnika Swietokrzyska

Dynamics of a ball moving in gravitational field and colliding with a moving table is studied in this paper. The motion of the limiter is assumed as periodic with piecewise constant velocity—it is assumed that the table moves up with a constant velocity and then moves down with another constant *** Poincaré map,describing evolution from an impact to the next impact,is derived and scenarios of transition to chaotic dynamics are investigated analytically and numerically.

关键词： Nonsmooth dynamics · Bouncing ball · Exact solutions

An IPMC actuated robotic surgery end effector with force sensing

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International Journal of Smart and Nano Materials 2013年第4期4卷 246-256页

作者： Kean aw Lixue Fu Andrew McDaid Mechanical Engineering The University of AucklandAucklandNew Zealand

Growth in patient acceptance of robotic-assisted surgery has led to increased demand and has stimulated research in many new surgical robotic *** some cases,the performance of robotic surgery has proven to surpass that of human surgeons alone.A new research area which uses the inherently force-compliant and back-drivable properties of polymers,ionic polymer–metal composite(IPMC)in this case,has shown potential to undertake precise surgical procedures in the delicate environments related to medical *** is because IPMCs have similar actuation characteristics to real biological systems,which can help ensure *** this,little has been done in developing IPMCs for a rotary joint actuator for functional surgical *** research proposes and demonstrates the design of a single degree of freedom(1-DOF)robotic surgical instrument with one skeleton-joint mechanism actuated by IPMC with an embedded strain gauge as a feedback *** system performance with a developed gain-schedule PI controller is *** the simplicity of the system,it was proven to be able to cut to the desired depth using the implemented force control(up to 8 gf cutting force).

关键词： IPMC integrated sensing surgical robot force control

Spatiotemporal analysis of elastic and inelastic deformations in roof-rocks from seismological observations

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International Journal of Mining Science and Technology 2021年第2期31卷 241-251页

作者： Maciej JMendecki RafałPakosz Łukasz Wojtecki Wacław MZuberek Faculty of Environmental Sciences the University of Silesia in Katowice41-200 SosnowiecPoland Polish Mining Group 40-039 KatowicePoland Central Mining Institute 40-166 KatowicePoland

The spatiotemporal analysis of seismic zones characterised by the scattering and accumulation of strain energy in the roof-rocks of the excavated longwall panel where inelastic or elastic deformations occurred during hard coal seam mining is *** studied longwall panel was designed to utilize the effect of partial stress relaxation caused by the earlier extraction of the coal seams located above.A full seismic moment tensor and spectral source parameter analyses were used to obtain information about the degree of inelastic and elastic coseismic *** study also showed that these deformation changes correspond to variation in the Benioff strain release ***,analyses of deformation zones were compared with the relationship between radiated energy and the excavated volume of rocks per *** concept of balanced seismic energy release assumed the exponential increase of released seismic energy with the increase in the volume of excavated *** between the observed and predicted radiated energies indicated that strain energy in selected zones in the rock mass was either scattered if the prediction was overestimated,or accumulated if ***,the study showed that elastic deformation in one zone can lead to inelastic deformation in the same zone.

关键词： Mining seismicity Seismic source volume Apparent volume Hard coal mine Longwall mining Benioff strain

Hylocomium splendens (Hedw.) *** Pleurozium schreberi (Brid.) *** trace element bioindicators:Statistical comparison of bioaccumulative properties

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Journal of Environmental Sciences 2013年第2期25卷 340-347页

作者： Sabina Doegowska Zdzisaw M.migaszewski Artur Michalik Geochemistry and the Environment Division Institute of ChemistryJan Kochanowski University15GSwietokrzyska St25-406 KielcePoland

The principal objective of this study was to compare bioaccumulative properties of two terrestrial moss species Hylocomium splendens and Pleurozium schreberi from the Kielce area （south-central Poland）, using various statistical techniques. Forty-six moss samples from 23 sampling sites located within the city limits were analyzed for 33 trace elements. The results indicated that 17 elements （Ba, Ce, Co, Cu, Eu, Fe, Gd, Hg, La, Mo, Nd, Ni, Pb, Pr, Sm, V, Y） dominated in H. splendens, whereas only three elements （Mn, Sr, Zn） occurred in excessive amounts in P. schreberi. No differences in the distribution pattern of Dy, Er, Ho, Sn, Tb, Th and Yb were observed. The element concentration ratio （PI/Hy） varied from 0.50 to 1.19. For 14 elements （Ce, Co, Cu, Fe, Gd, Hg, La, Mo, Nd, Ni, Pb, Sm, Th, V）, PI/Hy 〈 1; for 4 elements （Cd, Mn, Sr, Zn）, PI/Hy 〉 1; for 7 elements （Ba, Dy, Er, Eu, Pr, Y, Yb）, PI/Hy = equalled 1. Czekanowski＇s method showed similarities in rare earth element concentrations for both moss species. The cluster analysis exhibited three significant clusters at D link /D max × 100 〈 50 for both moss species. Strong positive Spearman correlations between both moss species were recorded for the following pairs：Ba-Ba, Co-Co, Er-Er, Eu-Eu, Gd Gd, Mn-Mn, Ni-Ni, Pb-Pb, Pr-Pr, Sm-Sm, Th-Th, Y-Y, and Yb-Yb. Nonparametric tests （Sign test, Wilcoxon tests） showed statistically significant differences only for Cd, Ce, Co, Cu, Hg, Mo, Ni, Pb and Sr. The scanning electron microscope study of H. splendens and P. schreberi revealed a different morphology of these species with no injuries.

关键词： biomonitoring trace elements moss species accumulative properties comparison

Deadwood affects the soil organic matter fractions and enzyme activity of soils in altitude gradient of temperate forests

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Forest Ecosystems 2023年第3期10卷 316-327页

作者： Ewa Błońska Wojciech Prazuch Jarosław Lasota Department of Ecology and Silviculture Faculty of ForestryUniversity of Agriculture in Krakow29 Listopada 46 Str.31-425KrakowPoland

The main objective of our study has been to determine the role of deadwood in the shaping of the amount of soil organic matter fractions in mountain forest *** this purpose,a climosequence approach comprising north(N)and south(S)exposure along the altitudinal gradient(600,800,1000 and 1200 m a.s.l.)was set *** comparing the properties of decomposing deadwood and those of the soils located directly beneath the decaying wood we drew conclusions about the role of deadwood in the shaping of soil organic matter fractions and soil carbon storage in different climate *** basic properties,enzymatic activity and fractions of soil organic matter(SOM)were determined in deadwood and affected directly by the components released from decaying *** decomposed deadwood impacts soil organic matter stabilization more strongly than the less decayed deadwood and the light fraction of SOM is more sensitive to deadwood effects than the heavy fraction regardless of the location in the altitude *** in SOM mineral-associated fraction C content is more pronounced in soils under the influence of deadwood located in lower locations of warmer *** released from decaying wood stimulate the enzymatic activity of soils that are within the range of deadwood influence.

关键词： Enzyme activity Forest soils Heavy fraction Light fraction Soil organic matter

The comparative effects of aqueous extract of Tetracarpidium conophorum seeds and Proviron on the sperm parameters of male guinea pigs

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Asian Pacific Journal of Tropical Medicine 2009年第6期2卷 11-15页

作者： Obianime aw Uche FI Department of Pharmacology University of Port HarcourtNigeria Department of Pharmacognosy and Ethno Therapy University of Port Harcourt Nigeria

Objective:To investigation the comparative effects of the aqueous extracts of the seeds of Tetracarpidium conophorum (***) and Proviron on the sperm parameters of male guinea pigs,and screen phytochemical constituents of the seeds of ***:The sperm count,motility and morphology of the male guinea pigs were done using Neubauer chamber(Haemocytometer),light microscope and dilute carbol Fuchsin(1:20) method,*** screening was done by standard ***: The aqueous extract of the *** seeds(100 -400 mg/kg) caused statistically significant increase (P < 0.05,ANOVA) in the sperm count and motility,from 67.7±2.10 and 56.5±2.40 to 78.0±3.5 and 75.0±2.8,*** highest effect was obtained at 300 mg/kg of *** this dose, the sperm count and motility of the male guinea pigs administered with *** were the same with the group administered 12.5 mg/kg *** values were 78.0±3.50 and 75.0±2.80,respectively for sperm count and motility(P <0.001,ANOVA).At 400 mg/kg,*** caused a slight decline in sperm count and *** effects were dose-dependent and comparable to the observed effects of Proviron (12.5 mg/kg) on sperm parameters of male guinea *** time-dependent study,the observed effect of T. conophorum(300 mg/kg) and Proviron on the values of sperm count and motility at 14th day were almost the *** values are 58.0±1.80 and 70.0±2.60,respectively for sperm motility and ***, on the 7th day of treatment,*** exhibited highest effect which was higher than that of Proviron. These effects decreased progressively from the 14th to the 28th *** Proviron showed the highest effect on the 28th *** effects were all time-dependent and statistically significant at P < 0.05(ANOVA).Finally, the phytochemical screening of the seeds of *** revealed the presence of flavonoids,tannins, alkaloids,terpenoids,carbohydrates,volatile oil

关键词： Tetracarpidium conophorum Sperm parameters Proviron Male guinea pigs Phytochemical screening

TLR3-independent activation of mast cells by cytomegalovirus contributes to control of pulmonary infection

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Cellular & Molecular Immunology 2017年第6期14卷 479-481页

作者： Niels aw Lemmermann Matthias J Reddehase Institute for Virology and Research Center forImmunotherapy (FZI) University Medical Centerof the Johannes Gutenberg University MainzGermany.

Interstitial pneumonia is a life-threatening clinical manifestation of human cytomegalovirus （hCMV） infection. In particular, it can be deadly in patients with hematopoietic malignancies who undergo hematopoietic cell transplantation （HCT） in whom a ＇window of risk＇, which is defined by transient immunodeficiency, occurs between hematoablative therapeutic treatment and immunological reconsfi- tution.

关键词： activation cytomegalovirus pulmonary

Palladium/ceramic composite membranes prepared by novel electroless plating procedure

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Chinese Science Bulletin 1997年第11期42卷 903-907页

作者： Zhao, HB Li, aw Gu, JH Xiong, GX CHINESE ACAD SCI DALIAN INST CHEM PHYSSTATE KEY LAB CATALYSISDALIAN 116023PEOPLES R CHINA

THIN films have become more and more important in advanced technology,hence attracted theresearch interest in material science and *** chemistry,thin films are classified intoorganic and inorganic *** with organic mem... 详细信息

关键词： sol-gel self-catalysis deposition palladium composite membrane.

Intestinal Kaposi's sarcoma may mimic gastrointestinal stromal tumor in HIV infection

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World Journal of Gastroenterology 2007年第33期13卷 4514-4516页

作者： A Zoufaly S Schmiedel aw Lohse J van Lunzen Department of Medicine 1 University Medical Center Hamburg-Eppendorf Hamburg Germany Infectious Diseases Unit University Medical Center Hamburg-Eppendorf Hamburg Germany

Diffuse intestinal Kaposi＇s sarcoma shares macroscopic and histopathologic features with gastrointestinal stromal tumors. Correct diagnosis may pose a clinical challenge. We describe the case of a young HIV-1-infected African lady without advanced immunodeficiency, who presented with a diffuse spindle cell tumor of the gut. Initial diagnosis was of a gastrointestinal stromal tumor, based on endoscopy and histopathology. Further evaluation revealed evidence for human herpesvirus 8 （HHV8） and the diagnosis had to be changed to diffuse intestinal Kaposi＇s sarcoma. Antiretroviral triple therapy together with chemotherapy was commenced, and has led to the rapid remission of intestinal lesions. With a background of HIV infection, the presence of HHV8 as the causative agent of Kaposi＇s sarcoma should be determined, as distinct treatment is indicated.

关键词： Gastrointestinal stromal tumor Kaposi's sarcoma HIV infection Human herpesvirus 8 c-kit