Arc ion plating (AIP) is applied to form Ti/(Ti,Cr)N/CrN multilayer coating on the surface of 316L stainless steel (SS316L) as bipolar plates for proton exchange membrane fuel cells (PEMFCs). The characterizations of ...Arc ion plating (AIP) is applied to form Ti/(Ti,Cr)N/CrN multilayer coating on the surface of 316L stainless steel (SS316L) as bipolar plates for proton exchange membrane fuel cells (PEMFCs). The characterizations of the coating are analyzed by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Interfacial contact resistance (ICR) between the coated sample and carbon paper is 4.9 m Omega cm(2) under 150 N/cm(2), which is much lower than that of the SS316L substrate. Potentiodynamic and potentiostatic tests are performed in the simulated PEMFC working conditions to investigate the corrosion behaviors of the coated sample. Superior anticorrosion performance is observed for the coated sample, whose corrosion current density is 0.12 mu A/cm(2). Surface morphology results after corrosion tests indicate that the substrate is well protected by the multilayer coating. Performances of the single cell with the multilayer coated SS316L bipolar plate are improved significantly compared with that of the cell with the uncoated SS316L bipolar plate, presenting a great potential for PEMFC application. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.展开更多
The presence of insufficient bone volume affects the implant healing and success.The aim of this study was to evaluate osteogenic capacity of dental pulp stem cells(DPSCs) on micro-arc oxidation(MAO) titanium surface....The presence of insufficient bone volume affects the implant healing and success.The aim of this study was to evaluate osteogenic capacity of dental pulp stem cells(DPSCs) on micro-arc oxidation(MAO) titanium surface.DPSCs were challenged at MAO and smooth titanium surface separately for different durations,and the bone marrow mesenchymal stem cells(BMSCs) served as the positive controls.The osteogenic capacity of DPSCs on MAO titanium surface was assessed by using scanning electron microscopy,energy dispersive spectroscopy,biochemical tests and real-time quantitative PCR.Data showed that DPSCs differentiated into osteoblasts and expressed bone morphogenetic genes on MAO titanium surface.The results of this study revealed that DPSCs had good potential to generate mineralized tissue on MAO titanium plates.The differential potential of DPSCs may be regulated by MAO titanium surface.The osteogenesis potential of DPSCs on the MAO titanium was similar with BMSCs.展开更多
Background: Giant cell tumors of the lumbar spine are rare and complete resection without major functional comprise is challenging despite advancements in spine surgery techniques. Radiation therapy has been an option...Background: Giant cell tumors of the lumbar spine are rare and complete resection without major functional comprise is challenging despite advancements in spine surgery techniques. Radiation therapy has been an option in such cases;however there are high concerns for associated high small bowel toxicity and lack of dose escalation to achieve local control. With advent of intensity modulated radiation therapy (IMRT) it is now possible to give high radiation dose to tumor with minimal toxicity. Herein we present a rare case of giant cell tumor of fourth lumbar (L4) vertebra treated with RapidArc intensity modulated arc therapy (IMAT) with relevant review of literature. Methods: A 30-year-old female had low back pain for 6 months. She underwent surgical decompression at another hospital as having a L4-5 protruded intervertebral disc 2 months previously, but her back pain progressed with weakness of both legs with restricted movement. Radiological and pathological work-up confirmed the diagnosis of giant cell tumor of L4 vertebra. She refused further surgery and was referred to us for radiotherapy. Treatment plans for prescribed radiation dose of 59.4 Gy in 30 fractions were made by 3DCRT and RapidArc IMAT and comparison was made. Student’s unpaired t test was used to determine the significance of the difference between two plans in terms of dose to the tumor and small bowel. A p value of 0.05 was considered statistically significant. Related literature was searched. Results: In RapidArc IMAT and 3DCRT plans mean doses to planning treatment volume (PTV) were 61.24 Gy (55.98 - 66.23) and 60.71 Gy (49.87 - 63.74) respectively (p 0.04) and mean doses to small bowel were found lesser in RapidArc plan [14.78 Gy (range: 0.39 - 53.15)] as compared to 3DCRT plan. Patient was started on RapidArc IMRT and she completed the course without any major sequelae. Conclusion: Lumbar spine giant cell tumors are rare and complete resection is often not possible. RapidArc IMAT is a feasible option for such patients to deliver high dose radiation to achieve good local control with marked symptom relief and without severe toxicity.展开更多
The conversion of sunlight into electricity via photovoltaics presents tremendous opportunities for the generation of renewable energy. However, solar cells still face several challenges and limitations to further red...The conversion of sunlight into electricity via photovoltaics presents tremendous opportunities for the generation of renewable energy. However, solar cells still face several challenges and limitations to further reduce manufacturing costs and increase module efficiency. Photon management is paramount to increase the efficiency of the mainstream silicon-based cell and always includes a suitable antireflection coating (ARC) structure to decrease the reflectance (R) at the top surface. We propose a novel triple-layer anti-reflective coating (TLAR) consisting of three layers sandwiched between the upper cover (glass) and the substrate (silicon). The inner three layers are graded refractive index material (GIM) as an active layer, titanium dioxide (TiO<sub>2</sub>), and zinc sulfide (ZnS), respectively. The optical properties of the TLAR have been investigated using the transfer matrix method (TMM). The results of using GIM as the active medium lead to the reflection decaying to the minimum value, and the transmittance reaching the maximum values at a specific wavelength range. The proposed triple-layer anti-reflective coating (TLAR) structure presents a promising solution for enhancing the efficiency of solar cells. Its unique design and utilization of graded refractive index material (GIM) as the active layer make it a novel and innovative approach that holds great potential for advancing solar cell technology.展开更多
Region partition(RP) is the key technique to the finite element parallel computing(FEPC),and its performance has a decisive influence on the entire process of analysis and computation.The performance evaluation index ...Region partition(RP) is the key technique to the finite element parallel computing(FEPC),and its performance has a decisive influence on the entire process of analysis and computation.The performance evaluation index of RP method for the three-dimensional finite element model(FEM) has been given.By taking the electric field of aluminum reduction cell(ARC) as the research object,the performance of two classical RP methods,which are Al-NASRA and NGUYEN partition(ANP) algorithm and the multi-level partition(MLP) method,has been analyzed and compared.The comparison results indicate a sound performance of ANP algorithm,but to large-scale models,the computing time of ANP algorithm increases notably.This is because the ANP algorithm determines only one node based on the minimum weight and just adds the elements connected to the node into the sub-region during each iteration.To obtain the satisfied speed and the precision,an improved dynamic self-adaptive ANP(DSA-ANP) algorithm has been proposed.With consideration of model scale,complexity and sub-RP stage,the improved algorithm adaptively determines the number of nodes and selects those nodes with small enough weight,and then dynamically adds these connected elements.The proposed algorithm has been applied to the finite element analysis(FEA) of the electric field simulation of ARC.Compared with the traditional ANP algorithm,the computational efficiency of the proposed algorithm has been shortened approximately from 260 s to 13 s.This proves the superiority of the improved algorithm on computing time performance.展开更多
目的:比较碳离子二维放射治疗(two-dimensional carbon-ion radiotherapy,2D-CIRT)计划与光子容积调强放射治疗(volume modulated arc therapy,VMAT)计划在Ⅲ期非小细胞肺癌中剂量学优劣,为临床碳离子治疗提供依据。方法:选取我中心13...目的:比较碳离子二维放射治疗(two-dimensional carbon-ion radiotherapy,2D-CIRT)计划与光子容积调强放射治疗(volume modulated arc therapy,VMAT)计划在Ⅲ期非小细胞肺癌中剂量学优劣,为临床碳离子治疗提供依据。方法:选取我中心13例Ⅲ期非小细胞肺癌患者,使用相同的处方剂量及危及器官约束条件,分别在Ciplan计划系统上设计2D-CIRT计划和Eclipse计划系统上设计VMAT计划,比较剂量-体积直方图,评价靶区剂量分布及危及器官受量。采用SPSS 22.0软件进行数据分析。结果:CIRT和VMAT计划肿瘤覆盖率均较好,PTV1的D_(98)、D_(95)、D_(50)差异无统计学意义,两种计划的均匀性指数(homogeneity index,HI)相似(CIRT与VMAT:0.39 Gy与0.38 Gy,P>0.05)。PTV2两种方案在D_(95)、D_(98)、D_(50)、D_(2)均有显著性差异,PTV2采用CIRT的HI也明显优于VMAT(CIRT vs VMAT:0.08 Gy vs 0.16 Gy,P=0.003)。与光子VMAT相比,CIRT计划中健侧肺的V_(5)、V_(10)、V_(20)、V_(30)、V_(40)和D_(mean)明显降低。患侧肺中CIRT的V_(5)低于VMAT(CIRT vs VMAT:53.00 vs 64.41,P=0.003),V_(10)、V_(20)、V_(30)、V_(40)、D_(mean)两种计划均无统计学差异;CIRT有较低的脊髓D max(CIRT vs VMAT:18.61 Gy vs 43.03 Gy,P=0.000)、食管D_(mean)(CIRT vs VMAT:16.25 Gy vs 20.38 Gy,P=0.031)和V_(5)0(CIRT vs VMAT:4.49 Gy vs 11.43 Gy,P=0.005)、骨V_(10)和V_(30),以及气管和支气管树的V_(5)0。结论:与光子VMAT相比,2D-CIRT被动束流扫描技术在Ⅲ期非小细胞肺癌治疗中显著降低了对危及器官的辐射剂量,对正常组织有更好的保护作用。展开更多
基金financially supported by the National Basic Research Program of China (973 Program) (no. 2012CB215500)the National Key Technology Research and Development Program of China (no. 2015BAG06B00)+1 种基金Major Program of the National Natural Science Foundation of China (no. 61433013)National Natural Science Foundation of China (no. 21206012)
文摘Arc ion plating (AIP) is applied to form Ti/(Ti,Cr)N/CrN multilayer coating on the surface of 316L stainless steel (SS316L) as bipolar plates for proton exchange membrane fuel cells (PEMFCs). The characterizations of the coating are analyzed by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Interfacial contact resistance (ICR) between the coated sample and carbon paper is 4.9 m Omega cm(2) under 150 N/cm(2), which is much lower than that of the SS316L substrate. Potentiodynamic and potentiostatic tests are performed in the simulated PEMFC working conditions to investigate the corrosion behaviors of the coated sample. Superior anticorrosion performance is observed for the coated sample, whose corrosion current density is 0.12 mu A/cm(2). Surface morphology results after corrosion tests indicate that the substrate is well protected by the multilayer coating. Performances of the single cell with the multilayer coated SS316L bipolar plate are improved significantly compared with that of the cell with the uncoated SS316L bipolar plate, presenting a great potential for PEMFC application. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.
基金supported by the Innovation Fund of Huazhong University of Science and Technology,Wuhan,P.R. China (No.2011JC018)
文摘The presence of insufficient bone volume affects the implant healing and success.The aim of this study was to evaluate osteogenic capacity of dental pulp stem cells(DPSCs) on micro-arc oxidation(MAO) titanium surface.DPSCs were challenged at MAO and smooth titanium surface separately for different durations,and the bone marrow mesenchymal stem cells(BMSCs) served as the positive controls.The osteogenic capacity of DPSCs on MAO titanium surface was assessed by using scanning electron microscopy,energy dispersive spectroscopy,biochemical tests and real-time quantitative PCR.Data showed that DPSCs differentiated into osteoblasts and expressed bone morphogenetic genes on MAO titanium surface.The results of this study revealed that DPSCs had good potential to generate mineralized tissue on MAO titanium plates.The differential potential of DPSCs may be regulated by MAO titanium surface.The osteogenesis potential of DPSCs on the MAO titanium was similar with BMSCs.
文摘Background: Giant cell tumors of the lumbar spine are rare and complete resection without major functional comprise is challenging despite advancements in spine surgery techniques. Radiation therapy has been an option in such cases;however there are high concerns for associated high small bowel toxicity and lack of dose escalation to achieve local control. With advent of intensity modulated radiation therapy (IMRT) it is now possible to give high radiation dose to tumor with minimal toxicity. Herein we present a rare case of giant cell tumor of fourth lumbar (L4) vertebra treated with RapidArc intensity modulated arc therapy (IMAT) with relevant review of literature. Methods: A 30-year-old female had low back pain for 6 months. She underwent surgical decompression at another hospital as having a L4-5 protruded intervertebral disc 2 months previously, but her back pain progressed with weakness of both legs with restricted movement. Radiological and pathological work-up confirmed the diagnosis of giant cell tumor of L4 vertebra. She refused further surgery and was referred to us for radiotherapy. Treatment plans for prescribed radiation dose of 59.4 Gy in 30 fractions were made by 3DCRT and RapidArc IMAT and comparison was made. Student’s unpaired t test was used to determine the significance of the difference between two plans in terms of dose to the tumor and small bowel. A p value of 0.05 was considered statistically significant. Related literature was searched. Results: In RapidArc IMAT and 3DCRT plans mean doses to planning treatment volume (PTV) were 61.24 Gy (55.98 - 66.23) and 60.71 Gy (49.87 - 63.74) respectively (p 0.04) and mean doses to small bowel were found lesser in RapidArc plan [14.78 Gy (range: 0.39 - 53.15)] as compared to 3DCRT plan. Patient was started on RapidArc IMRT and she completed the course without any major sequelae. Conclusion: Lumbar spine giant cell tumors are rare and complete resection is often not possible. RapidArc IMAT is a feasible option for such patients to deliver high dose radiation to achieve good local control with marked symptom relief and without severe toxicity.
文摘The conversion of sunlight into electricity via photovoltaics presents tremendous opportunities for the generation of renewable energy. However, solar cells still face several challenges and limitations to further reduce manufacturing costs and increase module efficiency. Photon management is paramount to increase the efficiency of the mainstream silicon-based cell and always includes a suitable antireflection coating (ARC) structure to decrease the reflectance (R) at the top surface. We propose a novel triple-layer anti-reflective coating (TLAR) consisting of three layers sandwiched between the upper cover (glass) and the substrate (silicon). The inner three layers are graded refractive index material (GIM) as an active layer, titanium dioxide (TiO<sub>2</sub>), and zinc sulfide (ZnS), respectively. The optical properties of the TLAR have been investigated using the transfer matrix method (TMM). The results of using GIM as the active medium lead to the reflection decaying to the minimum value, and the transmittance reaching the maximum values at a specific wavelength range. The proposed triple-layer anti-reflective coating (TLAR) structure presents a promising solution for enhancing the efficiency of solar cells. Its unique design and utilization of graded refractive index material (GIM) as the active layer make it a novel and innovative approach that holds great potential for advancing solar cell technology.
基金Project(61273187)supported by the National Natural Science Foundation of ChinaProject(61321003)supported by the Foundation for Innovative Research Groups of the National Natural Science Foundation of China
文摘Region partition(RP) is the key technique to the finite element parallel computing(FEPC),and its performance has a decisive influence on the entire process of analysis and computation.The performance evaluation index of RP method for the three-dimensional finite element model(FEM) has been given.By taking the electric field of aluminum reduction cell(ARC) as the research object,the performance of two classical RP methods,which are Al-NASRA and NGUYEN partition(ANP) algorithm and the multi-level partition(MLP) method,has been analyzed and compared.The comparison results indicate a sound performance of ANP algorithm,but to large-scale models,the computing time of ANP algorithm increases notably.This is because the ANP algorithm determines only one node based on the minimum weight and just adds the elements connected to the node into the sub-region during each iteration.To obtain the satisfied speed and the precision,an improved dynamic self-adaptive ANP(DSA-ANP) algorithm has been proposed.With consideration of model scale,complexity and sub-RP stage,the improved algorithm adaptively determines the number of nodes and selects those nodes with small enough weight,and then dynamically adds these connected elements.The proposed algorithm has been applied to the finite element analysis(FEA) of the electric field simulation of ARC.Compared with the traditional ANP algorithm,the computational efficiency of the proposed algorithm has been shortened approximately from 260 s to 13 s.This proves the superiority of the improved algorithm on computing time performance.
文摘目的:比较碳离子二维放射治疗(two-dimensional carbon-ion radiotherapy,2D-CIRT)计划与光子容积调强放射治疗(volume modulated arc therapy,VMAT)计划在Ⅲ期非小细胞肺癌中剂量学优劣,为临床碳离子治疗提供依据。方法:选取我中心13例Ⅲ期非小细胞肺癌患者,使用相同的处方剂量及危及器官约束条件,分别在Ciplan计划系统上设计2D-CIRT计划和Eclipse计划系统上设计VMAT计划,比较剂量-体积直方图,评价靶区剂量分布及危及器官受量。采用SPSS 22.0软件进行数据分析。结果:CIRT和VMAT计划肿瘤覆盖率均较好,PTV1的D_(98)、D_(95)、D_(50)差异无统计学意义,两种计划的均匀性指数(homogeneity index,HI)相似(CIRT与VMAT:0.39 Gy与0.38 Gy,P>0.05)。PTV2两种方案在D_(95)、D_(98)、D_(50)、D_(2)均有显著性差异,PTV2采用CIRT的HI也明显优于VMAT(CIRT vs VMAT:0.08 Gy vs 0.16 Gy,P=0.003)。与光子VMAT相比,CIRT计划中健侧肺的V_(5)、V_(10)、V_(20)、V_(30)、V_(40)和D_(mean)明显降低。患侧肺中CIRT的V_(5)低于VMAT(CIRT vs VMAT:53.00 vs 64.41,P=0.003),V_(10)、V_(20)、V_(30)、V_(40)、D_(mean)两种计划均无统计学差异;CIRT有较低的脊髓D max(CIRT vs VMAT:18.61 Gy vs 43.03 Gy,P=0.000)、食管D_(mean)(CIRT vs VMAT:16.25 Gy vs 20.38 Gy,P=0.031)和V_(5)0(CIRT vs VMAT:4.49 Gy vs 11.43 Gy,P=0.005)、骨V_(10)和V_(30),以及气管和支气管树的V_(5)0。结论:与光子VMAT相比,2D-CIRT被动束流扫描技术在Ⅲ期非小细胞肺癌治疗中显著降低了对危及器官的辐射剂量,对正常组织有更好的保护作用。
