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The effects of electron irradiation on the optical properties of the organic semiconductor polypyrrole

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Journal of Semiconductors 2013年第9期34卷 11-15页

作者： J.V.Thombare M.c.Rath S.H.Han V.J.Fulari Holography and Materials Research Laboratory Department of PhysicsShivaji University Radiation and Photochemistry Division BARC Department of chemistry Hanyang University

The optical properties of polypyrrole （Ppy） thin films upon 2 MeV electron beam irradiation changes with different doses. The induced changes in the optical properties for Ppy thin films were studied in the visible range 300 to 800 nm at room temperature. The optical band gap of the pristine Ppy was found to be 2.19 cV and it decreases up to 1.97 eV for a 50 kGy dose of 2 MeV electron beam. The refractive index dispersion of the samples obeys the single oscillator model. The obtained results suggest that electron beam irradiation changes the optical parameters of Ppy thin films.

关键词： polypyrrole electron beam irradiation optical band gap

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哲学与现代派艺术

DEPENDENcE OF MIcROSTRUcTURE ScALES OF EUTEcTIcS ON ca-Si MODIFIER AMOUNT IN AUSTENITE STEEL cOMPOSITES

作者： (苏)N.c.库列科娃

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Acta Metallurgica Sinica(English Letters) 2004年第5期17卷 651-654页

作者： G.F.Liang Z.M.Xu Q.c.Jiang J.G.Li SchoolofMaterialsScienceandTechnology ShanghaiJiaotongUniversityShanghai200030China SchoolofEnvironmentalScienceandEngineeringJiaotongUniversity Shanghai200030China SchoolofMaterialsScience JilinUniversityChangchun130025China

Results presented in this paper contribute to investigation of the effect of the added ca-Si modifier amount ( ) on the microstructure scales of granular γ-(Fe,Mn)3c eutectics such as the volume fraction (f) and diameter (d) in the austenite steel matrix composites (EAMc). Directional solidification of EAMc has been carried out using vertical Bridgman method at 50.6μms-1 with a constant temperature gradient about 800Kcm-1. The higher constitutional supercooling ahead of solid-liquid interface attributing to the larger results in the enlargement of γ-(Fe,Mn)3c coupled-zone and the increment of the nucleation rate of eutectics. Therefore, f increases with increasing . The branches of the primary austenite dendrites develop more greatly as increases, which limits the growth of eutectics. As a result, d decreases with increasing .

关键词： austenite steel eutectic microstructure directional solidification

Experimental and numerical analyses of magnesium alloy hot workability

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Journal of Magnesium and Alloys 2016年第4期4卷 295-301页

作者： F.Abbassi M.Srinivasan c.Loganathan R.Narayanasamy M.Gupta Mechanical engineering department college of engineeringdhofar universityp.o.box 2509211 salalahoman Urmssdt ensituniversity of tunis5 avenue taha husseinbp56bâb manara 1008tunisia Department of mechanical engineering chartered institute of technologyabu roadsirohirajasthan 307510india Department of production engineering national institute of technologytiruchirappallitamil nadu 620015india Department of mechanical engineering national university of singapore

Due to their hexagonal crystal structure,magnesium alloys have relatively low workability at room *** this study,the hot workability behavior of cast-extruded AZ31B magnesium alloy is studied through hot compression testing,numerical modeling and microstructural *** deformation tests are performed at temperatures of 250℃ to 400℃ under strain rates of 0.01 to 1.0 s^(−1).Transmission electron microscopy is used to reveal the presence of dynamic recrystallization(DRX),dynamic recovery(DRY),cracks and shear *** predict plastic instabilities during hot compression tests of AZ31B magnesium alloy,the authors use Johnson–cook damage model in a 3D finite element *** optimal hot workability of magnesium alloy is found at a temperature(T)of 400℃ and strain rate(ε)of 0.01 s^(−1).Stability is found at a lower strain rate,and instability is found at a higher strain rate.

关键词： AZ31B magnesium alloy Hot workability Damage Plastic instability TEM analysis FEM

A ruptured recurrent small bowel gastrointestinal stromal tumour causing hemoperitoneum

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Frontiers of Medicine 2015年第1期9卷 108-111页

作者： Eric c.H. Lai Kam Man chung Stephanie H.Y. Lau Wan Yee Lau Faculty of Medicine The Chinese University of Hong Kong Shatin Hong Kong SAR China Dr. K.M. chung's clinic Rm 807 Hang Seng Tsimshatsui Building 18 Carnarvon Road Tsimshatsui Hong Kong SAR China Department of Surgery Pamela Youde Nethersole Eastern Hospital Hong Kong SAR China Department of Surgery Queen Elizabeth Hospital Hong Kong SAR China

Hemoperitoneum is a rare and potentially life-threatening complication of GIST. We reported a 54- year-old man who developed disseminated intra-abdominal recurrence from a previously resected gastrointestinal stromal tumour （GIST） of the small bowel, and the patient presented with hemoperitoneum. Emergent debulking surgery was performed. A high dose imatinib was prescribed. Despite the presence of residual disease, the patient was well clinically 8 months after the operation. Even though, there is no evidence to support the routine use of debulking surgery in the management of GIST. In our patient, disease progression after second line targeted therapy and the absence of alternative treatment options for spontaneous rupture and hemoperitoneum prompted us to treat the patient aggressively. Resection of the ruptured GIST was carried out for control of bleeding and to prevent recurrent bleeding in this patient with good surgical risks. During the treatment decision-making, the patient＇s general condition, the risk of surgery and the extent of dissemination were taken into consideration. In this patient who presented with spontaneous rupture of a small intestinal GIST, the novel use of targeted therapy and aggressive surgical treatment produced reasonably good survival outcome.

关键词： gastrointestinal stromal tumour hemoperitoneum small bowel GIST small bowel neoplasm imatinib

Phase stability,elastic properties and electronic structures of Mg-Y intermetallics from first-principles calculations

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Journal of Magnesium and Alloys 2015年第2期3卷 127-133页

作者： J.Zhang c.Mao c.G.Long J.chen K.Tang M.J.Zhang P.Peng Key Laboratory of Lightweight and Reliability Technology for Engineering Vehicle The Education Department of Hunan ProvinceChangsha University of Science and TechnologyChangsha 410114China Key Laboratory of Efficient and clean Energy Utilization College of Hunan ProvinceChangsha University of Science and TechnologyChangsha 410114China college of Materials Science and Engineering Hunan UniversityChangsha 410082China

The phase stability,elastic properties and electronic structures of three typical Mg-Y intermetallics including Mg_(24)Y_(5),Mg_(2)Y and MgY are systematically investigated using first-principles calculations based on density functional *** optimized structural parameters including lattice constants and atomic coordinates are in good agreement with experimental *** calculated cohesive energies and formation enthalpies show that either phase stability or alloying ability of the three intermetallics is gradually enhanced with increasing Y *** single-crystal elastic constants c_(ij) of Mg-Y intermetallics are also calculated,and the bulk modulus B,shear modulus G,Young's modulus E,Poisson ratio v and anisotropy factor A of polycrystalline materials are *** is suggested that the resistances to volume and shear deformation as well as the stiffness of the three intermetallics are raised with increasing Y ***,these intermetallics all exhibit ductile characteristics,and they are isotropic in compression but anisotropic to a certain degree in shear and ***,Mg_(24)Y_(5) presents a relatively higher ductility,while MgY has a relatively stronger anisotropy in shear and *** analysis of electronic structures indicates that the phase stability of Mg-Y intermetallics is closely related with their bonding electrons numbers below Fermi ***,the more bonding electrons number below Fermi level corresponds to the higher structural stability of Mg-Y intermetallics.

关键词： Magnesium alloys Intermetallics Phase stability Elastic properties Electronic structure

喷雾热解法在硅衬底上生长定向碳纳米管阵列(英文)

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新型炭材料 2013年第4期28卷 284-288页

作者： V S Angulakshmi K Rajasekar c Sathiskumar S Karthikeyan Department of chemistry Kathir college of EngineeringCoimbatoreTNIndia Department of Nanotechnology Anna University of TechnologyCoimbatoreTNIndia Department of chemistry Chikkanna Govt.Arts CollegeTirupurTNIndia

以向日葵油的甲基酯为碳源,二茂铁为催化剂前驱体,Ar为载气,通过喷雾热解法在硅衬底上合成定向碳纳米管阵列。结果表明,在硅衬底上原位形成Fe催化剂纳米颗粒。由拉曼光谱、透射电镜图和X-射线衍射谱图显示所制定向碳纳米管阵列具有较好... 详细信息

以向日葵油的甲基酯为碳源,二茂铁为催化剂前驱体,Ar为载气,通过喷雾热解法在硅衬底上合成定向碳纳米管阵列。结果表明,在硅衬底上原位形成Fe催化剂纳米颗粒。由拉曼光谱、透射电镜图和X-射线衍射谱图显示所制定向碳纳米管阵列具有较好的石墨化程度,其直径为1 0～3 0 nm,管壁约为1 0 nm。所制定向碳纳米管阵列中残留的催化剂含量可以忽略。

关键词：喷雾热解法定向碳纳米官阵列二茂铁硅衬底化学气相沉积

Effect of bisphenol A and co-administration of bisphenol Aand vitamin c on epididymis of adult rats:A histological and biochemical study

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Asian Journal of Andrology 2003年第3期5卷 203-208页

作者： K.c.chitra K.Ramachandra Rao P.P.Mathur School of Life Sciences Pondicherry University Pondicherry 605 014 IndiaDepartment of Anatomy Jawaharlal Institute of Postgraduate Medical Education and Research Pondicherry 605 006 IndiaSchool of Life Sciences Pondicherry University Pondicherry 605014 India

Aim: To study the effect of bisphenol A on the epididymis and epididymal sperm of rats and the possible amelioration action of co-administration with vitamin c. Methods: Male Wistar rats were orally administered bisphenol A (0.2 μg·kg-1·day-1, 2 μg·kg-1·day-1 and 20 μg·kg-1·day-1) and 0.2 μg, 2μg and 20 μg bisphenol A + 40 mg vitamin c·kg-1·day-1 for 60 days. On day 61, rats were killed with anesthetic ether and sperm collected from epididymis were used for assessment of sperm count, motility and viability and biochemical studies. A 1 % homogenate of epididymis was prepared and used for biochemical estimations. caput, corpus and cauda epididymis were fixed in Bouin's fixative for histological studies. Results: Administration of bisphenol A caused a reduction in the epididymal sperm motility and count and the sperm viability remained unchanged. The activities of superoxide dismutase and glu-tathione peroxidase decreased, while the levels of lipid peroxidation increased in epididymal sperm and epididymis at all doses. co-administration with vitamin c reversed the effect of bisphenol A-induced oxidative stress in epididymal sperm and epididymis. A complete degeneration of epididymal epithelium in caput, corpus and cauda regions with reduction in the number of sperms were observed at all doses of bisphenol A-treated rats. conclusion: Bisphenol A induced oxidative stress in epididymis and caused degeneration of the epididymal epithelium of rats. co-administration with vitamin c had a protective effect against the bisphenol A-induced toxicity in epididymal sperm and epididymis.

关键词： bisphenol A epididymis spermatozoa ascorbic acid antioxidant enzymes lipid peroxidation reactive oxygen species oxidative stress

Genetic interactions between polycystin-1 and Wwtr1 in osteoblasts define a novel mechanosensing mechanism regulating bone formation in mice

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Bone Research 2023年第4期11卷 772-783页

作者： Zhousheng Xiao Li cao Micholas Dean Smith Hanxuan Li Wei Li Jeremy c.Smith Leigh Darryl Quarles Department of Medicine University of Tennessee Health Science CenterMemphisTN 38163USA UT/ORNL center for Molecular Biophysics Oak Ridge National LaboratoryOak RidgeTN 37830USA Department of Biochemistry and cellular and Molecular Biology The University of Tennessee-KnoxvilleKnoxvilleTN 37996-1939USA Department of Pharmaceutical Sciences University of Tennessee Health Science CenterMemphisTN 38163USA

Molecular mechanisms transducing physical forces in the bone microenvironment to regulate bone mass are poorly ***,we used mouse genetics,mechanical loading,and pharmacological approaches to test the possibility that polycystin-1 and Wwtr1 have interdependent mechanosensing functions in *** created and compared the skeletal phenotypes of control Pkd1^(flox/)+;Wwtr1^(flox/)+,Pkd1^(Oc-cKO),Wwtr1^(Oc-cKO),and Pkd1/Wwtr1^(Oc-cKO)mice to investigate genetic *** with an interaction between polycystins and Wwtr1 in bone in vivo,Pkd1/Wwtr1^(Oc-cKO)mice exhibited greater reductions of BMD and periosteal MAR than either Wwtr1Oc-cKOor Pkd1^(Oc-cKO)***-cT 3D image analysis indicated that the reduction in bone mass was due to greater loss in both trabecular bone volume and cortical bone thickness in Pkd1/Wwtr1Oc-cKO mice compared to either Pkd1Oc-cKOor Wwtr1^(Oc-cKO)***1/Wwtr1^(Oc-cKO)mice also displayed additive reductions in mechanosensing and osteogenic gene expression profiles in bone compared to Pkd1Oc-cKOor Wwtr1^(Oc-cKO)***,we found that Pkd1/Wwtr1^(Oc-cKO)mice exhibited impaired responses to tibia mechanical loading in vivo and attenuation of loadinduced mechanosensing gene expression compared to control ***,control mice treated with a small molecule mechanomimetic,MS2 that activates the polycystin complex resulted in marked increases in femoral BMD and periosteal MAR compared to vehicle *** contrast,Pkd1/Wwtr1^(Oc-cKO)mice were resistant to the anabolic effects of *** findings suggest that Pc1 and Wwtr1 form an anabolic mechanotransduction signaling complex that mediates mechanical loading responses and serves as a potential novel therapeutic target for treating osteoporosis.

关键词： mec impaired additive