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Beyond 600G fiber-THz wireless seamless integration system employing cascaded MIMO equalizers

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Science China Technological Sciences 2024年第7期67卷 2274-2276页

作者： ding junjie TONG WeiDong LI XinTong ZHANG Zheng ZHANG Jiao CAI YuanCheng LEI MingZheng HUA BingChang CHEN XingYu YU JianJun ZHU Min Purple Mountain Laboratories National Mobile Communications Research Laboratory Southeast University Fudan University

Terahertz(THz)-wave communication, with sufficient spectrum resources(0.3 THz～10 THz), can meet the needs of future 6G large-capacity mobile communication services[1-9]. Recently, the seamless integration of existing...

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Biomineralization of soil with crude soybean urease using different calcium salts

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第5期16卷 1788-1798页

作者： Yajie Weng junjie Zheng Hanjiang Lai Mingjuan Cui Xingzhi ding School of Civil and Hydraulic Engineering Huazhong University of Science and TechnologyWuhan430074China Zijin School of Geology and Mining Fuzhou UniversityFuzhou350108China College of Civil Engineering Fuzhou UniversityFuzhou350116China

Calcium salt is an important contributing factor for calcium-based biomineralization.To study the effect of calcium salt on soil biomineralization using crude soybean urease,the calcium salts,including the calcium chloride (CaCl_(2)),calcium acetate ((CH_(3)COO)_(2)Ca) and calcium nitrate (Ca(NO_(3))_(2)),were used to prepare the biotreatment solution to carry out the biomineralization tests in this paper.Two series of biomineralization tests in solution and sand column,respectively,were conducted.Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were performed to determine the microscopic characteristics of the precipitated calcium carbonate (CaCO_(3)) crystals.The experimental results indicate that the biomineralization effect is the best for the CaCl2 case,followed by (CH_(3)COO)_(2)Ca,and worst for Ca(NO_(3))_(2) under the test conditions of this study (i.e.1 mol/L of calcium salt-urea).The mechanism for the effect of the calcium salt on the biomineralization of crude soybean urease mainly involves: (1) inhibition of urease activity,and (2) influence on the crystal size and morphology of CaCO_(3).Besides Ca^(2+) ,the anions in solution can inhibit the activity of crude soybean urease,and NO_(3)− has a stronger inhibitory effect on the urease activity compared with both CH_(3)COO^(−) and Cl^(−) .The co-inhibition of Ca^(2+) and NO_(3)− on the activity of urease is the key reason for the worst biomineralization of the Ca(NO_(3))_(2) case in this study.The difference in biomineralization between the CaCl_(2) and (CH_(3)COO)_(2) Ca cases is strongly correlated with the crystal morphology of the precipitated CaCO_(3).

关键词： Biomineralization Crude soybean urease Calcium salt Influence mechanism

Strongly Coupled Ag/Sn-SnO_(2)Nanosheets Toward CO_(2)Electroreduction to Pure HCOOH Solutions at Ampere‑Level Current

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Nano-Micro Letters 2024年第3期16卷 212-226页

作者： Min Zhang Aihui Cao Yucui Xiang Chaogang Ban Guang Han junjie ding Li‑Yong Gan Xiaoyuan Zhou College of Physics and Center of Quantum Materials and Devices Chongqing UniversityChongqing 401331People’s Republic of China State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of Sciences(CAS)Fuzhou 350002People’s Republic of China College of Materials Science and Engineering Chongqing UniversityChongqing 400044People’s Republic of China Institute of New Energy Storage Materials and Equipment Chongqing 401135People’s Republic of China State Key Laboratory of Coal Mine Disaster Dynamics and Control Chongqing UniversityChongqing 400044People’s Republic of China

Electrocatalytic reduction of CO_(2) converts intermittent renewable electricity into value-added liquid products with an enticing prospect,but its practical application is hampered due to the lack of high-performance electrocatalysts.Herein,we elaborately design and develop strongly coupled nanosheets composed of Ag nanoparticles and Sn-SnO_(2) grains,designated as Ag/Sn-SnO_(2) nanosheets(NSs),which possess optimized electronic structure,high electrical conductivity,and more accessible sites.As a result,such a catalyst exhibits unprecedented catalytic performance toward CO_(2)-to-formate conversion with near-unity faradaic efficiency(≥90%),ultrahigh partial current density(2,000 mA cm^(−2)),and superior long-term stability(200 mA cm^(−2),200 h),surpassing the reported catalysts of CO_(2) electroreduction to formate.Additionally,in situ attenuated total reflection-infrared spectra combined with theoretical calculations revealed that electron-enriched Sn sites on Ag/Sn-SnO_(2)NSs not only promote the formation of*OCHO and alleviate the energy barriers of*OCHO to*HCOOH,but also impede the desorption of H*.Notably,the Ag/Sn-SnO_(2)NSs as the cathode in a membrane electrode assembly with porous solid electrolyte layer reactor can continuously produce~0.12 M pure HCOOH solution at 100 mA cm^(−2)over 200 h.This work may inspire further development of advanced electrocatalysts and innovative device systems for promoting practical application of producing liquid fuels from CO_(2).

关键词： Electrochemical CO_(2)reduction Coupled Ag/Sn-SnO_(2)nanosheets Electronic structure Porous solid electrolyte Pure

Demonstration of 5.12-Tbps THz-over-fiber transmission in 80 channel WDM system

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Science China(Technological Sciences) 2023年第5期66卷 1480-1482页

作者： ZHAO Li LONG JianYu ding junjie YU JianJun Department of Communication Science and Engineering Fudan UniversityShanghai 200433China

The arrival of 5G and the incoming 6G era demand ultralarge-capacity and long-distance transmission for wired and wireless communications.With adequate bandwidth,the terahertz(THz)-wave(0.3 THz–10 THz)is very promising and has the ability to carry ultra-high-speed signals[1–7].However,there has been little research on THz-over-fiber technology until now.Therefore,it is extremely competitive and challenging to achieve the potential THz-over-fiber communication for the 6G technology in the near future.

关键词： fiber WDM carry

Record 50.7-Tbit/s WDM coherent transmission in hollow-core fiber

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中国科学:技术科学英文版 2023年第9期66卷 2755-2756页

作者： ZHU BoWen WANG CaoYuan ZHU Jie WEI Yi ding junjie ZHAI ZhenDe XIAO LiMin YU JianJun School of Information Science and Technology Fudan UniversityShanghai 200433China Shenzhen Sublime Photonics Co. Ltd.Shenzhen 518109China

Over the past half-century, the emergence of technologies such as erbium-doped fiber amplifier(EDFA), wavelength division multiplexing(WDM), coherent transmission and advanced digital signal processing(DSP) has led to... 详细信息

关键词： fiber WDM amplifier

地理空间数据等积全球格网多模式三维扩展方法

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测绘学报 2024年第1期53卷 173-188页

作者：周建彬丁俊杰贲进陈艺航梁启爽信息工程大学地理空间信息学院河南郑州450001

全球离散格网系统是新型地理空间数据组织框架,等面积格网由于在采样和空间分析方面的独特优势而备受关注,但相关研究囿于地球表面,缺乏扩展至三维广域空间的一般方法。本文首先提出将等积球面格网系统扩展为球体格网系统的多种剖分模式... 详细信息

全球离散格网系统是新型地理空间数据组织框架,等面积格网由于在采样和空间分析方面的独特优势而备受关注,但相关研究囿于地球表面,缺乏扩展至三维广域空间的一般方法。本文首先提出将等积球面格网系统扩展为球体格网系统的多种剖分模式,并实现其统一数学描述和详细数学证明;然后引入体积和紧致度指标定量评价不同剖分模式的体元性质,并与球体退化八叉树格网(SDOG)、大圆弧八叉树格网(SGOG)作对比;最后初步探索了本文方法的应用案例,讨论了不同应用需求下选择剖分模式的原则。对比试验结果表明,退化剖分的体元各项指标均优于规则剖分,等体积和退化剖分的体积性质优于SDOG,紧致度性质优于SGOG。本文多剖分模式三维扩展方法不仅符合国际标准等体积的要求,而且兼顾常规剖分设计选项,为不同应用需求提供了参考依据。

关键词：等面积全球离散格网系统三维扩展剖分等体积紧致度

C-Band 53.76 Tbit/s Transmission Based on Bit Allocation Optimization with Raman Amplification

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激光与光电子学进展 2023年第7期60卷 430-434页

作者： ding junjie Wang Chen Ju Zhou Zhu Bowen Sang Bohan Liu Bo Yu Jianjun Key Laboratory for Information Science of Electromagnetic Waves(MoE) Fudan UniversityShanghai 200433China Nanjing University of Information Science and Technology Nanjing 210044JiangsuChina

We experimentally demonstrate an 80-channel wavelength division multiplexing(WDM)transmission system over a 400 km fiber link.Raman amplification results in a non-flat WDM signal spectrum.Therefore,bit allocation optimization is used to enable different channels to carry different order quadrature amplitude modulation signals according to their optical signal-noise-ratios.A neural network equalizer based on a convolutional neural network(CNN),long shortterm memory(LSTM)network,and fully connected(FC)layer structure is adopted in Rx digital signal processing,in which CNN is used for characteristic extraction,LSTM is used for equalization and demodulation,and FC layers are used for output.After transmission,the bit error rate of all channels is below the 25%soft-decision forward error correction threshold,and the line rate reaches 53.76 Tbit/s.

关键词： wavelength division multiplexing transmission Raman amplification bit allocation optimization neural network equalizer

4.096 Tbit/s multidimensional multiplexing signals transmission over 1000 km few mode fiber

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Chinese Optics Letters 2024年第1期22卷 8-13页

作者：张宇王晨王凯辉丁俊杰朱博文沈磊张磊王瑞春闫长鹍刘博余建军 School of Information Science and Technology Fudan UniversityShanghai 200433China Changfei Optical Fiber and Cable Joint Stock Limited Company Wuhan 430073China Nanjing University of Information Science&Technology Nanjing 210000China

We experimentally transmit eight wavelength-division-multiplexing(WDM)channels,16 quadratic-amplitude-modulation(QAM)signals at 32-GBaud,over 1000 km few mode fiber(FMF).In this experiment,we use WDM,mode division multiplexing,and polarization multiplexing for signal transmission.Through the multiple-input-multiple-output(MIMO)equalization algorithms,we achieve the total line transmission rate of 4.096 Tbit/s.The results prove that the bit error rates(BERs)for the16QAM signals after 1000 km FMF transmission are below the soft-decision forward-error-correction(SD-FEC)threshold of2.4×10^(-2),and the net rate reaches 3.413 Tbit/s.Our proposed system provides a reference for the future development of high-capacity communication.

关键词： optical fiber communication mode division multiplexing few-mode fiber multiple-input-multiple-output high-capacity transmission long-distance transmission

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钾氨电子化合物中的准二维自旋-派尔斯相变

Science Bulletin 2024年第8期69卷 1027-1036页

作者：丁驰鲁清郭照芃黄天衡王俊杰韩瑜邢定钰孙建 National Laboratory of Solid State Microstructures School of Physics and Collaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing 210093China

Electron-phonon interactions and electron-electron correlations represent two crucial facets of condensed matter physics.For instance,in a half-filled spin-1/2 anti-ferromagnetic chain,the lattice dimerization induced by electron-nucleus interaction can be intensified by onsite Coulomb repulsion,resulting in a spin-Peierls state.Through first-principles calculations and crystal structure prediction methods,we have identified that under mild pressures,potassium and ammonia can form stable compounds:R3m K(NH_(3))_(2),Pm3 m K(NH_(3))_(2),and Cm K_(2)(NH_(3))_(3).Our predictions suggest that the R3 m K(NH_(3))_(2)exhibits electride characteristics,marked by the formation of interstitial anionic electrons(IAEs)in the interlayer space.These IAEs are arranged in quasi-two-dimensional triangular arrays.With increasing pressure,the electronic van-Hove singularity shifts toward the Fermi level,resulting in an augmented density of states and the onset of both Peierls and magnetic instabilities.Analyzing these instabilities,we determine that the ground state of the R3 m K(NH_(3))_(2)is the dimerized P2_(1)/m phase with zigzag-type anti-ferromagnetic IAEs.This state can be described by the triangular-lattice antiferromagnetic Heisenberg model with modulated magnetic interactions.Furthermore,we unveil the coexistence and positive interplay between magnetic and Peierls instability,constituting a scenario of spin-Peierls instability unprecedented in realistic 2D materials,particularly involving IAEs.This work provides valuable insights into the coupling of IAEs with the adjacent lattice and their spin correlations in quantum materials.

关键词： Quasi-two-dimensional Interstitial anionic electrons Potassium ammonia compounds Spin-Peierls transition Antiferromagnetism