Nanjing University of Science and Technology
Nanjing, China

Nanjing University of Science and Technology or NUST is one of the national key universities under the Ministry of Industry and Information Technology of China. The university was derived from the Institute of Military Engineering of the PLA, which was the highest institution of military technology in China established in 1953. The institute was successively called Artillery Engineering Institute, Engineering Institute of Eastern China, and East China Institute of Technology, and finally to its current name in 1993. It is a science-oriented university located in Xuanwu District in the east suburban area of Nanjing, China. The university places emphasis on both education and research, and is listed in the national 211 Project. The main campus is located in 200 Xiaolingwei, Xuanwu district, Nanjing, Jiangsu Province, China. Wikipedia.

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Nanjing University of Science and Technology | Date: 2017-08-16

A TiAl intermetallic compound single crystal material and a preparation method therefor are disclosed. The alloy composition of the material comprises Ti_(a)Al_(b)Nb_(c)(C, Si)_(d), wherein 43b49, 2c10, a+b+c=100, and 0d1 (at. %).

Tang J.,Nanjing University of Science and Technology
IEEE Transactions on Pattern Analysis and Machine Intelligence | Year: 2017

Age progression is defined as aesthetically re-rendering the aging face at any future age for an individual face. In this work, we aim to automatically render aging faces in a personalized way. Basically, for each age group, we learn an aging dictionary to reveal its aging characteristics (e.g., wrinkles), where the dictionary bases corresponding to the same index yet from two neighboring aging dictionaries form a particular aging pattern cross these two age groups, and a linear combination of all these patterns expresses a particular personalized aging process. Moreover, two factors are taken into consideration in the dictionary learning process. First, beyond the aging dictionaries, each person may have extra personalized facial characteristics, e.g. mole, which are invariant in the aging process. Second, it is challenging or even impossible to collect faces of all age groups for a particular person, yet much easier and more practical to get face pairs from neighboring age groups. To this end, we propose a novel Bi-level Dictionary Learning based Personalized Age Progression (BDL-PAP) method. Here, bi-level dictionary learning is formulated to learn the aging dictionaries based on face pairs from neighboring age groups. Extensive experiments well demonstrate the advantages of the proposed BDL-PAP over other state-of-the-arts in term of personalized age progression, as well as the performance gain for cross-age face verification by synthesizing aging faces. IEEE

Su T.-W.,University of California at Los Angeles | Xue L.,University of California at Los Angeles | Xue L.,Nanjing University of Science and Technology | Ozcan A.,University of California at Los Angeles
Proceedings of the National Academy of Sciences of the United States of America | Year: 2012

Dynamic tracking of human sperms across a large volume is a challenging task. To provide a high-throughput solution to this important need, here we describe a lensfree on-chip imaging technique that can track the three-dimensional (3D) trajectories of >1,500 individual human sperms within an observation volume of approximately 8-17 mm3. This computational imaging platform relies on holographic lensfree shadows of sperms that are simultaneously acquired at two different wavelengths, emanating from two partially-coherent sources that are placed at 45° with respect to each other. This multiangle and multicolor illumination scheme permits us to dynamically track the 3D motion of human sperms across a field-of-view of >17 mm2 and depth-of-field of approximately 0.5-1 mm with submicron positioning accuracy. The large statistics provided by this lensfree imaging platform revealed that only approximately 4-5% of the motile human sperms swim along well-defined helices and that this percentage can be significantly suppressed under seminal plasma. Furthermore, among these observed helical human sperms, a significant majority (approximately 90%) preferred right-handed helices over left-handed ones, with a helix radius of approximately 0.5-3 μm, a helical rotation speed of approximately 3-20 rotations?s and a linear speed of approximately 20-100 μm?s. This high-throughput 3D imaging platform could in general be quite valuable for observing the statistical swimming patterns of various other microorganisms, leading to new insights in their 3D motion and the underlying biophysics.

Gao L.,Nanjing University of Science and Technology
Small | Year: 2017

Graphene-like single- or few-layer semiconductors, such as dichalcogenides and buckled nanocrystals, possess direct and tunable bandgaps, and excellent electrical, optical, mechanical and thermal properties. This unique set of desirable properties of 2D semiconductors has triggered great interest in developing ultra-thin 2D flexible electronic devices, which ranges from realizing better material quality and simplified fabrication processes, to improving device performance and expanding the application horizon. The most explored 2D flexible devices based on transition metal dichalcogenides and black phosphorous include field-effect transistors, optoelectronics, electronic sensors and supercapacitors. By taking advantage of a large portfolio of materials and properties of 2D crystals, a new generation of low-cost, high-performance, transparent, flexible and wearable devices looks attractive and promising in advancing flexible electronic technologies. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Zhu Y.,Nanjing University of Science and Technology
IEEE Transactions on Systems, Man, and Cybernetics, Part B: Cybernetics | Year: 2011

In the case that a system is affected by fuzzy factors, a fuzzy optimal-control problem is proposed. A fuzzy optimal-control problem for a multistage fuzzy system is considered to optimize the expected value of a fuzzy objective function subject to a multistage fuzzy system where, at every stage, the system is disturbed by a fuzzy variable. Based on Bellman's Principle of Optimality, a recurrence equation for the problem is presented. A linear quadratic fuzzy optimal-control problem is shown to have an exact solution by the recurrence equation if the system is affected by triangular fuzzy variables. For general cases, two methods, the hybrid intelligent algorithm and the finite-search method, are established to approximate the solutions of the problem. Finally, an example is used to show that these two methods are effective to solve a fuzzy optimal-control problem for a multistage fuzzy system. © 2011 IEEE.

Gao W.,Nanjing University of Science and Technology
Optics Letters | Year: 2010

The effect of the two-point spatial correlation function of human tissue on the spectrum of scattered light is considered within the accuracy of the first Born approximation. An expression for the maximum of the spectrum of the scattered light at various scattering angles is derived. It is shown that for most biological tissues the spectrum of the backscattered light is centered at a higher frequency with respect to the incident spectrum. © 2010 Optical Society of America.

Zhu Y.,Nanjing University of Science and Technology | Wei Y.,Nanjing University of Science and Technology
Chemical Science | Year: 2014

A novel Cu-catalyzed direct alkenylation of simple alkanes with styrenes was described. In the presence of a catalytic amount of Cu(OTf)2, a diverse range of alkenes undergo coupling with cycloalkanes to produce (E)-alkyl alkenes. This transformation is proposed to proceed via a radical process. This journal is © the Partner Organisations 2014.

Chen G.,Nanjing University of Science and Technology
Nature Materials | Year: 2016

TiAl alloys are lightweight, show decent corrosion resistance and have good mechanical properties at elevated temperatures, making them appealing for high-temperature applications. However, polysynthetic twinned TiAl single crystals fabricated by crystal-seeding methods face substantial challenges, and their service temperatures cannot be raised further. Here we report that Ti–45Al–8Nb single crystals with controlled lamellar orientations can be fabricated by directional solidification without the use of complex seeding methods. Samples with 0° lamellar orientation exhibit an average room temperature tensile ductility of 6.9% and a yield strength of 708 MPa, with a failure strength of 978 MPa due to the formation of extensive nanotwins during plastic deformation. At 900 °C yield strength remains high at 637 MPa, with 8.1% ductility and superior creep resistance. Thus, this TiAl single-crystal alloy could provide expanded opportunities for higher-temperature applications, such as in aeronautics and aerospace. © 2016 Nature Publishing Group

Han Y.,Nanjing University of Science and Technology
IEEE Transactions on Signal Processing | Year: 2012

A particle filter approach is proposed for adaptive narrowband beamforming in the presence of strong interference and uncertain steering vector of interest signal. From the viewpoint of subspace decomposition, we first describe the known subspace projection beamformer as an orthogonal component of the steering vector that is perpendicular to the interference space. Then a Rao-Blackwellized particle filter algorithm is designed to estimate the subspace projection beamforming weights. All steps including the important sampling, weight updating, resampling and analytical computation have been discussed in detail. Finally, the overall adaptive beamforming algorithm is summarized and the computational complexity analysis is presented. The main contribution of this paper is to apply and formulate Rao-Blackwellized particle filtering to estimate the distribution over the subspace projection beamforming weights. Different from other two particle-filter-based beamformers proposed by Li and Chandrasekar, it is a STI-based method with unknown source steering vector. The sampled state variables are the signal power, noise power and a model parameter for beamformer weights transition; the marginalized analytical state variables are the subspace projection beamforming weights; and the measurements are a series of constructed signal samples by using the estimated projection operator and random noise loading. Numerical simulations show that the proposed beamformer outperforms linearly constrained minimum variance, subspace projection, Bayesian and other two particle-filter-based beamformers. After convergence, it has similar performance to the optimal max-SINR beamformer which uses the true steering vector and ideal interference-plus-noise covariance matrix. © 2012 IEEE.

Nanjing University of Science, Technology and Zhou | Date: 2013-03-06

A bidirectional pressure self-balancing stop valve includes a valve body (1), a valve disc(4), a press ring(16), a valve bonnet(17), a valve rod(19) and a balance hole(21).The valve disc (4) is located inside a chamber of the valve body(1), the press ring (16) is disposed on the upper side of the chamber of the valve body(1). The excircle of the valve disc(4), the press ring(16) and the valve body(1) form an annular groove, inside which is disposed with a composite seal ring that is high temperature resistant or corrosion resistant. The composite seal ring includes an upper washer(14), an upper seal ring(13), an upper distance ring(12), a blocking ring(11), a lower distance ring(10), a lower seal ring(8) and a lower washer(7) from top to bottom. A lower end surface (22) of the upper washer (14) and an upper end surface (25) of the upper distance ring (12) are in the shapes of a conical surface, an inclined plane or a spherical surface, formed by squeezing the upper seal ring (13) towards the internal direction of the valve disc. A lower end surface (26) of the upper distance ring (12) and an upper end surface (28) of the lower distance ring (10) are in the shapes of a cylindrical surface, a conical surface, an inclined plane or a spherical surface, formed by squeezing the blocking ring (11) towards the external direction of the valve body; and a lower end surface (29) of the lower distance ring (10) and an upper end surface (32) of the lower washer (7) are in the shapes of a conical surface, an inclined plane or a spherical surface, formed by squeezing the lower seal ring (8) towards the internal direction of the valve disc. The stop valve have pressure self sealing characteristic and long reliable sealing quality.

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