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Low-permittivity LiLn(PO3)4(Ln=La,Sm,Eu)dielectric ceramics for microwave/millimeter-wave communication

Journal of Advanced Ceramics 2024年第5期13卷 602-620页

作者： Huanrong Tian Xiaohan zhang Zidong zhang yao Liu Haitao Wu Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials(Ministry of Education) Shandong UniversityJinan 250061China School of Materials Science and Engineering Shandong UniversityJinan 250061China School of Environmental and Material Engineering Yantai UniversityYantai 264005China

The development of dielectric materials with low permittivity and low loss is a great challenge in wireless communication.In this study,LiLn(PO_(3))_(4)(Ln=La,Sm,Eu)ceramic systems were successfully prepared using the traditional solid-state method.X-ray diffraction analysis indicated that the LiLn(PO_(3))_(4)ceramics crystallized in a monoclinic structure when sintered at 850–940℃.The characteristic peak shifted to higher angles with variations in the Ln element,which was ascribed to a reduction in the cell volume.Further analysis by structure refinement revealed that the reduction in the cell volume resulted from the decrease in chemical bond lengths and the compression of[LiO4]and[PO4]tetrahedra.Remarkably,the LiLn(PO_(3))_(4)ceramic system displayed exceptional performance at low sintering temperatures(910–925℃),including a high quality factor(Q·f)of 41,607–75,968 GHz,low temperature coefficient of resonant frequency(τf)ranging from−19.64 to−47.49 ppm/℃,low permittivity(εr)between 5.04 and 5.26,and low density(3.04–3.26 g/cm^(3)).The application of Phillips–van Vechten–Levine(P–V–L)theory revealed that the increased Q·f value of the LiLn(PO_(3))_(4)systems can be attributed to the enhanced packing fraction,bond covalency,and lattice energy,and the stability ofτf was associated with the increase in the bond energy.Furthermore,a prototype microstrip patch antenna using LiEu(PO3)4 ceramics was fabricated.The measurement results demonstrated excellent antenna performance with a bandwidth of 360 MHz and a peak gain of 5.11 dB at a central frequency of 5.08 GHz.Therefore,low-εr LiLn(PO_(3))_(4)ceramic systems are promising candidates for microwave/millimeter-wave communication.

关键词： low permittivity LiLn(PO_(3))_(4) microwave dielectric properties Phillips-van Vechten-Levine(P-V-L)theory microstrip patch antenna

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Ambient particle composition and toxicity in 31 major cities in China

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Fundamental Research 2024年第3期4卷 505-515页

作者： Lu zhang Maosheng yao State Key Joint Laboratory of Environmental Simulation and Pollution Control College of Environmental Sciences and EngineeringPeking UniversityBeijing 100871China

Current assessment of air quality or control effectiveness is solely based on particulate matter(PM)mass levels,without considering their toxicity differences in terms of health benefits.Here,we collected a total of 465 automo-bile air conditioning filters from 31 major Chinese cities to study the composition and toxicity of PM at a national scale.Dithiothreitol assay showed that normalized PM toxicity(NIOG)in different Chinese cities varied greatly from the highest 4.99×10^(-3)for Changsha to the lowest 7.72×10^(-4)for Yinchuan.NI0G values were observed to have significant correlations with annual PM_(10) concentration(r=-0.416,p=0.020)and some PM components(total fungi,so.2-and calcium element).The concentrations of different elements and water-soluble ions in PM also varied by several orders of magnitude for 31 cities in China.Endotoxin concentrations in PM analyzed using limulus amebocyte lysate assay ranged from 2.88 EU/mg PM(Hangzhou)to 62.82 EU/mg PM(Shijiazhuang)among 31 Chinese cities.Besides,real-time qPCR revealed 10~100-fold differences in total bacterial and fungal levels among 31 Chinese cities.The concentrations of chemical(water soluble ions and trace elements)and bi-ological(fungi,bacteria and endotoxin)components in PM were found to be significantly correlated with some meteorological factors and gaseous pollutants such as SO_(2).Our results have demonstrated that PM toxicity from 31 major cities varied greatly up to 6.5 times difference;and components such as fungi and SO_(4)^(2-)in PM could play important roles in the observed PM toxicity.The city-specific air pollution control strategy that integrates toxicity factors should be enacted in order to maximize health and economic co-benefits.This work also provides a comprehensive view on the overall PM pollution situation in China.

关键词： PM toxicity Oxidative potential Biologicals Chemical components Endotoxin

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The role of inflammasomes in human diseases and their potential as therapeutic targets

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Signal Transduction and Targeted Therapy 2024年第2期9卷 479-508页

作者： Jing yao Keenan Sterling Zhe Wang Yun zhang Weihong Song The National Clinical Research Center for Geriatric Disease Xuanwu HospitalCapital Medical UniversityBeijing 100053China Townsend Family Laboratories Department of PsychiatryBrain Research CenterThe University of British Columbia2255 Wesbrook MallVancouverBC V6T 1Z3Canada Key Laboratory of Neurodegenerative Diseases Ministry of EducationBeijingP.R.China Zhejiang Clinical Research Center for Mental Disorders Key Laboratory of Alzheimer’s Disease of Zhejiang ProvinceSchool of Mental Health and The Affiliated Kangning HospitalInstitute of AgingWenzhou Medical UniversityWenzhouZhejiang 325000China Oujiang Laboratory(Zhejiang Lab for Regenerative Medicine Vision and Brain Health)WenzhouZhejiang 325000China

Inflammasomes are large protein complexes that play a major role in sensing inflammatory signals and triggering the innate immune response.Each inflammasome complex has three major components:an upstream sensor molecule that is connected to a downstream effector protein such as caspase-1 through the adapter protein ASC.Inflammasome formation typically occurs in response to infectious agents or cellular damage.The active inflammasome then triggers caspase-1 activation,followed by the secretion of pro-inflammatory cytokines and pyroptotic cell death.Aberrant inflammasome activation and activity contribute to the development of diabetes,cancer,and several cardiovascular and neurodegenerative disorders.As a result,recent research has increasingly focused on investigating the mechanisms that regulate inflammasome assembly and activation,as well as the potential of targeting inflammasomes to treat various diseases.Multiple clinical trials are currently underway to evaluate the therapeutic potential of several distinct inflammasome-targeting therapies.Therefore,understanding how different inflammasomes contribute to disease pathology may have significant implications for developing novel therapeutic strategies.In this article,we provide a summary of the biological and pathological roles of inflammasomes in health and disease.We also highlight key evidence that suggests targeting inflammasomes could be a novel strategy for developing new disease-modifying therapies that may be effective in several conditions.

关键词： inflam therapeutic potential

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Diabetic retinopathy identification based on multi-sourcefree domain adaptation

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International Journal of Ophthalmology(English edition) 2024年第7期17卷 1193-1204页

作者： guang-Hua zhang guang-Ping Zhuo Zhao-Xia zhang Bin Sun Wei-Hua Yang Shao-Chong zhang School of Big Data Intelligent Diagnosis&Treatment Industry Taiyuan UniversityTaiyuan 030032Shanxi ProvinceChina Shanxi Key Laboratory of Intelligent Optimization Computing and Blockchain Technology Taiyuan Normal UniversityTaiyuan 030619Shanxi ProvinceChina Shanxi Eye Hospital Taiyuan 030002Shanxi ProvinceChina College of Computer Science and Technology Taiyuan Normal UniversityTaiyuan 030619Shanxi ProvinceChina Shenzhen Eye Institute Shenzhen Eye HospitalJinan UniversityShenzhen 518040Guangdong ProvinceChina

AIM:To address the challenges of data labeling difficulties,data privacy,and necessary large amount of labeled data for deep learning methods in diabetic retinopathy(DR)identification,the aim of this study is to develop a source-free domain adaptation(SFDA)method for efficient and effective DR identification from unlabeled data.METHODS:A multi-SFDA method was proposed for DR identification.This method integrates multiple source models,which are trained from the same source domain,to generate synthetic pseudo labels for the unlabeled target domain.Besides,a softmax-consistence minimization term is utilized to minimize the intra-class distances between the source and target domains and maximize the inter-class distances.Validation is performed using three color fundus photograph datasets(APTOS2019,DDR,and EyePACS).RESULTS:The proposed model was evaluated and provided promising results with respectively 0.8917 and 0.9795 F1-scores on referable and normal/abnormal DR identification tasks.It demonstrated effective DR identification through minimizing intra-class distances and maximizing inter-class distances between source and target domains.CONCLUSION:The multi-SFDA method provides an effective approach to overcome the challenges in DR identification.The method not only addresses difficulties in data labeling and privacy issues,but also reduces the need for large amounts of labeled data required by deep learning methods,making it a practical tool for early detection and preservation of vision in diabetic patients.

关键词： diabetic retinopathy multisource-free domain adaptation pseudo-label generation softmaxconsistence minimization

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Characteristics and quality of clinical practice guidelines for diabetic kidney disease: a systematic review

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Journal of Traditional Chinese Medicine 2024年第3期44卷 609-619页

作者： WANG Yuhuang zhang Le zhang Zhengshan yao Zhi LI Xiyao SUN Luying LIAO Xing Department of Nephropathy and Endocrine Dongzhimen HospitalBeijing University of Chinese Medicine Centre for Evidence-Based Chinese Medicine Institute of Basic Research in Clinical MedicineChina Academy of Chinese Medical Sciences Department of Endocrine One Zone Fangshan HospitalBeijing University of Chinese Medicine

OBJECTIVE: To assess the quality of Clinical practice guidelines(CPGs) in the context of diabetic kidney disease(DKD) and determine whether any factors affect the quality. METHODS: We searched eight databases along with five international and national organizations to develop or archive guidelines from their inception to July 2023, with an additional search of ***. And the authoritative organizations related to nephrology. CPGs and consensus statements created using direct differential diagnosis or therapy for DKD were included without language restrictions. Their quality was evaluated by four reviewers using the Appraisal of Guidelines for Research and Evaluation Ⅱ(AGREE Ⅱ) instrument. Along with the item and domain scores, the guideline was also allocated an overall quality score, which ranged from 1(lowest possible quality) to 7(highest possible quality). Moreover, an overall recommendation for use was also assigned(“recommended”, “recommended with modifications” or “not recommended”). RESULTS: A total of 16 CPGs were included, of which 14 were from Asia and the remaining two from Europe. These two CPGs were updated in the third version. Six CPGs were recommended for use because their primary domains scored in the medium or high category. Furthermore, five CPGs were recommended with modifications as the stakeholder involvement, applicability, and editorial independence domains were evaluated as low categories. In all domains, the lowest average score was for rigour of development(33%), followed by application(36%), and stakeholder involvement(51%). The highest average score was for scope and purpose(79%), followed by clarity of presentation(75%). None of the CPGs considered the patient's viewpoint, and six of 16 CPGs did not use any grading system to translate the evidence into recommendations. Additionally, only three of 16 CPGs shared search strategy, and eight of 16 CPGs did not declare a funding source. CONCLUSIONS: According to the AGREE II evaluation, more than one in four CPGs for DKD had poor methodolo

关键词： appraisal of guidelines for research and evaluation II diabetic nephropathies practice guideline quality assessment systematic review

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Selective nickel-electrocatalyzed benzylic C-H oxygenation of functionalized alkyl arenes

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Chinese Chemical Letters 2024年第2期35卷 396-401页

作者： Shunyao Tang Siyi Wang Dongmei zhang Xinxing zhang guang Yang Yanwei Wang Youai Qiu State Key Laboratory of Elemento-Organic Chemistry Frontiers Science Center for New Organic MatterCollege of ChemistryNankai UniversityTianjin 300071China College of Chemistry Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education)Renewable Energy Conversion and Storage Center (RECAST)Frontiers Science Center for New Organic MatterNankai UniversityTianjin 300071China

Herein, a site-selective paired electrochemical C–H oxidation of functionalized alkyl arenes promoted by nickel catalyst is disclosed. A Ni(Ⅱ)-dioxygen species formed in situ efficiently enable the oxidation process under mild conditions with a broad substrate scope with excellent functional group compatibilities,such as free carboxylic acid, aldehyde, halogen(including aryl iodide), amide and amino acid. The use of the nickel catalyst in combination with water provides a safe, green and economical method for oxidation of a range of molecules varying in complexity and drug derivatives, demonstrating its potential application in organic synthesis and the pharmaceutical industry. Reaction outcomes and mechanistic studies revealed the key role of the in situ Ni(Ⅱ)-dioxygen species for the subsequent oxidation of C(sp^(3))–H bonds,and short-lived reactive intermediates(aryl radical cation) was rapidly captured by the combination of a bipolar ultramicroelectrode(BUME) with nano-electrospray ionization mass spectrometry.

关键词： Electrochemical C-H oxidation Functionalized alkyl arenes Paired nickel-electrocatalysis H_(2)O oxidation Ketones

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Coherent link between a Ti:sapphire comb and a 1.5μm laser via nonlinear interaction in photonic crystal fiber

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Photonics Research 2024年第2期12卷 350-355页

作者： YUAN yao HAOSEN SHI guang YANG BO LI CONGYU WANG HONGFU YU LONGSHENG MA YANYI JIANG State Key Laboratory of Precision Spectroscopy East China Normal UniversityShanghai 200062China Collaborative Innovation Center of Extreme Optics Shanxi UniversityTaiyuan 030006China

Optical clock networks have distinct advantages for the dissemination of time/frequency,geodesy,and fundamental research.To realize such a network,the telecom band and optical atomic clocks have to be coherently bridged.Since the telecom band and optical atomic clocks reside in a distinct spectral region,second-harmonic generation is usually introduced to bridge the large frequency gap.In this paper,we introduce a new method to coherently link a 1550 nm continuous wave laser with a Ti:sapphire mode-locked laser-based optical frequency comb.By coupling the 1550 nm continuous wave laser light and the Ti:sapphire comb light together into a photonic crystal fiber,nonlinear interaction takes place,and new comblike frequency components related to the 1550 nm laser frequency are generated in the visible region.Consequently,we can detect beat notes between two combs in the visible region with a signal-to-noise ratio of more than 40 dB in a resolution bandwidth of300 kHz.With this signal,we realize an optical frequency divider for converting the frequency of optical clocks in the visible region to the telecom band at 1.55μm.An out-of-loop measurement shows that the additional noise and uncertainty induced in optical frequency conversion are 5×10^(-18)at 1 s averaging time and 2.2×10^(-19),respectively,which are limited by the uncompensated light path fluctuation but fulfill precision measurement using state-of-the-art optical clocks.

关键词： fiber interaction nonlinear

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Prescribed time control based on the periodic delayed sliding mode surface without singularities

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Science China(Information Sciences) 2024年第7期67卷 256-270页

作者： Bin ZHOU Yi DING Kang-Kang zhang guang-Ren DUAN Center for Control Theory and Guidance Technology Harbin Institute of Technology

In this paper, nonsingular prescribed-time control is studied based on periodic delayed sliding mode surfaces. Different from the existing sliding mode control, where either singularity problems may appear or the convergence time depends on the initial state, the proposed sliding mode control approaches can achieve prescribed-time convergence without singularity. The proposed nonsingular sliding mode control approaches can be applied to both second-order and high-order nonlinear systems with prescribed-time convergence. As applications of the proposed sliding mode control approaches, the control of hypersonic vehicle systems is revisited. Numerical simulations on the nonlinear model of the hypersonic vehicle system show the effectiveness of the proposed methods.

关键词： prescribed-time control smooth periodic delayed feedback sliding mode control high-order nonlinear systems hypersonic vehicle systems

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A model reduction approach for discrete-time linear time-variant systems with delayed inputs

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Science China(Information Sciences) 2024年第4期67卷 197-217页

作者： Ai-Guo WU guang-Ren DUAN Yu WANG Jie zhang School of Mechanical Engineering and Automation Harbin Institute of Technology(Shenzhen) HIT Wuhu Robot Technology Research Institute Center for Control Science and Technology Southern University of Science and Technology

A model reduction approach is presented for discrete-time linear time-variant input-delayed systems. According to this proposed approach, a dynamical variable is constructed by taking advantage of the current state and historical information of input. It is revealed that the behavior of this dynamical variable is governed by a discrete-time linear delay-free system. It is worth noting that the presented variable transformation does not require the system matrix to be invertible. Based on the reduced delay-free models,stabilizing control laws can be easily obtained for the original delayed system. For the case with a single input delay, the constructed variable is an exact prediction for the future state, and thus the stabilizing control law could be designed by replacing the future state with its prediction. Finally, three discrete-time periodic systems with delayed input are employed to illustrate how to utilize the presented model reduction approaches.

关键词： reduction approach predictor-based feedback time-varying systems delayed input periodic system

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Impact wear properties of dissimilar joints between bainitic frogs and pearlite rails

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Journal of Iron and Steel Research(International) 2024年第1期31卷 275-287页

作者： Pin-yong Zeng Chun-guang Zuo Xiao-yu zhang Wei Li Tribology Research Institute Southwest Jiaotong UniversityChengdu610031SichuanChina

The impact wear behavior and damage mechanism of dissimilar welded joints between U26Mn frog and U75 V rail before and after normalizing treatment were studied by cyclic impact tests.The experiment indicated that the impact wear volume of the joints increased with the increasing number of impact cycles.The main wear mechanisms include pitting wear,mild fatigue wear,delamination wear,and fatigue wear,and plastic deformation was the primary impact wear mechanism.Among them,fatigue wear had the greatest influence on wear volume,while other wear mechanisms had limited effect.The impact wear resistance of the base material was better than that of the heat-affected zone.Normalizing treatment was beneficial to improving the impact wear resistance of welded joints owing to its effect to promote pearlite recovery,grain refinement,and uniform distribution of grains.The martensite generated in the rail welded joints aggravated the impact wear damage to the materials,which should be avoided.

关键词： Dissimilar welded joint Impact wear Bainitic steel Damage mechanism Wear rate

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