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Nitrogen-doped flower-like porous carbon materials directed by in situ hydrolysed MgO： Promising support for Ru nanoparticles in catalytic hydrogenations

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Nano Research 2016年第10期9卷 3129-3140页

作者： mingming Li MinghuiTang jiang Deng Yong Wang Advanced Materials and Catalysis Group ZJU-NHU United R&D Center Department of Chemistry Zhejiang University Hangzhou310028 China

The development of novel simple, and convenient techniques for the fabrication of porous carbon materials with desirable properties, such as tunable pore structures and the presence of nitrogen functionalities, from renewable and abundant biomasses is required. We herein describe an in situ directing method for the preparation of a nitrogen-doped flower-like porous carbon （NFPC） employing arbitrarily shaped MgO from bio-derived glucosamine chloride （GAH）. Experimental evidence demonstrated that the structure directing effect of the Mg（OH）2 nanosheets formed in situ from MgO hydrolysis was key to this process, with the original MgO morphology being irrelevant. Furthermore, this method was applicable for a wide variety of biomass-derived carbon precursors. The resulting NFPC exhibited a high nitrogen content of 〈9 wt.%, and was employed as a support to anchor small Ru nanoparticles （average size = 2.7 nm）. The resulting Ru/NFPC was highly active in heterogeneous hydrogenations of toluene and benzoic acid, which demonstrated the advantages of nitrogen doping in terms of boosting catalytic performance.

关键词： nitrogen-doped porous carbon MgO in situ hydrolysis ruthenium aromatic hydrogenation

Switch type PANI/ZnO core-shell microwire heterojunction for UV photodetection

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Journal of Materials Science & Technology 2022年第10期105卷 259-265页

作者： Yihan Chen Longxing Su mingming jiang Xiaosheng Fang Department of Materials Science Fudan UniversityShanghai 200433China Department of Physical Science and Technology ShanghaiTech UniversityShanghai 201210China College of Science Nanjing University of Aeronautics and AstronauticsNanjing 211106China

In this study,single crystal ZnO microwires(MW)with size of~5.4 mm×30μm are prepared through a chemical vapor deposition technique at high temperature(1200℃).Subsequently,p-type conducting polyaniline(PANI)polymers with different conductivities are densely coated on part of the ZnO MW to construct organic/inorganic core-shell heterojunction *** hetero-diodes reach an extremely high rectifcation ratio(I_(+3V)/I_(-3V))of 749230,and a maximum rejection ratio(I_(350nm)/I_(dark))of 3556(at-3 V),indicating great potential as rectifed *** the heterojunction devices exhibit strong response to ultraviolet(UV)radiation with high response ***,the obvious photovoltaic behavior can also be obtained,allowing the device to operate as an independent and stable unit without externally supplied *** 0 V bias voltage,the self-powered photodetector shows a maximum responsivity of 0.56 mA W~(-1)and a rapid response speed of 0.11 ms/1.45 ms(rise time/decay time).Finally,a fnite difference time domain(FDTD)simulation is performed to further demonstrate the interaction mechanism between the incident light feld and the hexagonal cavity,which strongly supports the enhancement of the light absorption in whispering-gallery-mode resonator.

关键词： Core-shell structure Heterojunction High rectifcation ratio Self-powered Photodetector

A Bayesian Recommender Model for User Rating and Review Profiling

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Tsinghua Science and Technology 2015年第6期20卷 634-643页

作者： mingming jiang Dandan Song Lejian Liao Feida Zhu School of Computer Science and Technology Beijing Institute of Technology School of Information Systems Singapore Management University

Intuitively, not only do ratings include abundant information for learning user preferences, but also reviews accompanied by ratings. However, most existing recommender systems take rating scores for granted and discard the wealth of information in accompanying reviews. In this paper, in order to exploit user profiles’ information embedded in both ratings and reviews exhaustively, we propose a Bayesian model that links a traditional Collaborative Filtering(CF) technique with a topic model seamlessly. By employing a topic model with the review text and aligning user review topics with 'user attitudes'(i.e., abstract rating patterns) over the same distribution, our method achieves greater accuracy than the traditional approach on the rating prediction task. Moreover, with review text information involved, latent user rating attitudes are interpretable and 'cold-start' problem can be *** property qualifies our method for serving as a 'recommender' task with very sparse datasets. Furthermore,unlike most related works, we treat each review as a document, not all reviews of each user or item together as one document, to fully exploit the reviews’ information. Experimental results on 25 real-world datasets demonstrate the superiority of our model over state-of-the-art methods.

关键词： collaborative filtering topic model recommender sy

Lattice-based sequential aggregate signatures with lazy verification

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The Journal of China Universities of Posts and Telecommunications 2015年第6期22卷 36-44页

作者： Zhang Yanhua Hu Yupu jiang mingming Xue Lili State Key Laboratory of Integrated Service Networks Xidian University School of Computer Science and Technology Huaibei Normal University

This paper proposes the first lattice-based sequential aggregate signature （SAS） scheme with lazy verification that is provably secure in the random oracle model. As opposed to large integer factoring and discrete logarithm based systems, the security of the construction relies on worst-case lattice problem, namely, under the small integer solution （SIS） assumption. Generally speaking, SAS schemes enable any group of signers ordered in a chain to sequentially combine their signatures such that the size of the aggregate signature is much smaller than the total size of all individual signatures. Unlike prior such proposals, the new scheme does not require a signer to retrieve the keys of other signers and verify the aggregate-so-far before adding its own signature, and the signer can add its own signature to an unverified aggregate and forward it along immediately, postponing verification until load permits or the necessary public keys are obtained. Indeed, the new scheme does not even require a signer to know the public keys of other signers.

关键词： sequential aggregate signatures lattice-based cryptography lazy verification small integer solution

Construction of a key-dependent message secure symmetric encryption scheme in the ideal cipher model

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Frontiers of Computer Science 2014年第3期8卷 469-477页

作者： Qiqi LAI Yuan CHEN Yupu HU Baocang WANG mingming jiang State Key Laboratory of Integrated Service Networks Xidian University Xi'an 710071 China

Key-dependent message （KDM） security is an important security issue that has attracted much research in recent years. In this paper, we present a new construction of the symmetric encryption scheme in the the ideal cipher model （ICM）; we prove that our scheme is KDM secure against active attacks with respect to arbitrary polynomialtime challenge functions. Our main idea is to introduce a universal hash function （UHF） h as a random value for each encrypfion, and then use s = h（sk） as the key of the ideal cipher F, where sk is the private key of our symmetric encryption scheme. Although many other schemes that are secure against KDM attacks have already been proposed, in both the ideal standard models, the much more significance of our paper is the simplicity in which we implement KDM security against active attacks.

关键词： symmetric encryption key-dependent message,challenge function universal hash function ideal cipher model

Lattice-based certificateless encryption scheme

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Frontiers of Computer Science 2014年第5期8卷 828-836页

作者： mingming jiang Yupu HU Hao LEI Baocang WANG Qiqi LAI State Key Laboratory of Integrated Service Networks Xidian University Xi'an 710071 China Security and Privacy Lab CRDU Huawei Technologies Co. LTD. Beijing 100095 China

Certificateless public key cryptography （CL- PKC） can solve the problems of certificate management in a public key infrastructure （PKI） and of key escrows in identity-based public key cryptography （ID-PKC）. In CL- PKC, the key generation center （KGC） does not know the private keys of all users, and their public keys need not be cer- tificated by certification authority （CA）. At present, however, most certificateless encryption schemes are based on large in- teger factorization and discrete logarithms that are not secure in a quantum environment and the computation complexity is high. To solve these problems, we propose a new certificate- less encryption scheme based on lattices, more precisely, us- ing the hardness of the learning with errors （LWE） problem. Compared with schemes based on large integer factoriza- tion and discrete logarithms, the most operations are matrix- vector multiplication and inner products in our scheme, our approach has lower computation complexity. Our scheme can be proven to be indistinguishability chosen ciphertext attacks （IND-CPA） secure in the random oracle model.

关键词： lattice-based cryptography LWE identity-based encryption (IBE) post-quantum cryptography certifi-cateless encryption

Crustal S-velocity structure and radial anisotropy beneath the southern part of central and western North China Craton and the adjacent Qilian Orogenic Belt from ambient noise tomography

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Science China Earth Sciences 2017年第10期60卷 1752-1768页

作者： LING Yuan CHEN Ling WEI ZiGen jiang mingming WANG Xu State Key Laboratory of Lithospheric Evolution Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China College of Earth Sciences University of Chinese Academy of Sciences Beijing 100049 CAS Center for Excellence in Tibetan Plateau Earth Sciences Beijing 100101 China State Key Laboratory of Geodesy and Earth's Dynamics Institute of Geodesy and Geophysics Chinese Academy of Sciences Wuhan 430077 China Key Laboratory of the Earth and Planetary Physics Chinese Academy of Sciences Beijing 100029 China

The crustal S-velocity structure and radial anisotropy along a dense linear portable seismic array with 64 broadband seismic stations were investigated from ambient noise tomography with about one-year-long ambient noise recordings. The array transverses the southern part of the central North China Craton(CNCC) and western NCC(WNCC) from east to west and reaches the adjacent Qilian Orogenic Belt(QOB). The phase velocity structures of Rayleigh waves at 5–35 s and Love waves at 5–30 s were measured. The crustal S-velocity structures(Vsv and Vsh) were constructed from the dispersion data(Rayleigh and Love waves,respectively) from point-wise linear inversion with prior information of the Moho depth and average crustal Vp/Vs ratio. The radial anisotropy along the profile was calculated based on the discrepancies between Vsv and Vsh as 2×(***)/(Vsh+Vsv). The results show distinct structural variations in the three major tectonic units. The crustal architecture in the southern CNCC is complicated and featured with wide-distributed low-velocity zones(LVZs), which may be a reflection of crustal modification resulting from Mesozoic-Cenozoic tectonics and magmatic activities. The pronounced positive radial anisotropy in the lower-lowermost crust beneath the Shanxi-Shaanxi Rift and the neighboring areas could be attributed to the underplating of mantle mafic-ultramafic materials during the Mesozoic-Cenozoic tectonic activation. In southern Ordos, the overall weak lateral velocity variations, relative high velocity and large-scale positive radial anisotropy in mid-lower crust probably suggest that the current crustal structure has preserved its Precambrian tectonic characteristics. The low-velocity westward-dipping sedimentary strata in the Ordos Block could be attributed to the Phanerozoic whole-basin tilting and the uneven erosion since late Cretaceous. Integrated with previous studies, the systematic comparison of crustal architecture was made between the southern and nor

关键词： North China Craton Qilian Orogenic Belt Ambient noise tomography Crustal S-velocity structure Radial anisotropy

Coseismic deformation of the 2020 Yutian MW 6.4 earthquake from Sentinel-1A and the slip inversion

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Earthquake Research Advances 2021年第2期1卷 26-32页

作者： Xin jiang Wei Li Shijie Wang mingming jiang Faculty of Geomatics Lanzhou Jiaotong UniversityLanzhou730070China Nation-Local Joint Engineering Research Center of Technologies and Applications for National Geographic State Monitoring Lanzhou730070China Gansu Provincial Engineering Laboratory for National Geographic State Monitoring Lanzhou730070China

A remarkable earthquake struck Yutian,China on June 26th,***,we use Sentinel-1 images to investigate the deformation induced by this *** invert the InSAR observations using a two-step approach:a nonlinear inversion to constrain fault geometries with uniform slip based on the rectangular plane dislocation in an elastic half-space,followed by a linear inversion to retrieve the slip distribution on the fault *** results show that the maximum LOS displacement is 22.6 cm,and the fault accessed to the ruptured characteristics of normal faults with the minor left-lateral strike-slip *** fault model indicates a 210*** main rupture zone concentrates in the depth of 5-15 km,and the fault slip peaks at 0.89 m at the depth of 9 ***,we calculate the variation of the static Coulomb stress based on the optimal fault model,the results suggest that the Coulomb stress of the Altyn Tagh fault and other neighboring faults has increased and more attention should be paid to possible seismic risks.

关键词： Yutian earthquake InSAR Fault slip Static coulomb stress

High-mobility induced high-performance self-powered ultraviolet photodetector based on single ZnO microwire/PEDOT:PSS heterojunction via slight ga-doping

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Journal of Materials Science & Technology 2021年第34期93卷 33-40页

作者： Peng Wan mingming jiang Tong Xu Yang Liu Caixia Kan College of Science MIIT Key Laboratory of Aerospace Information Materials and PhysicsKey Laboratory for Intelligent Nano Materials and DevicesNanjing University of Aeronautics and AstronauticsNo.29 Jiangjun RoadNanjing 211106P.R.China

Semiconductor micro/nanostructures with broad bandgap can provide powerful candidates for fabricating ultraviolet photodetectors(PDs)due to their proper bandgap,unique optoelectronic properties,large surface-to-volume ratio and good ***,semiconducting micro/nanostructures suffer from low electron conductivity and abundant surface defects,which greatly limits their practical application in developing *** this work,an ultraviolet PD consisting of single Ga-doped ZnO microwire(ZnO:Ga MW)and p-type poly(3,4 ethylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS)was *** exposed to ultraviolet illumination,the PD exhibits excellent performance(responsivity~185 m A/W,detectivity~2.4×10^(11) Jones,and fast response speed of~212μs for rise time and~387μs for decay time)under self-driven *** with that of an undoped Zn O MWbased PD,the responsivity and detectivity of ZnO:Ga MW/PEDOT:PSS PD are significantly enhanced over 400%and 600%,*** to the incorporation of Ga element,the charge transport properties of a ZnO:Ga MW,specifically for the mobility,are effectively enhanced,which can substantially facilitate the generation,separation,transport and harvest efficiency of photo-generated carriers in the asfabricated ***,the Ga-incorporation improves the crystalline quality of MWs and reduces surface state density,further suggesting a high-quality ZnO:Ga MW/PEDOT:PSS *** work provides a potential approach for designing high-performance self-powered ultraviolet PDs from the aspect of enhancing carrier transport through fine doping.

关键词： UV Photodetectors Self-powered Mobility High performance Microwire