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Microwatts continuous-wave pumped second harmonic generation in few- and mono-layer GaSe

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Light(Science & Applications) 2017年第1期6卷 276-281页

作者： Xue-Tao Gan Chen-Yang zhao Si-Qi Hu Tao Wang Yu Song Jie Li Qing-Hua zhao Wan-Qi Jie jian-lin zhao MOE Key Laboratory of Space Applied Physics and Chemistry and Shaanxi Key Laboratory of Optical Information Technology School of ScienceNorthwestern Polytechnical UniversityXi’an 710072China State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi’an 710072China

We demonstrate the first achievement of continuous-wave(CW)pumped second harmonic generation(SHG)in few-and monolayer gallium selenide(GaSe)flakes,which are coated on silicon photonic crystal(PC)*** of ultrahigh second order nonlinearity of the two-dimensional(2D)GaSe and localized resonant mode in the PC cavity,SHG’s pump power is greatly reduced to *** a nine-layer GaSe coated PC cavity,while the optical power inside the GaSe flake is only 1.5%of that in the silicon PC slab,the SHG in GaSe is more than 650 times stronger than the third harmonic generation in silicon slab,indicating 2D GaSe’s great potentials to strengthen nonlinear processes in silicon *** study opens up a new view to expand 2D materials’optoelectronic applications in nonlinear regime and chip-integrated active devices.

关键词： gallium selenide photonic crystal cavity second harmonic generation two-dimensional materials

Subwavelength asymmetric Au–VO_2 nanodisk dimer for switchable directional scattering

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Chinese Physics B 2018年第11期27卷 321-326页

作者： Han-Mou Zhang Wu-Yun Shang HuaLu Fa-Jun Xiao jian-lin zhao MOE Key Laboratory of Material Physics and Chemistry under Extraordinary Conditions and Shaanxi Key Laboratory of Optical Information Technology School of Science Northwestern Polytechnical University Xi＇ an 710129 China

We propose an asymmetric Au–VO_2 nanodisk dimer for realizing a switchable directional scattering. Specifically, the directional scattering can be triggered on/off through controlling the phase transition of the VO_2 nanodisk from metallic to semiconductor state. More strikingly, an obvious directional scattering with the directivity of ～40 dB is achieved under the metallic state of VO_2 nanodisk. This tunable directional scattering is further explained with an interference model where the Au and VO_2 nanodisks are treated as two weakly interacting electric dipoles. The phase transition controlled scattering patterns of asymmetric Au–VO_2 nanodisk dimer are then well interpreted from the phase difference between these two dipoles.

关键词： localized surface plasmon resonance directional scattering vanadium dioxide

Coupling-induced spectral splitting for plasmonic sensing with ultra-high figure of merit

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Chinese Physics B 2018年第11期27卷 327-331页

作者： Hua Lu Yi-Cun Fan Si-Qing Dai Dong Mao Fa-Jun Xiao Peng Li jian-lin zhao MOE Key Laboratory of Material Physics and Chemistry under Extraordinary Conditions and Shaanxi Key Laboratory of Optical Information Technology. School of Science Northwestern Polytechnical University. Xi＇an 710072 China

We investigate a kind of spectral splitting effect in a plasmonic multilayer system, which consists of stacked Al_2 O_3 and SiO_2 layers, a thin metal film, and a dielectric prism substrate. The results illustrate that an obvious peak appears in the center of the surface plasmon resonance（SPR）-induced reflection spectral dip in the structure with the SiO_2/Al_2 O_3/SiO_2 layers. This spectral splitting response can be regarded as an electromagnetically induced transparency（EIT） like effect,which is attributed to the coupling and interference between the SPR on the metal film and guided-mode resonance（GMR）in the Al_2 O_3 layer. The theoretical calculations agree well with the numerical simulations. It is also found that the reflection spectrum will be further split by the introduction of another Al_2 O_3 layer into the multilayer structure. The reintroduced GMR in the Al_2 O_3 layer changes the coupling and interference process between the SPR and GMR field, giving rise to the generation of ultra-narrow reflection dip. Especially, the spectral splitting can facilitate the realization of plasmonic sensors with ultra-high figure of merit（583）, which is about 5 times larger than that of traditional SPR sensors. These results will provide a new avenue to the light field manipulation and optical functionalities, especially biochemical and environmental sensing.

关键词： surface plasmon polaritons multilayer optical sensors

Channel pruning on frequency response

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Science China(Information Sciences) 2025年第1期68卷 159-170页

作者： Hang lin Yifan PENG lin BIE Chenggang YAN Xibin zhao Yue GAO School of Software Tsinghua University School of Automation Hangzhou Dianzi University

Network pruning has a significant role in reducing network parameters and accelerating the inference time of the network. Some existing methods prune the network based on the frequency of the data, and finally obtain a sub-network with high accuracy. However, according to our experimental analysis, different frequencies of information in the data contribute differently to the accuracy of the model, and using this information directly for pruning without making a selection will lead to incorrect results. We believe that pruning should retain the convolutional kernels in the network that process important information, while those kernels that process unimportant information should be removed. In this paper, we first investigate the meaning of each frequency band information in the spectrum and their contribution to the prediction accuracy of the network,and according to these results, we propose a new pruning method based on frequency response(PFR). Our PFR finds and removes the convolutional kernels in the network that specialize in processing unimportant information, resulting in a compact neural network model. PFR obtains significant experimental results on different datasets, for example, a 56.0% raduction of float points operations(FLOPs) on Res Net-50 and only 0.37% of Top-1 accuracy degradation on the Image Net dataset.

关键词： deep learning model compression filter pruning channel pruning frequency response

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Recent development in electrode design for wide-temperature supercapacitors

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Science China Chemistry 2025年第1期68卷 96-117页

作者： jianhong Liu Qiang Zhou Yuxiao lin Xinsheng zhao Guangmin Zhou Xiaoxiao Li School of Physics and Electronic Engineering Jiangsu Normal University Tsinghua-Berkeley Shenzhen Institute & Tsinghua Shenzhen International Graduate School Tsinghua University

An ever-increasing market demand has stimulated the soaring enthusiasm of researchers to develop wide-temperature supercapacitors(SCs). The active electrode is one of the most important parts of SC, which is directly related to the energy density,power transmission and long-term cyclability of the device in the wide-temperature environment. Compared with the SC electrodes aimed for room-temperature application, the SC electrodes for operating at wide-temperature scene often face greater challenges. In this review, the main challenges of SC electrodes under various temperature conditions, including low, high and cross-fade temperatures, are summarized. The relevant performance decay and failure mechanisms of wide-temperature SC electrodes are analyzed. In addition, this review deals with the recent studies and developments in robust wide-temperature SC electrodes with respect to the rational design of electrode structures and the exploitation of advanced active materials. Finally, the future directions for exploring reliable wide-temperature SCs are also proposed.

关键词： supercapacitor wide-temperature electrode design active materials

基于字典学习和Fisher判别稀疏表示的行人重识别方法

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华南理工大学学报（自然科学版） 2017年第7期45卷 55-62页

作者：张见威林文钊邱隆庆华南理工大学计算机科学与工程学院广东广州510006

针对目前的字典学习方法对不同摄像机视角行人特征的联系考虑不足的问题,提出了一种新的基于字典学习和Fisher判别稀疏表示的行人重识别方法.该方法考虑不同场景中同一行人的特征应该具有相似的稀疏表示,提出行人重识别离散度函数的概念... 详细信息

针对目前的字典学习方法对不同摄像机视角行人特征的联系考虑不足的问题,提出了一种新的基于字典学习和Fisher判别稀疏表示的行人重识别方法.该方法考虑不同场景中同一行人的特征应该具有相似的稀疏表示,提出行人重识别离散度函数的概念,加入约束稀疏表示的正则化项,最大化不同行人稀疏表示的类间离散度,同时最小化同一行人稀疏表示的类内离散度,通过学习到的字典得到具较强区分识别能力的稀疏表示.在公开数据集VIPeR、PRID 450s和CAVIAR4REID上的实验表明,文中方法的识别率高于目前基于字典学习的行人重识别方法.

关键词：行人重识别 Fishei 判别字典学习食疏表示离散度

Transforming waste particles into valuable adsorbents via amyloid-mediated molecular engineering

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Science China Chemistry 2025年第1期68卷 317-328页

作者： Qingmin Yang jian zhao Yujia Zhang Xingyu Zhou Hao Ren Bowen Hu Zhongli Lei Lixin Chen Peng Yang School of Material and Chemical Engineering Bengbu University Anhui Provincial Engineering Laboratory of Silicon-Based Materials School of Chemistry and Chemical Engineering Northwestern Polytechnical University Key Laboratory of Applied Surface and Colloid Chemistry Ministry of Education School of Chemistry and Chemical EngineeringShaanxi Normal University Xi'an Key Laboratory of Polymeric Soft Matter School of Chemistry and Chemical Engineering Shaanxi Normal University International Joint Research Center on Functional Fiber and Soft Smart Textile School of Chemistry and Chemical EngineeringShaanxi Normal University

The high-value utilization of industrial solid waste using a facile and eco-friendly process is of great interest and significance in reducing environmental pollution and developing a green circular economy. Herein, we propose an amyloid-mediated molecular engineering strategy to transform particulate waste into valuable adsorbents for metal ions. Our method has the advantage of aqueous solution fabrication under mild conditions without the use of high-temperature hydrothermal methods and toxic chemical reagents. Amyloid-mediated molecular engineering manipulates the phase transition of bovine serum albumin(BSA)on particulate waste surfaces, resulting in a remarkable ～3.1 times improvement in the adsorption capacity of fly ash, a typical industrial solid waste for gold ions after modification with the phase-transitioned BSA(PTB). The resultant adsorption ability was 69–1,980 times higher than those of conventional and emerging adsorbent materials such as ion exchange resins, activated carbon(AC), covalent organic frameworks(COFs), and metal-organic frameworks(MOFs). We further demonstrated the application of our PTB-modified materials in the recovery of precious metals from low-grade gold ore and electronic waste leachates. Consequently, this strategy could increase the value of waste materials nearly 27 times. In addition, this method is generally extendable to other conventional industrial adsorbents such as resin, clay, and Al2O3, and enhances their adsorption capabilities at least twofold. Overall, this work provides a simple and green approach for improving the adsorption performance of solid particles, and is expected to develop into a universal strategy for transforming waste particles into high-value-added products.

关键词： amyloid-like protein aggregates surface engineering fly ash solid waste adsorption

“Zero‑Strain” NiNb_(2)O_(6) Fibers for All‑Climate Lithium Storage

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Nano-Micro Letters 2025年第1期17卷 348-360页

作者： Yan zhao Qiang Yuan Liting Yang Guisheng Liang Yifeng Cheng Limin Wu Chunfu lin Renchao Che College of Physics Donghua UniversityShanghai 201620People’s Republic of China School of Materials Science and Engineering Institute of Materials for Energy and EnvironmentQingdao UniversityQingdao 266071People’s Republic of China Laboratory of Advanced Materials Shanghai Key Laboratory of Molecular Catalysis and Innovative MaterialsAcademy for Engineering&TechnologyFudan UniversityShanghai 200438People’s Republic of China Zhejiang Laboratory Hangzhou 311100People’s Republic of China Inner Mongolia University Hohhot 010021People’s Republic of China

Niobates are promising all-climate Li^(+)-storage anode material due to their fast charge transport,large specific capacities,and resistance to electrolyte ***,their moderate unit-cellvolume expansion(generally 5%–10%)during Li^(+)storage causes unsatisfactory long-term ***,“zero-strain”NiNb_(2)O_(6) fibers are explored as a new anode material with comprehensively good electrochemical *** Li^(+)storage,the expansion of electrochemical inactive NiO_(6) octahedra almost fully offsets the shrinkage of active NbO_(6) octahedra through reversible O *** superior volume-accommodation capability of the NiO_(6) layers guarantees the“zero-strain”behavior of NiNb_(2)O_(6) in a broad temperature range(0.53%//0.51%//0.74%at 25//−10//60℃),leading to the excellent cyclability of the NiNb_(2)O_(6) fibers(92.8%//99.2%//91.1%capacity retention after 1000//2000//1000 cycles at 10C and 25//−10//60℃).This NiNb_(2)O_(6) material further exhibits a large reversible capacity(300//184//318 mAh g−1 at 0.1C and 25//−10//60℃)and outstanding rate performance(10 to 0.5C capacity percentage of 64.3%//50.0%//65.4%at 25//−10//60℃).Therefore,the NiNb_(2)O_(6) fibers are especially suitable for large-capacity,fast-charging,long-life,and all-climate lithium-ion batteries.

关键词： NiNb_(2)O_(6)porous fiber “Zero-strain”mechanism Electrochemical property Harsh-temperature operation Operando characterization

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循环肿瘤DNA在临床应用中的研究进展

中国医学科学院学报 2016年第5期38卷 594-600页

作者：李妙竹林健振赵海涛美国杜克大学人群衰老健康研究所北卡罗来纳州27705 中国医学科学院北京协和医学院北京协和医院肝脏外科北京100730

分子诊断检测肿瘤相关突变正越来越多的被应用于癌症患者的临床护理和管理。含有肿瘤突变的循环肿瘤DNA(ct DNA)可以在疾病进程中被多次采集,是一种简单有效的非侵入性"液体活检"技术。作为一种潜在的肿瘤标志物,ct DNA检测有望在肿瘤... 详细信息

分子诊断检测肿瘤相关突变正越来越多的被应用于癌症患者的临床护理和管理。含有肿瘤突变的循环肿瘤DNA(ct DNA)可以在疾病进程中被多次采集,是一种简单有效的非侵入性"液体活检"技术。作为一种潜在的肿瘤标志物,ct DNA检测有望在肿瘤治疗中对疾病预后判断、动态监测、用药指导和异质评估发挥重要的临床应用价值。但ct DNA检测技术需要进一步规范检测流程,提高检测的可重复性和准确性,才能更好服务于精准医疗。

关键词：循环肿瘤DNA 肿瘤基因突变动态监测异质性