检索结果-南通市图书馆

碳纳米管内水吸附行为及等量吸附热的巨正则Monte Carlo模拟

同方期刊数据库

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

计算物理 2024年第2期41卷 203-213页

作者：刘晨刘忠军赵明慧敖庆波西安石油大学材料科学与工程学院陕西西安710065 西北有色金属研究院金属多孔材料国家重点实验室陕西西安710016

采用巨正则蒙特卡罗方法对单壁碳纳米管-水吸附体系进行计算模拟,通过对吸附和脱附等温线、局部密度分布、等量吸附热等进行表征,系统研究298 K时孔长、孔径以及表面强度对孔隙内水吸附行为的影响。结果表明:孔径效应对孔内水吸附行为... 详细信息

采用巨正则蒙特卡罗方法对单壁碳纳米管-水吸附体系进行计算模拟,通过对吸附和脱附等温线、局部密度分布、等量吸附热等进行表征,系统研究298 K时孔长、孔径以及表面强度对孔隙内水吸附行为的影响。结果表明:孔径效应对孔内水吸附行为影响显著,随着孔径逐渐增大,水分子先后以单链水、双链空心水环、水团簇的排列状态在孔内完成吸附。孔长在4~8 nm范围内时,随着孔长变大,发生吸附的初始压力越来越小,但当孔长增加到10 nm时,其对初始吸附压力的影响不再明显。最后,随着表面强度增大,发生水吸附的初始压力越来越小;同时,较小表面强度水分子的毛细蒸发相变过程瞬间完成,而当表面强度提高到40 K时,毛细蒸发相变过程则呈现出连续、逐渐完成的特点。

关键词：碳纳米管吸附作用蒙特卡罗模拟等量吸附热相变

在线全文

学校读者我要写书评

暂无评论

Fe-5%Si多孔材料的制备及透气性研究

钢铁钒钛 2024年第3期45卷 176-181,187页

作者：姬帅袁佳乐刘忠军西安石油大学材料科学与工程学院陕西西安710065 南京工业大学材料化学工程国家重点实验室江苏南京210009

将三组相同的Fe-5%Si混合粉末分别在1050、1100、1150℃的温度下高温烧结2 h,对各个试样进行金相(OM)及扫描(SEM)显微组织观察、XRD物相分析,并采用自组装多孔材料性能检测仪测试其透气性。结果表明,烧结温度越高,多孔材料的孔径尺寸越... 详细信息

将三组相同的Fe-5%Si混合粉末分别在1050、1100、1150℃的温度下高温烧结2 h,对各个试样进行金相(OM)及扫描(SEM)显微组织观察、XRD物相分析,并采用自组装多孔材料性能检测仪测试其透气性。结果表明,烧结温度越高,多孔材料的孔径尺寸越小,1150℃试样的截面上会形成膜层;Fe-5%Si多孔材料的截面由Fe和Si的氧化物组成,且烧结温度越高,氧化物种类越少,即1050℃下有SiO_(2)、Fe_(2)O_(3)、FeO、Fe_(2)O_(4)四种物质,1100℃下有Fe_(3)O_(4)、FeO、SiO_(2),1150℃下有FeO、SiO_(2);1050℃下试样的气体流量随着通气压力的增大明显变大,当通气压力为140 kPa时,气体流量约为9200 mL/min;1100℃及1150℃下试样的气体流量随着通气压力的增大变化不大,当通气压力均为140 kPa时,二者的气体流量约为1000 mL/min。

关键词： Fe-5%Si多孔材料真空烧结孔形貌透气性

在线全文

学校读者我要写书评

暂无评论

过滤用金属多孔材料力学性能研究进展

粉末冶金技术 2024年第1期42卷 59-67页

作者：梁凯刘忠军姬帅高博阳西安石油大学材料科学与工程学院西安710065

金属多孔材料作为功能与结构兼具的一类新型材料,已被广泛应用于吸声、吸能、流体分布、换热、催化、过滤分离等领域,其中在过滤分离领域应用最为广泛。金属多孔材料在石油石化、精细化工、煤化工等领域可以实现不同流体的液–固、气–... 详细信息

金属多孔材料作为功能与结构兼具的一类新型材料,已被广泛应用于吸声、吸能、流体分布、换热、催化、过滤分离等领域,其中在过滤分离领域应用最为广泛。金属多孔材料在石油石化、精细化工、煤化工等领域可以实现不同流体的液–固、气–固过滤分离,不同领域对所用金属多孔材料的材质及力学性能要求也不尽相同。过滤用金属多孔材料的制备工艺已相对成熟,但对其耐蚀性能及力学性能的表征研究较少,金属过滤元件的力学性能及耐腐蚀性能将直接关系到该类材料的使用效果和寿命。本文总结了近几年过滤用金属多孔材料力学性能及耐腐蚀行为的研究进展,探讨了该类材料在腐蚀与力学行为中存在的问题,最后展望了过滤用金属多孔材料的发展方向。

关键词：金属多孔材料过滤分离力学性能腐蚀行为

在线全文

学校读者我要写书评

暂无评论

自稳式人工椎体在颈椎前路手术中的应用

北京大学学报（医学版） 2024年第1期56卷 161-166页

作者：胡攀攀李彦刘啸唐彦超李梓赫刘忠军北京大学第三医院骨科骨与关节精准医学工程研究中心脊柱疾病研究北京市重点实验室北京100191

目的:探讨自稳式人工椎体(artificial vertebral body,AVB)在颈前路椎体次全切除内固定融合手术(anterior cervical corpectomy and fusion,ACCF)中的短期应用效果。方法:遵循牛津IDEAL(Idea,Development,Exploration,Assessment,and Long-term Follow-up)方法学原则,采用单臂探索型研究的方法,纳入脊髓型颈椎病患者进行回顾性分析。所有患者均接受单节段ACCF手术,术中植入3D打印自稳式AVB,术后规律随访。采用日本骨科协会(Japanese Orthopedics Association,JOA)脊髓损害评分表评估手术前后神经功能改善情况,依据术后6个月的影像学测量数据评估融合情况。结果:共纳入11例病例,随访时间均超过6个月,手术时的平均年龄(57.2±10.2)岁,平均手术时间(76.1±23.1)min,中位出血量150(100,200)mL。术后无吞咽困难、血肿形成、神经功能损伤加重等并发症出现。至末次随访,JOA评分由术前的13.2±2.2恢复至末次随访时的16.3±0.8,恢复率为85.9%。假体平均沉降距离为(1.2±1.1)mm,1例假体出现超出3 mm的严重沉降(9.1%)。颈椎前凸角度较术前显著改变(P=0.013)。至术后6个月时,所有病例均实现融合。结论:自稳式AVB在单节段ACCF中的短期应用效果良好,融合率高,具有零切迹的优势,并发症少。

关键词：人工椎体自稳式零切迹 3D打印脊髓型颈椎病

维普期刊数据库博看期刊

High efficacy of tetra-PEG hydrogel sealants for sutureless dural closure

在线全文

学校读者我要写书评

暂无评论

Bioactive Materials 2022年第2期7卷 12-19页

作者： Tengjiao Zhu Hufei Wang Zehao Jing Daoyang Fan zhongjun liu Xing Wang Yun Tian Department of Orthopaedics Peking University Third HospitalBeijing100191China Beijing Key Laboratory of Spinal Disease Research Beijing100191China Engineering Research Center of Bone and Joint Precision Medicine Ministry of EducationBeijing100191China Beijing National Laboratory for Molecular Sciences Institute of ChemistryChinese Academy of SciencesBeijing100190China University of Chinese Academy of Sciences Beijing 100049China

Advances in meticulous dural closure technique remain a great challenge for watertight dural closure in the aged society,because the cerebrospinal fluid(CSF)leakage after spinal surgery is often accompanied with the disgusting wound infection,meningitis and ***,a tetra-poly(ethylene glycol)(PEG)-based hydrogel sealant is developed with collective advantages of facile operation,high safety,quick set time,easy injectability,favorable mechanical strength and powerful tissue adhesion for effective sutureless dural closure during the surgery ***,this tetra-PEG sealant can instantaneously adhere to the irregular tissue surfaces even in a liquid environment,and effectively prevent or block off the intraoperative CSF leakage for sutureless dural closure and dura ***,this sutureless tetra-PEG adhesive can be utilized as a very promising alternative for high-efficient watertight dural closure of the clinical patients who incidentally or deliberately undergo the durotomy during the spinal surgery.

关键词： CSF leakage Dural repair Watertight closure Sutureless Tetra-PEG hydrogel

Surface treatment of 3D printed porous Ti6Al4V implants by ultraviolet photofunctionalization for improved osseointegration

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Bioactive Materials 2022年第1期7卷 26-38页

作者： Chuan Yin Teng Zhang Qingguang Wei Hong Cai Yan Cheng Yun Tian Huijie Leng Caimei Wang Shiqing Feng zhongjun liu Department of Orthopedics Peking University Third HospitalBeijing100191People’s Republic of China Department of Orthopedics Qilu Hospital of Shandong UniversityJinan250012People’s Republic of China Center for Biomedical Materials and Tissue Engineering Academy for Advanced Interdisciplinary StudiesPeking UniversityBeijing100871People’s Republic of China Beijing AKEC Medical Company Ltd. Beijing102200People’s Republic of China

Three-dimensional(3D)-printed porous Ti6Al4V implants play an important role in the reconstruction of bone ***,its osseointegration capacity needs to be further improved,and related methods are inadequate,especially lacking customized surface treatment ***,we aimed to design an omnidirectional radiator based on ultraviolet(UV)photofunctionalization for the surface treatment of 3D-printed porous Ti6Al4V implants,and studied its osseointegration promotion effects in vitro and in vivo,while elucidating related *** UV treatment,the porous Ti6Al4V scaffolds exhibited significantly improved hydrophilicity,cytocompatibility,and alkaline phosphatase activity,while preserving their original mechanical *** increased osteointegration strength was further proven using a rabbit condyle defect model in vivo,in which UV treatment exhibited a high efficiency in the osteointegration enhancement of porous Ti6Al4V scaffolds by increasing bone ingrowth(BI),the bone-implant contact ratio(BICR),and the mineralized/osteoid bone *** advantages of UV treatment for 3D-printed porous Ti6Al4V implants using the omnidirectional radiator in the study were as follows:1)it can significantly improve the osseointegration capacity of porous titanium implants despite the blocking out of UV rays by the porous structure;2)it can evenly treat the surface of porous implants while preserving their original topography or other morphological features;and 3)it is an easy-to-operate low-cost process,making it worthy of wide clinical application.

关键词： Three-dimensional-printed porous implants UV photofunctionalization Omnidirectional UV radiator Osseointegration

Circumferential decompression via the posterior approach for the surgical treatment of multilevel thoracic ossification of the posterior longitudinal ligaments： a single institution comparative study

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Medical Journal 2014年第19期127卷 3371-3377页

作者： liu Xiao Zhu Bin liu Xiaoguang liu zhongjun Dang Gengting Department of Orthopaedics Peking University Third HospitalBeijing 100191

Background The treatment strategies for multilevel thoracic ossification of the posterior longitudinal ligaments （T-OPLL） were rarely reported. The aim of this study was to investigate the clinical outcomes and complications of circumferential decompression for multilevel T-OPLL and compare two different methods in the management of the OPLL （resection or floating）. Methods Data of sequentially treated patients who received surgical treatment for thoracic spinal stenosis caused by multilevel T-OPLL from January 2005 to February 2012 were retrospectively reviewed. Based on the surgical approaches applied, the patients were divided into two groups. Group A consisted the patients who received posterior decompression and group B consisted the patients who received circumferential decompression via the posterior approach. Group B was further divided into two subgroups： subgroup 1 （the resection group） where the OPLL was completely resected and subgroup 2 （the floating group） where the OPLL was floated. Results A total of 49 patients were included in the study. Fourteen patients with single posterior decompression were included in group A and 35 patients who received circumferential decompression were included in group B. In group B, 29 patients had complete resection of the ossified posterior longitudinal ligaments, while the other six underwent a flotation procedure. The follow-up data were available in 39 patients. Mean JOA scores improved from 5.4 ± 1.8 to 7.5 ± 2.8 in group A and from 3.7 ± 1.8 to 7.9 ± 2.4 in group B. The main complications included cerebrospinal fluid （CSF） leakage and postoperative neurelogic deterioration （ND）. Twenty-three of the 25 cases with postoperative CSF leakage achieved a complete recovery at the last follow-up and 12 of the 15 cases with ND achieved some neurological improvement at the last follow-up. Conclusions Circumferential decompression via the posterior approach is an effective surgical method for thoracic spinal stenosis caused

关键词： ossification of the posterior longitudinal ligament multilevel thoracic spinal stenosis intraoperative ultrasonography

Optimizing high-coordination shell of Co-based single-atom catalysts for efficient ORR and zinc-air batteries

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2024年第8期95卷 306-314,I0007页

作者： Yugang Qi Qing Liang Kexin Song Xinyan Zhou Meiqi liu Wenwen Li Fuxi liu Zhou Jiang Xu Zou zhongjun Chen Wei Zhang Weitao Zheng Key Laboratory of Automobile Materials MOE School of Materials Science&Engineering Electron Microscopy Centerand International Center of Future ScienceJilin Provincial International Cooperation Key Laboratory of High-Efficiency Clean Energy MaterialsJilin UniversityChangchun 130012JilinChina Institute of High Energy Physics Chinese Academy of SciencesBeijing 100049China

Atom-level modulation of the coordination environment for single-atom catalysts(SACs)is considered as an effective strategy for elevating the catalytic *** the MNxsite,breaking the symmetrical geometry and charge distribution by introducing relatively weak electronegative atoms into the first/second shell is an efficient way,but it remains challenging for elucidating the underlying mechanism of ***,a practical strategy was reported to rationally design single cobalt atoms coordinated with both phosphorus and nitrogen atoms in a hierarchically porous carbon derived from metal-organic frameworks.X-ray absorption spectrum reveals that atomically dispersed Co sites are coordinated with four N atoms in the first shell and varying numbers of P atoms in the second shell(denoted as Co-N/P-C).The prepared catalyst exhibits excellent oxygen reduction reaction(ORR)activity as well as zinc-air battery *** introduction of P atoms in the Co-SACs weakens the interaction between Co and N,significantly promoting the adsorption process of ^(*)OOH,resulting in the acceleration of reaction kinetics and reduction of thermodynamic barrier,responsible for the increased intrinsic *** discovery provides insights into an ultimate design of single-atom catalysts with adjustable electrocatalytic activities for efficient electrochemical energy conversion.

关键词： Electrocatalytic Oxygen reduction reaction Single atom catalyst Shell coordination optimization

Manipulating Na occupation and constructing protective film of P2-Na_(0.67)Ni_(0.33)Mn_(0.67)O_(2) as long-term cycle stability cathode for sodium-ion batteries

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2024年第1期88卷 603-611,I0013页

作者： Yiran Sun Pengfei Zhou Siyu liu zhongjun Zhao Yihao Pan Xiangyan Shen Xiaozhong Wu Jinping Zhao Junying Weng Jin Zhou School of Chemistry and Chemical Engineering Shandong University of TechnologyZibo 0255000ShandongChina School of Materials Science and Engineering Shandong University of TechnologyZibo 255049ShandongChina

P2-Na_(0.67)Ni_(0.33)Mn_(0.67)O_(2)(NNMO)is promising cathode material for sodium-ion batteries(SIBs)due to its high specific capacity and fast Na+diffusion ***,the irreversible P2-O_(2)phase transformation,Na+/vacancy ordering,and transition metal(TM)dissolution seriously damage its cycling stability and restrict its commercialization ***,Na occupation manipulation and interface stabilization are proposed to strengthen the phase structure of NNMO by synergistic Zn/Ti co-doping and introducing lithium difluorophosp(LiPO_(2)F_(2))film-forming electrolyte *** Zn/Ti co-doping regulates the occupancy ratio of Nae/Nafat Na sites and disorganizes the Na+/vacancy ordering,resulting in a faster Na+diffusion kinetics and reversible P2-Z phase transition for P2-Na_(0.67)Ni_(0.28)Zn_(0.05)Mn_(0.62)Ti_(0.05)O_(2)(NNZMTO).Meanwhile,the LiPO_(2)F_(2)additive can form homogeneous and ultrathin cathode-electrolyte interphase(CEI)on NNZMTO surface,which can stabilize the NNZMTO-electrolyte interface to prevent TM dissolution,surface structure transformation,and micro-crack *** studies of in situ and ex situ characterizations and theoretical calculations were used to elucidate the storage mechanism of NNZMTO with Li PO_(2)F_(2)*** a result,the NNZMTO displays outstanding capacity retention of 94.44%after 500 cycles at 1C with 0.3 wt%Li PO_(2)F_(2),excellent rate performance of 92.5 mA h g^(-1)at 8C with 0.1 wt%Li PO_(2)F_(2),and remarkable full cell *** work highlights the important role of manipulating Na occupation and constructing protective film in the design of layered materials,which provides a promising direction for developing high-performance cathodes for SIBs.

关键词： Layered cathode Zn/Ti co-doping Na occupation Electrolyte additive Sodium-ion batteries