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Synthesis and characterization of photo-responsive azobenzene side-chain liquid crystalline polystyrenes with a mesogenic phase of wide temperature range

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DYES AND PIGMENTS 2023年 210卷

作者： zhang, Ruixue Ma, Hongwei Li, xuwen Yang, Jiaxin Lai, Meng zhang, Xueli Wang, Yu Li, Yang Han, Li Dalian Univ Technol Sch Chem Engn Dept Polymer Sci & Engn State Key Lab Fine ChemLiaoning Key Lab Polymer S Dalian 116024 Peoples R China

Polystyrenes (PSs) that provide photochemical stability are commonly used as the chromophore macromolecular carriers. Herein, PS-based alternating copolymers, i.e., alt-P(D-SiH/Ip), alt-P(D-2SiH/Ip) and alt-P(D-SiH/St), are synthesized through anionically copolymerized Si-H functionalized 1,1-diphenylethylene (DPE-SiH/2SiH) with isoprene (Ip)/styrene (St). Anionically polymerized (4-vinylphenyl)-dimethyl-silane is used as the uniform hydrosilylated PS, i.e., Uni.-P(St-SiH). A series of photo-responsive azobenzene side-chain liquid crystalline PSs combine the above PS-based main chains and the mesogenic moiety composed of azobenzene (Azo) and cholesterol (Chol) groups, i.e., Azo-Chol (M), via the hydrosilylation. The polarized optical microscopic (POM) morphologies and thermal properties of Azo-Chol (M) and Azo-Chol-PSs are studied. As desired, they produce the cholesteric phase of wide temperature range due to the PSs and Chol-groups. Moreover, the photo-responsive behavior irradiated under UV-light of different wavelengths are quantitatively evaluated by time-dependent UV-Vis spectroscopy. Azo-Chol-PSs undergo rapid and reversible trans-cis isomerization under the alternating irradiation of UV and visible light. The trans-to -cis isomerization efficiency under 365 nm UV-light is over that under 290-320 nm UV-light, while over 80% of cis-to-trans efficiency can be realized under 400-500 nm Vis-light irradiation This work would provide guidelines for the effective design of photo-responsive anisotropic materials.

关键词： Polystyrenes Living anionic copolymerization Side-chain liquid crystalline polymers Photo-responsive Cholesteric phase

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Development of hard X-ray spectrometer with full digital data acquisition for runaway electron studies at HL-2M

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JOURNAL OF INSTRUMENTATION 2023年第2期18卷 T02006页

作者： Cheng, Shikui zhang, Jie zhang, Yipo He, Li Xu, Hongbing Zhu, Yuxuan Zhan, xuwen Shi, Zhongbing Zhong, Wulv Southwestern Inst Phys Chengdu 610041 Sichuan Peoples R China Chengdu Univ Technol Coll Nucl Technol & Automat Engn Chengdu 610059 Sichuan Peoples R China

The development of hard X-ray (HXR) spectrometers with full digital data acquisition for runaway electron studies on the HL-2M tokamak is presented. Consisting of large-sized NaI:Tl detectors and high-performance multichannel analyzers, this system can realize the measurement of HXR with energies ranging from 0.5 to 10 MeV, and spectrum temporal resolution of 1 ms. An average energy resolution of 56 keV at 662 keV has been achieved at counts rates of about 100 kcps. The spectra data is acquired by a digital-based data acquisition system with fast digitization and software signal processing technology. The energy calibrations are performed by using several radioisotope gamma-ray sources, and the detection efficiencies are simulated by MCNP code. First experimental results from HL-2M Ohmic discharges are presented in this paper.

关键词： Nuclear instruments and methods for hot plasma diagnostics Gamma detectors (scin- tillators CZT HPGe HgI etc) X-ray detectors

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Erosion wear resistance mechanism of erosion ripples

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PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART C-JOURNAL OF MECHANICAL ENGINEERING SCIENCE 2022年第19期236卷 10359-10369页

作者： zhang, Yan Zhao, xuwen Wang, Qi Wang, Tianqi Tang, Yuling Tianjin Univ Sci & Technol Tianjin Key Lab Integrated Design & On Line Monit Tianjin Peoples R China Tianjin Univ Sci & Technol Coll Mech Engn Tianjin Peoples R China

Erosion ripples widely exist on natural and industrial surfaces suffering gas-solid flow erosion. During the steady state of erosion ripples formation, the material removal and plastic flow rate of the material basically reach a dynamic equilibrium. In this state, the erosion rate of the surface material is steady and at a low level. In this paper, the relationship between erosion ripples and the erosion characteristics of surface materials was explored by experimental and simulation methods. Under the conditions of air pressures of 0.3, 0.4 and 0.5 MPa and erosion angles of 30 degrees, 40 degrees and 50 degrees, several erosion ripples were prepared on the surface of 1060 aluminium alloy samples by sandblasting. According to the obtained morphological parameters and orthogonal test design, rippled samples with rectangular, triangular and semicircular groove sections were designed. The effect of morphology parameters on the erosion resistance of the sample was analysed by a sandblasting test. The results showed that the rippled samples have lower erosion rates than the plate sample. The cross-sectional shape of grooves is the most obviously affected factor. The velocity distribution and surface pressure distribution on the surface of rippled and plate samples were analysed by FLUENT software, and the results showed that the low-speed reflow vortex will be formed in grooves of erosion ripples that can change the near-wall flow field conditions. The differential pressure generated on two sides of the ridge between adjacent grooves, as well as the area decrease of erosion caused by the "shaded effect," may be the cause of the erosion resistance. The results of this study can provide new insight into the active erosive wear resistance method of mechanical components.

关键词： erosive wear erosion ripple gas-solid flow sandblasting near-wall flow field

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A Compact Optically Pumped Cesium Beam Clock with a Differential Detection Scheme

A Compact Optically Pumped Cesium Beam Clock with a Differen...

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European Frequency and Time Forum (EFTF)

作者： Chao Li Fuyu Sun xuwen Hu Jie Liu Xiaofeng Li Shougang zhang National Time Service Center Chinese Academy of Sciences Xi'an China Key Laboratory of Time Reference and Applications Chinese Academy of Sciences Xi'an China

ISBN: (数字)9798350354270

ISBN: (纸本)9798350354287

Compact optically pumped cesium beam clocks have become a focus in cesium clock research due to their high atomic utilization and excellent short-term frequency stability. However, stray light noise, one of the main noise sources, limits the stability improvement. In this paper, we present a compact optically pumped cesium clock that uses differential detection to reduce the impact of stray light on clock performance. It incorporates an additional fluorescence collector to capture stray light during detection and subtract it from the clock transition signal, effectively reducing stray light level. Consequently, this scheme significantly enhances the signal-to-noise ratio, improving the short-term frequency stability of the compact optically pumped cesium clock.

关键词： Time-frequency analysis Atom optics Stray light Laser stability Cesium Optical pumping Optical noise Laser beams Optical beams Clocks

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Transcytosis-Triggering Nanoparticles for Overcoming Stromal Barriers and Reversing Immunosuppression in Pancreatic Cancer Combinatorial Therapy

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NANO LETTERS 2025年第7期25卷 2949-2959页

作者： zhang, Shilin You, Haoyu Fan, Hongrui Chen, Yun Song, Haolin Zhao, Zhenhao Chen, Qinjun Wang, Yu Tian, Zonghua Wu, Yuxing Zhou, Zheng Guo, Yun Su, Boyu Li, xuwen Jia, Ru Fang, Mingzhu Jiang, Chen Sun, Tao Fudan Univ Minhang Hosp Key Lab Smart Drug Delivery State Key Lab Med NeurobiolMinist Educ Shanghai 201203 Peoples R China Fudan Univ Frontiers Ctr Brain Sci Sch Pharm MOE Shanghai 201203 Peoples R China Quzhou Fudan Inst Quzhou 324003 Peoples R China Fujian Med Univ Binhai Campus Affiliated Hosp 1 Natl Reg Med Ctr Dept Digest Dis Fuzhou 350212 Peoples R China

In pancreatic ductal adenocarcinoma (PDAC), stromal cells and matrix proteins form a dense physical barrier that, while preventing the outward spread of tumor cells, also limits the penetration of drugs and CD8+ T cells inward. Additionally, the overactivated TGF-beta/SMAD signaling pathway further promotes matrix proliferation and immune suppression. Therefore, crossing the stromal barrier while preserving the integrity of the stroma, releasing drugs intratumorally, remodeling the stroma, and activating the immune system is a promising drug delivery strategy. In this work, a type of enamine N-oxides modified nanoparticle was prepared, with stearic acid-modified gemcitabine prodrug (GemC18) and pSMAD2/3 inhibitor galunisertib encapsulated. The peripheral enamine N-oxides can trigger transcytosis and then respond to hypoxia and acidic microenvironments, turning the surface charge of the nanoparticles to a positive charge and enhancing penetration. The released galunisertib inhibits the TGF-beta/SMAD signaling pathway, reshapes the matrix, activates antitumor immunity, and combines with gemcitabine (Gem) to kill tumor cells.

关键词： Drug delivery system transcytosis tumor penetration enamine N-oxide TGF-beta/SMAD signalingpathway

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Polyphenols-inspired interface modification and reduced agglomeration of solid propellants via a functionalized fluorine-containing organic substance coating layer

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SURFACE & COATINGS TECHNOLOGY 2024年 477卷

作者： Li, Jiao zhang, Jian zhang, Hongyu Wang, xuwen Lu, Taojie Liang, Jiayan Yang, Yulin Lin, Kaifeng Xia, Debin Harbin Inst Technol Sch Chem & Chem Engn MIIT Key Lab Crit Mat Technol New Energy Convers & Harbin 150001 Heilongjiang Peoples R China Harbin Inst Technol Sch Chem & Chem Engn Harbin 150001 Peoples R China

Interface modification of aluminum particles plays a crucial part in reducing the agglomeration during the combustion of solid propellants. In this study, the aluminum (Al) particles are pretreated with gallic acid (GA) to get Al@GA with an adhesion-favorable surface, which facilitates the further coating procedure. One new fluorine-containing organic substance is prepared, namely p-HFBA. The p-HFBA further coats the Al@GA to produce Al@GA/p-HFBA. The interface between Al@GA and the coating layer p-HFBA forms Al-F bonds and induces a pre-ignition reaction with an aluminum oxide shell. Hence, the agglomerate size of propellants containing Al@GA/p-HFBA significantly decreases from 176.30 mu m to 84.72 mu m. The agglomerates volume is reduced by approximately 97 %. Additionally, more gaseous products investigated by TG-MS provide the Al particles with greater impetus (aerodynamic forces, Fae), enabling them to leave the burning surface and reduce the residence time. The rise in Fae and drop in adhesion force (Fad) effectively reduce the agglomeration intensity according to the skeleton layer model. This work proves that interface modification can effectively enhance the combustion performance of aluminized solid propellants.

关键词： Interface modification Fluorine-containing organic substance Coatings Pre-ignition reaction Agglomeration Skeleton layer model

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Screening and Expression Analysis of POD Gene in POD-H2O2 Pathway on Bud Dormancy of Pear (Pyrus pyrifolia)

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FORESTS 2024年第3期15卷 434页

作者： Xiang, xuwen Song, Keke Li, Yinyin zhang, Chenyu Zhou, Ruiqi Feng, Yu You, Jingnan Wu, Jingdong zhang, Yanhui Jiang, Cuicui Li, Yongyu Fujian Agr & Forestry Univ Coll Hort Key Lab Minist Educ Genet Breeding & Multiple Utilizat Cro Fuzhou 350002 Peoples R China Fujian Agr & Forestry Univ Inst Nat Prod Hort Plants Fuzhou 350002 Peoples R China Agr & Rural Bur Jianning Cty Econ Crop Stn Sanming 354500 Peoples R China Agr & Rural Bur Yongtai Cty Econ Crop Stn Fuzhou 350700 Peoples R China Fujian Acad Agr Sci Fruit Res Inst Fuzhou 350002 Peoples R China

Bud endodormancy represents a pivotal and intricate biological process influenced by both genetic and epigenetic factors, the exact mechanism of which remains elusive. Hydrogen peroxide (H2O2) functions as a signalling molecule in the regulation of dormancy, with peroxidase (POD) playing a crucial role in governing H2O2 levels. Our prior transcriptomic and metabolomic investigations into diverse pear dormancy phases posited that POD predominantly oversees pear bud dormancy. In this study, we utilised qRT-PCR to screen the most significantly expressed gene, Pyrus pyrifolia POD4-like (PpPOD4-like), from seven POD genes. Subsequently, H2O2 test kits, overexpression methods, and subcellular localisation techniques were employed to assess changes in H2O2 content, POD activity, PpPOD4-like expression, and its cellular positioning during pear bud dormancy. Subcellular localisation experiments revealed that PpPOD4-like is situated on the cell membranes. Notably, H2O2 content exhibited a rapid increase during endodormancy and decreased swiftly after ecodormancy. The fluctuation pattern of POD activity aligned with that of H2O2 content. Additionally, PpPOD4-like expression was markedly upregulated, displaying an overall upward trajectory. Our findings indicate that PpPOD4-like modulates H2O2 levels by regulating POD activity, thereby actively participating in the intricate regulation of pear dormancy processes.

关键词： endodormancy overexpression H2O2 POD genes

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Seed biostimulant Bacillus sp. MGW9 improves the salt tolerance of maize during seed germination

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AMB EXPRESS 2021年第1期11卷 74页

作者： Li, Heqin Yue, Haiwang Li, Li Liu, Yu zhang, Haiyan Wang, Jianhua Jiang, xuwen Qingdao Agr Univ Dryland Technol Key Lab Shandong Prov Qingdao 266109 Peoples R China Hebei Acad Agr & Forestry Sci Dryland Farming Inst Hengshui 053000 Peoples R China China Agr Univ Seed Sci & Technol Res Ctr Beijing 100193 Peoples R China

Crop performance is seriously affected by high salt concentrations in soils. To develop improved seed pre-sowing treatment technologies, it is crucial to improve the salt tolerance of seed germination. Here, we isolated and identified the strain Bacillus sp. MGW9 and developed the seed biostimulant MGW9. The effects of seed biopriming with the seed biostimulant MGW9 in maize (Zea mays L.) under saline conditions were studied. The results show that the strain Bacillus sp. MGW9 has characteristics such as salt tolerance, nitrogen fixation, phosphorus dissolution, and indole-3-acetic acid production. Seed biopriming with the seed biostimulant MGW9 enhanced the performance of maize during seed germination under salinity stress, improving the germination energy, germination percentage, shoot/seedling length, primary root length, shoot/seedling fresh weight, shoot/seedling dry weight, root fresh weight and root dry weight. Seed biostimulant MGW9 biopriming also alleviated the salinity damage to maize by improving the relative water content, chlorophyll content, proline content, soluble sugar content, root activity, and activities of superoxide dismutase, catalase, peroxidase and ascorbate peroxidase, while decreasing the malondialdehyde content. In particular, the field seedling emergence of maize seeds in saline-alkali soil can be improved by biopriming with the seed biostimulant MGW9. Therefore, maize seed biopriming with the seed biostimulant MGW9 could be an effective approach to overcoming the inhibitory effects of salinity stress and promoting seed germination and seedling growth.

关键词： Salt stress Seed biostimulant Seed germination Zea mays Bacillus sp

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Enhanced Near-Infrared Electrochemiluminescence from Trinary Ag-In-S to Multinary Ag-Ga-In-S Nanocrystals via Doping-in-Growth and Its Immunosensing Applications

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ANALYTICAL CHEMISTRY 2021年第4期93卷 2160-2165页

作者： Fu, Li Fu, Kena Gao, xuwen Dong, Shuangtian zhang, Bin Fu, Shanji Hsu, Hsien-Yi Zou, Guizheng Shandong Univ Sch Chem & Chem Engn Jinan 250100 Peoples R China City Univ Hong Kong Sch Energy & Environm Kowloon Tong Hong Kong 999077 Peoples R China City Univ Hong Kong Dept Mat Sci & Engn Kowloon Tong Hong Kong 999077 Peoples R China Shandong Univ Dept Clin Lab Qilu Hosp Jinan 250012 Peoples R China

Screening toxic-element-free and biocompatible electrochemiluminophores was crucial for electrochemiluminescence (ECL) evolution. Herein, L-glutathione (GSH)-capped Ag-Ga-In-S (AGIS) nanocrystals (NCs) were prepared by doping Ag-In-S (AIS) NCs in a doping-in-growth way and utilized as a model for both ECL modulating and developing multinary NC-based electrochemiluminophores with enhanced ECL performance than trinary NCs. AGIS NCs not only primarily preserved the morphology, size, phase structure, and water monodisperse characteristics of MS NCs with broadened band gap but also demonstrated obviously enhanced oxidative-reduction ECL than MS NCs. Importantly, ECL of AGIS NCs was located at the near-infrared region with a maximum emission wavelength of 744 nm and could be utilized for an ECL immunoassay with human prostate-specific antigen (PSA) as a model, which exhibited a linearity range from 0.05 pg/mL to 1.0 ng/mL and a low limit of detection of 0.01 pg/mL (S/N = 3). This work provided a promising alternative to the traditional binary NCs for developing toxic- element-free and biocompatible electrochemiluminophores with efficient near-infrared ECL.

关键词： Electrochemiluminescence Infrared

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Adaptive Temporal High-pass Infrared Non-uniformity Correction Algorithm Based on Guided Filter 2021

Adaptive Temporal High-pass Infrared Non-uniformity Correcti...

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7th International Conference on Computing and Artificial Intelligence, ICCAI 2021

作者： zhang, Y.I. Li, xuwen Zheng, Xin Wu, Qiang Beijing University of Technology Beijing China

ISBN: (纸本)9781450389501

In the scene-based infrared focal plane non-uniformity correction algorithm, the temporal high-pass filter non-uniformity correction algorithm is widely cited in various system platforms due to its low hardware platform requirements, but this algorithm is prone to "ghosting"problems and the corrected image still contains certain non-uniformity problems. To solve these problems, this paper proposes an adaptive temporal high-pass filter algorithm based on guided filter. The algorithm uses guided filter to accurately separate high-frequency components containing a large amount of fixed noise and image details, and performs image motion through adjacent frame residual images detection to determine whether to use high-frequency components for iterative operations in the temporal high-pass algorithm, and use the current image detail information to adaptively update the correction parameters of the temporal high-pass filter to avoid the accumulation of image detail information to complete the entire infrared non-uniformity correction . The algorithm in this paper uses actual infrared scene images to compare with the traditional temporal high-pass filter algorithm and bilateral filtering temporal high-pass algorithm. The results show that the algorithm proposed in this paper not only has a good correction effect, but also effectively suppresses the "ghosting"problem. © 2021 ACM.

关键词： High pass filters

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