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Morphology effect of zirconia support on the catalytic performance of supported Ni catalysts for dry reforming of methane 被引量:5
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作者 李伟作 赵忠奎 +1 位作者 焦艳华 王桂茹 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2016年第12期2122-2133,共12页
An immature pinecone shaped hierarchically structured zirconia (ZrO2-ipch) and a cobblestone-like zirconia nanoparticulate (ZrO2-cs), both with the monoclinic phase (m-phase), were synthesized by the facile hydr... An immature pinecone shaped hierarchically structured zirconia (ZrO2-ipch) and a cobblestone-like zirconia nanoparticulate (ZrO2-cs), both with the monoclinic phase (m-phase), were synthesized by the facile hydrothermal method and used as the support for a Ni catalyst for the dry reforming of methane (DRM) with CO2. ZrO2-ipch is a much better support than ZrO2-cs and the traditional ZrO2 irregular particles made by a simple precipitation method (ZrO2-ip). The supported Ni catalyst on ZrO2-ipch (Ni/ZrO2-ipch) exhibited outstanding catalytic activity and coke-resistant stability compared to the ones on ZrO2-cs (Ni/ZrO2-cs) and ZrO2-ip (Ni/ZrO2-ip). Ni/ZrO2-ip exhibited the worst catalytic performance. The origin of the significantly enhanced catalytic performance was revealed by characterization including XRD, N2 adsorption measurement (BET), TEM, H2-TPR, CO chemisorption, CO2-TPD, XPS and TGA. The superior catalytic activity of Ni/ZrO2-ipch to Ni/ZrO2-cs or Ni/ZrO2-ip was ascribed to a higher Ni dispersion, increased reducibility, enhanced oxygen mo- bility, and more basic sites with a higher strength, which were due to the unique hierarchically structural morphology of the ZrO2-ipch support. Ni/ZrO2-ipch exhibited better stability for the DRM reaction than Ni/ZrO2-ip, which was ascribed to its higher resistance to Ni sintering due to a strengthened metal-support interaction and the confinement effect of the mesopores and coke deposition resistance. The higher coking resistance of Ni/ZrO2-ipch for the DRM reaction in comparison with Ni/ZrOz-ip orignated from the coke-removalabitity of the higher amount of lattice oxygen and more basic sites, confirmed by XPS and CO2-TPD analysis, and the stabilized Ni on the Ni/ZrO2-ipch catalyst by the confinement effect of the mesopores of the hierarchical ZrO2-ipch sup- port. The superior catalytic performance and coking resistance of the Ni/ZrO2-ipch catalyst makes it a promising candidate for synthesis gas production from the DRM reaction. 展开更多
关键词 Ni-based catalystZrO2 supportHierarchical structure morphology effect Dry reforming of methane Synthesis gas Coke resistance
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Morphology effect on catalytic performance of ebullated-bed residue hydrotreating over Ni-Mo/Al_(2)O_(3)catalyst:a kinetic modeling study
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作者 Zhe Liu Juncong Yuan +5 位作者 Zongzhuang Sun Xiang Feng Yibin Liu Huihong Zhu Chong Peng Chaohe Yang 《Green Chemical Engineering》 EI CSCD 2024年第1期60-67,共8页
Upgrading of vacuum residue is of prime industrial significance due to the increasing demand for light oils.Elucidating the effect of catalyst morphology on vacuum residue hydrotreating performance by kinetic modeling... Upgrading of vacuum residue is of prime industrial significance due to the increasing demand for light oils.Elucidating the effect of catalyst morphology on vacuum residue hydrotreating performance by kinetic modeling is therefore of great importance.Herein,kinetic analysis of hydrodemetallization(HDM)and hydrodeconradsoncarbon-residue(HDCCR)performances on industrial Ni-Mo/Al_(2)O_(3)catalysts with spherical and cylindrical morphologies in ebullated-bed were evaluated for more than 1600 h.It was found that the percentage of light impurities easier to be removed on spherical catalysts were 78.20%and 39.43%in HDM and HDCCR reactions,respectively,higher than 65.20%and 17.50%on cylindrical catalysts.This suggests that catalyst morphology affects the impurity removal ability and the impurity properties,resulting in better hydrotreating performance of spherical catalysts.This work not only combines catalyst morphology with impurity removal capability through kinetic modeling,but also provides new insights into the design of efficient hydrotreating catalysts. 展开更多
关键词 morphology effect Kinetic analysis Vacuum residue HYDROTREATING
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Morphology effects in MnCeO_(x)solid solution-catalyzed NO reduction with CO:Active sites,water tolerance,reaction pathway
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作者 Quanquan Shi Yifei Zhang +4 位作者 Zhiwen Li Zhongkang Han Liangliang Xu Alfons Baiker Gao Li 《Nano Research》 SCIE EI CSCD 2023年第5期6951-6959,共9页
Morphological effects of nanoparticles are crucial in many solid-catalyzed chemical transformations.We herein prepared two manganese-ceria solid solutions,well-defined MnCeO_(x)nanorods and MnCeO_(x)-nanocubes,exposin... Morphological effects of nanoparticles are crucial in many solid-catalyzed chemical transformations.We herein prepared two manganese-ceria solid solutions,well-defined MnCeO_(x)nanorods and MnCeO_(x)-nanocubes,exposing preferentially(111)and(100)facets of ceria,respectively.The incorporation of Mn dopant into ceria lattice strongly enhanced the catalytic performance in the NO reduction with CO.MnCeO_(x)(111)catalyst outperformed MnCeO_(x)(100)counterpart due to its higher population density of oxygen vacancy defects.In-situ infrared spectroscopy investigations indicated that the reaction pathway over MnCeO_(x)and pristine CeO_(2)is similar and that besides the direct pathway,an indirect pathway via adsorbed hyponitrite as an intermediate cannot be ruled out.X-ray photoelectron and Raman spectroscopies as well as first-principles density functional theory(DFT)calculations indicate that the enhanced catalytic performance of MnCeO_(x)can be traced back to its“Mn–OL(VÖ)–Mn–OL(VÖ)–Ce”connectivities.The Mn dopant strongly facilitates the formation of surface oxygen vacancies(VÖ)by liberating surface lattice oxygen(OL)via CO*+OL→CO_(2)*+VÖand promotes the reduction of NO,according to NO*+VÖ→N*+OL and 2N*→N_(2).The Mn dopant impact on both the adsorption of CO and activation of OL reveals that a balance between these two effects is critical for facilitating all reaction steps. 展开更多
关键词 NO reduction with CO manganese-ceria solid solution morphology effects reaction mechanism active sites
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Effects of Co_3O_4 nanocatalyst morphology on CO oxidation:Synthesis process map and catalytic activity 被引量:6
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作者 曾良鹏 李孔斋 +2 位作者 黄樊 祝星 李宏程 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2016年第6期908-922,共15页
This study focuses on drawing a hydrothermal synthesis process map for Co3O4 nanoparticles with various morphologies and investigating the effects of Co3O4 nanocatalyst morphology on CO oxidation.A series of cobalt-hy... This study focuses on drawing a hydrothermal synthesis process map for Co3O4 nanoparticles with various morphologies and investigating the effects of Co3O4 nanocatalyst morphology on CO oxidation.A series of cobalt-hydroxide-carbonate nanoparticles with various morphologies(i.e.,nanorods,nanosheets,and nanocubes) were successfully synthesized,and Co3O4 nanoparticles were obtained by thermal decomposition of the cobalt-hydroxide-carbonate precursors.The results suggest that the cobalt source is a key factor for controlling the morphology of cobalt-hydroxide-carbonate at relatively low hydrothermal temperatures(≤ 140℃).Nanorods can be synthesized in CoCl2 solution,while Co(NO3)2 solution promotes the formation of nanosheets.Further increasing the synthesis temperature(higher than 140 ℃) results in the formation of nanocubes in either Co(NO3)2 or CoCl2 solution.The reaction time only affects the size of the obtained nanoparticles.The presence of CTAB could improve the uniformity and dispersion of particles.Co3O4 nanosheets showed much higher catalytic activity for CO oxidation than nanorods and nanocubes because it has more abundant Co^(3+) on the surface,much higher reducibility,and better oxygen desorption capacity. 展开更多
关键词 Cobalt oxide nanocatalyst Synthesis process map morphology effect Catalytic activity Carbon monoxide oxidation
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Morphology Effect of Metal-organic Framework HKUST-1 as a Catalyst on Benzene Oxidation 被引量:3
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作者 LIU Yanfeng LIU Boliang +2 位作者 ZHOU Qingfeng ZHANG Tianyong WU Wubin 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2017年第6期971-978,共8页
An attempt was made to study whether the morphology effect of metal-organic frameworks HKUST-1 could significantly influence the chemical reaction of benzene oxidation. Four representative cupric salts, CuSO4' 5H20,... An attempt was made to study whether the morphology effect of metal-organic frameworks HKUST-1 could significantly influence the chemical reaction of benzene oxidation. Four representative cupric salts, CuSO4' 5H20, Cu(OAc)a-H20, CuCI2.2H20 and Cu(NO3)2 3H20, were treated with 1,3,5-benzenetricarboxylic acid under ultrasound or with static method at room temperature to prepare metal-organic frarneworks(12 types of HKUST-1 samples). And the as-prepared HKUST-1 materials were comprehensively investigated by X-ray diffraction, scanning electron microscopy and N2 adsorption-desorption. The HKUST-1 samples with different morphologies and characterisitcs were employed as catalysts for benzene oxidation with H2O2 as oxidant at 60 ℃ in acetonitrile to achieve the aromatic oxygenates and test their yields. In all the HKUST-1 samples, the HKUST-1/SA, HKUST-1/SA0 and HKUST-1/UN had the higher catalytic activities with the yields of benzene oxygenates of 15.9%, 16.6% and 11.7%, respectively, which can be ascribed to the larger pore volume, the stronger benzene adsorption and the smaller fme crystal particles. Comparatively, the HKUST-1/SN0 and HKUST-1/SC0 with more intact crystal, larger surface area, lower pore volume and weaker benzene adsorption had the lower catalytic activities with the yields of benzene oxygenates not more than 4%. Therefore, our results confumed that employing various cupric precursors to prepare the HKUST-1 samples with different morphologies and characteristics can be considered as a worth strategy to design many more powerful heterogeneous catalysts. 展开更多
关键词 HKUST-1 Metal-organic framework morphology effect Catalytic reaction BENZENE
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Morphology and crystal-plane effects of Zr-doped CeO2 nanocrystals on the epoxidation of styrene with tert-butylhydroperoxide as the oxidant 被引量:2
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作者 Jia Ren Xin Liu +1 位作者 Ruihua Gao Wei-Lin Dai 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2017年第4期681-687,共7页
The morphology effect of Zr-doped CeOwas studied in terms of their activities in the selective oxidation of styrene to styrene oxide using tert-butyl hydroperoxide as the oxidant. In the present work, Zrdoped CeOnanor... The morphology effect of Zr-doped CeOwas studied in terms of their activities in the selective oxidation of styrene to styrene oxide using tert-butyl hydroperoxide as the oxidant. In the present work, Zrdoped CeOnanorods exhibited the highest catalytic performance(yield of styrene oxide and TOF value)followed by nanoparticles and nanocubes. For the Zr-doped CeOnanorods, the apparent activation energy is 56.3 k J/mol, which is much lower than the values of catalysts supported on nanoparticles and nanocubes(73.3 and 93.4 k J/mol). The high resolution transmission electron microscopy results indicated that(100) and(110) crystal planes are predominantly exposed for Zr-doped CeOnanorods while(100)and(111) for nanocubes,(111) for nanoparticles. The remarkably increased catalytic activity of the Zrdoped CeOnanorods is mainly attributed to the higher percentage of Cespecies and more oxygen vacancies, which are associated with their exposed(100) and(110) crystal planes. Furthermore, recycling studies proved that the heterogeneous Zr-doped CeOnanorods did not lose its initial high catalytic activity after five successive recycles. 展开更多
关键词 morphology effect Zr-doped CeO2 Styrene Selective oxidation Oxygen vacancies
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Effects of Infrasound on Gastric Motility, Gastric Morphology and Expression of Nitric Oxide Synthase in Rat 被引量:1
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作者 zhao ju hui wang jin hai +3 位作者 luo jin yan guo xiao yan wang yan cheng yan 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2018年第5期399-402,共4页
Infrasound widely condition, productive exists in nature, our living and traffic environment. Gastrointestinal tract is relatively sensitive to infrasound. However, the effect of infrasound on gastrointestinal functio... Infrasound widely condition, productive exists in nature, our living and traffic environment. Gastrointestinal tract is relatively sensitive to infrasound. However, the effect of infrasound on gastrointestinal function is unclear. Therefore, the purpose of our study was to observe the effects of infrasound on gastric motiliW and gastric morphology and to assess the expression of nitric oxide synthase (NOS) in gastric antrum after exposure to infrasound of 8 Hz - 130 dB for 2 hours per day for 14 consecutive days. Gastric motility was assessed by gastric fluid-emptying rate. Gastric morphology was evaluated by HE. The expression of NOS was measured by tissue microarray technology. The results would contribute to understand the role of infrasound in gastroenterology, and help to explain the mechanism of infrasound on gastroenterology. 展开更多
关键词 NOS In effects of Infrasound on Gastric Motility Gastric morphology and Expression of Nitric Oxide Synthase in Rat
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Hydrodynamic Effects on Surface Morphology Evolution of Titanium Alloy under Intense Pulsed Ion Beam Irradiation
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作者 董艇舰 荣翠华 +13 位作者 梁家昌 刘波 赵小勇 陈董燕 张彬 王浩 李海波 张世贵 蒋玉平 罗兵 周小文 王涛 喻晓 乐小云 《Chinese Physics Letters》 SCIE CAS CSCD 2017年第5期84-87,共4页
The hydrodynamic effects of molten surface of titanium alloy on the morphology evolution by intense pulsed ion beam (IPIB) irradiation are studied. It is experimentally revealed that under irradiation of IPIB pulses... The hydrodynamic effects of molten surface of titanium alloy on the morphology evolution by intense pulsed ion beam (IPIB) irradiation are studied. It is experimentally revealed that under irradiation of IPIB pulses, the surface morphology of titanium alloy in a spatial scale of μm exhibits an obvious smoothening trend. The mechanism of this phenomenon is explained by the mass transfer caused by the surface tension of molten metal. Hydrodynamic simulation with a combination of the finite element method and the level set method reveals that the change in curvature on the molten surface leads to uneven distribution of surface tension. Mass transfer is caused by the relief of surface tension, and meanwhile a flattening trend in the surface morphology evolution is achieved. 展开更多
关键词 Hydrodynamic effects on Surface morphology Evolution of Titanium Alloy under Intense Pulsed Ion Beam Irradiation
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Effect of cerebral lymphatic block on cerebral morphology and cortical evoked potential in rats
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作者 Zuoli Xia1, Baoliang Sun2, Mingfeng Yang1, Dongmei Hu2, Tong Zhao2, Jingzhong Niu2 1Institute of Brain Microcirculation, Taishan Medical College, Taian 271000, Shandong Province, China 2Department of Neurology, Affiliated Hospital of Taishan Medical College, Taian 271000, Shandong Province, China 《Neural Regeneration Research》 SCIE CAS CSCD 2006年第7期657-660,共4页
BACKGROUND: It has been shown that although brain does not contain lining endothelial lymphatic vessel, it has lymphatic drain. Anterior lymphatic system of lymphatic vessel in brain tissue plays a key role in introdu... BACKGROUND: It has been shown that although brain does not contain lining endothelial lymphatic vessel, it has lymphatic drain. Anterior lymphatic system of lymphatic vessel in brain tissue plays a key role in introducing brain interstitial fluid to lymphatic system; however, the significance of lymphatic drain and the effect on cerebral edema remains unclear. OBJECTIVE: To investigate the effect of cerebral lymphatic block on cerebral morphology and cortical evoked potential in rats. DESIGN: Randomized controlled animal study. SETTING: Institute of Cerebral Microcirculation of Taishan Medical College and Department of Neurology of Affiliated Hospital. MATERIALS: A total of 63 healthy adult male Wistar rats weighing 300-350 g were selected in this study. Forty-seven rats were used for the morphological observation induced by lymphatic drain and randomly divided into three groups: general observation group (n =12), light microscopic observation group (n =21) and electronic microscopic observation group (n =14). The rats in each group were divided into cerebral lymphatic block subgroup and sham-operation control subgroup. Sixteen rats were used for observing the effect of cerebral lymphatic block on cortical evoked potential, in which the animals were randomly divided into sham-operation group (n =6) and cerebral lymphatic block group (n =10). METHODS: The experiment was carried out in the Institute of Cerebral Microcirculation of Taishan Medical College from January to August 2003. Rats in cerebral lymphatic block group were anesthetized and separated bilateral superficial and deep cervical lymph nodes under sterile condition. Superior and inferior boarders of lymph nodes were ligated the inputting and outputting channels, respectively, and then lymph node was removed so as to establish cerebral lymphatic drain disorder models. Rats in sham-operation control group were not ligated the lymphatic vessel and removed lymph nodes, and other operations were as the same as those in cerebral lymphatic block group. Morphological changes of the brain and alterations of latency of cortical evoked potential were detected on the 1st, 2nd, 3rd, 5th, 7th, 10th and 15th days after operation under general, light microscope and electronic microscope observations. MAIN OUTCOME MEASURES: ① Cerebral morphological changes; ② latent changes of cortical evoked potential. RESULTS: A total of 63 rats were involved in the final analysis. ① Cerebral morphological changes: General observation showed that, for cerebral lymphatic block rats, the surface of brain was pale and full, and cerebral gyrus was wide and flattened sulci after cerebral lymphatic block; and cerebral tissue space prolongation, increased interstitial fluid, neuronal degeneration and necrosis, diffused phagocytes and satellitosis were observed under light microscope. Neuronal swell and necrosis, glial cell swell, apparent subcellular changes such as mitochondron were observed under electronic microscope. ② Latent changes of cortical evoked potential: As compared with sham-operation control group, latency of cortical evoked potential in cerebral lymphatic blockage group prolonged on the 5th day and 7th day after cerebral lymphatic block [(6.28±0.23), (6.97±0.35) ms; (6.23±0.22), (7.12±0.20) ms; P < 0.01]. CONCLUSION: ① Cerebral lymphatic block plays an important role in cerebral morphology, and may result in abnormality of sensitive impulse conduction and prolong latency of cortical evoked potential. ② Examination of cortical evoked potential is easy and convenient, so it is regarded as a key index for lymphatic disturbed cerebral injury. 展开更多
关键词 effect of cerebral lymphatic block on cerebral morphology and cortical evoked potential in rats
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Understanding morphology-dependent Cu Ox-CeO2 interactions from the very beginning 被引量:5
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作者 Yuxian Gao Zhenhua Zhang +1 位作者 Zhaorui Li Weixin Huang 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2020年第6期1006-1016,共11页
Elucidation of the CuOx-CeO2 interactions is of great interest and importance in understanding complex CuOx-CeO2 interfacial catalysis in various reactions. In the present work, we have investigated structures and cat... Elucidation of the CuOx-CeO2 interactions is of great interest and importance in understanding complex CuOx-CeO2 interfacial catalysis in various reactions. In the present work, we have investigated structures and catalytic activity in CO oxidation of CuOx species on CeO2 rods, cubes and polyhedra predominantly exposing {110}+{100}, {100} and {111} facets by the incipient wetness impregnation method with the lowest Cu loading of 0.025%. The structural evolution of CuOx species was found to depend on both the Cu loading and the CeO2 morphology. As the Cu loading increases, CuOx species are deposited preferentially on the surface defect of CeO2 and then aggregate and grow, accompanied by the formation of isolated Cu ions, CuOx clusters strongly/weakly interacting with the CeO2, highly dispersed Cu O nanoparticles, and large Cu O nanoparticles. The isolated Cu^+ species and CuOx clusters weakly interacting with the CeO2 were observed mainly on the O-terminated CeO2{100} facets. Meanwhile, more Cu(I) species are stabilized during CO reduction processes in CuOx/c-CeO2 catalysts than in CuOx/r-CeO2 and CuOx/p-CeO2 catalysts. The catalytic activities of various CuOx/CeO2 catalysts in CO oxidation vary with both the CuOx species and the CeO2 morphology. These results comprehensively elucidate the CuOx-CeO2 interactions and exemplify their morphology-dependence. 展开更多
关键词 CeO2 nanocrystals Cu Ox/CeO2 catalysts Metal-support interactions CO oxidation morphology effect
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Numerical modeling of seabed morphological effects from the construction of artificial islands in Danzhou, Hainan
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作者 英晓明 贾后磊 +1 位作者 曹玲珑 谢健 《Marine Science Bulletin》 CAS 2014年第2期37-45,共9页
Haihua Islands is a large artificial island in Danzhou, Hainan. The construction of Haihua Islands changes the hYdrodynamic environment of Yangpu waters, and further affects its morphological change. Delft3D is used t... Haihua Islands is a large artificial island in Danzhou, Hainan. The construction of Haihua Islands changes the hYdrodynamic environment of Yangpu waters, and further affects its morphological change. Delft3D is used to set up a two dimensional nested hydrodynamic and sediment model for Yangpu waters in this paper, and this paper focuses on simulating the velocity and morphological change due to the construction of Haihua Islands after the verification of the model. The seabed deposition is small because of low suspended sediment concentration and less sand source near Yangpu waters. The bed level erodes in the south area of Xiaochan Reef and the Yangpu channel due to the velocity increase in the area. 展开更多
关键词 Haihua Islands seabed morphological effect numerical modeling
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Copper Ion Beam Irradiation-Induced Effects on Structural,Morphological and Optical Properties of Tin Dioxide Nanowires
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作者 M.A.Khan A.Qayyum +5 位作者 I.Ahmed T.Iqbal A.A.Khan R.Waleed B.Mohuddin M.Malik 《Chinese Physics Letters》 SCIE CAS CSCD 2016年第7期178-181,共4页
The 0.8 Me V copper ( Cu) ion beam irradiation-induced effects on structural, morphological and optical properties of tin dioxide nanowires (Sn02 NWs) are investigated. The samples are irradiated at three differen... The 0.8 Me V copper ( Cu) ion beam irradiation-induced effects on structural, morphological and optical properties of tin dioxide nanowires (Sn02 NWs) are investigated. The samples are irradiated at three different doses 5 × 10^12 ions/cm2, 1 ×10^13 ions/cm2 and 5 × 10^13 ions/em2 at room temperature. The XRD analysis shows that the tetragonal phase of Sn02 NWs remains stable after Cu ion irradiation, but with increasing irradiation dose level the crystal size increases due to ion beam induced coalescence of NWs. The FTIR spectra of pristine Sn02 NWs exhibit the chemical composition of SnO2 while the Cn-O bond is also observed in the FTIR spectra after Cu ion beam irradiation. The presence of Cu impurity in SnO2 is further confirmed by calculating the stopping range of Cu ions by using TRM/SRIM code. Optical properties of SnO2 NWs are studied before and after Cu ion irradiation. Band gap analysis reveMs that the band gap of irradiated samples is found to decrease compared with the pristine sample. Therefore, ion beam irradiation is a promising technology for nanoengineering and band gap tailoring. 展开更多
关键词 of CM Copper Ion Beam Irradiation-Induced effects on Structural Morphological and Optical Properties of Tin Dioxide Nanowires in is that for been on
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Settling velocity of equiaxed dendrites in a tube 被引量:1
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作者 周鹏 王猛 +1 位作者 林鑫 黄卫东 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第1期518-523,共6页
The settling velocity of equiaxed dendrites can cause macrosegregation and influence the structure of the equiaxed zone during the casting solidification process. So an understanding of the settling characteristics is... The settling velocity of equiaxed dendrites can cause macrosegregation and influence the structure of the equiaxed zone during the casting solidification process. So an understanding of the settling characteristics is needed to predict the structure and segregation in castings. The settling velocity of NH4Cl equiaxed dendrites of non-spherical geometry was studied experimentally in an NH4Cl-70wt.%H2O solution. A calculation formula was proposed to calculate the settling velocity of sediment equiaxed dendrites in a tube filled with saturated solution at a moderate Reynolds number region. The retardation effects of the wall and morphology of the equiaxed dendrite on the settling velocity were taken into account in the development of the calculation formula, and the correction function B of the drag coefficient with consideration of the retardation effects of the wall and morphology of the equiaxed dendrite on the settling velocity of the equiaxed dendrite was calibrated according to the experimental results. A comparison showed that the formula has a good accordance with the experimental results. 展开更多
关键词 equiaxed dendrite settling velocity morphology effect wall effect
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Influence of Genista Tinctoria L or Methylparaben on Subchronic Toxicity of Bisphenol A in Rats 被引量:2
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作者 Daniela-Saveta POPA Pompei BOLFA +6 位作者 Bela KISS Laurian VLASE Ramona PLTINEAN Anca POP Cornel CTOI Gianina CRISAN Felicia LOGHIN 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2014年第2期85-96,共12页
Objective To evaluate the influence of an extract of Genista tinctoria L. herba (GT) or methylparaben (MP) on histopathological changes and 2 biomarkers of oxidative stress in rats subchronicly exposed to bispheno... Objective To evaluate the influence of an extract of Genista tinctoria L. herba (GT) or methylparaben (MP) on histopathological changes and 2 biomarkers of oxidative stress in rats subchronicly exposed to bisphenol A (BPA). Methods Adult female Wistar rats were orally exposed for 90 d to BPA (50 mg/kg), BPA+GT (35 mg isoflavones/kg) or BPA+MP (250 mg/kg). Plasma and tissue samples were taken from liver, kidney, thyroid, uterus, ovary, and mammary gland after 30, 60, and 90 d of exposure respectively. Lipid peroxidation and in vivo hydroxyl radical production were evaluated by histological analysis along with malondialdehyde and 2,3-dihydroxybenzoic acid detection. Results The severity of histopathological changes in liver and kidneys was lower after GT treatment than after BPA or BPA+MP treatment. A minimal thyroid receptor antagonist effect was only observed after BPA+MP treatment. The abnormal folliculogenesis increased in a time-dependent manner, and the number of corpus luteum decreased. No significant histological alterations were found in the uterus. The mammary gland displayed specific estrogen stimulation changes at all periods. Both MP and GT revealed antioxidant properties reducing lipid peroxidation and BPA-induced hydroxyl radical generation. Conclusion GT L. extract ameliorates the toxic effects of BPA and is proved to have antioxidant potential and antitoxic effect. MP has antioxidant properties, but has either no effect or exacerbates the BPA-induced histopathological changes. 展开更多
关键词 Food contaminant PHYTOESTROGEN Morphological effect Lipid peroxidation Hydroxylradical
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The characteristics of consolidation settlement and its contribution to the topographical change in the northern modern Huanghe River subaqueous delta in China 被引量:2
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作者 LIU Jie LI Ping +2 位作者 LIU Xiao XU Yuanqin GAO Wei 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2015年第9期136-142,共7页
The sediments of the modern Huanghe River subaqueous delta are easily to generate settlement and lead to topography change which is due to fast deposition rate, high void ratio, moisture content and compressibility. T... The sediments of the modern Huanghe River subaqueous delta are easily to generate settlement and lead to topography change which is due to fast deposition rate, high void ratio, moisture content and compressibility. The sediment consolidation settlements and its contribution to the topography change in the northern modern Huanghe River subaqueous delta are studied based on drilling data, laboratory experiment results, and water depth measurements of different time. The results show that the final consolidation settlement of drill holes in the study area is between 1.17 and 3.21 m, and mean settlement of unit depth is between 2.30 and 5.30 cm/m based on the one-dimensional consolidation theory and Plaxis numerical model. The final consolidation settlement obtained by Plaxis numerical model is smaller than that obtained by the one-dimensional consolidation theory, and the difference is 3.4%-39.9% between the methods. The contribution of the consolidation settlement to the topographical change is at 20.2%-86.6%, and the study area can be divided into five different regions based on different contribution rates. In the erosion area, the actual erosion depth caused by hydrodynamics is lower than the changes of measured water depth, however, the actual deposition amount caused by hydrodynamics is much larger than the changes of water depth obtained by measured data in the equilibrium and deposition areas. 展开更多
关键词 sediment consolidation water depth variation morphological effect core analysis northern HuangheRiver subaqueous delta
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EFFECT OF WARM ISCHEMIC INJURY ON MORPHOLOGY AND VIABILITY OF AORTIC VALVES IN RATS
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作者 陈钢 刘维永 俞世强 《Chinese Medical Journal》 SCIE CAS CSCD 1995年第1期24-27,共4页
Warm ischemia is one of the most important causes of valvular damage from death of donor to its valve harvesting. This study aimed at using qualitative and quantitative methods to characterize warm ischemic injury thr... Warm ischemia is one of the most important causes of valvular damage from death of donor to its valve harvesting. This study aimed at using qualitative and quantitative methods to characterize warm ischemic injury through models of SD rat's aortic valves and design to show the relationship among ultrastructural, biological and biochemical changes concerning with the length of warm ischemia time (WIT). 102 harvested SD rat's aortic valves were divided into 6 groups of different ischemic time for this study. 432 photomicrographs of transmission electron microscopy (TEM) were put into computer for analysis. The volume ratio of nucleus to plasma in cells (Vnp) and the ratio of extramembrane area to volume of mitochondria (S / V) were used to characterize the degree of valvular cell injuries. Valvular cells culture and biochemical metabolism including glucose degredation and H-3-TdR absorption rate were adopted. The valvular cells depicted a significant decrease and H-3-TdR taking-up also being inhibited under the influence of prolonged WIT. 展开更多
关键词 WIT In effect OF WARM ISCHEMIC INJURY ON morphology AND VIABILITY OF AORTIC VALVES IN RATS
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Effect of metal surface morphology on nano-structured patterns induced by a femtosecond laser pulse and its experimental verification
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作者 宋海英 谭胜旺 +4 位作者 诗梦 张艳杰 刘世炳 李瑶 刘海云 《Chinese Optics Letters》 SCIE EI CAS CSCD 2018年第7期88-91,共4页
The effect of material surface morphology on the periodic subwavelength of nano-structures induced by a femtosecond(fs) laser was investigated systematically from the initial surface roughness, the different scratch... The effect of material surface morphology on the periodic subwavelength of nano-structures induced by a femtosecond(fs) laser was investigated systematically from the initial surface roughness, the different scratches, the pre-formed ripples, and the "layer-carving" technology experiments. The results of the comparative experiments indicate that the initial surface conditions of the target surface have no obvious effects on the spatial structured periods(SSPs) and the ripple orientation of the periodic nano-structures induced by a fs laser, which agreed well with the foretold present surface two-plasmon resonance(STPR) model. Furthermore, different shapes of nanogrids with high regularity and uniformity were obtained by fs-laser fabrication. 展开更多
关键词 effect of metal surface morphology on nano-structured patterns induced by a femtosecond laser pulse and its experimental verification
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EFFECT OF VACUUM ON THE CRYSTAL FORM AND MORPHOLOGY OF THE EVAPORATED FILM OF COPPER PHTHALOCYANINE
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作者 石祖荣 杨启云 常龙存 《Chinese Science Bulletin》 SCIE EI CAS 1986年第16期1108-1111,共4页
In a previous paper, we have reported the relationship between the crystallite orientation of the evaporated film of copper phthalacyanine (PcCu) (α-form) and the incident angle of molecular beam at 10-5 torr. In... In a previous paper, we have reported the relationship between the crystallite orientation of the evaporated film of copper phthalacyanine (PcCu) (α-form) and the incident angle of molecular beam at 10-5 torr. In this paper, we shall show some research results about vacuum effects on the crystal forms and the morphology of the evaporat- 展开更多
关键词 In effect OF VACUUM ON THE CRYSTAL FORM AND morphology OF THE EVAPORATED FILM OF COPPER PHTHALOCYANINE
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Effects ofm perioperative cimetidine administration on tumor cell nuclear morphology and DNA content in patients with gastric and colorectal cancer
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作者 李雁 白德骄 +3 位作者 杨国梁 袁宏银 王坤 汪艳 《Chinese Medical Journal》 SCIE CAS CSCD 1999年第6期77-77,共1页
Objective To explore the effects of perioperative cimetidine administration on tumor cell nuclear morphometric parameters and DNA content in patients with gastric and colorectal adenocarcinoma (GCRA) Past studies h... Objective To explore the effects of perioperative cimetidine administration on tumor cell nuclear morphometric parameters and DNA content in patients with gastric and colorectal adenocarcinoma (GCRA) Past studies have attributed the antitumor effect of cimetidine to its immunomodulatory property, which led to an increase of cellular immunity Whether there are other possible mechanisms by which cimetidine exerts its antitumor function is unknown 49 patients with GCRA were randomized into treatment group (n=25) and control group (n=24) based on whether cimetidine was applied to them during the perioperative periold The treatment group started oral cimetidine intake 400mg, tid, 7-10d before oiperation, followed by curative surgery 'The control group did not receive cimetidine Tumor specimens were paraffin embedded for 4μm thick microsection and stained with (1) hematoxylin and eosin (HE) for the morphometric measurements of tumor cell nuclear area (NA), nuclear perimeter (NP), maximal nuclear diameter (MMND) and minimal nuclea4r diameter (MNND); (2) feulgen stain for tumor nuclear DNA content analysis by IBAS Image Analyzer The percentages (%) of diploidy (2C), tripletetraploidy (3C 4C), quintuple ploidy (5C) and >quintuple ploidy (>5C) tumor cells were calculated, using the mean value of DNA content of 50 lymphocytes as normal 2C control 3C 5C cells were designated as law aneuploid cells and >5C cells as high aneupoid cells Results The clinicopathological variables between the two groups were balanced and comparable There were no statistically significant differences between bthe treatment and control groups in regard of the following parameters: age, gender, tumor location, pathological type, TNM stage, and degree of differentiation The NA (μm 2), NP (μm), MMND (μm) and MNND (μm) for treatm ent group/control group were 23 54±5 08/34 698±10 18 ( P <0 001), 22 06±4 43/24 88±4 05 ( P <0 05),7 84±1 64/8 62±1 24 ( P >0 05), and 4 42±0 61/5 41±0 89 ( P <0 001), respectively The percentages (%) of 2C, 3C 4C, 5C and >5C tumor cells for treatment group/control group were 16 64±2 58/5 35±2 14 ( P <0 002), 39 84±2 28/35 70±3 58 ( P >0 50), 12 42±5 00/14 48±0 74 ( P >0 20), 31 11±6 86/45 97±3 82 ( P <0 005), respectively In the treatment group, there was a tendency tiowards low aneuploid tumor cells from high an euploid tumor cells However, high aneuploid tumor cells predominated in the control group Conclusion Perioperative administration of cimetidine to GCRA patients could decrease the size of tumor cell nuclei, raise the percentage of diploid tumor cells, and partially convery high aneuploid tumor cells into low aneuploid tumor cells All of these effects may in turn help reduce the proliferative potential and invasiveness of tumor cells The direct inhibitory functions on tumor cell nuclei may be a new antitumor mechanism of cimetidine, in addition to its immunomodulatory action 展开更多
关键词 DNA cell effects ofm perioperative cimetidine administration on tumor cell nuclear morphology and DNA content in patients with gastric and colorectal cancer
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CeO_(2)with diverse morphologies-supported IrOx nanocatalysts for efficient oxygen evolution reaction—Commemorating the 100th anniversary of the birth of Academician Guangxian Xu 被引量:3
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作者 Qingqing Li Zhichao Zeng +2 位作者 Xiaolei Sun Feng Luo Yaping Du 《Journal of Rare Earths》 SCIE EI CAS CSCD 2021年第4期357-363,共7页
IrOx-based catalysts are considered the most promising candidates for oxygen evolution reaction(OER)due to their high efficiency.However,improving their intrinsic catalytic activity is essential for practical applicat... IrOx-based catalysts are considered the most promising candidates for oxygen evolution reaction(OER)due to their high efficiency.However,improving their intrinsic catalytic activity is essential for practical application.In this work,CeO_(2)with three different morphologies(rod,cube,octahedron)and supported IrOx nanoparticles were fabricated,and they display morphology-dependent OER activity.The IrOx/CeO_(2)-rod shows the highest activity;the catalysts have a catalytic activity sequence of rod>cube>octahedron.A plausible mechanism was proposed:the CeO_(2)support with different morphologies modulates the electronic structure of IrOx by the synergistic interaction promoted by oxygen vacancies between the active component and the support,thereby altering the catalytic activity of the IrOx/CeO_(2)catalyst. 展开更多
关键词 IrOx/CeO_(2)catalyst Oxygen evolution reaction morphology effect Oxygen vacancy Rare earths
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