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Effect of fracture fluid flowback on shale microfractures using CT scanning

Journal of Rock Mechanics and Geotechnical Engineering 2024年第2期16卷 426-436页

作者： Jiale He Zhihong Zhao Yiran Geng Yuping Chen Jianchun Guo Cong Lu shouyi wang Xueliang Han Jun Zhang State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum UniversityChengdu610500China Key Laboratory of Thermo-Fluid Science and Engineering of Ministry of Education School of Energy and Power EngineeringXi’an Jiaotong UniversityXi’an710049China Drilling Test Engineering Department of Longdong Oil and Gas Development Company Changqing OilfieldPetroChina Company LimitedQingyang745000China Tight Oil and Gas Exploration and Development Project Department PetroChina Southwest Oil and Gas Field CompanyChengdu610056China No.11 Oil Production Plant Changqing Oilfield CompanyPetroChina Company LimitedQingyang745000China

The field data of shale fracturing demonstrate that the flowback performance of fracturing fluid is different from that of conventional reservoirs,where the flowback rate of shale fracturing fluid is lower than that of conventional reservoirs.At the early stage of flowback,there is no single-phase flow of the liquid phase in shale,but rather a gas-water two-phase flow,such that the single-phase flow model for tight oil and gas reservoirs is not applicable.In this study,pores and microfractures are extracted based on the experimental results of computed tomography(CT)scanning,and a spatial model of microfractures is established.Then,the influence of rough microfracture surfaces on the flow is corrected using the modified cubic law,which was modified by introducing the average deviation of the microfracture height as a roughness factor to consider the influence of microfracture surface roughness.The flow in the fracture network is simulated using the modified cubic law and the lattice Boltzmann method(LBM).The results obtained demonstrate that most of the fracturing fluid is retained in the shale microfractures,which explains the low fracturing fluid flowback rate in shale hydraulic fracturing.

关键词： Shale Flowback of fracturing fluid Microfracture Lattice Boltzmann method(LBM)

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SWG: an architecture for sparse weight gradient computation

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Science China(Information Sciences) 2024年第2期67卷 302-321页

作者： Weiwei WU Fengbin TU Xiangyu LI Shaojun WEI shouyi YIN School of Integrated Circuits Tsinghua University Department of Electronic and Computer Engineering The Hong Kong University of Science and Technology

On-device training for deep neural networks(DNN) has become a trend due to various user preferences and scenarios. The DNN training process consists of three phases, feedforward(FF), backpropagation(BP), and weight gradient(WG) update. WG takes about one-third of the computation in the whole training process. Current training accelerators usually ignore the special computation property of WG and process it in a way similar to FF/BP. Besides, the extensive data sparsity existing in WG, which brings opportunities to save computation, is not well explored. Nevertheless, exploiting the optimization opportunities would meet three underutilization problems, which are caused by(1) the mismatch between WG data dimensions and hardware parallelism,(2) the full sparsity, i.e., the sparsity of feature map(Fmap),error map(Emap), and gradient, and(3) the workload imbalance resulting from irregular sparsity. In this paper, we propose a specific architecture for sparse weight gradient(SWG) computation. The architecture is designed based on hierarchical unrolling and sparsity-aware(HUSA) dataflow to exploit the optimization opportunities of the special computation property and full data sparsity. In HUSA dataflow, the data dimensions are unrolled hierarchically on the hardware architecture. A valid-data trace(VDT) mechanism is embedded in the dataflow to avoid the underutilization caused by the two-sided input sparsity. The gradient is unrolled in PE to alleviate the underutilization induced by output sparsity while maintaining the data reuse opportunities. Besides, we design an intra-and inter-column balancer(IIBLC) to dynamically tackle the workload imbalance problem resulting from the irregular sparsity. Experimental results show that with HUSA dataflow exploiting the full sparsity, SWG achieves a speedup of 12.23× over state-of-the-art gradient computation architecture, Train Ware. SWG helps to improve the energy efficiency of the state-of-the-art training accelerator LNPU from 7.56 to 10.58 TOPS/W.

关键词： CNN training gradient computation sparsity architecture

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Review of chiplet-based design: system architecture and interconnection

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Science China(Information Sciences) 2024年

作者： Yafei LIU Xiangyu LI shouyi YIN School of Integrated Circuits Tsinghua University Laboratory of Integrated Circuits and Intelligence Systems Research Institute of Tsinghua University in Shenzhen

Abstract Chiplet-based design, which breaks a system into multiple smaller dice (or “chiplets”) and reassembles them into a new system chip through advanced packaging, has received extensive attention in the post Moore’s law era due to its advantages in terms of cost, performance, and agility. However, significant challenges arise in this implementation approach, including the mapping of functional components onto chiplets, co-optimization of package and architecture, handling the increased latency of communication across functions in different dies, the uncertainty problems of fragment communication subsystems, such as maintaining deadlock-free when independently designed chiplets are combined. Despite various design approaches that attempt to address these challenges, surveying these approaches one-after-another is not the most helpful way to offer a comparative viewpoint. Accordingly, in this paper, we present a more comprehensive and systematic strategy to survey the various approaches. First, we divide them into chiplet-based system architecture design and interconnection design, and further classify them based on different architectures and building blocks of interconnection. Then, we analyze and cross-compare each classification separately, and in addition, we present a topical discussion on the evolution of memory architectures, design automation, and other relevant topics in chiplet-based designs. Finally, some discussions on important topics are presented,emphasizing future needs and challenges in this rapidly evolving field.

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Short-wavelength light induces broiler’s behavioral and physiological syndrome through a misaligned eating rhythm

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International Journal of Agricultural and Biological Engineering 2022年第3期15卷 47-54页

作者： Yefeng Yang Qiong Liu shouyi wang Li Zeng Chenghao Pan Ahmed Jado Yasser Elhadidi Kai Liu Jinming Pan Department of Biosystems Engineering Zhejiang UniversityHangzhou 310058China Department of Agricultural Engineering Mansoura UniversityMansoura 35516Egypt Department of Infectious Diseases and Public Health City University of Hong KongHong Kong SARChina Key Laboratory of Intelligent Equipment and Robotics for Agriculture of Zhejiang Province Hangzhou 310058China

Previous work shows that long-wavelength light has a robust circadian rhythmic pattern in the expression of clock genes of chickens,whereas short-wavelength light leads to an arrhythmic oscillation of some clock genes(e.g.,cClock,cCry1,cCry2,cPer2,and cPer3).However,knowledge about the consequences of LED lights on the physiological and behavioral phenotype was still not clear.This experiment hypothesize that short-wavelength light disturbs chicken’s eating rhythm and leads to a wrong time to eat,resulting in metabolic syndrome.“Meihuang”broilers were housed in monochromatic LED blue light,green light,yellow light,red light,or white light with a very low dose(15 lx).Multiply physiological parameters were measured and the 24-h eating behavior was determined.The effects of LED light on physiological status and behavioral phenotype showed a wavelength-dependent manner.Short-wavelength light significantly decreased the level of total triglycerides and total cholesterol but increased triiodothyronine concentration.Inversely,long-wavelength light increased the triglycerides and total cholesterol and reduced the level of triiodothyronine.Further,it was found that short-wavelength light significantly boosted body weight compared with long-wavelength light,despite equivalent levels of food intake.Short-wavelength light induced 23.4%and 14.1%of food consumption during subjective nights,but long-wavelength light did not.These results imply that when chickens eat mattered,not just what they eat.Thus,low as 15 lx of blue light exposure during the typical dark period is sufficient to leads an individual to eat at“wrong”time,causing metabolic dysfunction.

关键词： short-wavelength light broiler behavior physiology environmental control circadian rhythm intermittent eating

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明代历史小说结构的伦理阐释

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学术研究 2024年第2期 161-168页

作者：江守义南京师范大学文学院江苏南京200437

明代历史小说的结构可以从3个方面加以考察:一是外在表现上的编年式结构和纪传式结构,二是内在理路上的线性结构和网状结构,三是深层逻辑上的二元对立和同类相应。这3个方面的结构都有其伦理意蕴。编年式结构通过时间更替、王朝更迭显... 详细信息

明代历史小说的结构可以从3个方面加以考察:一是外在表现上的编年式结构和纪传式结构,二是内在理路上的线性结构和网状结构,三是深层逻辑上的二元对立和同类相应。这3个方面的结构都有其伦理意蕴。编年式结构通过时间更替、王朝更迭显示历史沧桑感,纪传式结构通过三段论、按类分卷、版块对照、设局解密等方式,对历史人物进行道德评判;以人物为线索的糖葫芦式单线结构、以事件为线索的串珠式单线结构、多线并行的复线结构、牵一发动全身的网状结构,都与小说的伦理说教宗旨有关;二元对立主要表现为忠奸对立的伦理冲突,同类相应主要表现为善恶有报的伦理归宿。

关键词：结构伦理明代历史小说

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中西小说叙述者意图伦理之比较

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中国文学批评 2024年第1期 102-113,M0005页

作者：江守义南京师范大学文学院南京210097

中国古典小说和西方小说叙述者意图伦理的差异,可以从小说的外在面貌和叙述者的视角选择两个方面来展开。小说的外在面貌包括小说命名和章节编排,叙述者选择的视角主要是全知视角和人物视角。就小说命名看,前者的命名带有较强的伦理说... 详细信息

中国古典小说和西方小说叙述者意图伦理的差异,可以从小说的外在面貌和叙述者的视角选择两个方面来展开。小说的外在面貌包括小说命名和章节编排,叙述者选择的视角主要是全知视角和人物视角。就小说命名看,前者的命名带有较强的伦理说教色彩或补史意图,后者的命名则体现为中性概括或个性化的伦理倾向;就章节编排看,前者一般通过章回体对相关内容进行道德评判,后者往往就内容来随机进行章节编排,少有道德评判;就全知视角看,前者的史官式视角和说书型视角方便叙述者以传统伦理规范来引导叙事,后者的全知视角没有史官式或说书型的限制,方便叙述者表达自己的伦理立场;就人物视角看,与其密切相关的是伦理个性,前者的伦理个性最终折射出社会伦理规范,后者则呈现出伦理个性的不同面貌。

关键词：叙述者意图伦理古典小说西方小说

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古代小说评点和伦理的沟通路径

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中国高校社会科学 2024年第2期 144-156,M0006页

作者：江守义南京师范大学文学院南京210097

古代小说评点往往就小说内容和形式进行伦理解读。伦理解读的背后,隐藏着评点和伦理的沟通路径。沟通路径主要有以下几种:一是将评点引导到伦理上来的路径,即引导路径,主要有导读法和反思法;二是评点表达小说伦理内涵的路径,即表达路径... 详细信息

古代小说评点往往就小说内容和形式进行伦理解读。伦理解读的背后,隐藏着评点和伦理的沟通路径。沟通路径主要有以下几种:一是将评点引导到伦理上来的路径,即引导路径,主要有导读法和反思法;二是评点表达小说伦理内涵的路径,即表达路径,包括直接表达路径和间接表达路径;三是评点影响表达效果的路径,即效果路径,主要有以恶去恶、以善劝善、善恶对举三类情形。在诸多沟通路径的指引下,古代小说评点表现出鲜明的伦理倾向。

关键词：小说评点伦理引导路径表达路径效果路径

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中西小说接受伦理阐释之比较

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南京师大学报（社会科学版） 2024年第1期 147-156页

作者：江守义南京师范大学文学院南京210097

中西小说接受伦理的比较,突出表现为伦理阐释的比较,包括阐释形式的比较和阐释对象的比较。就阐释形式看,中国古典小说的阐释形式主要是和小说融为一体的评点,西方小说的阐释形式则是和小说分离的专论、书评、通信等。就阐释对象看,包... 详细信息

中西小说接受伦理的比较,突出表现为伦理阐释的比较,包括阐释形式的比较和阐释对象的比较。就阐释形式看,中国古典小说的阐释形式主要是和小说融为一体的评点,西方小说的阐释形式则是和小说分离的专论、书评、通信等。就阐释对象看,包含对小说内容的阐释和对小说形式的阐释。中国古典小说对内容的阐释多于对形式的阐释,西方小说则兼顾内容和形式。就内容阐释而言,中国古典小说秉持伦理教化的宗旨,西方小说则从具体情境来分析人物和情节的伦理意蕴,二者的差异在对爱情故事的理解上有鲜明表现;就形式阐释而言,中国古典小说的评点在结构、文法、修辞三个方面显示出其伦理姿态,西方小说则强调语言、技巧和伦理之间的关系,二者的差异可通过果报模式的差异以见一斑。

关键词：接受伦理伦理阐释古典小说西方小说

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Assessment of tree-ring mercury radial translocation and age effect in Masson pine:Implications for historical atmospheric mercury reconstruction

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Journal of Environmental Sciences 2024年第4期138卷 266-276页

作者： Xu Liu Xun wang Dingyong wang College of Resources and Environment Southwest UniversityChongqing 400715China State Key Laboratory of Environmental Geochemistry Institute of GeochemistryChinese Academy of SciencesGuiyang 550081China

The tree ring has been regarded as an emerging archive to reconstruct historical atmospheric mercury(Hg)trends,but with the large knowledge gaps in the reliability.In this study,we comprehensively evaluated the Hg source,radial translocation and age effect of Masson pine(Pinus massoniana)tree ring at Mt.Jinyun in Chongqing,to assess the suitability of such tree ring as the archive of atmospheric Hg.Results showed that distinct variabilities among Masson pine tree-ring Hg concentration profiles.The Hg concentration significantly increased along with stem height(P<0.05),indicating the Hg in tree rings mainly derived from foliage uptake atmospheric Hg.We found a distinct age effect that the tree ring of young trees had the higher Hg concentration.Besides,we used the advection-diffusion model to demonstrate how Hg concentration shifted by the advection or/and diffusion in tree rings.The modeling results showed that the advection induced radial translocation during the young growth period of tree was a plausible mechanism to result in the tree-ring Hg record largely different from the trend of anthropogenic Hg emissions in Chongqing.We finally suggest that in further Hg dendrochemistry,better discarding the tree-ring Hg profile of the young growth period to reduce impacts of the radial translocation and age effect.

关键词： Masson pine Tree-ring mercury Radial translocation Tree age effect

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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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