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Theoretical study on mechanical and electronic properties of ternary diborides Sc0.5V0.5B2, Sc0.5Nb0.5B2 and Sc0.5Ta0.5B2

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MATERIALS TODAY COMMUNICATIONS 2023年 35卷

作者： Xie, Quanmin Yao, Yingkang Liu, xuwen sun, Jinshan Zhang, Zheng Chen, Lei Jianghan Univ State Key Lab Precis Blasting Wuhan 430056 Peoples R China Jianghan Univ Hubei Key Lab Blasting Engn Wuhan 430056 Peoples R China Baoji Univ Arts & Sci Coll Phys & Optoelect Technol Baoji 721016 Peoples R China Sichuan Jiaoda Engn Detect & Consulting Co Ltd Chengdu Peoples R China Jianghan Univ State Key Lab Precis Blasting Wuhan 430056 Peoples R China

Owing to the high thermal stability and superior mechanical properties, the transition-metal (TM) diborides have been proved to be a class of promising hard materials used as protective films. In the present work, a new type of ternary diborides Sc0.5V0.5B2, Sc0.5Nb0.5B2 and Sc0.5Ta0.5B2 alloyed by doping the TM scandium into VB2, NbB2 and TaB2 are systematically investigated using first-principle density functional theory (DFT) calculations. These ternary systems all possess higher hardness of up to about 45 GPa relative to their parent binary diborides ScB2, VB2, NbB2 and TaB2, suggesting they could be viewed as promising candidates of superhard materials. An improved structure searching approach was employed to explore the potential stable and metastable structures of them under the pressure of 0 similar to 100 GPa. The hexagonal AlB2-type structure (P6/mmm) was confirmed to be their ambient phase, which can retain the stability up to 100 GPa. Meanwhile, their ideal tensile and pure shear strengths all reached about 40 GPa, demonstrating their superhard nature. The origin of the enhanced mechanical properties of these ternary systems was resolved in details by electronic analysis at fundamental level. Thanks to the introduction of the Sc, the p-d interactions between TM and B atoms are greatly enhanced. This remarkable enhancement of p-d coupling hybridization together with the pure covalent B-B bonds results in their high hardness property.

关键词： Transition-metal diborides Superhard material First-principles Ideal strength Electronic structure

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A pH and Temperature Dual-Responsive Microgel-Embedded, Adhesive, and Tough Hydrogel for Drug Delivery and Wound Healing

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ACS APPLIED MATERIALS & INTERFACES 2023年第15期15卷 19560-19573页

作者： Peng, xuwen Peng, Qian Wu, Meng Wang, Wenda Gao, Yongfeng Liu, Xiong sun, Yongxiang Yang, Diling Peng, Qiongyao Wang, Tao Chen, Xing-Zhen Liu, Jifang Zhang, Hao Zeng, Hongbo Univ Alberta Dept Chem & Mat Engn Edmonton AB 619 Canada Guangzhou Med Univ Affiliated Hosp 5 Guangzhou 510700 Guangdong Peoples R China Univ Alberta Fac Med & Dent Dept Physiol Edmonton AB 627 Canada

Stimuli-responsive hydrogels have attracted much attention over the past decade for potential bioengineering applications such as wound dressing and drug delivery. In this work, a pH and temperature dual-responsive microgel-embedded hydrogel has been fabricated by incorporating poly(N-isopropylacrylamide-co-acrylic acid) (PNIPAAm-co-AAc) based microgel particles into polyacrylamide (PAAm)/chitosan (CS) semi-interpenetrating polymer network (semi-IPN), denoted as microgel@PAM/ CS. The resultant hydrogel possesses excellent mechanical properties including stretchability, compressibility, and elasticity. In addition, the microgel@PAM/CS hydrogels can tightly adhere to the surfaces of a variety of tissues such as porcine skin, kidney, intestine, liver, and heart. Moreover, it shows controlled dual-drug release profile of both bovine serum albumin (BSA) (as a model protein) and sulfamethoxazole (SMZ), an antibiotic. Excellent antimicrobial properties are obtained for SMZ-loaded microgel@ PAM/CS hydrogels. Compared with traditional drug administration methods such as by mouth, injection, and inhalation, the microgel@PAM/CS hydrogels possess advantages such as higher drug loading efficiency (by more than 80%) and controllable and sustained (over 48 h) release. The microgel@PAM/ CS hydrogels can significantly enhance the wound healing process. This work provides a facile approach for the fabrication of multifunctional stimuli-responsive microparticle-embedded hydrogels with semi-IPN structures, and the as-prepared microgel@ PAM/CS hydrogels have great potential for applications as smart wound dressing materials in biomedical engineering.

关键词： stimuli-responsive hydrogel multifunctional hydrogel interfacial interaction drug delivery wound dressing

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Enhancing gas production and CO2 sequestration from marine hydrate reservoirs through optimized CO2 hydrate cap

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ENERGY 2024年 303卷

作者： Guo, Yang Li, Shuxia sun, Hao Wu, Didi Liu, Lu Zhang, Ningtao Qin, xuwen Lu, Cheng China Univ Petr East China State Key Lab Deep Oil & Gas Qingdao 266580 Peoples R China China Univ Petr East China Sch Petr Engn Qingdao 266580 Peoples R China East China Bur Sinopec Explorat & Dev Res Inst Nanjing 210019 Peoples R China China Geol Survey China Aero Geophys Survey & Remote Sensing Ctr Nat Beijing 100083 Peoples R China China Geol Survey Minist Nat Resources Oil & Gas Resources Survey Beijing 100083 Peoples R China

The invasion of formation water during marine hydrate production gravely affects gas productivity. CO2 hydrate caps effectively inhibit water invasion while sequestering CO2, which is considered an excellent prospective application. However, forming field -scale artificial CO2 hydrate caps remains a global challenge. This study proposed an innovative method for forming an artificial CO2 hydrate cap. The fracture length, injection time, production pressure, and production well distance, which are all factors that affect sealing capacity and production enhancement, were optimized. Results indicated that the sealing capacity exhibited a trend of initially increasing and subsequently decreasing with fracture length. The injection time was positively correlated with the sealing capacity and was sufficient to seal both vertically and horizontally once it reached 4 years. In addition to sequestering CO2, the CO2 hydrate cap enhanced gas production by 146.56 % and reduced water production by 37.47 % compared to direct depressurization. CO2 invasion occurred when the well spacing was too close, while being distant was not favorable for pressure propagation and heat utilization by the CO2 hydrate cap. This method simultaneously achieves multiple goals for energy and environmental, providing essential implications for the future commercial application of marine hydrates.

关键词： Gas hydrate CO2 hydrate cap Enhanced gas production CO2 sequestration Numerical simulation

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A novel remediation strategy of mixed calcium peroxide and degrading bacteria for polycyclic aromatic hydrocarbon contaminated water

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JOURNAL OF HAZARDOUS MATERIALS 2024年 470卷 134122页

作者： Tang, Lei sun, Yulong Lu, Wenyi Chen, xuwen Mosa, Ahmed Minkina, Tatiana Gao, Yanzheng Ling, Wanting Nanjing Agr Univ Inst Organ Contaminant Control & Soil Remediat Coll Resources & Environm Sci Nanjing 210095 Peoples R China Mansoura Univ Fac Agr Soils Dept Mansoura 35516 Egypt Southern Fed Univ Acad Biol & Biotechnol Rostov Na Donu 344090 Russia

Polycyclic aromatic hydrocarbons (PAHs) are a class of toxic organic pollutants commonly detected in the aqueous phase. Traditional biodegradation is inefficient and advanced oxidation technologies are expensive. In the current study, a novel strategy was developed using calcium peroxide (CP) and PAH-degrading bacteria (PDB) to effectively augment PAH degradation by 28.62 - 59.22%. The PDB consisted of the genera Acinetobacter , Stenotrophomonas, and Comamonas . Applying the response surface model (RSM), the most appropriate parameters were identified, and the predictive degradation rates of phenanthrene (Phe), pyrene (Pyr), and Sigma PAHs were 98%, 76%, and 84%, respectively. The constructed mixed system could reduce 90% of Phe and more than 60% of Sigma PAHs and will perform better at pH 5 - 7 and lower salinity. Because PAHs tend to bind to dissolved organic matter (DOM) with larger molecular weights, humic acid (HA) had a larger negative effect on the PAHdegradation efficiency of the CP-PDB mixed system than fulvic acid (FA). The proposed PAH-degradation pathways in the mixed system were based on the detection of intermediates at different times. The investigation constructed and optimized a novel environmental PAH-degradation strategy. The synergistic application of PDB and oxidation was extended for organic contaminant degradation in aqueous environments.

关键词： Polycyclic aromatic hydrocarbons Biodegradation effect Oxidation degradation Mixed degradation strategy

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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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An Improved Design of Atomic-Beam Fluorescence Collector

An Improved Design of Atomic-Beam Fluorescence Collector

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European Frequency and Time Forum (EFTF)

作者： xuwen Hu Fuyu sun Chao Li 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

Efficient fluorescence detection is crucial in the field of precision spectral analysis. This paper presents an improved design of an atomic-beam fluorescence collector that utilizes the convergence characteristics of ellipsoidal surfaces and the reflection characteristics of spherical surfaces. It calculates the parameter relationship for achieving full-angle fluorescence collection. The study fine-tunes the structural parameters and simulates the fluorescence collection efficiency and losses under different conditions when emitting from a non-ideal point light source. The improved fluorescence collector captures photons with nearly 4n solid angle coverage, allowing photons to be reflected at most twice before reaching the photo detector, thereby increasing collection efficiency. This improved collector can be used in various fields for detecting weak fluorescence signals.

关键词： Time-frequency analysis Europe Detectors Fluorescence Solids Reflection Structural engineering Spectral analysis Photonics Light sources

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Research progress and scientific challenges in the depressurization exploitation mechanism of clayey-silt natural gas hydrates in the northern South China Sea

ADVANCES IN GEO-ENERGY RESEARCH

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ADVANCES IN GEO-ENERGY RESEARCH 2023年第1期10卷 14-20页

作者： Lu, Cheng Qin, xuwen sun, Jinsheng Wang, Ren Cai, Jianchao China Geol Survey Minist Nat Resources Oil & Gas Resources Survey Beijing 100083 Peoples R China Natl Engn Res Ctr Gas Hydrate Explorat & Dev Guangzhou 510075 Guangdong Peoples R China China Geol Survey China Aero Geophys Survey & Remote Sensing Ctr Na Beijing 100083 Peoples R China China Univ Petr East China Sch Petr Engn Qingdao 266580 Peoples R China CNPC Engn Technol R&D Co Ltd Beijing 102206 Peoples R China China Univ Petr Natl Key Lab Petr Resources & Engn Beijing 102249 Peoples R China

Natural gas hydrate reservoirs in the northern South China Sea primarily comprise clayey silt, making exploitation more challenging relative to sandy reservoirs in other countries and regions. This paper provides an overview of the latest research developments in the exploitation mechanism covering the past five years, focusing on hydrate phase transition, multiphase flow in the decomposition zone, the seepage regulation of reservoir stimulation zone, and production capacity simulation, all of which are relevant to the previously conducted two rounds of hydrate trial production in offshore areas of China. The results indicate that the phase transition of clayey-silt hydrate remains in a dynamic equilibrium, with the decomposition efficiency mainly controlled by the coupling of heat and flow and high heat consumption during decomposition. The decomposition zone exhibits strong hydrophilicity, easy adsorption, and sudden permeability changes. A temperature drop is present that is concentrated near the wellbore, and once a water lock has formed, the gas-phase flow capacity significantly decreases, leading to potential secondary hydrate formation. To enhance permeability and increase production, it is imperative to implement reservoir and temperature field reconstruction based on initial formation alterations, which will further optimize and improve the transport capacity of the reservoir.

关键词： Clayey-silt hydrate phase transition multiphase flow seepage regulation production simulation

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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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Hydrogels for the removal of the methylene blue dye from wastewater: a review

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ENVIRONMENTAL CHEMISTRY LETTERS 2022年第4期20卷 2665-2685页

作者： Yang, Yinchuan Zhu, Qinlin Peng, xuwen sun, Jingjing Li, Cong Zhang, Xinmiao Zhang, Hao Chen, Jiabin Zhou, Xuefei Zeng, Hongbo Zhang, Yalei Tongji Univ Coll Environm Sci & Engn State Key Lab Pollut Control & Resources Reuse Shanghai 200092 Peoples R China Tongji Univ Shanghai Inst Pollut Control & Ecol Secur Shanghai 200092 Peoples R China Univ Alberta Dept Chem & Mat Engn Edmonton AB T6G IH9 Canada Univ Shanghai Sci & Technol Coll Environm & Architecture Shanghai 200093 Peoples R China Sinopec Beijing Res Inst Chem Ind Environm Protect Res Inst Beijing 100013 Peoples R China

Water pollution is a major environmental issue with the rapid development of industry. Therefore, advanced technologies and materials are needed to remove pollutants from contaminated waters. The adsorption process displays many advantages such as high adaptability and removal efficiency for water sources of varying quality. Hydrogels have recently attracted attention due to their high adsorption capacity and structural stability, yet several issues remain to be explored, such as the number of reuse and engineering applications. Here, we review hydrogels for the removal of methylene blue from wastewater, with focus on hydrogel preparation and properties, adsorption performance and mechanisms, reusability and comparison with biological and chemical oxidation methods.

关键词： Hydrogel Methylene blue Adsorption Dye Wastewater treatment

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Low-level laser activates Wnt/β-catenin signaling pathway-promoting hair follicle stem cell regeneration and wound healing: Upregulate the expression of key downstream gene Lef 1

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SKIN RESEARCH AND TECHNOLOGY 2024年第6期30卷 e13807页

作者： BangHong, Jiang YuKun, Wang Ao, Shi Tao, sun PeiJun, Song xuwen, Li Lin, Li ZhuYou, Xiong Li, Zhang Bengbu Med Coll Affiliated Hosp 1 Dept Plast Surg Bengbu Peoples R China Lanzhou Univ Hosp & Clin Med Sch 2 Lanzhou Peoples R China Bengbu Med Coll Affiliated Hosp 1 Dept Neurosurg Bengbu Peoples R China

BackgroundThe objective of this study is to investigate the mechanism by which low-level laser stimulation promotes the proliferation of intraepithelial hair follicle stem cells (HFSCs) in wounds. This research aims to expand the applications of laser treatment, enhance wound repair methods, and establish a theoretical and experimental foundation for achieving accelerated wound *** experimental approach involved irradiating a cell model with low-level laser to assess the proliferation of HFSCs and examine alterations in the expression of proteins related to the Wnt/beta-catenin signaling pathway. A mouse back wound model was established to investigate the effects of low-level laser irradiation on wound healing rate, wound microenvironment, and the proliferation of HFSCs in relation to the Wnt/beta-catenin signaling *** research findings indicate that low-level laser light effectively activates the Wnt signaling pathway, leading to the increased accumulation of core protein beta-catenin and the upregulation of key downstream gene Lef 1. Consequently, this regulatory mechanism facilitates various downstream biological effects, including the notable promotion of HFSC proliferation and differentiation into skin appendages and epithelial tissues. As a result, the process of wound healing is significantly *** levels of laser activates the Wnt signalling pathway, promotes the regeneration of hair follicle stem cells and accelerates wound healing.

关键词： carcinogenesis low-level laser stem cells Wnt/beta-catenin pathway wound healing

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