Multi-view Clustering by Spectral Structure Fusion and Novel Low-rank Approximation

Yin Lon,Xiaobo Liu,Simon Murphy 한국인터넷정보학회 2022 KSII Transactions on Internet and Information Syst Vol.16 No.3

In multi-view subspace clustering, how to integrate the complementary information between perspectives to construct a unified representation is a critical problem. In the existing works, the unified representation is usually constructed in the original data space. However, when the data representation in each view is very diverse, the unified representation derived directly in the original data domain may lead to a huge information loss. To address this issue, different to the existing works, inspired by the latest revelation that the data across all perspectives have a very similar or close spectral block structure, we try to construct the unified representation in the spectral embedding domain. In this way, the complementary information across all perspectives can be fused into a unified representation with little information loss, since the spectral block structure from all views shares high consistency. In addition, to capture the global structure of data on each view with high accuracy and robustness both, we propose a novel low-rank approximation via the tight lower bound on the rank function. Finally, experimental results prove that, the proposed method has the effectiveness and robustness at the same time, compared with the state-of-art approaches.

Tunable Low Phase-noise Microwave Generation Utilizing an Optoelectronic Oscillator and a Fiber Bragg Grating

Zhuansun, Xiaobo,Chen, Yiwang,Zhang, Pin,Yin, Qin,Ni, Jiazheng,Dong, Xiaohua Optical Society of Korea 2018 Current Optics and Photonics Vol.2 No.1

A tunable low-phase-noise microwave generation structure that utilizes an optoelectronic oscillator (OEO) and a fiber Bragg grating (FBG) is proposed and experimentally demonstrated in this article. This structure has no particular requirement for the band width of the laser, and its tunability is realized through adjusting the central frequency of the tunable FBG. A detailed theoretical analysis is established and confirmed via an experiment. A high-purity microwave signal with a frequency tunable from 6 to 12 GHz is generated. The single-sideband phase noise of the generated signal at 10.2 GHz is -117.2 dBc/Hz, at a frequency offset of 10 kHz.

Solar spectral management for natural photosynthesis: from photonics designs to potential applications

Shen Lihua,Yin Xiaobo 나노기술연구협의회 2022 Nano Convergence Vol.9 No.36

Photosynthesis is the most important biological process on Earth that converts solar energy to chemical energy (biomass) using sunlight as the sole energy source. The yield of photosynthesis is highly sensitive to the intensity and spectral components of light received by the photosynthetic organisms. Therefore, photon engineering has the potential to increase photosynthesis. Spectral conversion materials have been proposed for solar spectral management and widely investigated for photosynthesis by modifying the quality of light reaching the organisms since the 1990s. Such spectral conversion materials manage the photon spectrum of light by a photoconversion process, and a primary challenge faced by these materials is increasing their efficiencies. This review focuses on emerging spectral conversion materials for augmenting the photosynthesis of plants and microalgae, with a special emphasis on their fundamental design and potential applications in both greenhouse settings and microalgae cultivation systems. Finally, a discussion about the future perspectives in this field is made to overcome the remaining challenges.

Effect of compound coupling agent treatment on mechanical property and water absorption of hollow glass microspheres/epoxy composite

Zhaolin Zhu,Yin Liu,Guiyang Xian,Yan Wang,Chongmei Wu,Xiaobo Peng,Jinxiang Wang,Lingbing Kong 한국고분자학회 2023 Macromolecular Research Vol.31 No.8

Hollow glass microspheres (HGMs), as a reinforcing material to prepare lightweight high-performance composites, have excellent mechanical properties. However, the composites prepared by simply mixing hollow glass microspheres with polymer resin have poor performance. In this study, compound coupling agent-modified HGM/EP composites were prepared by casting process with two silane coupling agents as compound coupling agents. Scanning electron microscopy and infrared (IR) spectroscopy were used to characterize the treated HGM. Meanwhile density, water absorption behavior, and mechanical properties of the modified HGM-filled epoxy composites were examined. It is found that the compound coupling agent could effectively improve the interfacial bonding between HGM and the matrix resin. A new chemical bond was formed between HGM and EP, which was confirmed by IR spectroscopy. Compared with their untreated counterparts, the composites treated with the complex coupling agent exhibited excellent mechanical properties, along with lower density and lower water absorption.

Synthesis and Characterization of Compound Coupling Agent-Modified Hollow Glass Microspheres/Epoxy Composites

Zhaolin Zhu,Yin Liu,Guiyang Xian,Yan Wang,Chongmei Wu,Xiaobo Peng,Lingbing Kong 한국섬유공학회 2023 Fibers and polymers Vol.24 No.9

In this study, hollow glass microsphere/epoxy composites modified with compound coupling agent of titanate (CS201) and silane (KH540) were prepared and characterized. The addition of the compound coupling agent improves the interfacial bonding between the microbeads and the resin matrix. Scanning electron microscopy results indicated that the compound coupling agent can effectively reduce the number of voids between the microbeads and the resin. FTIR and XPS spectra showed that new chemical bonds were formed between the hollow glass microspheres and resin, which enhanced the interfacial bonding between them. By testing the water absorption and mechanical properties of the composites, it found that the addition of the hybrid coupling agent can reduce the water absorption to a minimum level of 1.184%. Due to the improvement of interfacial compatibility, mechanical properties of the composites were enhanced, (with tensile strength of 43.03 MPa, bending strength of 44.56 MPa, bending modulus of 1407 MPa and compressive strength of 81.55 MPa). When the content of the coupling agent was 5% and the volume ratio of CS201 to KH540 was 1:1, the synergistic enhancement effect was the most significant.

Caenorhabditis elegans as a useful model to assess the effect of spermiogenesis induced by three teratogens

Yunhui Li,Minhui Zhang,Xiaobo Li,Juan Zhang,Ran Liu,Geyu Liang,Yuepu Pu,Lihong Yin 대한독성 유전단백체 학회 2015 Molecular & cellular toxicology Vol.11 No.2

Caenorhabditis elegans (C. elegans), with homologous genes and conservative spermiogenesis in mammals, has a series of advantages to illuminate and study many biological processes including reproductive toxicity. So it is a very useful model to assess environmental and ecological toxicity. Here we introduce C. elegans as an animal model and three known mammalian sperm teratogens methyl methanesulfonate, mitomycin C and cyclophosphamide as experimental materials to elucidate the efficient and reliability for the assessment of chemicals altering spermiogenesis. The results showed that, with the aid of the brood size, spermatids activation, trans-activation, sperm competition as the endpoints, the adverse effects of three teratogens on C. elegans were detected. Thus, while the data of chemicals induced spermiogenesis abnormality is incomplete, we speculated that C. elegans could be a useful animal model to explore the effects on spermiogenesis of chemicals. And we propose an increased application of C. elegans that complements other model system in the reproductive toxicity.

O-alkylation of disodium salt of diethyl 3,4-dihydroxythiophene-2,5-dicarboxylate with 1,2-dichloroethane catalyzed by ionic type phase transfer catalyst and potassium iodide

Huasheng Lu,Hengbo Yin,Aili Wang,Jun Shen,Xiaobo Yan,Yumin Liu,Changhua Zhang 한국화학공학회 2014 Korean Journal of Chemical Engineering Vol.31 No.1

Diethyl 3,4-ethylenedioxythiophene-2,5-dicarboxylate was efficiently synthesized via the O-alkylation of disodium salt of diethyl 3,4-dihydroxythiophene-2,5-dicarboxylate with 1,2-dichloroethane over ionic type phase transfer catalysts, such as tetrabutyl ammonium bromide and benzyltriethyl ammonium chloride. The ionic type phase transfer catalysts showed higher catalytic activities than the nonionic type phase transfer catalysts, such as triethylamine,pyridine, 18-crown-6, and polyethylene glycol 400/600, in the O-alkylation reaction. The conversion of the disodium salt of more than 97% and the selectivity of diethyl 3,4-ethylenedioxythiophene-2,5-dicarboxylate of more than 98%were achieved when the O-alkylation reaction was synergistically catalyzed by tetrabutyl ammonium bromide and potassium iodide.

Preparation of high surface area carborundum-supported cobalt catalysts for hydrogen production by ammonia decomposition

Li Guoru,Tan Yuhang,Lei Zhiping,Yin Fengxiang,He Xiaobo 한국탄소학회 2023 Carbon Letters Vol.33 No.3

Ammonia is a potential fuel for producing and storing hydrogen, but its usage is constrained by the high cost of the noble metal catalysts to decompose NH3. Utilizing non-precious catalysts to decompose ammonia increases its potential for hydrogen production. In this study, carborundum (SiC)-supported cobalt catalysts were prepared by impregnating Co3O4 nanoparticles (NPs) on SiC support. The catalysts were characterized by high-resolution transmission electron microscope, X-ray photoelectron spectroscopy, temperature programmed reduction, etc. The results show that the large specific surface area of SiC can introduce highly distributed Co3O4 NPs onto the surface. The amount of Co in the catalysts has a significant effect on the catalyst structure, particle size and catalytic performances. Due to the interaction of cobalt species with SiC, the 25Co/SiC catalyst provided the optimal ammonia conversion of 73.2% with a space velocity of 30,000 mL gcat−1 h−1 at 550 °C, corresponding to the hydrogen production rate of 24.6 mmol H2 gcat−1 min−1. This research presents an opportunity to develop highly active and cost-effective catalysts for hydrogen production via NH3 decomposition.

Comparison of the Adhesion and Proliferation Characteristics of HUVEC and Two Endothelial Cell Lines (CRL 2922 and CRL 2873) on Various Substrata

Boon Chin Heng,Yun Xia,Xiaobo Shang,Peter Rainer Preiser,S. K. Alex Law,Freddy Yin-Chiang Boey,Subbu S. Venkatraman 한국생물공학회 2011 Biotechnology and Bioprocess Engineering Vol.16 No.1

Endothelial cell coverage of blood-contacting devices is crucial to their eventual success in the clinic. Two established human cell lines derived from HUVEC (human umbilical vascular endothelial cells), CRL 2922and CRL 2873, have been widely utilized to study and model endothelial cell biology. However, it is not clear if these two cell lines would be useful for modeling primary endothelial cell interaction with newly-formulated biomaterials in tissue engineering applications. Hence, this study was conducted to compare the adhesion and proliferation characteristics of HUVEC grown on seven different substrata, tissue culture polystyrene (TCPS), gelatin,chitosan, poly-L-lysine, hyaluronan, poly-L-lactic acid (PLLA), and polylactic-co-glycolic acid (PLGA). The short-term adhesive behavior (2 h) of HUVEC on the various substrata was not closely-replicated by either CRL 2873 or CRL 2922. This was likely because the 2 h timeframe is too short for identification of differences in the interaction among the three cell types grown on various substrata. There was much faster proliferation of CRL 2922 on all seven substrata when compared to HUVEC and CRL 2873. Moreover, the proliferation rates of CRL 2922 on the various substrata showed little variation. In contrast, HUVEC and CRL 2873 displayed similar trends in proliferation rates, with gelatin and TCPS yielding the highest rates, and PLLA and PLGA yielding the lowest rates. Hence, CRL 2873 is better suited for modeling primary endothelial cell interaction with newly-formulated biomaterials than CRL 2922. The advantage of using CRL 2873 over HUVEC for biomaterial screening is that it is immortalized and displays much less inter-batch variability than primary culture.

Switching terahertz waves with gate-controlled active graphene metamaterials

Lee, Seung Hoon,Choi, Muhan,Kim, Teun-Teun,Lee, Seungwoo,Liu, Ming,Yin, Xiaobo,Choi, Hong Kyw,Lee, Seung S.,Choi, Choon-Gi,Choi, Sung-Yool,Zhang, Xiang,Min, Bumki Nature Publishing Group 2012 Nature materials Vol.11 No.11

The extraordinary electronic properties of graphene provided the main thrusts for the rapid advance of graphene electronics. In photonics, the gate-controllable electronic properties of graphene provide a route to efficiently manipulate the interaction of photons with graphene, which has recently sparked keen interest in graphene plasmonics. However, the electro-optic tuning capability of unpatterned graphene alone is still not strong enough for practical optoelectronic applications owing to its non-resonant Drude-like behaviour. Here, we demonstrate that substantial gate-induced persistent switching and linear modulation of terahertz waves can be achieved in a two-dimensional metamaterial, into which an atomically thin, gated two-dimensional graphene layer is integrated. The gate-controllable light??matter interaction in the graphene layer can be greatly enhanced by the strong resonances of the metamaterial. Although the thickness of the embedded single-layer graphene is more than six orders of magnitude smaller than the wavelength (<貫/1,000,000), the one-atom-thick layer, in conjunction with the metamaterial, can modulate both the amplitude of the transmitted wave by up to 47% and its phase by 32.2째 at room temperature. More interestingly, the gate-controlled active graphene metamaterials show hysteretic behaviour in the transmission of terahertz waves, which is indicative of persistent photonic memory effects.