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Symmetry Chirp Spread Spectrum Modulation Used in LEO Satellite Internet of Things

IEEE COMMUNICATIONS LETTERS 2018年第11期22卷 2230-2233页

作者： Qian, Yubi Ma, Lu liang, xuwen Chinese Acad Sci Shanghai Inst Microsyst & Informat Technol Shanghai 100049 Peoples R China Chinese Acad Sci Shanghai Engn Ctr Microsatellites Shanghai 100049 Peoples R China Univ Chinese Acad Sci Beijing 100049 Peoples R China Shanghai SpaceOK Aerosp Technol Co Ltd Shanghai 201802 Peoples R China

With the development of Internet of Things (IoT), the world gradually moves toward the interconnection of all things. In terrestrial networks, narrowband-IoT and Long Rage (LoRa) are used widely in the IoT industry. For low-earthorbit (LEO) satellites, they have a lot of conspicuous advantages, such as broader coverage and lower construction cost. In this letter, we place emphasis on the application of LoRa-related technologies to LEO satellite communication systems, and the modulation is the prior research. Chirp spread spectrum (CSS) modulation is the most important technology in LoRa. Therefore, the research of CSS modulation used in the satellite IoT is imperative.

关键词： loT LEO Satellite NB-IoT LoRa CSS SCSS

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On-Orbit Estimation and Calibration of GPS Antenna Geometry Offsets for Attitude Determination of LEO Satellites

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IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES 2018年第3期E101A卷 644-648页

作者： Hou, Huiling Hu, Weisheng Wu, Kang liang, xuwen Chinese Acad Sci Shanghai Inst Microsyst & Informat Technol Shanghai Peoples R China Chinese Acad Sci Shanghai Engn Ctr Microsatellites Shanghai Peoples R China Univ Chinese Acad Sci Beijing Peoples R China

In this letter, a novel on-orbit estimation and calibration method of GPS antenna geometry offsets for attitude determination of LEO satellites is proposed. Both baseline vectors in the NED coordinate system are achieved epoch-by-epoch firstly. Then multiple epochs' baseline vectors are united to compute all the offsets via an UKF for a certain long time. After on-orbit estimation and calibration, instantaneous and accurate attitude can be achieved. Numerical results show that the proposed method can obtain the offsets of each baseline in all directions with high accuracy estimation and small STDs, and effective attitudes can be achieved after antenna geometry calibration using the estimated offsets. The high accuracy give the proposed scheme a strong practical-oriented ability.

关键词： offset estimation calibration attitude determination LEO satellites

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桂东大瑶山成矿带鸡笼顶金矿地质特征及找矿前景

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矿产与地质 2020年第3期34卷 432-438页

作者：梁徐文林冰霞广西壮族自治区二七二地质队广西南宁530031 中国-东盟地学合作中心(南宁) 广西南宁530023

鸡笼顶金矿地处广西重要的大瑶山金、银、铜多金属成矿带,为构造破碎带—蚀变岩型金矿。矿区金矿体主要赋存于寒武系黄洞口组第一段(∈h^1)与第二段(∈h^2),近SN向的F1、F3断裂构造控制了矿区两个主要金矿化带,断裂构造既是本区控矿构... 详细信息

鸡笼顶金矿地处广西重要的大瑶山金、银、铜多金属成矿带,为构造破碎带—蚀变岩型金矿。矿区金矿体主要赋存于寒武系黄洞口组第一段(∈h^1)与第二段(∈h^2),近SN向的F1、F3断裂构造控制了矿区两个主要金矿化带,断裂构造既是本区控矿构造又是容矿构造。矿石物质组分简单,金矿物主要以自然金单体形态赋存于氧化矿石、原生矿石中。通过分析其成矿地质条件,对矿床地质特征进行了总结,认为该矿具有较大的找矿潜力,为今后矿区扩大资源量提供了依据。

关键词：鸡笼顶金矿床大瑶山成矿带成矿地质条件找矿前景

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CUG-STCN: A seabed topography classification framework based on knowledge graph-guided vision mamba network

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INTERNATIONAL JOURNAL OF APPLIED EARTH OBSERVATION AND GEOINFORMATION 2025年 136卷

作者： Wang, Haoyi Chen, Weitao Li, Xianju liang, Qianyong Qin, xuwen Li, Jun China Univ Geosci Fac Comp Sci Wuhan 430074 Peoples R China China Univ Geosci Key Lab Geol Survey & Evaluat Minist Educ Wuhan 430074 Peoples R China China Geol Survey Guangzhou Marine Geol Survey Guangzhou 511400 Peoples R China China Geol Survey China Aero Geophys Survey & Remote Sensing Ctr Nat Beijing 100083 Peoples R China

Multibeam sounding is a high-precision remote sensing method for seabed detection. Seabed topography classification is crucial for marine science research, resource exploration and engineering. When using multibeam data for seabed topography automatic classification, the fuzzy boundaries of different topographic entities, redundancy of multimodal data, and the lack of geological knowledge guidance have led to low classification accuracy. Thus, a knowledge graph-guided vision mamba seabed topography classification network (CUG-STCN) was constructed, consisting of three modules: (1) The long sequence modeling mamba-based encoder addresses the fuzzy seabed topography boundary. It uses 2D-selective-scan to create image blocks in different scanning directions. By combining with the selective state space model to capture long-range dependencies and ensure transmission of spatial context information while maintaining linear computational complexity. (2) The crossmodal information interaction and fusion module addresses the redundancy of multimodal information. By employing a bidirectional information interaction mechanism, it captures the correlations of seabed topography between different modalities and achieving feature fusion. (3) The seabed topography knowledge graph-guided semantic perception module guides the geological knowledge. It constructs seabed topography knowledge vectors through entity query and word embedding, using the similarity between vectors to create a similarity measurement matrix. It provides geological knowledge, enhancing the modeling capability of complex seabed topography relationship. CUG-STCN achieves OA of 90.11% and mIOU of 48.50%, outperforming six mainstream networks, which at most, achieve the OA and mIOU improvements of 5.37% and 14.18%. Notably, the application of CUG-STCN in other regions demonstrates its strong generalization performance.

关键词： Multibeam Seabed topography Mamba Knowledge graph Remote sensing

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Hollow-structured elastic aerogel fibers enabling simultaneous EMI shielding, infrared stealth, and thermal management

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JOURNAL OF COLLOID AND INTERFACE SCIENCE 2025年 694卷

作者： Sui, xuwen Lian, Qingsong Huo, Qiangqiang Huang, Shaoliang Xue, Fuping liang, Chaobo North Univ China Coll Mat Sci & Engn Key Lab Funct Nanocomposites Shanxi Prov Taiyuan 030051 Peoples R China

Electromagnetic interference (EMI) shielding materials that also possess thermal management capabilities are crucial for safeguarding sensitive information against interception or disruption in electronic countermeasure applications. Furthermore, these materials are adept at maintaining a stable internal temperature within their structural framework, even under the most severe cold conditions. In this work, we fabricated elastic hollow porous polyurethane (HPU) fibers incorporating silver-coated copper nanosheets (Cu@Ag NS) as fillers, which exhibit low mid-infrared emissivity and exceptional electrical conductivity. These fibers were subsequently woven into HPU textile using a shuttle weaving technique, resulting in the textile with superior EMI shielding and excellent thermal management properties. The results indicate that the HPU textile can attain an adjustable EMI shielding effectiveness (SE) ranging from 21.11 to 57.53 dB, depending on the angle between HPU textile and the electric field of the incident electromagnetic wave. The HPU textile exhibits a thermal conductivity of 0.06 Wm(-1)K(-1), offering excellent thermal insulation. Moreover, it demonstrates an elongation of 490 %, underscoring its exceptional flexibility. These outstanding EMI shielding capabilities, combined with its adaptable thermal response and superior thermal management properties, make the HPU textile highly appropriate for use in wearable devices and architectural applications.

关键词： Multifunctional polymer textile Electromagnetic interference shielding Multiple thermal response Wearable textile Joule heating

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Stable self-crosslinking phase change composites with vertically aligned boron nitride for high thermal conductivity thermal interface materials

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CERAMICS INTERNATIONAL 2024年第11期50卷 19829-19837页

作者： Liu, Chunlei Duan, Xiaoyuan Zhang, Wei Huo, Qianqiang Sui, xuwen Liu, Yaqing liang, Chaobo North Univ China Coll Mat Sci & Engn Key Lab Funct Nanocomposites Shanxi Prov Taiyuan 030051 Peoples R China Northwestern Polytech Univ Sch Chem & Chem Engn Shaanxi Key Lab Macromol Sci & Technol Xian 710072 Peoples R China

Thermal interface materials (TIMs) must have a high through-plane thermal conductivity in order to efficiently transfer the heat generated by electronic components to heat sinks. Nevertheless, the achievement of high through-plane thermal conductivity is still a great challenge due to the inadequate thermal conductivity network as well as the lack of thermal response from the polymer matrix. Herein, we have developed a solid-solid phase change polymer matrix achieved through self-crosslinking polyethylene glycol (SCPEG). Subsequently, highperformance TIMs based on the SCPEG matrix and vertically aligned boron nitride (BN) nanosheets are obtained by bidirectional freezing, hot pressing, and longitudinal slicing. The prepared BN/SCPEG composites (BN content of 80 vol%) with a vertically oriented network achieved a through-plane thermal conductivity of 23.03 W m-1 K-1. More importantly, the vertically aligned BN nanosheets improve the thermal conductivity of composites, while the SCPEG matrix can reduce the hardness of composites by absorbing the heat, thus decreasing the contact thermal resistance.

关键词： Thermal interface materials Solid-solid phase change polymer matrix Self-crosslinking polyethylene glycol Vertically aligned boron nitride nanosheets

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Efficient Production of Melanin by Aureobasidium Melanogenum Using a Simplified Medium and pH-Controlled Fermentation Strategy with the Cell Morphology Analysis

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APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY 2024年第2期196卷 1122-1141页

作者： Zhou, Ran Ma, Lan Qin, xuwen Zhu, Hui Chen, Guiguang liang, Zhiqun Zeng, Wei Guilin Med Univ Key Lab Biochem & Mol Biol Educ Dept Guangxi Zhuang Autonomous Reg 1 Zhiyuan Rd Guilin 541199 Guangxi Peoples R China Guilin Med Univ Sch Intelligent Med & Biotechnol 1 Zhiyuan Rd Guilin 541199 Guangxi Peoples R China Guangxi Univ Coll Life Sci & Technol Guangxi Microorganism & Enzyme Res Ctr Engn Techno State Key Lab Conservat & Utilizat Subtrop Agrobio 100 Daxue Rd Nanning 530004 Guangxi Peoples R China

Natural melanin is a biopolymer with wide application prospects in medicine, food, cosmetics, environmental protection, agriculture, and so on. Microbial fermentation is an important and effective way to produce melanin. In this study, Aureobasidium melanogenum, known as black yeast with cellular pleomorphism, was used for the production of melanin. Based on the characteristic of A. melanogenum secreting melanin under oligotrophic stress, a simple medium containing only glucose, MgSO4 center dot 7H(2)O, and KCl was constructed for the production of melanin. The melanin titer of 6.64 +/- 0.22 g/L was obtained after 20 days of fermentation without pH control. The cell morphological changes of A. melanogenum during the production of melanin were recorded, and the results showed that chlamydospore might be the most favorable cell morphology for melanin synthesis. Then, different fermentation strategies with cell morphology analysis were developed to further improve the production of melanin in a 5-L fermenter. Results showed that the maximum titer of melanin reached 18.50 g/L by using the fermentation strategy integrating pH control, ammonium salt addition, and H2O2 stimulation, which increased by 178.6% than that of the strategy without pH control. Furthermore, the melanin obtained from the fermentation broth was characterized as eumelanin containing an indole structure. This study provided a potentially feasible fermentation strategy for the industrial production of melanin.

关键词： Melanin Aureobasidium melanogenum Simplified medium pH-controlled strategy Cell morphology Characterization

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TMEM35B as a novel biomarker for diagnosing gliomas

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BIOMARKERS IN MEDICINE 2024年第24期18卷 1103-1111页

作者： liang, Gongbo Lai, xuwen Yan, Guangning He, Wenyuan Su, Longjun Luo, Jinxia Wang, Zhuocai Gen Hosp Southern Theater Command Dept Pathol 111 LiuHua Rd Guangzhou 510010 Peoples R China

AimsThere is little information about transmembrane protein 35B (TMEM35B) expression in glioma, and its functions in glioma remains no *** & MethodsImmunohistochemistry was used to measure TMEM35B expression levels and CCK8 and Transwell assays were analyzed the proliferative and migratory and ***35B protein was significantly higher in gliomas and correlated with a higher tumor TNM stages. Receiver operating characteristic curve analysis revealed that TMEM35B had high diagnostic value in distinguishing among glioma, normal tissues, tumor stages III+IV, and I+II. Additionally, TMEM35B knockdown inhibited the proliferative, migratory, and invasive capacities of glioma ***35B expression is upregulated in gliomas, and its knockdown hinders tumor progression, highlighting the protein as a potential biomarker for glioma diagnosis.

关键词： Glioma TMEM35B proliferation metastasis biomarker

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"Twisted" small molecule donors with enhanced intermolecular interactions in the condensed phase towards efficient and thick-film all-small-molecule organic solar cells

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JOURNAL OF MATERIALS CHEMISTRY A 2023年第26期11卷 13984-13993页

作者： Cheng, Xiafei liang, Ziqi liang, Shifeng Zhang, xuwen Xu, Jie Xu, Yan Ni, Wang Li, Miaomiao Geng, Yanhou Tianjin Univ Sch Mat Sci & Engn Tianjin Key Lab Mol Optoelect Sci Tianjin 300072 Peoples R China Tianjin Inst Power Sources Sci & Technol Power Sources Lab Tianjin 300384 Peoples R China Sinopec Beijing Res Inst Chem Ind Co Ltd Beijing 100013 Peoples R China Joint Sch Natl Univ Singapore & Tianjin Univ Int Campus Tianjin Univ Fuzhou 350207 Peoples R China

How to achieve high crystallinity and suitable phase scale simultaneously from the perspective of molecular engineering remains a long-standing challenge for all-small-molecule organic solar cells (ASM-OSCs). Herein, two small molecule donors, named DRTT-2Se (with two alkylselenophenyl chains) and DRTT-6Se (with six alkylselenophenyl chains), were designed and synthesized by introducing "twisted" backbones and building units with strong intermolecular interactions. The "twisted" skeletons of the molecules can suppress the molecular crystallization and avoid excessive aggregation during the film forming process, while the strong intermolecular interactions of the building units can encourage the formation of ordered molecular packing and nanoscale phase separation via post-treatments. Owing to the enhanced intermolecular interactions induced by alkylselenophenyl side chains, DRTT-2Se and DRTT-6Se with a "twisted" structure displayed more ordered pi-pi packing, and retained the similar nanoscale microstructures in the blend films in comparison to the "twisted" molecule with alkylthiophenyl side chains (DRTT-T), yielding improved hole transport and reduced charge recombination in OSCs. In addition, the alkylselenophenyl substituted molecules showed higher HOMO energy levels, which caused the larger HOMO offset to drive exciton dissociation, but did not increase the energy loss. As a result, the ASM-OSCs based on the selenophene-containing donors exhibited higher FF and J(sc), and similar V-oc, yielding superior PCEs (14.79% and 15.03%) compared to the DRTT-T based device (13.37%). More importantly, the appropriate film morphology made the device efficiency of DRTT-2Se and DRTT-6Se less sensitive to the thickness of active layers. This study provides some implications in designing small molecule donors with suitable crystallization behavior towards high-performance ASM-OSCs.

关键词： Molecules

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基于实体嵌入和长短时记忆网络的入侵检测方法

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中国科学院大学学报（中英文） 2020年第4期37卷 553-561页

作者：赖训飞梁旭文谢卓辰李宗旺中国科学院上海微系统与信息技术研究所上海200050 上海科技大学信息学院上海201210 中国科学院上海微小卫星工程中心上海201203 中国科学院大学北京100049

针对网络入侵检测过程中无法有效处理入侵数据中分类变量的表示,导致网络入侵检测准确率低、漏报率高等问题,提出一种基于实体嵌入和长短时记忆网络(long short-term memory network,LSTM)相结合的网络入侵检测方法。首先,在数据预处理... 详细信息

针对网络入侵检测过程中无法有效处理入侵数据中分类变量的表示,导致网络入侵检测准确率低、漏报率高等问题,提出一种基于实体嵌入和长短时记忆网络(long short-term memory network,LSTM)相结合的网络入侵检测方法。首先,在数据预处理时,将表示网络特征数据中的数值型变量和分类型变量数据分开,通过实体嵌入方法将分类型变量数据映射在一个欧几里得空间,得到一个向量表示,再将这个向量嵌入到数值型数据后面得到输入数据。然后,通过把数据输入到长短时记忆网络中去训练,通过时间反向传播更新参数,得到最优嵌入向量作为输入特征的同时,也得到一个相对最优的LSTM网络的检测模型。在数据集NSL-KDD上进行实验验证,结果表明实体嵌入是一种有效处理网络入侵数据中分类变量的方法,它和LSTM网络相结合组成的模型能够有效提高入侵检测率。在数据预处理时对分类变量的处理中,实体嵌入方法与传统的One-Hot编码方法相比,检测的准确率提高1.44个百分点,漏报率降低2.99个百分点。

关键词：实体嵌入长短时记忆网络入侵检测分类变量

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