Construction and effect of intramolecular hydrogen bond on solvent resistance of polymeric membranes and their application in impermeable membranes

Xiaoyun Li,Zhen Wang,Xin Jing,Xudong Li,Junwei Wang,Mao-qing Kang,Yuhua Zhao,Qifeng Li 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.107 No.-

Hydrogen bonds, which can be divided into many types along with the deepening of research, exist inmany compounds and have certain impact on properties of substances. In this work, effect of intramolecularhydrogen bond on solvent resistance of polymeric membranes was studied from two aspects. On theone hand, the existence of intramolecular hydrogen bond on solvent resistance of polymeric membraneswas studied by constructing and shielding special hydroxyl groups in typical polymer polyurethane. Onthe other hand, content of intramolecular hydrogen bond on solvent resistance was investigated by buildingdifferent ratios of inter- and intra-molecular hydrogen bonds in polyvinyl alcohols. The structures,solvent resistance and hydrogen bonding interactions were systematically investigated by FT-IR, XRD,Ds and performances before and after immersed in solvents. Permeabilities of the membranes for practicalapplication were also characterized. The results showed that distinct type and ratio of hydrogenbonds played different role on solvent resistance. A good agreement between the swelling performancesand content of intramolecular hydrogen bond proved the positive effect of intramolecular hydrogen bondon solvent durability of polymeric membranes. In addition, polyurethane membranes exhibited goodimpermeability to water vapor, oxygen and chloride ions which showed potential application in manyfields.

Effect of material mechanical differences on shear properties of contact zone composite samples: Experimental and numerical studies

Weiqi Wang,Yicheng Ye,Qihu Wang,Xiaoyun Liu,Fan Yang,Wenkan Tan 국제구조공학회 2020 Structural Engineering and Mechanics, An Int'l Jou Vol.76 No.2

Aiming at the mechanical and structural characteristics of the contact zone composite rock, the shear tests and numerical studies were carried out. The effects of the differences in mechanical properties of different materials and the normal stress on shear properties of contact zone composite samples were analyzed from a macro-meso level. The results show that the composite samples have high shear strength, and the interface of different materials has strong adhesion. The differences in mechanical properties of materials weakens the shear strength and increase the shear brittleness of the sample, while normal stress will inhibit these effect. Under low/high normal stress, the sample show two failure modes, at the meso-damage level: elastic-shearing-frictional sliding and elastic-extrusion wear. This is mainly controlled by the contact and friction state of the material after damage. The secondary failure of undulating structure under normal-shear stress is the nature of extrusion wear, which is positively correlated to the normal stress and the degree of difference in mechanical properties of different materials. The increase of the mechanical difference of the sample will enhance the shear brittleness under lower normal stress and the shear interaction under higher normal stress.

Effects of Differences in Mechanical Parameters of Media on Mechanical Properties and Failure Form of Composite Samples

Weiqi Wang,Yicheng Ye,Qihu Wang,Xiaoyun Liu,Zhouhao Yuan,Pengcheng Li 대한토목학회 2020 KSCE JOURNAL OF CIVIL ENGINEERING Vol.24 No.2

The deformation and failure of composite rock masses at the contact zone can cause serious safety hazards in underground engineering. Therefore, uniaxial compression experiment and numerical studies of composite samples were conducted. Combined with theoretical analysis, the effects of differences in the mechanical properties of two media on the mechanical properties and failure form of composite samples were investigated. The results show that the difference in mechanical properties of two media weakened the strength and elastic modulus of the composite sample and resulted in complex failure form of the sample. Additionally, the peaks of the AE frequencies of the two media occurred successively after the peak stress of the sample. At the macrolevel, the two media failed successively. These effects are more pronounced as the degree of difference in the mechanical properties of the two media increased. The difference in mechanical properties of the two media resulted in uncoordinated deformation and constrained stress near the contact interface, and the difference in Poisson's ratio is the main factor. The influence (enhanced or weakened) of uncoordinated deformation on the mechanical properties of the composite sample is affected by differences in the elastic modulus and Poisson's ratios of the two media.

HMM and HSS Based Social Behavior of Intelligent Vehicles for Freeway Entrance Ramp

Guangming Xiong,Yong Li,Shiyuan Wang,Xiaoyun Li,Peng Liu 보안공학연구지원센터 2014 International Journal of Control and Automation Vol.7 No.10

In this paper, a novel approach of intelligent vehicle to interact and cooperate with other human driving vehicles is proposed at the freeway entrance ramp scenario. The system consists of a Safety Alert Module and Vehicle Control Module. The Safety Alert System module includes intention estimation and conflict judgment. A two dimension Hidden Markov Model (2DHMM) is used to estimate social vehicle’s driving intention in the intention estimation module. Then the conflict judgment module predicts the potential conflicts between the intelligent vehicle and social vehicle. Moreover, the hybrid state system (HSS) is introduced to control the intelligent vehicle while considering its decision making, states and dynamics. Co-simulation using PreScan and Simulink is conducted. The experiment results show that the intelligent vehicle performs well with a commendable social behavior in the freeway entrance ramp.

Lightweight design of hinge beam based on Kriging agent model

Guizhong Xie,Shixin Zhang,Liangwen Wang,Xiaoyun Gong,Tao Wang,Shuguang Wang,Zhiqiang Chen,Zeheng Zhi 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.7

This paper presents an optimization method based on the Kriging and multiobjective genetic algorithm. First, taking the hinged beam structure of the cubic diamond press as the design object, the optimization design mathematical model was established with the mass as the objective function, the stress and displacement peak as the constraint conditions. Second, in combination with SolidWorks and ANSYS Workbench, parametric modeling analysis was conducted to obtain a large number of sample points sparing less time, and the agent model constructed by Kriging was trained and verified. Finally, taking advantage of global search of the multi-objective genetic algorithm, a lightweight design was realized and the mass of the hinge beam structure was effectively reduced, which would be a guiding significance for the lightweight design of other mechanical parts.

Use of Magnetic Resonance Neurography for Evaluating the Distribution and Patterns of Chronic Inflammatory Demyelinating Polyneuropathy

Xiaoyun Su,Xiangquan Kong,Zuneng Lu,Min Zhou,Jing Wang,Xiaoming Liu,Xiangchuang Kong,Huiting Zhang,Chuansheng Zheng 대한영상의학회 2020 Korean Journal of Radiology Vol.21 No.4

Objective: To evaluate the distribution and characteristics of peripheral nerve abnormalities in chronic inflammatory demyelinating polyneuropathy (CIDP) using magnetic resonance neurography (MRN) and to examine the diagnostic efficiency. Materials and Methods: Thirty-one CIDP patients and 21 controls underwent MR scans. Three-dimensional sampling perfections with application-optimized contrasts using different flip-angle evolutions and T1-/T2- weighted turbo spinecho sequences were performed for neurography of the brachial and lumbosacral (LS) plexus and cauda equina, respectively. Clinical data and scores of the inflammatory Rasch-built overall disability scale (I-RODS) in CIDP were obtained. Results: The bilateral extracranial vagus (n = 11), trigeminal (n = 12), and intercostal nerves (n = 10) were hypertrophic. Plexus hypertrophies were observed in the brachial plexus of 19 patients (61.3%) and in the LS plexus of 25 patients (80.6%). Patterns of hypertrophy included uniform hypertrophy (17 [54.8%] brachial plexuses and 21 [67.7%] LS plexuses), and multifocal fusiform hypertrophy (2 [6.5%] brachial plexuses and 4 [12.9%] LS plexuses) was present. Enlarged and/or contrast-enhanced cauda equina was found in 3 (9.7%) and 13 (41.9%) patients, respectively. Diameters of the brachial and LS nerve roots were significantly larger in CIDP than in controls (p < 0.001). The largest AUC was obtained for the L5 nerve. There were no significant differences in the course duration, I-RODS score, or diameter between patients with and without hypertrophy. Conclusion: MRN is useful for the assessment of distribution and characteristics of the peripheral nerves in CIDP. Compared to other regions, LS plexus neurography is more sensitive for CIDP.

Mesocarbon microbead densified matrix graphite A3-3 for fuel elements in molten salt reactors

Wang, Haoran,Xu, Liujun,Zhong, Yajuan,Li, Xiaoyun,Tang, Hui,Zhang, Feng,Yang, Xu,Lin, Jun,Zhu, Zhiyong,You, Yan,Lu, Junqiang,Zhu, Libing Korean Nuclear Society 2021 Nuclear Engineering and Technology Vol.53 No.5

This study aims to provide microstructural characterization for the matrix graphite which molten salt reactors (MSRs) use, and improve resistance to molten salt infiltration of the matrix graphite for fuel elements. Mesocarbon microbeads (MCMB) densified matrix graphite A3-3 (MDG) was prepared by a quasi-isostatic pressure process. After densification by MCMBs with average particle sizes of 2, 10, and 16 ㎛, the pore diameter of A3-3 decreased from 924 nm to 484 nm, 532 nm, and 778 nm, respectively. Through scanning electron microscopy, the cross-section energy spectrum and time-of-flight secondary ion mass spectrometry, resistance levels of the matrix graphite to molten salt infiltration were analyzed. The results demonstrate that adding a certain proportion of MCMB powders can improve the anti-infiltration ability of A3-3. Meanwhile, the closer the particle size of MCMB is to the pore diameter of A3-3, the smaller the average pore diameter of MDG and the greater the densification. As a matrix graphite of fuel elements in MSR was involved, the thermal and mechanical properties of matrix graphite MDG were also studied. When densified by the MCMB matrix graphite, MDGs can meet the molten salt anti-infiltration requirements for MSR operation.

Potent antibacterial and antibiofilm activities of TICbf-14, a peptide with increased stability against trypsin

Wang Liping,Liu Xiaoyun,Ye Xinyue,Zhou Chenyu,Zhao Wenxuan,Zhou Changlin,Ma Lingman 한국미생물학회 2022 The journal of microbiology Vol.60 No.1

The poor stability of peptides against trypsin largely limits their development as potential antibacterial agents. Here, to obtain a peptide with increased trypsin stability and potent antibacterial activity, TICbf-14 derived from the cationic peptide Cbf-14 was designed by the addition of disulfide-bridged hendecapeptide (CWTKSIPPKPC) loop. Subsequently, the trypsin stability and antimicrobial and antibiofilm activities of this peptide were evaluated. The possible mechanisms underlying its mode of action were also clarified. The results showed that TICbf-14 exhibited elevated trypsin inhibitory activity and effectively mitigated lung histopathological damage in bacteria-infected mice by reducing the bacterial counts, further inhibiting the systemic dissemination of bacteria and host inflammation. Additionally, TICbf-14 significantly repressed bacterial swimming motility and notably inhibited biofilm formation. Considering the mode of action, we observed that TICbf-14 exhibited a potent membrane-disruptive mechanism, which was attributable to its destructive effect on ionic bridges between divalent cations and LPS of the bacterial membrane. Overall, TICbf-14, a bifunctional peptide with both antimicrobial and trypsin inhibitory activity, is highly likely to become an ideal candidate for drug development against bacteria.

A Hybrid CBPWM Scheme for Single-Phase Three-Level Converters

Wang, Shunliang,Song, Wensheng,Feng, Xiaoyun,Ding, Rongjun The Korean Institute of Power Electronics 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.2

A novel hybrid carrier-based pulse width modulation (CBPWM) scheme that combines unipolar and dipolar modulations is proposed for single-phase three-level rectifiers, which are widely applied in railway traction drive systems. The proposed CBPWM method can satisfy the volt-second balancing principle in the complete modulation index region through overmodulation compensation. The modulation scheme features two modulation modes: unipolar and dipolar. The operation range limits of these modulation modes can be modified by changing the separation coefficient. In comparison with the traditional unipolar CBPWM, the proposed hybrid CBPWM scheme can provide advantageous features, such as lower high-order harmonic distortion of the line current and better utilization of switching frequency. The separation coefficient value is optimized to achieve the maximum utilization of these advantages. The experimental results verify the feasibility and effectiveness of the proposed hybrid CBPWM scheme.

Surprise, Image and Life: Take the “life lost” event in the Oriental life world as an example

Li Xiaoyun,Wang ping,Hou jialin 아시아사회과학학회 2021 Jornal of Asia Social Science Vol.5 No.3

In the face of images, people s feelings are not necessarily rich, but may also be confused. Whether it is rational or aesthetic. Because emotionally, what they bring is tiredness and boredom. They are narrow-minded and not full. The simple idea of life world is the perfect existence. Even the “life lost”event can also “transform” our spirit. Simple life, not simple life.