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作者： Zhenfei PENG Qiang SU xuwen ni

标准号: US20230006623(A1)

A bias circuit of a power amplifier includes a first part circuit, a second part circuit and a power supply, in which the power supply is connected with a power supply end of the first part circuit;two ends of the first part circuit are connected in parallel with two ends of the second part circuit, and after parallel connection one end of a parallel circuit is connected with a gate of the first transistor of the power amplifier in a signal amplification circuit;the first part circuit is configured to provide a first bias voltage, and the second part circuit is configured to provide a second bias voltage;the two bias voltages are superimposed to provide a stable bias voltage;and an impedance of the bias circuit is in a preset range of the impedance.

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BIAS CIRCUIT OF POWER AMPLIFIER, AND APPARATUS AND DEVICE

BIAS CIRCUIT OF POWER AMPLIFIER, AND APPARATUS AND DEVICE

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作者： PENG, Zhenfei 彭振飞 SU, Qiang 苏强 ni, xuwen 倪旭文

标准号: WO2022/170816(A1)

Disclosed are a bias circuit of a power amplifier, and an apparatus and a device. The circuit comprises a first-part circuit, a second-part circuit and a power source, wherein the power source is connected to a power source end of the first-part circuit;two ends of the first-part circuit are connected to two ends of the second-part circuit in parallel, and one end following parallel connection is connected to a gate electrode of a first transistor of the power amplifier;the gate electrode of the first transistor is provided with a first bias voltage and a second bias voltage by the first-part circuit and the second-part circuit respectively, the voltages are superposed, and then a stable bias voltage is provided;and the impedance of the bias circuit is within a preset impedance range. Therefore, a power amplifier is provided with a first bias voltage by a first-part circuit, the power amplifier is provided with a second bias voltage by a second-part circuit, and the second bias voltage can be used to adjust the first bias voltage, so as to provide the power amplifier with a stable bias voltage;and the impedance of a bias circuit is within a preset impedance range, thereby ensuring the linearity performance of the power amplifier, and reducing the memory effect of the power amplifier.

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A Time-Dependent Inclusion-Based Method for Continuous Collision Detection between Parametric Surfaces

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ACM TRANSACTIONS ON GRAPHICS 2024年第6期43卷 1-11页

作者： Chen, xuwen Yu, Cheng ni, Xingyu Chu, Mengyu Wang, Bin Chen, Baoquan Peking Univ Sch Intelligence Sci & Technol Beijing Peoples R China Peking Univ Sch Comp Sci Beijing Peoples R China Peking Univ State Key Lab Gen Artificial Intelligence Beijing Peoples R China BIGAI State Key Lab Gen Artificial Intelligence Beijing Peoples R China

Continuous collision detection (CCD) between parametric surfaces is typically formulated as a five-dimensional constrained optimization problem. In the field of CAD and computer graphics, common approaches to solving this problem rely on linearization or sampling strategies. Alternatively, inclusion-based techniques detect collisions by employing 5D inclusion functions, which are typically designed to represent the swept volumes of parametric surfaces over a given time span, and narrowing down the earliest collision moment through subdivision in both spatial and temporal dimensions. However, when high detection accuracy is required, all these approaches significantly increases computational consumption due to the Intelligence, Peking University, high-dimensional searching space. In this work, we develop a new time- dependent inclusion-based CCD framework that eliminates the need for temporal subdivision and can speedup conventional methods by a factor ranging from 36 to 138. To achieve this, we propose a novel time-dependent inclusion function that provides a continuous representation of a moving surface, along with a corresponding intersection detection algorithm that quickly identifies the time intervals when collisions are likely to occur. We validate our method across various primitive types, demonstrate its efficacy within the simulation pipeline and show that it significantly improves CCD efficiency while maintaining accuracy.

关键词： parametric surface continuous collision detection interval analysis

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Simulation and Optimization of Magnetoelastic Thin Shells

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ACM TRANSACTIONS ON GRAPHICS 2022年第4期41卷 p1-18页

作者： Chen, xuwen ni, Xingyu Zhu, Bo Wang, Bin Chen, Baoquan Peking Univ CFCS Beijing Peoples R China Dartmouth Coll Hanover NH 03755 USA Beijing Inst Gen Artificial Intelligence Beijing Peoples R China Peking Univ Sch AI Beijing Peoples R China

Magnetoelastic thin shells exhibit great potential in realizing versatile functionalities through a broad range of combination of material stiffness, remnant magnetization intensity, and external magnetic stimuli. In this paper, we propose a novel computational method for forward simulation and inverse design of magnetoelastic thin shells. Our system consists of two key components of forward simulation and backward optimization. On the simulation side, we have developed a new continuum mechanics model based on the Kirchhoff-Love thin-shell model to characterize the behaviors of a megnetolelastic thin shell under external magnetic stimuli. Based on this model, we proposed an implicit numerical simulator facilitated by the magnetic energy Hessian to treat the elastic and magnetic stresses within a unified framework, which is versatile to incorporation with other thin shell models. On the optimization side, we have devised a new differentiable simulation framework equipped with an efficient adjoint formula to accommodate various PDE-constraint, inverse design problems of magnetoelastic thin-shell structures, in both static and dynamic settings. It also encompasses applications of magnetoelastic soft robots, functional Origami, artworks, and meta-material designs. We demonstrate the efficacy of our framework by designing and simulating a broad array of magnetoelastic thin-shell objects that manifest complicated interactions between magnetic fields, materials, and control policies.

关键词： magnetic simulation thin shell magnetoelastic coupling

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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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One-Pot Construction of β-Selective Quinolines with γ-Quaternary Carbon from Vinylquinolines with Active Ylides via Pd/Sc/Bronsted Acid Co-Catalysis

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ACS CATALYSIS 2023年第10期13卷 6509-6517页

作者： Song, Longlong Xiong, Lulu ni, Dan Chen, Weixiong Ji, Jian Xue, Jian Chen, xuwen Wu, Xiang He, Xiao Liu, Shunying East China Normal Univ Shanghai Engn Res Ctr Mol Therapeut & New Drug Dev Sch Chem & Mol Engn Shanghai 200062 Peoples R China New York Univ Shanghai New York Univ East China Normal Univ Ctr Computat Shanghai 200062 Peoples R China

Vinyl-substituted N-heterocycles, as more challenginginert olefinswith more stable reactivity, have brought about widespread attentionin the reaction of aza-Michael addition or reduction coupling ***, we report a [Pd-(eta(3)-C3H5)-Cl](2)/Sc-(OTf)(3)-catalyzed catalytic processaccelerated by Bronsted acids with a beta-selective aza-Michaeladdition to yield a gamma-quaternary carbon from vinyl-substitutedquinolines, diazos, and anilines/alcohols in one pot. The generationof anhydride analogues from Bronsted acid and the counter anion(OTf-) of Lewis acid promotes the activation ofthe corresponding Lewis acid and the nearly quantitative *** pi-cation and coordination interactions play pivotal rolesin the activation of the vinyl-quinoline substrates by the activatedLewis acid Sc-(OTf)(3). The control mechanistic evidence andDFT calculations presented a Pd/Sc/Bronsted acid co-catalyzedaddition mechanism. The triple co-catalytic system provides a strategyfor the activation of vinyl-quinolines with a linear selectivity containing gamma-quaternary carbon, and the developed method shows a broadsubstrate scope varying from alkyl/aryl alcohols and amines whichprovides a general and rapid strategy for the quinoline-based diverselibrary construction.

关键词： Pd Sc co-catalysis one-pot reaction vinylquinolines active ylide quaternary carbon

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Simulating Thin Shells by Bicubic Hermite Elements

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COMPUTER-AIDED DESIGN 2024年 174卷

作者： ni, Xingyu Chen, xuwen Yu, Cheng Wang, Bin Chen, Baoquan Peking Univ Sch CS Beijing Peoples R China Peking Univ Sch IST Beijing Peoples R China Peking Univ Sch EECS Beijing Peoples R China Peking Univ State Key Lab Gen Artificial Intelligence Beijing Peoples R China Beijing Inst Gen Artificial Intelligence BIGAI State Key Lab Gen Artificial Intelligence Beijing Peoples R China

In this study, we present the bicubic Hermite element method (BHEM), a new computational framework devised for the elastodynamic simulation of thin-shell structures. The BHEM is constructed based on quadrilateral Hermite patches, which serve as a unified representation for shell geometry, simulation, collision avoidance, as well as rendering. Compared with the commonly utilized linear FEM, the BHEM offers higher-order solution spaces, enabling the capture of more intricate and smoother geometries while employing significantly fewer finite elements. In comparison to other high-order methods, the BHEM achieves conforming C 1 continuity for Kirchhoff-Love (KL) shells with minimal complexity. Furthermore, by leveraging the subdivision and convex hull properties of Hermite patches, we develop an efficient algorithm for ray-patch intersections, facilitating collision handling in simulations and ray tracing in rendering. This eliminates the need for laborious remodeling of the pre-existing surface as the conventional approaches do. We substantiate our claims with comprehensive experiments, which demonstrate the high accuracy and versatility of the proposed method.

关键词： Thin-shell simulation High-order finite elements Hermite interpolation

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A 0.42-mW 1-Mb/s 3-to4-GHz Transceiver in 0.18-μm CMOS With Flexible Efficiency, Bandwidth, and Distance Control for IoT Applications

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IEEE JOURNAL OF SOLID-STATE CIRCUITS 2017年第6期52卷 1479-1494页

作者： Liu, Dang ni, xuwen Zhou, Ranran Rhee, Woogeun Wang, Zhihua Tsinghua Univ Inst Microelect Beijing 100084 Peoples R China

This paper describes a short-range transceiver architecture using frequency-hopped sinusoidal OOK pulses. Since signal bandwidth does not necessarily have to satisfy > 500 MHz requirement like conventional ultra-wideband (UWB) pulses, the proposed transceiver named as a very-wide band (VWB) transceiver offers degrees of freedom to choose an optimum operation duty cycle in terms of energy efficiency, bandwidth efficiency, and communication range, while providing much lower operation duty cycle than that of narrow band OOK transceiver. The VWB transmission significantly relaxes the complexity of transceiver design without requiring advanced CMOS technology. In the transmitter, pulse generation circuit design is simplified with the duty-cycled sinusoidal signal compared to that in the impulse-radio UWB (IR-UWB) transmitter. In the receiver, an asynchronous energy detection topology is proposed to achieve robust energy detection by overcoming the synchronization issue as well as the saturation problem of the integrator circuit. A prototype 3-to-4 GHz VWB transceiver is implemented in 0.18 mu m CMOS. The transceiver achieves the communication distance of > 2 m at 1 Mb/s data rate with the peak-to-peak pulse amplitude of only 300 mV and the duty cycle of 0.6%, consuming 0.42 mW from a 1.8 V supply.

关键词： Bandwidth efficient energy detection energy efficient impulse radio (IR) transceiver ultra-wideband (UWB) wireless

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Simulating Parametric Thin Shells by Bicubic Hermite Elements

arXiv

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arXiv 2023年

作者： ni, Xingyu Chen, xuwen Yu, Cheng Wang, Bin Chen, Baoquan

In this study, we present the bicubic Hermite element method (BHEM), a new computational framework devised for the elastodynamic simulation of parametric thin-shell structures. The BHEM is constructed based on parametric quadrilateral Hermite patches, which serve as a unified representation for shell geometry, simulation, collision avoidance, as well as rendering. Compared with the commonly utilized linear FEM, the BHEM offers higher-order solution spaces, enabling the capture of more intricate and smoother geometries while employing significantly fewer finite elements. In comparison to other high-order methods, the BHEM achieves conforming C1 continuity for Kirchhoff-Love (KL) shells with minimal complexity. Furthermore, by leveraging the subdivision and convex hull properties of Hermite patches, we develop an efficient algorithm for ray-patch intersections, facilitating collision handling in simulations and ray tracing in rendering. This eliminates the need for laborious remodeling of the pre-existing parametric surface as the conventional approaches do. We substantiate our claims with comprehensive experiments, which demonstrate the high accuracy and versatility of the proposed method. Copyright © 2023, The Authors. All rights reserved.

关键词： Shells (structures)

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ECCParaCorp: a cross-lingual parallel corpus towards cancer education, dissemination and application

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BMC MEDICAL INFORMATICS AND DECISION MAKING 2020年第3期20卷 122-122页

作者： Ma, Hetong Yang, Feihong Ren, Jiansong Li, ni Dai, Min Wang, xuwen Fang, An Li, Jiao Qian, Qing He, Jie Chinese Acad Med Sci & Peking Union Med Coll Inst Med Informat Lib Beijing Peoples R China Chinese Acad Med Sci & Peking Union Med Coll Off Canc Screening Natl Clin Res Ctr Canc Natl Canc CtrCanc Hosp Beijing 100021 Peoples R China Chinese Acad Med Sci & Peking Union Med Coll Dept Thorac Surg Natl Clin Res Ctr Canc Natl Canc CtrCanc Hosp Beijing Peoples R China

BackgroundThe increasing global cancer incidence corresponds to serious health impact in countries worldwide. Knowledge-powered health system in different languages would enhance clinicians' healthcare practice, patients' health management and public health literacy. High-quality corpus containing cancer information is the necessary foundation of cancer education. Massive non-structural information resources exist in clinical narratives, electronic health records (EHR) etc. They can only be used for training AI models after being transformed into structured corpus. However, the scarcity of multilingual cancer corpus limits the intelligent processing, such as machine translation in medical scenarios. Thus, we created the cancer specific cross-lingual corpus and open it to the public for academic *** to build an English-Chinese cancer parallel corpus, we developed a workflow of seven steps including data retrieval, data parsing, data processing, corpus implementation, assessment verification, corpus release, and application. We applied the workflow to a cross-lingual, comprehensive and authoritative cancer information resource, PDQ (Physician Data Query). We constructed, validated and released the parallel corpus named as ECCParaCorp, made it openly accessible *** proposed English-Chinese Cancer Parallel Corpus (ECCParaCorp) consists of 6685 aligned text pairs in Xml, Excel, Csv format, containing 5190 sentence pairs, 1083 phrase pairs and 412 word pairs, which involved information of 6 cancers including breast cancer, liver cancer, lung cancer, esophageal cancer, colorectal cancer, and stomach cancer, and 3 cancer themes containing cancer prevention, screening, and treatment. All data in the parallel corpus are online, available for users to browse and download (http://***/ECCParaCorp/).ConclusionsECCParaCorp is a parallel corpus focused on cancer in a cross-lingual form, which is openly accessible. It would make up the imbalan

关键词： Medical parallel corpus Cancer information Cross language Bilingual Cancer data HealthNLP

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