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Generating Microstructures with Highly Variable Mechanical Performance using Two-Photon Lithography and Thiol-ene Photopolymerization

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Chinese Journal of Polymer Science 2023年第1期41卷 67-74页

作者： Xiao Yang Yan-fang niu Meng-Xiao Wei Jun-Ning Zhang Ke-Liang Liu Xin Du Zhong-Ze Gu State Key Laboratory of Bioelectronics School of Biological Science and Medical EngineeringSoutheast UniversityNanjing210096China

In this study,we investigate the effect of the exposure dose on the mechanical property of the photoresins generated with acrylate self-polymerization and thiol-ene polymerization.The results indicate that the mechanical performance of the thiol-ene photoresin is highly depended on the exposure dose during the solidification process.With 350-fold exposure dose change,the stiffness of the thiol-ene photoresin reached more that 700-fold change compare to 14-fold of the acrylate photoresin.We developed a TPL photoresist based on our results and show the capability to fabricate microstrucutres with high resolution and variable mechanical performances using this method.

关键词： Thiol-ene Two photo lithography 3D printing Photoresist

Tissue adhesive,ROS scavenging and injectable PRP-based‘plasticine’for promoting cartilage repair

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Regenerative Biomaterials 2024年第1期3卷 94-107页

作者： Shiao Li Dawei niu Haowei fang Yancheng Chen Jinyan Li Kunxi Zhang Jingbo Yin Peiliang Fu Department of Orthopedics Shanghai Changzheng HospitalNaval Medical UniversityShanghai 200003P.R.China Department of Polymer Materials School of Materials Science and EngineeringShanghai UniversityShanghai 200444P.R.China

Platelet-rich plasma(PRP)that has various growth factors has been used clinically in cartilage repair.However,the short residence time and release time at the injury site limit its therapeutic effect.The present study fabricated a granular hydrogel that was assembled from gelatin microspheres and tannic acid through their abundant hydrogen bonding.Gelatin microspheres with the gelatin concentration of 10wt%and the diameter distribution of 1-10 lm were used to assemble by tannic acid to form the granular hydrogel,which exhibited elasticity under low shear strain,but flowability under higher shear strain.The viscosity decreased with the increase in shear rate.Meanwhile,the granular hydrogel exhibited self-healing feature during rheology test.Thus,granular hydrogel carrying PRP not only exhibited well-performed injectability but also performed like a‘plasticine’that possessed good plasticity.The granular hydrogel showed tissue adhesion ability and reactive oxygen species scavenging ability.Granular hydrogel carrying PRP transplanted to full-thickness articular cartilage defects could integrate well with native cartilage,resulting in newly formed cartilage articular fully filled in defects and well-integrated with the native cartilage and subchondral bone.The unique features of the present granular hydrogel,including injectability,plasticity,porous structure,tissue adhesion and reactive oxygen species scavenging provided an ideal PRP carrier toward cartilage tissue engineering.

关键词： cartilage regeneration granular hydrogel gelatin tannic acid PRP

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低品位石煤钒矿两段逆流酸浸提钒的研究

稀有金属与硬质合金 2024年第1期52卷 44-50页

作者：牛芳银程倩梁效宁新霞吴天骄赵笑益王勇海王望泊西安西北有色地质研究院有限公司陕西西安710054

以陕南某低品位石煤钒矿为原料,在添加含氟助浸剂的条件下采用两段逆流硫酸浸出提钒。结果表明,在石煤钒矿磨矿细度为―0.074 mm占40%,助浸剂为1%NaClO_(3)+3%2^(#)含氟助浸剂,硫酸用量为22%,两段逆流浸出温度为90℃,一段浸出时间为1 h... 详细信息

以陕南某低品位石煤钒矿为原料,在添加含氟助浸剂的条件下采用两段逆流硫酸浸出提钒。结果表明,在石煤钒矿磨矿细度为―0.074 mm占40%,助浸剂为1%NaClO_(3)+3%2^(#)含氟助浸剂,硫酸用量为22%,两段逆流浸出温度为90℃,一段浸出时间为1 h,二段浸出时间为2 h的条件下,钒浸出率可以达到94.95%。该流程可有效降低硫酸用量,提高钒浸出率,节省药剂,并能适当简化后续提钒工艺。

关键词：石煤助浸剂硫酸浸出提钒逆流浸出

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对标世界一流企业的网络发展指标体系研究

电信工程技术与标准化 2024年第5期37卷 1-6,12页

作者：牛芳玲谢希宁李晓飞李双杰白杨中国移动通信集团设计院有限公司北京100080 中国移动通信集团有限公司北京100033

近年来,国务院国资委紧密部署安排中央企业加快建设世界一流企业工作,中国移动制定《中国移动加快建设世界一流企业实施方案》,贯彻落实国家决策部署。针对网络建设层面,本文搭建世界一流网络评估体系,对标国际国内领先信息服务科技公司... 详细信息

近年来,国务院国资委紧密部署安排中央企业加快建设世界一流企业工作,中国移动制定《中国移动加快建设世界一流企业实施方案》,贯彻落实国家决策部署。针对网络建设层面,本文搭建世界一流网络评估体系,对标国际国内领先信息服务科技公司,坚持目标引领、落实对标找差、把握体系提升,找出公司网络建设存在的优势与短板,为网络发展规划和计划建设部署等后续工作做好战略指引。

关键词：网络发展体系指标体系 AI

Enhanced thermal conductivity and mechanical properties of 2D C_(f)/SiC composites modified by in-situ grown carbon nanotubes

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Journal of Advanced Ceramics 2024年第1期13卷 19-33页

作者： Changhui niu Qing Zhang Laifei Cheng fang Ye Litong Zhang Min Huang Tao Yang Science and Technology on Thermostructure Composite Materials Laboratory Northwestern Polytechnical UniversityXi’an 710072China Civil Aviation Department Zhejiang Institute of CommunicationsHangzhou 311112China Zhejiang Provincial Key Laboratory for Cutting Tools Taizhou UniversityTaizhou 318000China

In this work,the effects of carbon nanotubes(CNTs)on the microstructure evolution,thermal conductivity,and mechanical properties of C_(f)/SiC composites during chemical vapor infiltration(CVI)densification were investigated in detail.Compared with composites without CNTs,the thermal conductivity,flexural strength,flexural modulus,fracture toughness,interfacial shear strength,and proportional limit stress of specimens with CNTs of 4.94 wt%were improved by 117%,21.8%,67.4%,10.3%,36.4%,and 71.1%,respectively.This improvement was attributed to the role of CNTs in the division of inter-layer pores,which provided abundant vapor growth sites for the ceramic matrix and promoted densification of the whole composite.In addition,the high thermal conductivity network formed by the overlap of CNTs and the rivet strengthening effect of CNTs were beneficial for synergistic improvement of thermal conductivity and mechanical properties of the composites.Therefore,this study has practical significance for the development of thermal protection composite components with enhanced thermal conductivity and mechanical characteristics.

关键词： ceramic−matrix composites carbon nanotubes microstructure thermal conductivity mechanical properties

On the Mixed Pólya–Szegö Principle

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Acta Mathematica Sinica,English Series 2021年第5期37卷 753-767页

作者： niu Fa fang Jia Zu ZHOU Chern Institute of Mathematics Nankai UniversityTianjin 300071P.R.China School of Mathematics and Statistics Southwest UniversityChongqing 400715P.R.China College of Science Wuhan University of Science and TechnologyWuhan 430081P.R.China

In this paper,the mixed Pólya-Szegöprinciple is established.By the mixed Pólya-Szegöprinciple,the mixed Morrey-Sobolev inequality and some new analytic inequalities are obtained.

关键词： Pólya–Szegöprinciple mixed Pólya–Szegöprinciple Sobolev inequality spherically symmetric rearrangement

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深度学习在糖尿病视网膜病变分级中的应用

计算机系统应用 2024年第1期33卷 231-244页

作者：张志强赵可辉牛惠芳张子宇周连田山东中医药大学智能与信息工程学院济南250355 山东中医药大学第二附属医院特检科济南250002 山东省药品不良反应监测中心济南250014 菏泽市中医医院碎石科菏泽274035

近年来,糖尿病视网膜病变(diabetic retinopathy,DR)成为全球失明人口增加的主要原因,早期的DR严重程度分级对防止DR患者视力丧失尤为重要.由于糖尿病患者数量的逐年上升,DR分级的需求量也不断增加,然而传统的人工分级不能满足日益增长... 详细信息

近年来,糖尿病视网膜病变(diabetic retinopathy,DR)成为全球失明人口增加的主要原因,早期的DR严重程度分级对防止DR患者视力丧失尤为重要.由于糖尿病患者数量的逐年上升,DR分级的需求量也不断增加,然而传统的人工分级不能满足日益增长的需求,且人工分级耗时费力.深度学习技术的发展,为DR检测和分级提供了高效率且更可靠的手段.虽然,目前的DR二元检测已经取得十分好的效果,然而由于糖尿病视网膜病变的复杂性和病变程度之间的差距细微,DR严重程度分级仍然是一个具有挑战性的问题.本文对近年来涌现的DR分级方法进行了研究和总结:介绍了基于VGG、InceptionNet、ResNet、EfficientNet、DenseNet、CapsNet模型的6种深度学习分级方法;并介绍了基于多网络融合的DR分级方法;最后对基于深度学习的DR分级方法的研究趋势进行总结和展望.

关键词：糖尿病视网膜病变深度学习卷积神经网络多网络融合多标签分类

In Situ Loading of Cu_(2)O Nanoparticles on a Hydroxyl Group Rich TiO_(2) Precursor as an Excellent Catalyst for the Ullmann Reaction

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Nano Research 2010年第11期3卷 757-763页

作者： fang niu Yan Jiang Weiguo Song Beijing National Laboratory for Molecular Sciences(BNLMS) Laboratory for Molecular Nanostructures and Nanotechnology Institute of ChemistryChinese Academy of SciencesBeijing 100190China The Graduate University of the Chinese Academy of Sciences YuquanluBeijing100049China

An in situ method has been used to load Cu_(2)O nanoparticles on the surface of a hydroxyl group rich TiO_(2)precursor.Cu_(2)O nanoparticles are formed by in situ reduction of Cu(OH)_(2) with Sn^(2+)ions linked to the surface of the TiO_(2)precursor.The initial Cu_(2)O nanoparticles serve as seeds for subsequent particle growth.The resulting Cu_(2)O nanoparticles are evenly dispersed on the surface of the TiO_(2)precursor,and are heat and air stable.The as-prepared composite is an excellent catalyst for Ullmann type cross coupling reactions of aryl halides with phenol.The composite catalyst also showed good stability,remaining highly active after five consecutive runs.

关键词： Cuprous oxide in situ composite structure titania precursor Ullmann type cross coupling

Application of a concrete thermal pile in cooling the warming permafrost under climate change

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Advances in Climate Change Research 2024年第1期15卷 170-183页

作者： Yun-Hu SHANG Fu-Jun niu Guo-Yu LI Jian-Hong fang Ze-Yong GAO State Key Laboratory of Frozen Soil Engineering Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China Da Xing'anling Observation and Research Station of Frozen-Ground Engineering and Environment Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesJagdaqi 165000China Qinghai Research Institute of Transportation Xining 810008China

Permafrost degradation caused by climate warming is posing a serious threat to the stability of cast-in-place pile foundations in warm permafrost regions.Ambient cold energy can be effectively utilized by two-phase closed thermosyphons(TPCTs)to cool the permafrost.Therefore,we installed TPCTs in a cast-in-place pile foundation to create a unique structure called a thermal pile,which effectively utilizes the TPCTs to regulate ground temperature.And we conducted a case study and numerical simulation to exhibit the cooling performance,and optimize the structure of the thermal pile.The purpose of this study is to promote the application of thermal piles in unstable permafrost regions.Based on the findings,the thermal pile operated for approximately 53%of the entire year and effectively reduced the deep ground temperature at a rate of at least-0.1℃per year.Additionally,it successfully raised the permafrost table that is 0.35 m shallower than the natural ground level.These characteristics prove highly beneficial in mitigating the adverse effects of permafrost degradation and enhancing infrastructure safety.Expanding the length of the condenser section and the diameter of the TPCT in a suitable manner can effectively enhance the cooling capability of the thermal pile and ensure the long-term mechanical stability of the pile foundation even under climate warming.

关键词： Heat transfer Cold energy Warm permafrost Two-phase closed thermosyphons Cast-in-place pile foundation