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1Fundamentals of phase-only liquid crystal on silicon (LCOS) devices显示文摘This paper describes the fundamentals of phase-only liquid crystal on silicon(LCOS)technology,which have not been previously discussed in detail.This technology is widely utilized in high efficiency applications for real-time holography and diffractive optics.The paper begins with a brief introduction on the developmental trajectory of phase-only LCOS technology,followed by the correct selection of liquid crystal(LC)materials and corresponding electro-optic effects in such devices.Attention is focused on the essential requirements of the physical aspects of the LC layer as well as the indispensable parameters for the response time of the device.Furthermore,the basic functionalities embedded in the complementary metal oxide semiconductor(CMOS)silicon backplane for phase-only LCOS devices are illustrated,including two typical addressing schemes.Finally,the application of phase-only LCOS devices in real-time holography will be introduced in association with the use of cutting-edge computer-generated holograms.Zichen Zhang Zheng You Daping Chu 2014Light(Science & Applications)2014,3,1:25
2Porous Graphene Microflowers for High-Performance Microwave Absorption显示文摘Graphene has shown great potential in microwave absorption(MA) owing to its high surface area, low density,tunable electrical conductivity and good chemical stability.To fully realize graphenes& MA ability, the microstructure of graphene should be carefully addressed. Here we prepared graphene microflowers(Gmfs) with highly porous structure for high-performance MA filler material. The efficient absorption bandwidth(reflection loss B-10 dB) reaches 5.59 GHz and the minimum reflection loss is up to -42.9 dB, showing significant increment compared with stacked graphene. Such performance is higher than most graphene-based materials in the literature. Besides, the low filling content(10 wt%) and low density(40–50 mg cm^(-3))are beneficial for the practical applications. Without compounding with magnetic materials or conductive polymers,Gmfs show outstanding MA performance with the aid of rational microstructure design. Furthermore, Gmfs exhibit advantages in facile processibility and large-scale production compared with other porous graphene materials including aerogels and foams.Chen Chen Jiabin Xi Erzhen Zhou Li Peng Zichen Chen Chao Gao 2018Nano-Micro Letters2018,10,2:20
3Dynamic Crushing Strength Analysis of Auxetic Honeycombs显示文摘The in-plane dynamic crushing behavior of re-entrant honeycomb is analyzed and compared with the conventional hexagon topology.Detailed deformation modes along two orthogonal directions are examined,where a parametric study of the effect of impact velocity and cell wall aspect ratio is performed.An analytical formula of the dynamic crushing strength is then deduced based on the periodic collapse mechanism of cell structures.Comparisons with the finite element results validate the effectiveness of the proposed analytical method.Numerical results also reveal higher plateau stress of re-entrant honeycomb over conventional hexagon topology,implying better energy absorption properties.The underlying physical understanding of the results is emphasized,where the auxetic effect(negative Poisson's ratio) induced in the re-entrant topology is believed to be responsible for this superior impact resistance.Xiuhui Hou Zichen Deng Kai Zhang 2016Acta Mechanica Solida Sinica2016,29,5:16
41990—2017年中国伤害负担:2017年全球疾病负担研究结果(摘译)显示文摘伤害是全球性的公共卫生挑战,涉及各年龄组和不同性别的人群。过去三十年来,中国经济快速发展,人口老龄化趋势加重,社会呈现出城镇化、机动化和老龄化等特征。随着人们生活环境和生活方式的改变,伤害已跃居人群致死原因第五位,仅排在恶性肿瘤、心脑血管疾病、呼吸系统疾病和心肌梗死之后。据估计,中国每年在伤害方面消耗的直接医疗费用约为650亿元人民币.林泽婷(译) 吕来文(译) 黄晓晴(译) 李丽萍(审校) Duan Leilei Ye Pengpeng Juanita A Haagsma Jin Ye Wang Yuan Er Yuliang Deng Xiao Gao Xin Ji Cuirong Wang Linhong Marlena S Bannick W Cli Mountjoy-Venning Caitlin N Hawley Zichen Liu Mari Smith Spencer L James Theo Vos Christopher J L Murray 2020伤害医学(电子版)2020,9,2:15
5Inhibitory effect of human telomerase antisense oligodeoxyribonucleotides on the growth of gastric cancer cell lines in variant tumor pathological subtype显示文摘AIM: To investigate the inhibitory effect of specialized human telomerase antisense oligodeoxyribonucleotides on the growth of well (MKN-28), moderately (SGC-7901)and poorly (MKN-45) differentiated gastric cancer cell lines under specific conditions and its inhibition mechanism,and to observe the correlation between the growth inhibition ratio and the tumor pathologic subtype of gastric cancer cells.METHODS: Telomerase activity in three gastric cancer cell lines of variant tumor pathologic subtype was determined by modified TRAP assay before and after the specialized human telomerase antisense oligodeoxyribonucleotides were dealt with under specific conditions. Effect of antisense oligomer under specific conditions of the growth and viability of gastric cancer cell lines was explored by using trypan blue dye exclusion assay, and cell apoptosis was detected by cell morphology observation, flow cytometry and TUNEL assay.RESULTS: Telomerase activity was detected in well,moderately and poorly differentiated gastric cancer cell lines (the quantification expression of telomerase activity was 43.7TPG, 56.5TPG, 76.7TPG, respectively).Telomerase activity was controlled to 30.2TPG, 36.3TPG and 35.2TPG for MKN-28, SGC-7901 and MKN-45 cell lines respectively after treatment with human telomerase antisense oligomers at the concentration of 5 μmol/L, and was entirely inhibited at 10 μmol/L, against the template region of telomerase RNA component, whereas no inhibition effect was detected in missense oligomers (P<0.05). After treatment with antisense oligomers at different concentrations under specific conditions for 96 h, significant growth inhibition effects were found in MKN-45 and SGC-7901gastric cancer cell lines (the inhibition ratio was 40.89%and 71.28%), but not in MKN-28 cell lines (15.86%). The ratio of inactive SGC-7901 cells increased according to the prolongation of treatment from 48 to 96 h. Missense oligomers could not lead to the same effect (P<0.05).Apoptosis of SGC-7901 and MKN-45 cells was detected not only by morphology and TUNEL assay but also by flow cytometry. The apoptotic rate reached 33.56% for SGC-7901 cells and 44.75% for MKN-45 cells.CONCLUSION: The viability and proliferation of gastric cancer cells can be inhibited by antisense telomerase oligomers. The growth inhibition of gastric cancer cells is correlated with concentration, time and sequence specialty of antisense oligomers. The inhibition mechanism of antisense human telomerase oligomers depends not only on the sequence specialty but also on the biological characteristics of gastric cancer cell lines.JingYe Yun-LinWu ShuZhang ZiChen Li-XiaGuo Ruo-YuZhou HongXie 2005World Journal of Gastroenterology2005,11,15:9
6MOTION VELOCITY SMOOTH LINK IN HIGH SPEED MACHINING显示文摘To deal with over-shooting and gouging in high speed machining,a novel approach for velocity smooth link is proposed. Considering discrete tool path,cubic spline curve fitting is used to find dangerous points,and according to spatial geometric properties of tool path and the kinematics theory,maximum optimal velocities at dangerous points are obtained. Based on method of velocity control characteristics stored in control system,a fast algorithm for velocity smooth link is analyzed and formulated. On-line implementation results show that the proposed approach makes velocity changing more smoothly compared with traditional velocity control methods and improves producti-vity greatly.REN Kun FU Jianzhong CHEN Zichen 2007Chinese Journal of Mechanical Engineering2007,20,2:9
7Attack on Libert et al.'s ID-Based Undeniable Signature Scheme显示文摘LI Zichen YAN Yunsheng ZHANG Juanmei 2008Chinese Journal of Electronics2008,17,4:7
8Coupling effects of tungsten and molybdenum on microstructure and stress-rupture properties of a nickel-base cast superalloy显示文摘In order to comprehensively understand the forming mechanism of abnormal phases solidified in a nickel-base cast superalloy with additives of tungsten and molybdenum, the coupling effects of W and Mo on the microstructure and stress-rupture properties were investigated in this paper. The results indicated that the precipitation of primary α-(W, Mo) phase depended tremendously on the amount of W and Mo addition. When the total amount of W and Mo was greater than 5.79 at%, α-(W, Mo) phase became easily precipitated in the alloy.With increasing of Mo/W ratio, the dendrite-like α-(W, Mo) phases were apt to convert into small bars or blockylike phases at the vicinities of γ′/γ eutectic. The morphological changes of α-(W, Mo) phase can be interpreted as the non-equilibrium solidification of W and Mo in the alloy. Since the large sized α-(W, Mo) phase has detrimental effects on stress-rupture properties in as-cast conditions, secondary cracks may mainly initiate at and then propagate along the interfaces of brittle phases and soft matrix. During exposing at 1100 ℃ for 1000 h, the α-(W, Mo) phases transformed gradually into bigger and harder M_6C carbide, which results in decreasing of stress-rupture properties of the alloy. Finally, the alloy with an addition of 14W-1Mo(wt%) maintained the longest stress lives at high temperatures and therefore it revealed the best microstructure stability after 1100 ℃/1000 h thermal exposure.Tongjin Zhou Wei Feng Huibin Zhao Yu Meng Huaxia Zhang Hongsheng Ding Zichen Wang 2018Progress in Natural Science:Materials International2018,28,1:7
9Targeted Fully Homomorphic Encryption Based on a Double Decryption Algorithm for Polynomials显示文摘Several public-key encryption schemes used to solve the problem of ciphertext data processing on the fly are discussed.A new targeted fully homomorphic encryption scheme based on the discrete logarithm problem is presented.Public-key encryption cryptosystems are classified to examine homomorphic encryption.Without employing techniques proposed by Gentry such as somewhat homomorphic and bootstrapping techniques,or relinearization technique proposed by Brakerski et al.,a new method called'Double Decryption Algorithm'is employed in our cryptography to satisfy a fully or targeted fully homomorphic property.Inspired by ElGamal and BGN cryptography,we obtain the desired fully homomorphic property by selecting a new group and adding an extra component to the ciphertext.Proof of semantic security is also demonstrated.Yatao Yang Shuang Zhang Junming Yang Jia Li Zichen Li 2014Tsinghua Science and Technology2014,19,5:6
10Electrical activities of neural systems exposed to sinusoidal induced electric field with random phase显示文摘The brain neural system is often disturbed by electromagnetic and noise environments, and research on dynamic response of its interaction has received extensive attention. This paper investigates electrical activity of Morris-Lecar neural systems exposed to sinusoidal induced electric field(IEF) with random phase generated by electromagnetic effect. By introducing a membrane depolarization model under the effect of random IEF, transition state of firing patterns, including mixed-mode oscillations(MMOs) with layered inter-spike intervals(ISI) and intermittency with a power law distribution in probability density function of ISI, is obtained in a single neuron. Considering the synergistic effects of frequency and noise, coherence resonance is performed by phase noise of IEF under certain parameter conditions. For the neural network without any internal coupling, we demonstrate that synchronous oscillations can be induced by IEF coupling, and suppression of synchronous spiking is achieved effectively by phase noise of IEF. Results of the study enrich the dynamical response to electromagnetic induction and provide insights into mechanisms of noise affecting information coding and transmission in neural systems.DU Lin CAO ZiLu LEI YouMing DENG ZiChen 2019Science China(Technological Sciences)2019,62,7:5
11First-generation EGFR tyrosine kinase inhibitor therapy in 106 patients with compound EGFR-mutated lung cancer: a single institution’s clinical practice experience显示文摘Background:The antitumour efficacy of tyrosine kinase inhibitors(TKIs)in lung cancer patients with compound epidermal growth factor receptor(EGFR)mutations has not been resolved.Our study summarizes a single institutional experience of first-generation TKI therapy for lung cancers with compound EGFR mutations.Methods:A total of 106 consecutive patients with tumours bearing compound EGFR mutations were identified between January 2012 and May 2016;all patients received first-generation TKI therapy.Deletions in exon 19 and the L858R point mutation in exon 21 were considered common mutations;T790M was considered separately because of its association with TKIs resistances.Any other mutation was defined as a rare mutation.Patients were divided as follows:double common mutations(group A);common plus T790M mutations(group B);common plus rare muta-tions(group C);double rare mutations(group D);and rare plus T790M mutations(group E).A separate group of 115 consecutive patients with a single common mutation was created for comparative analysis(group F).Results:The frequency of patients with compound EGFR was 2.9%(114/3925)and their response rate to first-genera-tion TKIs was 50.9%,which was not significantly different from group F(67.0%,P=0.088).The progression-free survival(PFS)of the 106 patients receiving TKI therapy was worse than that of group F(median,9.1 vs.13.0 months,respec-tively;P<0.001).The PFS of the compound mutation group was shorter than that of the single common mutation group(median,10.1 months in group A,P=0.240;9.1 months in group B,P<0.001;9.6 months in group C,P=0.010;6.5 months in group D,P=0.048;5.4 months in group E,P=0.017).Patients with a co-occurring mutation in exon 20(excluding T790M)exhibited significantly worse PFS than the patients with other compound mutations or with a single common mutation(median,6.5 vs.9.1 vs.13.0 months,respectively,P=0.002).Conclusions:There was significant heterogeneity among the compound EGFR mutations and their response to first-generation TKIs.Individualized treatment in clinical practice should be considered for each case.Xiangyang Yu Xuewen Zhang Zichen Zhang Yongbin Lin Yingsheng Wen Yongqiang Chen Weidong Wang Lanjun Zhang 2018Cancer Communications2018,38,1:5
12In situ synthesis and modification of calcium carbonate nanoparticles via a bobbling method显示文摘Modified calcium carbonate (CaCO3) nanoparticles with cubic- and spindle-like configuration were synthesized in situ by the typical bobbling (gas-liquid-solid) method. The modifiers, such as sodium stearate, octadecyl dihydrogen phosphate (ODP) and oleic acid (OA), were used to obtain hydrophobic nanoparticles. The different modification effects of the modifiers were investigated by measuring the active ratio, whiteness and the contact angle. Moreover, transmission electron microscopy (TEM), X-ray diffraction (XRD) and thermogravimetry analysis (TGA analysis) were employed to characterize the obtained products. A preliminary reaction mechanism was discussed. According to the results, the active ratio of CaCO3 modified by ODP was ca. 99.9% and the value of whiteness was 97.3% when the dosage of modifiers reached 2%. The contact angle was 122.25° for the CaCO3 modified in the presence of sodium stearate, ODP and OA. When modified CaCO3 was filled into PVC, the mechanical properties of products were improved greatly such as rupture intensity, pull intensity and fuse temperature. The compatibility and affinity between the modified CaCO3 nanoparticles and the organic matrixes were greatly improved.ZHAO LiNa FENG JingDong WANG ZiChen 2009Science China Chemistry2009,52,7:5
13Epstein-Barr virus-encoded RNAs as a survival predictor in nasopharyngeal carcinoma显示文摘Ke Kengjian Wang Haiyun Fu Sha Zhang Zichen Duan Liping Liu Dabo Ye Jin 2014Chinese Medical Journal2014,,2:5
14NON-CONTACT MEASUREMENT SYSTEM OF FREEFORM SURFACE AND NURBS RECONSTRUCTION OF MEASUREMENT POINTS显示文摘Based on the development of the non-contact measurement system of free-form surface, NURBS reconstruc-tion of measurement points of freeform surface is effectively realized by modifying the objective function and recursiveprocedure and calculating the optimum number of control points. The reconstruction precision is evaluated through Ja-cobi's transformation method. The feasibility of the measurement system and effectiveness of the reconstruction algo-rithm above are proved by experiment.Li Jian Wang Wen Chen Zichen Institute of Advanced Manufacturing Engineering, Zhejiang University, Hangzhou 310027, China 2002Chinese Journal of Mechanical Engineering2002,15,4:4
15Inhibition of in-stent restenosis after graphene oxide double-layer drug coating with good biocompatibility显示文摘In this study,we designed a double layer-coated vascular stent of 316L stainless steel using an ultrasonic spray system to achieve both antiproliferation and antithrombosis.The coating included an inner layer of graphene oxide(GO)loaded with docetaxel(DTX)and an outer layer of carboxymethyl chitosan(CMC)loaded with heparin(Hep).The coated surface was uniform without aggregation and shedding phenomena before and after stent expanded.The coating treatment was able to inhibit the adhesion and activation of platelets and the proliferation and migration of smooth muscle cells,indicating the excellent biocompatibility and antiproliferation ability.The toxicity tests showed that the GO/DTX and CMC/Hep coating did not cause deformity and organ abnormalities in zebrafish under stereomicroscope.The stents with GO double-layer coating were safe and could effectively prevent thrombosis and in-stent restenosis after the implantation into rabbit carotid arteries for 4–12 weeks.Shuang Ge Yadong Xi Ruolin Du Yuzhen Ren Zichen Xu Youhua Tan Yazhou Wang Tieying Yin Guixue Wang 2019Regenerative Biomaterials2019,6,5:4
16Aberrant seed development in Litchi chinensis is associated with the impaired expression of cell wall invertase genes显示文摘Cell wall invertase(CWIN)are known to play important roles in seed development.However,most reports to date have focused on a single gene family member,and have mainly investigated CWIN functions during the filling stage of seed development.In this study,we found significant lower levels of CWIN protein and activity associated with seed abortion in the Litchi chinensis cultivar“Nuomici.”We identified five litchi CWIN genes and observed that the expression of LcCWIN5 was limited to the flower tissues and decreased sharply with fruit development.Silencing of LcCWIN5 expression before 28 DAA(cell division stage)resulted in perturbed liquid endosperm development,smaller seeds,and higher seed abortion rate,while silencing after 28 DAA(filling stage)had no effect on seed development.In contrast,LcCWIN2 was mostly expressed in the funicle and seed coat,and increased with fruit development.Decreased LcCWIN2 expression and CWIN activity during early seed filling coincided with smaller seeds in the cultivar“Feizixiao.”Silencing of LcCWIN2 caused a reduction in the seed size without inducing seed abortion.We propose that CWIN activity in seed maternal tissues during cell division stage is likely due to LcCWIN5 expression,which regulates early seed development.On the other hand,CWIN activity during the filling stage is due to the expression of LcCWIN2,which may promote carbon import by creating a sucrose gradient.Comparable LcCWIN5 expression,but much lower CWIN activity,detected in the funicle of“Nuomici”is consistent with post-translational regulation.Jieqiong Zhang Zichen Wu Fuchu Hu Lian Liu Xuming Huang Jietang Zhao Huicong Wang 2018Horticulture Research2018,5,1:4
17Elastic Wave Propagation in Lattice Metamaterials with Koch Fractal显示文摘In this study,the wave propagation properties of lattice metamaterials with Koch fractal structures are investigated in terms of band structures and directional wave propagation.The analytical models of lattice metamaterials are established using the finite element method,and the dispersion relation is solved using the Bloch’s theorem.The band structures of the lattice metamaterials with different numbers of iterations are studied,and the group velocities at a selected frequency are calculated to analyze the directional wave propagation characteristics.Furthermore,dynamic responses of the finite structures are calculated using commercial finite element software to verify the band gaps and directional wave propagation behaviors in the lattice metamaterials.The results show that multiple and low band gaps are present in the lattice materials with various geometric parameters of the Koch fractal,and the position of the lowest band gap decreases as the number of iterations increases.The results indicate the potential applications of lattice metamaterials with Koch fractals for vibration isolation and multi-functional design.Pengcheng Zhao Kai Zhang Zichen Deng 2020Acta Mechanica Solida Sinica2020,33,5:4
18Regulating Mechanical Properties of Polymer-Supramolecular Double-Network Hydrogel by Supramolecular Self-assembling Structures显示文摘Main observation and conclusion Polymer-supramolecular double-network hydrogels(PS-DN hydrogels)often show much improved recovery rates than conventional double-network hydrogels because of the fast self-assembling properties,making them attractive candidates for tissue engineering and flexible electronics.However,as the supramolecular network is dynamic and susceptible to break under low strains,the overall mechanical properties of PS-DN hydrogels are still limited.Here,we report the mechanical properties for PS-DN hydrogels can be significantly improved by tuning the supramolecular network structures.A single amino acid change of the self-assembling peptide can tune the assembled structures from nanofiber to nanoribbon.Such a microscopic structural change can greatly increase the Young's modulus(107.4 kPa),fracture stress(0.48 MPa),and toughness(0.38 MJ·m^(–3))of the PS-DN hydrogels.Moreover,the structural change also leads to slightly faster recovery rates(<1 s).We propose that such dramatically different mechanical properties can be understood by the impact of individual peptide rupture events on the overall network connectivity in the two scenarios.Our study may provide new inspirations for combining high mechanical strength and fast recovery in double network hydrogels by tuning the supramolecular network structures.Tiankuo Wang Yu Zhang Zichen Gu Wei Cheng Hai Lei Meng Qin Bin Xue Wei Wang Yi Cao 2021Chinese Journal of Chemistry2021,39,10:4
19Minimum Control Energy of Spatial Beam with Assumed Attitude Adjustment Target显示文摘The dynamic analysis on the ultra-large spatial structure can be simplified drastically by ignoring the flexibility and damping of the structure.However,these simplifications will result in the erroneous estimate on the dynamic behaviors of the ultra-large spatial structure.Taking the spatial beam as an example,the minimum control energy defined by the difference between the initial total energy and the final total energy in the assumed stable attitude state of the beam is investigated by the structure-preserving method proposed in our previous studies in two cases:the spatial beam considering the flexibility as well as the damping effect,and the spatial beam ignoring both the flexibility and the damping effect.In the numerical experiments,the assumed simulation interval of three months is evaluated on whether or not it is long enough for the spatial flexible damping beam to arrive at the assumed stable attitude state.And then,taking the initial attitude angle and the initial attitude angle velocity as the independent variables,respectively,the minimum control energies of the mentioned two cases are investigated in detail.From the numerical results,the following conclusions can be obtained.With the fixed initial attitude angle velocity,the minimum control energy of the spatial flexible damping beam is higher than that of the spatial rigid beam when the initial attitude angle is close to or far away from the stable attitude state.With the fixed initial attitude angle,ignoring the flexibility and the damping effect will underestimate the minimum control energy of the spatial beam.Weipeng Hu Lingjun Yu Zichen Deng 2020Acta Mechanica Solida Sinica2020,33,1:4
20DESIGN OPTIMIZATION FOR TRUSS STRUCTURES UNDER ELASTO-PLASTIC LOADING CONDITION显示文摘在这篇论文,为设计优化的一个方法 elasto 塑料捆绑结构基于参量的变化原则(PVP ) 被建议。优化试图在许可的节点排水量的限制下面发现最小的重量 / 卷答案。Thedesign 优化是有平衡限制(MPEC ) 的数学编程的明确的表达。在优化克服互补限制的数字困难,重复进程,包括二次的编程(QP ) 和更新的进程,被采用著名计算机生产厂商他优化方法。而且, elasto 塑料的弄弯捆绑成员在设计优化被看作限制。combinational 优化策略为排水量限制和弄弯的限制被建议,它包括上面提及的方法和一个最佳的标准。三个数字例子被举证明方法的有效性求婚了。Liu Tao Deng Zichen 2006Acta Mechanica Solida Sinica2006,19,3:4
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