检索结果-内蒙古大学图书馆

Plasma-modified Co3O4 nanosheets for efficient CO detection: Insight into the structure-activity relationship

SENSORS AND ACTUATORS B-CHEMICAL 2024年 419卷

作者： wang, Bing wang, fuwen Song, Quzhi Liu, Tao Xu, Nana Natl Univ Def Technol Coll Aerosp Sci & Engn Sci & Technol Adv Ceram Fiber & Composites Lab Changsha 410073 Peoples R China

Exploring the correlation between crucial reactive sites and surface electron structure in the sensitive layer of gas sensors can achieve simultaneous optimization of kinetics and thermodynamics. In this work, Ar and O2 plasma sputtering are used to study how varying levels of Co3+ and oxygen vacancy affect the gas-sensitivity of Co3O4. The gas-sensing performance of Co3O4-O2PT (O2 plasma sputtering) is better than that of Co3O4-ArPT (Ar plasma sputtering), which exhibits a high response value (100 ppm-4.16) and quick response-recovery time (1.5 s/38 s). The enhancement of gas-sensing performance benefits from a high Co3+/Co2+ ratio, which provides strong COselective adsorption and oxidation capabilities. Therefore, the interfacial oxidation reaction reaches equilibrium rapidly. This work provides a straightforward and controllable modification approach and enhances the understanding of how oxygen vacancies and Co3+ affect Co3O4 gas sensors, which promotes the design and development of high-performance cobalt-based gas sensors.

关键词： CO detection Plasma sputtering Co3+/Co2+ratio Oxygen vacancies

来源：评论

学校读者我要写书评

暂无评论

Selecting Competent Reverse Transcription Strategies to Maximise Biodiversity Recovery With eRNA Metabarcoding

引用

MOLECULAR ECOLOGY RESOURCES 2025年第0期 e14092页

作者： wang, fuwen Xiong, Wei Huang, Xuena Zhan, Aibin Chinese Acad Sci Res Ctr Ecoenvironm Sci Beijing Peoples R China Univ Chinese Acad Sci Chinese Acad Sci Beijing Peoples R China

Both environmental DNA (eDNA) and environmental RNA (eRNA) have been widely adopted for biodiversity assessment. While eDNA often persists longer in environments, eRNA offers a more current view of biological activities. In eRNA metabarcoding, extracted eRNA is reverse transcribed into complementary DNA (cDNA) for metabarcoding. However, the efficacy of various reverse transcription strategies has not been evaluated. Here we compared the biodiversity recovery efficiency of three strategies: random priming with hexamers, oligo(dT) priming and taxa-specific priming using Mifish-U for fish in both high- and low-biodiversity regions. Our results demonstrate that reverse transcription strategies significantly impact biodiversity recovery. Random priming consistently detected the highest number of taxa in both low- and high-biodiversity regions. In low-biodiversity areas, oligo(dT) performed comparably to random hexamers;however, in high-biodiversity regions, random hexamers outperformed oligo(dT), particularly in recovering rare taxa. While taxa-specific priming was comparable to the other strategies for high-abundance taxa, it was less effective for rare taxa, thus limiting its utility for comprehensive biodiversity assessment. These differences are largely due to the multiple binding sites for random hexamers compared to the fewer or absent sites with oligo(dT) and taxa-specific primers under high eRNA degradation. Combining random hexamers and oligo(dT) significantly improved taxa recovery, especially for low-abundance species, supporting its best practice in eukaryotes. For prokaryotes or genes lacking polyadenylation, random priming is favoured over taxa- or gene-specific priming. Collectively, these findings underscore the critical importance of selecting appropriate reverse transcription strategies in eRNA metabarcoding, with significant implications for effective biodiversity monitoring and conservation efforts.

关键词： biodiversity eRNA metabarcoding oligo(dT) random priming reverse transcription specific priming

来源：评论

学校读者我要写书评

暂无评论

Semi-supervised instance segmentation algorithm based on transfer learning

引用

NONDESTRUCTIVE TESTING AND EVALUATION 2024年第1期39卷 185-203页

作者： Liu, Bing Yi, Ren Yu, Zhongquan wang, Shiyu Yang, Xuewen wang, fuwen Sichuan Prov Big Data Ctr Chengdu Peoples R China Sichuan Univ Sch Comp Sci Chengdu Peoples R China Civil Aviat Logist Technol Co Ltd Chengdu Peoples R China Sichuan Great Wall Comp Syst Co Luzhou Peoples R China

Semi-supervised instance segmentation algorithms are mainly divided into algorithms based on pseudo-label generation and algorithms based on transfer learning. The algorithms based on pseudo-label generation need to design a specific pseudo-label generation process, but the process is not scalable for different types of source tasks. The algorithms based on transfer learning that started late have relatively high scalability, but the algorithm research ideas are relatively simple. To expand the research on semi-supervised instance segmentation based on transfer learning, this paper proposes a feature transfer-based semi-supervised instance segmentation algorithm Feature Transfer Mask R-CNN (FT-Mask). The FT-Mask algorithm is more scalable than algorithms based on pseudo-label generation and can be used to transfer knowledge from different types of source tasks. Compared with other semi-supervised instance segmentation algorithms based on transfer learning, FT-Mask uses the feature transfer method to achieve semi-supervised instance segmentation for the first time. The experimental results show that the FT-Mask model improves the semi-supervised instance segmentation accuracy of the Mask R-CNN benchmark model through the semi-supervised learning process, and can achieve effective transfer learning.

关键词： Semi-supervised learning instance segmentation transfer learning

来源：评论

学校读者我要写书评

暂无评论

Online preparation of high-quality BN coatings with atomic diffusion based on carbon-free water-soluble precursor

引用

Journal of Advanced Ceramics 2024年第3期13卷 272-281页

作者： Yiang Du Bing wang Yunbo Zhang Quzhi Song fuwen wang Cheng Han Xiaoshan Zhang Yingde wang Science and Technology on Advanced Ceramic Fibers and Composites Laboratory College of Aerospace Science and EngineeringNational University of Defense TechnologyChangsha 410073China

Efficient and environmentally friendly production of high-quality continuous fiber coatings using current preparation methods is highly challenging due to issues such as scale and batch processing restrictions,low deposition rate,high energy consumption,and utilization of multiple environmentally hazardous *** address these challenges,we propose a stable and efficient wet chemical deposition coating method for high-throughput online continuous preparation of boron nitride(BN)coatings on ceramic fibers under an ambient *** process involves surface modification,in-situ wet chemical deposition,and heat treatment,and all seamlessly connecting with the ceramic fiber preparation process through continuous *** groups were introduced via surface modification enhancing wettability of the fiber surface with impregnating *** in-situ reaction and atom migration improve uniformity and binding of the *** a result,outstanding impregnation and adhesion properties are achieved.A comprehensive analysis to evaluate the impact of the BN coatings was conducted,which demonstrates that the BN-coated fibers exhibit a remarkable 36%increase in tensile strength,a 133%increase in fracture toughness,and enhanced temperature resistance of up to 1600℃.It provides a secure and efficient platform for cost-effective production of functional and high-quality coatings through targeted surface modification and rapid stretching impregnation.

关键词： polymer-derived ceramics SiC fibers wet chemical deposition atomic diffusion boron nitride(BN)coatings

来源：评论

学校读者我要写书评

暂无评论

Impact of low pH/high pCO2 on the physiological response and exopolysaccharide content in cyanobacteria Trichodesmium erythraeum

引用

AQUATIC ECOLOGY 2024年第4期58卷 1225-1236页

作者： Wu, Shijie Yu, Kaiqiang wang, fuwen Mi, Tiezhu Zhen, Yu Ningxia Normal Univ Coll Resources Environm & Life Sci Guyuan 756000 Peoples R China Southern Univ Sci & Technol Coll Engn Sch Environm Sci & Engn Shenzhen 518000 Peoples R China Qingdao Marine Sci & Technol Ctr Lab Marine Ecol & Environm Sci Qingdao 266237 Peoples R China Ocean Univ China Coll Environm Sci & Engn Key Lab Marine Environm & Ecol Minist Educ Qingdao 266100 Peoples R China

The acidification of the ocean caused by the diffusion of anthropogenic carbon dioxide (CO2) into seawater has been believed to threaten the stability of the marine ecosystem. As one of the major contributors to the primary production in oligotrophic oceans, the response of Trichodesmium to the acidification of the ocean has attracted a lot of attention. Therefore, in this study, we applied physiological and biochemical methods to identify the influences of high pCO(2) and low pH conditions on the growth of T. erythraeum. Our results showed that the low pH during the acidification of the ocean was the main factor inhibiting the growth of T. erythraeum. In addition, low pH caused oxidative stress to T. erythraeum, as evidenced by the increase of the reactive oxygen species and antioxidant enzyme's activities. The activity of carbonic anhydrase (CA) enzyme is dually regulated by pCO(2) and pH, and T. erythraeum can adapt to different levels of pCO(2) and pH in seawater by flexibly adjusting CA enzyme activity. We also discovered that the stimulatory effect of high pCO(2) on the exopolysaccharide (EPS) content of T. erythraeum outweighed the inhibitory effect of low pH during the process of ocean acidification. In conclusion, this study systematically revealed the effects of high pCO(2) and low pH caused by the acidification of the ocean on the growth and EPS of T. erythraeum. These results provide new insights into the response mechanisms of T. erythraeum in the acidified ocean under future climate conditions.

关键词： Trichodesmium erythraeum Ocean acidification Growth pH CO2

来源：评论

学校读者我要写书评

暂无评论

Rheology of polyborazanes with various molecular structures and dynamic transformation process

引用

JOURNAL OF POLYMER SCIENCE 2024年第15期62卷 3528-3540页

作者： Du, Yiang wang, Bing wang, fuwen Li, Wei Liu, Tao Zhang, Songhe Zhang, Yunbo Tan, Shixiang wang, Yingde Natl Univ Def Technol Coll Aerosp Sci & Engn Sci & Technol Adv Ceram Fibers & Composites Lab Changsha Peoples R China

The molecular structure of polymer precursors significantly affects their rheological properties, thermal stability, and ceramic conversion rates. For the first time, we revealed the effects of polyborazane molecular structure on rheology and molecular configuration dynamic transformation process. The systems studied are polyborazane precursors with rigid six-membered ring structures. We synthesized precursors with different molecular structures, including polyborazanes with varying degrees of branching and molecular chain flexibility, and investigated how molecular structure affects viscosity under different conditions of temperature, time, and shear rates. The results indicate that decreasing the branching degree enhances thermal stability and reduces both zero-shear viscosity and infinite-shear viscosity. Increasing the flexibility of molecular chains notably reduces infinite-shear viscosity, while having minimal impact on zero-shear viscosity and thermal stability. In conclusion, the ideal molecular structure should aim to increase the flexibility of the molecular chains while maintaining a certain degree of branching, such as a dendritic molecular configuration. By correlating viscosity data with molecular structure, we constructed a dynamic transition process of molecular chain entanglement, disentanglement, and crosslinking. This research is essential for understanding polymer rheology and its applications in industry, particularly in designing and synthesizing precursor structures for producing various ceramic fibers through Polymer-Derived Ceramics. image

关键词： dynamic transition process molecular structure polyborazane precursor polymer rheology polymer-derived ceramics

来源：评论

学校读者我要写书评

暂无评论

Tandem Electric-Fields Prolong Energetic Hot Electrons Lifetime for Ultra-Fast and Stable NO2 Detection

引用

ADVANCED MATERIALS 2024年第30期36卷 2403215-2403215页

作者： Ou, Yucheng wang, Bing Xu, Nana Song, Quzhi Liu, Tao Xu, Hui wang, fuwen Li, Siwei wang, Yingde Natl Univ Def Technol Coll Aerosp Sci & Engn Sci & Technol Adv Ceram Fiber & Composites Lab Changsha 410073 Peoples R China Natl Univ Def Technol Coll Adv Interdisciplinary Studies Changsha 410073 Peoples R China

Prolonging energetic hot electrons lifetimes and surface activity in the reactive site can overcome the slow kinetics and unfavorable thermodynamics of photo-activated gas sensors. However, bulk and surface recombination limit the simultaneous optimization of both kinetics and thermodynamics. Here tandem electric fields are deployed at (111)/(100)Au-CeO2 to ensure a sufficient driving force for carrier transfer and elucidate the mechanism of the relationship between charge transport and gas-sensing performance. The asymmetric structure of the (111)/(100)CeO2 facet junction provides interior electric fields, which facilitates electron transfer from the (100)face to the (111)face. This separation of reduction and oxidation reaction sites across different crystal faces helps inhibit surface recombination. The increased electron concentration at the (111)face intensifies the interface electric field, which promotes electron transfer to the Au site. The local electric field generated by the surface plasmon resonance effect promotes the generation of high-energy energy hot-electrons, which maintains charge concentration in the interface field by injecting into (111)/(100)CeO2, thereby provide thermodynamic contributions and inhibit bulk recombination. The tandem electric fields enable the (111)/(100)Au-CeO2 to rapidly detect 5 ppm of NO2 at room temperature with stability maintained within 20 s.

关键词： CeO2 facet junctions gas sensors NO2 detection photo-thermal effects

来源：评论

学校读者我要写书评

暂无评论

Strong Metal-Support Interaction Induces Dual Reaction Sites for Ultrasensitive and Stable NO2 Detection in Extreme Environments

引用

ADVANCED FUNCTIONAL MATERIALS 2025年第10期35卷

作者： Ou, Yucheng wang, Bing Xu, Nana Song, Quzhi Liu, Tao Xu, Hui wang, fuwen Cheng, Chuang Lu, Huimin wang, Yingde Natl Univ Def Technol Coll Aerosp Sci & Engn Sci & Technol Adv Ceram Fiber & Composites Lab Changsha 410073 Peoples R China Natl Univ Def Technol Coll Intelligence Sci & Technol Changsha 410073 Peoples R China

The tripartite combination of a high density and stability of surface reaction sites, complemented by the longevity and efficient transfer of interface carriers, along with the effective adsorption and activation of target gas molecules, jointly determines the efficiency of chemiresistors. In this work, the strong metal-support interaction (SMSI) of Pt & horbar;Ce3+ is formed by the NaBH4 reduction method and thus prepares metal-dynamically stable Pt-NR & horbar;CeO2 with Pt & horbar;Ce3+ and Pt & horbar;Pt reaction sites. The formation of SMSI induces the recombination of the chemical structure of the CeO2 surface causing the localization of electron-rich Ce3+, which greatly increases the charge concentration at the interface. The experimental findings of the strong interaction of Pt & horbar;Ce3+ bonding and the catalytic effect of Pt optimized the adsorption mode of Pt-NR & horbar;CeO2 on target gas, which maintains stable catalytic activity at 20-500 degrees C and achieving a notable detection response value of 1.43 for 20 ppb NO2. This work offers fresh insights into designing stable oxide chemiresistors with efficiency and stability by customizing reaction sites at the atomic level.

关键词： CeO2 extreme environments gas sensor NO2 detection SMSI

来源：评论

学校读者我要写书评

暂无评论

Embedding thermostable rGO/SiCxOy composite phase in SiC fibers for improved high temperature resistance

引用

CARBON 2025年 233卷

作者： Liu, Tao Han, Cheng wang, Shanshan Ou, Yucheng Zhang, Xiaoshan Zhang, Songhe Song, Quzhi Du, Yiang wang, fuwen wang, Yingde Natl Univ Def Technol Coll Aerosp Sci & Engn Sci & Technol Adv Ceram Fibers & Composites Lab Changsha 410073 Peoples R China

Silicon carbide (SiC) fibers exhibit exceptional potential in harsh environment applications such as aerospace and nuclear energy. However, the high temperature mechanical properties of SiC fibers are still limited by the unmanageable microstructure. Herein, we propose an amorphous phase stabilizing strategy by embedding thermostable reduced graphene oxide/silicon oxycarbide (rGO/SiCxOy) composite phase in SiC fibers via the polymer-derived ceramic (PDC) method. Homodisperse vinyl-bridged graphene oxide/polycarbosilane (PCS) precursor is designed to transform into rGO/SiC fibers, accompanied by the formation of a more stable rGO/ SiCxOy composite structure that intersperses between SiC grains. Additionally, the rGO plays a role in suppressing the decomposition of SiCxOy and the rapid growth of SiC grains at elevated temperatures. As a result, the tensile strength of as-received 0.5%-rGO/SiC (2.64 GPa) and 1%-rGO/SiC (2.28 GPa) fibers are elevated by 40 % and 21 % respectively. Noteworthily, 1%-rGO/SiC fibers maintain a tensile strength of 0.57 GPa even after undergoing 1700 degrees C heat treatment, while the 0%-rGO/SiC fibers have nearly lost mechanical strength after annealing at 1600 degrees C. Consequently, the rGO exhibits significant potential for improving the high temperature resistance of ceramic fibers.

关键词： Polymer-derived ceramics SiC fibers Graphene SiC x O y amorphous phase High temperature resistance

来源：评论

学校读者我要写书评

暂无评论

Grid-Forming Control and Experimental Validation for High Voltage Transformerless Battery Energy Storage System

引用

IEEE TRANSACTIONS ON POWER ELECTRONICS 2025年第4期40卷 4889-4901页

作者： Wu, Xiqi Wu, Shengbing wang, fuwen Wei, Chaofan Li, Rui Jiang, Xinyu Cai, Xu Shanghai Jiao Tong Univ Sch Elect Informat & Elect Engn Key Lab Control Power Transmiss & Convers Shanghai 200240 Peoples R China Guangzhou Zhiguang Energy Storage Technol Co Ltd Guangzhou 510760 Peoples R China Shanghai CGDG New Energy Technol Co Ltd Shanghai 201315 Peoples R China

Advantages of single-device large capacity of combining with grid forming (GFM) control effectively help high voltage transformerless battery energy storage system (BESS) to support grid frequency and voltage stability. However, the transient stability characteristics of the converter under current-limiting mode during a fault and its capability to provide effective support to the grid are the major differences from conventional synchronous machines. Therefore, this article first investigates transient synchronization stability problems at occurrence of high-voltage and low-voltage fault-ride-through by theoretically deduced virtual power angle curves considering current limitation mode. Then, the strategies of enhancing transient synchronization stability in face of grid voltage sag and rise are proposed and verified by simulation results. Thereafter, an adaptive gain coefficient is proposed to be embedded into power feedback loop to improve the capability of fast low voltage supporting during fault occurrence. More importantly, a practical 35 kV/10 MW/5 MWh Lithium BESS engineering project validates the GFM control in steady charging/discharging operation and its voltage fault ride through support ability.

关键词： Grid forming Voltage control Transient analysis Circuit faults Impedance Power system stability Reactive power Limiting Electric potential Admittance Battery energy storage system (BESS) fault ride through grid forming (GFM)

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：