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Social Sciences in China 2024年第1期45卷 89-105页

作者： Luo Yi'nan school of government Peking University

How to deal with differences is a question that any political body must respond to.The individualist perspective emphasizes that actors will adopt measures to exclude or even eliminate divergent claims in order to gain control over interests power or statutory policy,but the rich experience of traditional Chinese scholar officials offers the possibility of going beyond the limitations of this perspective.The perspective of“tianxia qingshi(world circumstances)”as a new narrative reveals a unique practical logic and dynamic mechanism in Chinese political civilization that have been overlooked by the individualist perspective.The“Green Sprouts policy(qing miao fa)polemic”in the early years of the New Policies era of the Northern Song dynasty(960-1127)presents a historical situation that has not been given full attention by existing research.

关键词： tianxia qingshi(world circumstances) “Green Sprouts policy polemic ”dispute practice scholar-official politics

Evolution of artificial ion channels

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National Science Review 2024年第1期11卷 72-73页

作者： Yugang Wang school of Physics Peking University

Protein ion channels on a cell membrane generate action potentials for cellular signal transduction, and regulate biological activities during life. Since the discovery of the asymmetric ion transport phenomenon in quartz nanopipettes by Bard and colleagues [1], synthetic nanofluidic materials and devices have attracted a lot of research interests from the scientific community,

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Pushing the boundaries: an interview with Dae-Hyun Kim on terahertz devices

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National Science Review 2024年第3期11卷 42-45页

作者： Defu Wang the Center for Carbon-based Electronics School of Electronics Peking University

Ⅲ–Ⅴ compound semiconductors, such as InGaAs/InAlAs, exhibit exceptional carrier transport properties, establishing them as fundamental elements in terahertz(THz) applications crucial for the development of 6G netwo...

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Post-layout simulation driven analog circuit sizing

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Science China(Information Sciences) 2024年第4期67卷 289-300页

作者： Xiaohan GAO Haoyi ZHANG Siyuan YE Mingjie LIU David Z.PAN Linxiao SHEN Runsheng WANG Yibo LIN Ru HUANG school of Integrated Circuits Peking University school of Computer Science Peking University Department of Electrical and Computer Engineering University of Texas at Austin Institute of Electronic Design Automation Peking University

Post-layout simulation provides accurate guidance for analog circuit design, but post-layout performance is hard to be directly optimized at early design stages. Prior work on analog circuit sizing often utilizes pre-layout simulation results as the optimization objective. In this work, we propose a post-layoutsimulation-driven(post-simulation-driven for short) analog circuit sizing framework that directly optimizes the post-layout simulation performance. The framework integrates automated layout generation into the optimization loop of transistor sizing and leverages a coupled Bayesian optimization algorithm to search for the best post-simulation performance. Experimental results demonstrate that our framework can achieve over 20% better post-layout performance in competitive time than manual design and the method that only considers pre-layout optimization.

关键词： analog EDA transistor sizing Bayesian optimization post-layout simulation

Versatile photonic molecule switch in multimode microresonators

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Light(Science & Applications) 2024年第3期13卷 498-509页

作者： Zihan Tao Bitao Shen Wencan Li Luwen Xing Haoyu Wang Yichen Wu Yuansheng Tao Yan Zhou Yandong He Chao Peng Haowen Shu Xingjun Wang State Key Laboratory of Advanced Optical Communications System and Networks School of ElectronicsPeking UniversityBeijing 100871China College of Engineering Peking UniversityBeijing 100871China school of Integrated Circuits Peking University100871 BejingChina peking university Yangtze Delta Institute of Optoelectronics Nantong 226010China Frontiers Science Center for Nano-optoelectronics Peking UniversityBeijing 100871China Peng Cheng Laboratory Shenzhen 518055China

Harnessing optical supermode interaction to construct artificial photonic molecules has uncovered a series of fundamental optical phenomena analogous to atomic physics.Previously,the distinct energy levels and interactions in such two-level systems were provided by coupled microresonators.The reconfigurability is limited,as they often require delicate external field stimuli or mechanically altering the geometric factors.These highly specific approaches also limit potential applications.Here,we propose a versatile on-chip photonic molecule in a multimode microring,utilizing a flexible regulation methodology to dynamically control the existence and interaction strength of spatial modes.The transition between single/multi-mode states enables the“switched-off/on”functionality of the photonic molecule,supporting wider generalized applications scenarios.In particular,“switched-on”state shows flexible and multidimensional mode splitting control in aspects of both coupling strength and phase difference,equivalent to the a.***.and d.c.Stark effect.“Switched-off”state allows for perfect low-loss single-mode transition(Qi~10 million)under an ultra-compact bend size(FSR~115 GHz)in a foundry-based silicon microring.It breaks the stereotyped image of the FSR-Q factor trade-off,enabling ultra-wideband and high-resolution millimeter-wave photonic operations.Our demonstration provides a flexible and portable solution for the integrated photonic molecule system,extending its research scope from fundamental physics to real-world applications such as nonlinear optical signal processing and sixth-generation wireless communication.

关键词： switched multimode millimeter

Perception field based imitation learning for unlabeled multi-agent pathfinding

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Science China(Information Sciences) 2024年第5期67卷 115-135页

作者： Wenjie CHU Ailun YU Wei ZHANG Haiyan ZHAO Zhi JIN school of Computer Science Peking University Key Laboratory of High-Confidence Software Technologies (peking university) Ministry of Education

This paper proposes an imitation learning method to learn a universal agent policy for unlabeled multi-agent pathfinding(unlabeled MAPF) in grid environments. The method transforms the unlabeled MAPF problem into a series of temporal-independent homogeneous classification problems for each agent.Based on this transformation, a neural network is designed to imitate a distance-optimal expert algorithm.The neural network consists of two successive modules: perception field learner and field integrating classifier.The former refines and encodes the current system state into a perception field for each agent by combining a set of learnable field-generating functions. The latter takes an agent's perception field as input and decides the agent's next action based on a triplet cross-attention mechanism. We evaluate our method on a diverse set of unlabeled MAPF tasks. Compared with state-of-the-art counterparts, the experimental results manifest the superiority of the proposed method in both generalization ability and scalability.

关键词： unlabeled multi-agent pathfinding perception field triplet cross-attention multi-agent imitation learning learning-based planning

Characterization of size-resolved effective density of atmospheric particles in an urban atmosphere in Southern China

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Journal of Environmental Sciences 2024年第7期141卷 194-204页

作者： Tingting Xie Liming Cao Jinyi Zheng Peng Xuan Xiaofeng Huang Laboratory of Atmospheric Observation Supersite School of Environment and EnergyPeking University Shenzhen Graduate SchoolShenzhen 518055China

Effective density(ρ_(eff))is one of the most important physical properties of atmospheric particles,providing important references in exploring the emissions and aging processes of fresh particles.In this study,a combined system of differential mobility analyzer,centrifugal particle mass analyzer,and condensation particle counter was used to periodically measure theρ_(eff)of atmospheric particles in Shenzhen from Oct.2021 to Jan.2022.Results showed that theρ_(eff)of particles with various size presented a bimodal distribution,which could be divided into main density(ρ_(m),main peak,corresponding to relatively dense particles after aging)and sub density(ρ_(s),sub peak,corresponding to fresh particles).The occurrence frequencies ofρ_(s)of particles with diameters of 50 and 80 nm were less than 20%,but were as high as about 40%of that with diameters from 120 to 350 nm.Theρ_(m)showed increasing trend with the size of particles,whileρ_(s)decreased as the increasing of the size of particles.Theρ_(eff)on pollution day varied significantly with chemical compositions.The increasing of the proportion of sulfate could promote the increasing ofρ_(eff),while black carbon and organic matter caused opposite effects,which may be related to various factors,including the difference of the material density and morphology of various chemical components.Theρ_(eff)of 50,80 and 120 nm particles decreased considerably during the new particle formation event,indicating that organic condensation was an important contributor to new particle growth.

关键词： DMA-CPMA-CPC Effective density Main/sub density Size distribution

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Establishment of a cholangiocarcinoma risk evaluation model based on mucin expression levels

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World Journal of Gastrointestinal Oncology 2024年第4期16卷 1344-1360页

作者： Chun-Yuan Yang Li-Mei Guo Yang Li Guang-Xi Wang Xiao-Wei Tang Qiu-Lu Zhang Ling-Fu Zhang Jian-Yuan Luo Department of Pathology Institute of Systems BiomedicineSchool of Basic Medical Sciences Peking UniversityPeking University Third HospitalPeking University Health Science CenterBeijing 100191China Department of General Surgery Peking University Third HospitalBeijing 100191China Department of Medical Genetics Department of Biochemistry and BiophysicsSchool of Basic Medical Sciences Peking UniversityPeking University Health Science CenterBeijing 100191China

BACKGROUND Cholangiocarcinoma(CCA)is a highly malignant cancer,characterized by frequent mucin overexpression.MUC1 has been identified as a critical oncogene in the progression of CCA.However,the comprehensive understanding of how the mucin family influences CCA progression and prognosis is still incomplete.AIM To investigate the functions of mucins on the progression of CCA and to establish a risk evaluation formula for stratifying CCA patients.METHODS Single-cell RNA sequencing data from 14 CCA samples were employed for elucidating the roles of mucins,complemented by bioinformatic analyses.Subse-quent validations were conducted through spatial transcriptomics and immuno-histochemistry.The construction of a risk evaluation model utilized the least absolute shrinkage and selection operator regression algorithm,which was further confirmed by independent cohorts and diverse data types.RESULTS CCA tumor cells with elevated levels of MUC1 and MUC4 showed activated nucleotide metabolic pathways and increased invasiveness.MUC5AC-high cells were found to promote CCA progression through WNT signaling.MUC5B-high cells exhibited robust cellular oxidation activities,leading to resistance against antitumoral treatments.MUC13-high cells were observed to secret chemokines,recruiting and transforming macrophages into the M2-polarized state,thereby suppressing antitumor immunity.MUC16-high cells were found to promote tumor progression through interleukin-1/nuclear factor kappa-light-chain-enhancer of activated B cells signaling upon interaction with neutrophils.Utilizing the expression levels of these mucins,a risk factor evaluation formula for CCA was developed and validated across multiple cohorts.CCA samples with higher risk factors exhibited stronger metastatic potential,chemotherapy resistance,and poorer prognosis.CONCLUSION Our study elucidates the functional mechanisms through which mucins contribute to CCA development,and provides tools for risk stratification in CCA.

关键词： Mucin Cholangiocarcinoma Single-cell RNA sequencing Spatial transcriptomics Prognosis

Cogeneration of Innovative Audio-visual Content: A New Challenge for Computing Art

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Machine Intelligence Research 2024年第1期21卷 4-28页

作者： Mengting Liu Ying Zhou Yuwei Wu Feng Gao Advanced Institute of Information Technology Peking UniversityHangzhou311215China school of Electronic and Computer Engineering Shenzhen Graduate SchoolPeking UniversityShenzhen 518000China Peng Cheng Laboratory Shenzhen 518000China school of Arts Peking UniversityBeijing 100871China

In recent years,computing art has developed rapidly with the in-depth cross study of artificial intelligence generated con-tent(AIGC)and the main features of artworks.Audio-visual content generation has gradually been applied to various practical tasks,including video or game score,assisting artists in creation,art education and other aspects,which demonstrates a broad application pro-spect.In this paper,we introduce innovative achievements in audio-visual content generation from the perspective of visual art genera-tion and auditory art generation based on artificial intelligence(Al).We outline the development tendency of image and music datasets,visual and auditory content modelling,and related automatic generation systems.The objective and subjective evaluation of generated samples plays an important role in the measurement of algorithm performance.We provide a cogeneration mechanism of audio-visual content in multimodal tasks from image to music and display the construction of specific stylized datasets.There are still many new op-portunities and challenges in the field of audio-visual synesthesia generation,and we provide a comprehensive discussion on them.

关键词： Artificial intelligence(AI)art audio-visual artificial intelligence generated content(AIGC) multimodal artistic evalu-ation

Pregnancy and the disease recurrence of patients previously treated for differentiated thyroid cancer:A systematic review and meta analysis

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Chinese Medical Journal 2024年第5期137卷 547-555页

作者： Rui Shan Xin Li Ming Tao Wucai Xiao Jing Chen Fang Mei Shibing Song Bangkai Sun Chunhui Yuan Zheng Liu Department of Maternal and Child Health School of Public HealthPeking UniversityBeijing 100191China Department of General Surgery Peking University Third HospitalBeijing 100191China Department of Pathology Peking University Third HospitalSchool of Basic Medical SciencesPeking University Health Science CenterBeijing 100191China Information Management and Big Data Center Peking University Third HospitalBeijing 100191China

Background:Differentiated thyroid cancer(DTC)is commonly diagnosed in women of child-bearing age,but whether pregnancy influences the prognosis of DTC remains controversial.This study aimed to summarize existing evidence regarding the association of pregnancy with recurrence risk in patients previously treated for DTC.Methods:We searched PubMed,Embase,Web of Science,Cochrane,and Scopus based on the prespecified protocol registered at PROSPERO(CRD42022367896).After study selection,two researchers independently extracted data from the included studies.For quantitative data synthesis,we used random-effects meta-analysis models to pool the proportion of recurrence(for pregnant women only)and odds ratio(OR;comparing the risk of recurrence between the pregnancy group and the nonpregnancy group),respectively.Then we conducted subgroup analyses to explore whether risk of recurrence differed by response to therapy status or duration of follow-up time.We also assessed quality of the included studies.Results:A total of ten studies were included.The sample size ranged from 8 to 235,with participants’age at pregnancy or delivery ranging from 28 to 35 years.The follow-up time varied from 0.1 to 36.0 years.The pooled proportion of recurrence in all pregnant patients was 0.13(95%confidence intervals[CI]:0.06-0.25;I^(2):0.58).Among six included studies reporting response to therapy status before pregnancy,we observed a trend for increasingly higher risk of recurrence from excellent,indeterminate,and biochemically incomplete to structurally incomplete response to therapy(P trend0.05)or the OR of recurrence in studies with a comparison group(P>0.05).Two included studies that focused on patients with distant metastasis

关键词： Thyroid cancer Pregnancy Recurrence Women Systematic review Meta-analysis

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