The 2021 ACM/SIGDA International Symposium on Field-Programmable Gate Arrays最新文献

筛选
英文 中文
Design Principles for Packet Deparsers on FPGAs fpga上分组分离器的设计原则
The 2021 ACM/SIGDA International Symposium on Field-Programmable Gate Arrays Pub Date : 2021-02-17 DOI: 10.1145/3431920.3439303
Thomas Luinaud, KaloomInc Montréal, Canada J.M. Pierre Langlois, Jeferson Santiago da Silva, J. Langlois
{"title":"Design Principles for Packet Deparsers on FPGAs","authors":"Thomas Luinaud, KaloomInc Montréal, Canada J.M. Pierre Langlois, Jeferson Santiago da Silva, J. Langlois","doi":"10.1145/3431920.3439303","DOIUrl":"https://doi.org/10.1145/3431920.3439303","url":null,"abstract":"The P4 language has drastically changed the networking field as it allows to quickly describe and implement new networking applications. Although a large variety of applications can be described with the P4 language, current programmable switch architectures impose significant constraints on P4 programs. To address this shortcoming, FPGAs have been explored as potential targets for P4 applications. P4 applications are described using three abstractions: a packet parser, match-action tables, and a packet deparser, which reassembles the output packet with the result of the match-action tables. While implementations of packet parsers and match-action tables on FPGAs have been widely covered in the literature, no general design principles have been presented for the packet deparser. Indeed, implementing a high-speed and efficient deparser on FPGAs remains an open issue because it requires a large amount of interconnections and the architecture must be tailored to a P4 program. As a result, in several works where a P4 application is implemented on FPGAs, the deparser consumes a significant proportion of chip resources. Hence, in this paper, we address this issue by presenting design principles for efficient and high-speed deparsers on FPGAs. As an artifact, we introduce a tool that generates an efficient vendor-agnostic deparser architecture from a P4 program.Our design has been validated and simulated with a cocotb-based framework.The resulting architecture is implemented on Xilinx Ultrascale+ FPGAs and supports a throughput of more than 200 Gbps while reducing resource usage by almost 10x compared to other solutions.","PeriodicalId":386071,"journal":{"name":"The 2021 ACM/SIGDA International Symposium on Field-Programmable Gate Arrays","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125034459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 3
GraSU GraSU
The 2021 ACM/SIGDA International Symposium on Field-Programmable Gate Arrays Pub Date : 2021-02-17 DOI: 10.1145/3431920.3439288
Qinggang Wang, Long Zheng, Yu Huang, Pengcheng Yao, Chuangyi Gui, Xiaofei Liao, Hai Jin, Wenbin Jiang, Fubing Mao
{"title":"GraSU","authors":"Qinggang Wang, Long Zheng, Yu Huang, Pengcheng Yao, Chuangyi Gui, Xiaofei Liao, Hai Jin, Wenbin Jiang, Fubing Mao","doi":"10.1145/3431920.3439288","DOIUrl":"https://doi.org/10.1145/3431920.3439288","url":null,"abstract":"Existing FPGA-based graph accelerators, typically designed for static graphs, rarely handle dynamic graphs that often involve substantial graph updates (e.g., edge/node insertion and deletion) over time. In this paper, we aim to fill this gap. The key innovation of this work is to build an FPGA-based dynamic graph accelerator easily from any off-the-shelf static graph accelerator with minimal hardware engineering efforts (rather than from scratch). We observe em spatial similarity of dynamic graph updates in the sense that most of graph updates get involved with only a small fraction of vertices. We therefore propose an FPGA library, called GraSU, to exploit spatial similarity for fast graph updates. GraSU uses a differential data management, which retains the high-value data (that will be frequently accessed) in the specialized on-chip UltraRAM while the overwhelming majority of low-value ones reside in the off-chip memory. Thus, GraSU can transform most of off-chip communications arising in dynamic graph updates into fast on-chip memory accesses. Our experiences show that GraSU can be easily integrated into existing state-of-the-art static graph accelerators with only 11 lines of code modifications. Our implementation atop AccuGraph using a Xilinx Alveo#8482; U250 board outperforms two state-of-the-art CPU-based dynamic graph systems, Stinger and Aspen, by an average of 34.24× and 4.42× in terms of update throughput, improving further overall efficiency by 9.80× and 3.07× on average.","PeriodicalId":386071,"journal":{"name":"The 2021 ACM/SIGDA International Symposium on Field-Programmable Gate Arrays","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128219946","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 18
MLBlocks: FPGA Blocks for Machine Learning Applications MLBlocks:机器学习应用的FPGA模块
The 2021 ACM/SIGDA International Symposium on Field-Programmable Gate Arrays Pub Date : 2021-02-17 DOI: 10.1145/3431920.3439479
Seyedramin Rasoulinezhad, D. Boland, P. Leong
{"title":"MLBlocks: FPGA Blocks for Machine Learning Applications","authors":"Seyedramin Rasoulinezhad, D. Boland, P. Leong","doi":"10.1145/3431920.3439479","DOIUrl":"https://doi.org/10.1145/3431920.3439479","url":null,"abstract":"The underlying goal of FPGA architecture research is to devise flexible substrates which implement a wide variety of circuits efficiently. Contemporary FPGA architectures have been optimized to support networking, signal processing and image processing applications through high precision digital signal processing (DSP) blocks. The recent emergence of machine learning has created a new set of demands characterized by: 1) higher computational density and 2) low precision arithmetic requirements. With the goal of exploring this new design space in a methodical manner, we first propose a problem formulation involving computing nested loops over multiply-accumulate (MAC) operations, which covers many basic linear algebra primitives and standard deep neural network (DNN) layers. A quantitative methodology for deriving efficient coarse-grained compute block architectures from benchmarks is then proposed together with a family of new compute units, called MLBlocks. These blocks are flexible mesh-based systolic array units parameterized with different data movements, data reuse, and multi-precision support. They utilize a columnar arrangement which is compatible with existing FPGA architectures. Finally, using synthetic benchmarks, we demonstrate that MLBlocks offer significantly improved performance over the commercial Xilinx DSP48E2, while maintaining similar area and timing requirements to current DSPs.","PeriodicalId":386071,"journal":{"name":"The 2021 ACM/SIGDA International Symposium on Field-Programmable Gate Arrays","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131291797","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 2
Reconfigurable Acceleration of Short Read Mapping with Biological Consideration 考虑生物因素的短读映射可重构加速
The 2021 ACM/SIGDA International Symposium on Field-Programmable Gate Arrays Pub Date : 2021-02-17 DOI: 10.1145/3431920.3439280
Ho-Cheung Ng, Izaak Coleman, Shuanglong Liu, W. Luk
{"title":"Reconfigurable Acceleration of Short Read Mapping with Biological Consideration","authors":"Ho-Cheung Ng, Izaak Coleman, Shuanglong Liu, W. Luk","doi":"10.1145/3431920.3439280","DOIUrl":"https://doi.org/10.1145/3431920.3439280","url":null,"abstract":"Existing FPGA accelerators for short read mapping often fail to utilize the complete biological information in sequencing data for simple hardware design, leading to missed or incorrect alignment. Furthermore, their performance may not be optimized across hardware platforms. This paper proposes a novel alignment pipeline that considers all information in sequencing data for biologically accurate acceleration of short read mapping. To ensure the performance of the proposed design optimized across different platforms, we accelerate the memory-bound operations which have been a bottleneck in short read mapping. Specifically, we partition the FM-index into buckets. The length of each bucket is equal to an optimal multiple of the memory burst size and is determined through data-driven exploration. A tool has been developed to obtain the optimal parameters of the design for different hardware platforms to enhance performance optimization. Experimental results indicate that our design maximizes alignment accuracy compared to the state-of-the-art software Bowtie, mapping reads 4.48x as fast. Compared to the previous hardware aligner, our achieved accuracy is 97.7% which reports 4.48 M more valid alignments with a similar speed.","PeriodicalId":386071,"journal":{"name":"The 2021 ACM/SIGDA International Symposium on Field-Programmable Gate Arrays","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122032534","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 3
Are We Alone? Searching for ET with FPGAs 我们是孤独的吗?用fpga搜索ET
The 2021 ACM/SIGDA International Symposium on Field-Programmable Gate Arrays Pub Date : 2021-02-17 DOI: 10.1145/3431920.3437118
D. Werthimer
{"title":"Are We Alone? Searching for ET with FPGAs","authors":"D. Werthimer","doi":"10.1145/3431920.3437118","DOIUrl":"https://doi.org/10.1145/3431920.3437118","url":null,"abstract":"What is the possibility of other intelligent life in the universe? Can we detect radio, infrared, or visible light signals from alien civilizations? Current and future projects searching for such signals may provide an answer. Dan will describe SETI@home, the new PANOSETI observatory, future searches, and show how FPGAs and new technologies are revolutionizing the search for extra-terrestrial intelligence (SETI). Dan will also describe the Collaboration for Astronomy Signal Processing and Electronics Research (CASPER) open source hardware, tools and libraries for FPGA based radio astronomy instrumentation that produced the first images of the black hole and discovered many fast radio bursts, pulsars, and a planet made from solid diamond. Next generation radio telescopes will be composed of hundreds to thousands of smaller telescopes; these large arrays require peta-ops per second of real time processing to combine telescope signals and generate spectral-images. Dan will describe these telescopes and their real time signal processing systems. Open source hardware, software, libraries, tools, reference designs and video training are available at http://casper.berkeley.edu","PeriodicalId":386071,"journal":{"name":"The 2021 ACM/SIGDA International Symposium on Field-Programmable Gate Arrays","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122668659","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
A Framework for Customizable FPGA-based Image Registration Accelerators 一个可定制的基于fpga的图像配准加速器框架
The 2021 ACM/SIGDA International Symposium on Field-Programmable Gate Arrays Pub Date : 2021-02-17 DOI: 10.1145/3431920.3439291
Davide Conficconi, E. D’Arnese, Emanuele Del Sozzo, D. Sciuto, M. Santambrogio
{"title":"A Framework for Customizable FPGA-based Image Registration Accelerators","authors":"Davide Conficconi, E. D’Arnese, Emanuele Del Sozzo, D. Sciuto, M. Santambrogio","doi":"10.1145/3431920.3439291","DOIUrl":"https://doi.org/10.1145/3431920.3439291","url":null,"abstract":"Image Registration is a highly compute-intensive optimization procedure that determines the geometric transformation to align a floating image to a reference one. Generally, the registration targets are images taken from different time instances, acquisition angles, and/or sensor types. Several methodologies are employed in the literature to address the limiting factors of this class of algorithms, among which hardware accelerators seem the most promising solution to boost performance. However, most hardware implementations are either closed-source or tailored to a specific context, limiting their application to different fields. For these reasons, we propose an open-source hardware-software framework to generate a configurable architecture for the most compute-intensive part of registration algorithms, namely the similarity metric computation. This metric is the Mutual Information, a well-known calculus from the Information Theory, used in several optimization procedures. Through different design parameters configurations, we explore several design choices of our highly-customizable architecture and validate it on multiple FPGAs. We evaluated various architectures against an optimized Matlab implementation on an Intel Xeon Gold, reaching a speedup up to 2.86x, and remarkable performance and power efficiency against other state-of-the-art approaches.","PeriodicalId":386071,"journal":{"name":"The 2021 ACM/SIGDA International Symposium on Field-Programmable Gate Arrays","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129010627","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 8
ScalaBFS: A Scalable BFS Accelerator on FPGA-HBM Platform 基于FPGA-HBM平台的可扩展BFS加速器
The 2021 ACM/SIGDA International Symposium on Field-Programmable Gate Arrays Pub Date : 2021-02-17 DOI: 10.1145/3431920.3439463
Chenhao Liu, Zhiyuan Shao, Kexin Li, Minkang Wu, Jiajie Chen, Ruoshi Li, Xiaofei Liao, Hai Jin
{"title":"ScalaBFS: A Scalable BFS Accelerator on FPGA-HBM Platform","authors":"Chenhao Liu, Zhiyuan Shao, Kexin Li, Minkang Wu, Jiajie Chen, Ruoshi Li, Xiaofei Liao, Hai Jin","doi":"10.1145/3431920.3439463","DOIUrl":"https://doi.org/10.1145/3431920.3439463","url":null,"abstract":"High Bandwidth Memory (HBM) provides massive aggregated memory bandwidth by exposing multiple memory channels to the processing units. To achieve high performance, an accelerator built on top of an FPGA configured with HBM (i.e., FPGA-HBM platform) needs to scale its performance according to the available memory channels. In this paper, we propose an accelerator for BFS (Breadth-First Search), named as ScalaBFS, which decouples memory accessing from processing to scale its performance with available HBM memory channels. Moreover, by configuring each HBM memory channel with multiple processing elements, ScalaBFS sufficiently exploits the memory bandwidth of HBM. We implement the prototype system of ScalaBFS and conduct BFS in both real-world and synthetic scale-free graphs on Xilinx Alveo U280 Data Center Accelerator card (real hardware). The experimental results show that ScalaBFS scales its performance almost linearly according to the available memory pseudo channels (PCs) from the HBM2 subsystem of U280. By fully using the 32 PCs and building 64 processing elements (PEs) on U280, ScalaBFS achieves a performance up to 19.7 GTEPS (Giga Traversed Edges Per Second). When conducting BFS in sparse real-world graphs, ScalaBFS achieves equivalent GTEPS to Gunrock running on the state-of-art Nvidia V100 GPU that features 64-PC HBM2 (twice memory bandwidth than U280).","PeriodicalId":386071,"journal":{"name":"The 2021 ACM/SIGDA International Symposium on Field-Programmable Gate Arrays","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128496481","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 9
S2N2: A FPGA Accelerator for Streaming Spiking Neural Networks S2N2:一种用于流脉冲神经网络的FPGA加速器
The 2021 ACM/SIGDA International Symposium on Field-Programmable Gate Arrays Pub Date : 2021-02-17 DOI: 10.1145/3431920.3439283
Alireza Khodamoradi, K. Denolf, R. Kastner
{"title":"S2N2: A FPGA Accelerator for Streaming Spiking Neural Networks","authors":"Alireza Khodamoradi, K. Denolf, R. Kastner","doi":"10.1145/3431920.3439283","DOIUrl":"https://doi.org/10.1145/3431920.3439283","url":null,"abstract":"Spiking Neural Networks (SNNs) are the next generation of Artificial Neural Networks (ANNs) that utilize an event-based representation to perform more efficient computation. Most SNN implementations have a systolic array-based architecture and, by assuming high sparsity in spikes, significantly reduce computing in their designs. This work shows this assumption does not hold for applications with signals of large temporal dimension. We develop a streaming SNN (S2N2) architecture that can support fixed-per-layer axonal and synaptic delays for its network. Our architecture is built upon FINN and thus efficiently utilizes FPGA resources. We show how radio frequency processing matches our S2N2 computational model. By not performing tick-batching, a stream of RF samples can efficiently be processed by S2N2, improving the memory utilization by more than three orders of magnitude.","PeriodicalId":386071,"journal":{"name":"The 2021 ACM/SIGDA International Symposium on Field-Programmable Gate Arrays","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133044983","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 28
RIFL: A Reliable Link Layer Network Protocol for FPGA-to-FPGA Communication 用于fpga到fpga通信的可靠链路层网络协议
The 2021 ACM/SIGDA International Symposium on Field-Programmable Gate Arrays Pub Date : 2021-02-17 DOI: 10.1145/3431920.3439467
Q. Shen, Jun Zheng, P. Chow
{"title":"RIFL: A Reliable Link Layer Network Protocol for FPGA-to-FPGA Communication","authors":"Q. Shen, Jun Zheng, P. Chow","doi":"10.1145/3431920.3439467","DOIUrl":"https://doi.org/10.1145/3431920.3439467","url":null,"abstract":"More and more latency-sensitive applications are being introduced into the data center. Performance of such applications can be limited by the high latency of the network interconnect. Because the conventional network stack is designed not only for LAN, but also for WAN, it carries a great amount of redundancy that is not required in a data center network. This paper introduces the concept of a three-layer protocol stack that can replace the conventional network stack and fulfill the exact demands of data center network communications. The detailed design and implementation of the first layer of the stack, which we call RIFL, is presented. A novel low latency in-band hop-by-hop re-transmission protocol is proposed and adopted in RIFL, which guarantees lossless transmission for links whose longest wire segment is no more than 150 meters. Experimental results show that RIFL achieves 218 nanoseconds round-trip latency on 3 meter zero-hop links, at a throughput of 104.7 Gbps. RIFL is a multi-lane protocol with scalable throughput from 500 Mbps to above 200 Gbps. It is portable to most of the recent FPGAs. It can be the enabler of low latency, high throughput, flexible, scalable, and lossless data center networks.","PeriodicalId":386071,"journal":{"name":"The 2021 ACM/SIGDA International Symposium on Field-Programmable Gate Arrays","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133435571","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
Efficient FPGA Modular Multiplication Implementation 高效的FPGA模块化乘法实现
The 2021 ACM/SIGDA International Symposium on Field-Programmable Gate Arrays Pub Date : 2021-02-17 DOI: 10.1145/3431920.3439306
M. Langhammer, B. Pasca
{"title":"Efficient FPGA Modular Multiplication Implementation","authors":"M. Langhammer, B. Pasca","doi":"10.1145/3431920.3439306","DOIUrl":"https://doi.org/10.1145/3431920.3439306","url":null,"abstract":"Barrett's algorithm is the most commonly known method of performing a modular multiplication, which is the core of many modern encryption algorithms such as RSA. Barrett's algorithm requires an accurate quotient estimation which in turn requires accurate multiplications. These multiplications operating on word sizes of thousands of bits are particularly expensive to implement in FPGAs, requiring many hundreds or even thousands of embedded DSP components along with large amounts of logic and routing. In this work we show that approximate quotient estimates as results of aggressive multiplier truncations can significantly reduce implementation cost. The looser modified Barrett's output [0; YM) is reduced to [0; M) using a shallow reduction technique based on table lookups and wide additions, taking advantage of new techniques which have recently been introduced for FPGA. We first use these techniques to develop an improved standard Barrett's implementation for 1024b modular multiplication, followed by our approximate method which reduces logic cost in the LSB truncated multiplier by approximately 10%. The effect is more pronounced for very large word sizes, where our relaxed error bounds in the LSB truncated multiplication can reduce the number of operations by 20%.","PeriodicalId":386071,"journal":{"name":"The 2021 ACM/SIGDA International Symposium on Field-Programmable Gate Arrays","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128982991","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 2
0
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
相关产品
×
本文献相关产品
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术官方微信