期刊文献+
共找到24,214篇文章
< 1 2 250 >
每页显示 20 50 100
Advanced Design of Soft Robots with Artificial Intelligence 被引量:1
1
作者 Ying Cao Bingang Xu +1 位作者 Bin Li Hong Fu 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第10期474-521,共48页
In recent years,breakthrough has been made in the field of artificial intelligence(AI),which has also revolutionized the industry of robotics.Soft robots featured with high-level safety,less weight,lower power consump... In recent years,breakthrough has been made in the field of artificial intelligence(AI),which has also revolutionized the industry of robotics.Soft robots featured with high-level safety,less weight,lower power consumption have always been one of the research hotspots.Recently,multifunctional sensors for perception of soft robotics have been rapidly developed,while more algorithms and models of machine learning with high accuracy have been optimized and proposed.Designs of soft robots with AI have also been advanced ranging from multimodal sensing,human-machine interaction to effective actuation in robotic systems.Nonethe-less,comprehensive reviews concerning the new developments and strategies for the ingenious design of the soft robotic systems equipped with AI are rare.Here,the new development is systematically reviewed in the field of soft robots with AI.First,background and mechanisms of soft robotic systems are briefed,after which development focused on how to endow the soft robots with AI,including the aspects of feeling,thought and reaction,is illustrated.Next,applications of soft robots with AI are systematically summarized and discussed together with advanced strategies proposed for performance enhancement.Design thoughts for future intelligent soft robotics are pointed out.Finally,some perspectives are put forward. 展开更多
关键词 soft robotic systems Artificial intelligence Design tactics Review and perspective
在线阅读 下载PDF
Correlation of microstructure and magnetic softness of Si-microalloying FeNiBCuSi nanocrystalline alloy revealed by nanoindentation
2
作者 Benjun Wang Wenjun Liu +9 位作者 Li Liu Yu Wang Yu Hang Xinyu Wang Mengen Shi Hanchen Feng Long Hou Chenchen Yuan Zhong Li Weihuo Li 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第12期351-359,共9页
Compared to the commercial soft-magnetic alloys,the high saturation magnetic flux density(Bs)and low coercivity(Hc)of post-developed novel nanocrystalline alloys tend to realize the miniaturization and lightweight of ... Compared to the commercial soft-magnetic alloys,the high saturation magnetic flux density(Bs)and low coercivity(Hc)of post-developed novel nanocrystalline alloys tend to realize the miniaturization and lightweight of electronic products,thus attracting great attention.In this work,we designed a new FeNiBCuSi formulation with a novel atomic ratio,and the microstructure evolution and magnetic softness were investigated.Microstructure analysis revealed that the amount of Si prompted the differential chemical fluctuations of Cu element,favoring the different nucleation and growth processes ofα-Fe nanocrystals.Furthermore,microstructural defects associated with chemical heterogeneities were unveiled using the Maxwell-Voigt model with two Kelvin units and one Maxwell unit based on creeping analysis by nanoindentation.The defect,with a long relaxation time in relaxation spectra,was more likely to induce the formation of crystal nuclei that ultimately evolved into theα-Fe nanocrystals.As a result,Fe_(84)Ni_(2)B_(12.5)Cu_(1)Si_(0.5)alloy with refined uniform nanocrystalline microstructure exhibited excellent magnetic softness,including a high B_(s)of 1.79 T and very low H_(c)of 2.8 A/m.Our finding offers new insight into the influence of activated defects associated with chemical heterogeneities on the microstructures of nanocrystalline alloy with excellent magnetic softness. 展开更多
关键词 nanocrystalline alloy magnetic softness MICROSTRUCTURES defects NANOINDENTATION
在线阅读 下载PDF
Estimating the yield stress of soft materials via laser-induced breakdown spectroscopy
3
作者 龚书航 李亚举 +7 位作者 钱东斌 叶晋瑞 赵扣 曾强 陈良文 张少锋 杨磊 马新文 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第3期428-432,共5页
Taking three typical soft samples prepared respectively by loose packings of 77-,95-,and 109-μm copper grains as examples,we perform an experiment to investigate the energy-dependent laser-induced breakdown spectrosc... Taking three typical soft samples prepared respectively by loose packings of 77-,95-,and 109-μm copper grains as examples,we perform an experiment to investigate the energy-dependent laser-induced breakdown spectroscopy(LIBS)of soft materials.We discovered a reversal phenomenon in the trend of energy dependence of plasma emission intensity:increasing initially and then decreasing separated by a well-defined critical energy.The trend reversal is attributed to the laser-induced recoil pressure at the critical energy just matching the sample's yield strength.As a result,a one-to-one correspondence can be well established between the samples'yield stress and the critical energy that is easily obtainable from LIBS measurements.This allows us to propose an innovative method for estimating the yield stress of soft materials via LIBS with attractive advantages including in-situ remote detection,real-time data collection,and minimal destructive to sample. 展开更多
关键词 laser-induced breakdown spectroscopy soft materials yield stress
在线阅读 下载PDF
MXenes for Bioinspired Soft Actuators:Advancements in Angle-Independent Structural Colors and Beyond
4
作者 Siavash Iravani Rajender S.Varma 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第8期18-34,共17页
Soft actuators have garnered substantial attention in current years in view of their potential appliances in diverse domains like robotics,biomedical devices,and biomimetic systems.These actuators mimic the natural mo... Soft actuators have garnered substantial attention in current years in view of their potential appliances in diverse domains like robotics,biomedical devices,and biomimetic systems.These actuators mimic the natural movements of living organisms,aiming to attain enhanced flexibility,adaptability,and versatility.On the other hand,angle-independent structural color has been achieved through innovative design strategies and engineering approaches.By carefully controlling the size,shape,and arrangement of nanostructures,researchers have been able to create materials exhibiting consistent colors regardless of the viewing angle.One promising class of materials that holds great potential for bioinspired soft actuators is MXenes in view of their exceptional mechanical,electrical,and optical properties.The integration of MXenes for bioinspired soft actuators with angle-independent structural color offers exciting possibilities.Overcoming material compatibility issues,improving color reproducibility,scalability,durability,power supply efficiency,and cost-effectiveness will play vital roles in advancing these technologies.This perspective appraises the development of bioinspired MXene-centered soft actuators with angleindependent structural color in soft robotics. 展开更多
关键词 MXenes MXene-based composites Bioinspired soft robotics Angle-independent structural color
在线阅读 下载PDF
MHz cut-off frequency and permeability mechanism of iron-based soft magnetic composites
5
作者 Xiao-Wei Jin Tong Li +1 位作者 Hui-Gang Shi De-Sheng Xue 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第9期560-564,共5页
The lack of soft magnetic composites with high power density in MHz frequency range has become an obstacle in the efficient operation of the electrical and electronic equipments.Here,a promising method to increase the... The lack of soft magnetic composites with high power density in MHz frequency range has become an obstacle in the efficient operation of the electrical and electronic equipments.Here,a promising method to increase the cut-off frequency of iron-based soft magnetic composites to hundreds of MHz is reported.The cut-off frequency is increased from 10 MHz to 1 GHz by modulating the height of the ring,the distribution of particles,and the particle size.The mechanism of cut-off frequency and permeability is the coherent rotation of domain modulated by inhomogeneous field due to the eddy current effect.An empirical formula for the cut-off frequency in a magnetic ring composed of iron-based particles is established from experimental data.This work provides an effective approach to fabricate soft magnetic composites with a cut-off frequency in hundreds of MHz. 展开更多
关键词 cut-off frequency PERMEABILITY eddy current effect soft magnetic composites
在线阅读 下载PDF
Iterative Signal Detection Based Soft Interference Cancellation for Satellite-Terrestrial Downlink NOMA Systems
6
作者 Sun Meng Zhang Qi +5 位作者 Yao Haipeng Gao Ran Xin Xiangjun Tian Feng Feng Weiying Chen Dong 《China Communications》 SCIE CSCD 2024年第8期249-263,共15页
To improve the bit error rate(BER)performance of multi-user signal detection in satelliteterrestrial downlink non-orthogonal multiple access(NOMA)systems,an iterative signal detection algorithm based on soft interfere... To improve the bit error rate(BER)performance of multi-user signal detection in satelliteterrestrial downlink non-orthogonal multiple access(NOMA)systems,an iterative signal detection algorithm based on soft interference cancellation with optimal power allocation is proposed.Given that power allocation has a significant impact on BER performance,the optimal power allocation is obtained by minimizing the average BER of NOMA users.According to the allocated powers,successive interference cancellation(SIC)between NOMA users is performed in descending power order.For each user,an iterative soft interference cancellation is performed,and soft symbol probabilities are calculated for soft decision.To improve detection accuracy and without increasing the complexity,the aforementioned algorithm is optimized by adding minimum mean square error(MMSE)signal estimation before detection,and in each iteration soft symbol probabilities are utilized for soft-decision of the current user and also for the update of soft interference of the previous user.Simulation results illustrate that the optimized algorithm i.e.MMSE-IDBSIC significantly outperforms joint multi-user detection and SIC detection by 7.57dB and 8.03dB in terms of BER performance. 展开更多
关键词 non-orthogonal multiple access(NOMA) resource allocation satellite-terrestrial communication signal detection soft interference cancellation
在线阅读 下载PDF
GRU-integrated constrained soft actor-critic learning enabled fully distributed scheduling strategy for residential virtual power plant
7
作者 Xiaoyun Deng Yongdong Chen +2 位作者 Dongchuan Fan Youbo Liu Chao Ma 《Global Energy Interconnection》 EI CSCD 2024年第2期117-129,共13页
In this study,a novel residential virtual power plant(RVPP)scheduling method that leverages a gate recurrent unit(GRU)-integrated deep reinforcement learning(DRL)algorithm is proposed.In the proposed scheme,the GRU-in... In this study,a novel residential virtual power plant(RVPP)scheduling method that leverages a gate recurrent unit(GRU)-integrated deep reinforcement learning(DRL)algorithm is proposed.In the proposed scheme,the GRU-integrated DRL algorithm guides the RVPP to participate effectively in both the day-ahead and real-time markets,lowering the electricity purchase costs and consumption risks for end-users.The Lagrangian relaxation technique is introduced to transform the constrained Markov decision process(CMDP)into an unconstrained optimization problem,which guarantees that the constraints are strictly satisfied without determining the penalty coefficients.Furthermore,to enhance the scalability of the constrained soft actor-critic(CSAC)-based RVPP scheduling approach,a fully distributed scheduling architecture was designed to enable plug-and-play in the residential distributed energy resources(RDER).Case studies performed on the constructed RVPP scenario validated the performance of the proposed methodology in enhancing the responsiveness of the RDER to power tariffs,balancing the supply and demand of the power grid,and ensuring customer comfort. 展开更多
关键词 Residential virtual power plant Residential distributed energy resource Constrained soft actor-critic Fully distributed scheduling strategy
在线阅读 下载PDF
Optical micro/nanofiber enabled tactile sensors and soft actuators:A review
8
作者 Lei Zhang Yuqi Zhen Limin Tong 《Opto-Electronic Science》 2024年第8期13-29,共17页
As a combination of fiber optics and nanotechnology,optical micro/nanofiber(MNF)is considered as an important multifunctional building block for fabricating various miniaturized photonic devices.With the rapid progres... As a combination of fiber optics and nanotechnology,optical micro/nanofiber(MNF)is considered as an important multifunctional building block for fabricating various miniaturized photonic devices.With the rapid progress in flexible optoelectronics,MNF has been emerging as a promising candidate for assembling tactile sensors and soft actuators owing to its unique optical and mechanical properties.This review discusses the advances in MNF enabled tactile sensors and soft actuators,specifically,focusing on the latest research results over the past 5 years and the applications in health monitoring,human-machine interfaces,and robotics.Future prospects and challenges in developing flexible MNF devices are also presented. 展开更多
关键词 flexible opto-electronic devices tactile sensors soft actuators optical micro/nanofibers
在线阅读 下载PDF
基于改进Soft-NMS的多实例行人检测算法
9
作者 王鹏 刘军清 李菁 《长江信息通信》 2024年第2期79-81,共3页
在行人检测任务中,最主要的是能够快速且精准识别图像或视频中的行人。由于在密集的场景中行人之间存在相互遮挡,导致目前行人检测算法普遍存在漏检和误检问题。为了解决上述问题,文章提出了一种基于改进Soft-NMS算法的多实例行人检测... 在行人检测任务中,最主要的是能够快速且精准识别图像或视频中的行人。由于在密集的场景中行人之间存在相互遮挡,导致目前行人检测算法普遍存在漏检和误检问题。为了解决上述问题,文章提出了一种基于改进Soft-NMS算法的多实例行人检测方法。为了减小由于行人之间重叠导致检测器无法做出准确预测,引入多实例检测方法来使检测器做出相对准确的预测。并且在Soft-NMS算法的基础上进行改进,提出了Set-Soft-NMS算法来减少行人检测中的漏检和误检问题。使用公开的行人检测数据集上对文章所提出的方法进行实验,结果表明该文提出方法的性能要优于其他主流的行人检测算法。 展开更多
关键词 行人检测 多实例检测 soft-NMS
在线阅读 下载PDF
Fracture initiation and propagation in soft hydraulic fracturing of hot dry rock
10
作者 ZHOU Xiaoxia LI Gensheng +5 位作者 MA Zhengchao HUANG Zhongwei ZHANG Xu TIAN Shouceng ZOU Wenchao WANG Tianyu 《Petroleum Exploration and Development》 2024年第6期1598-1610,共13页
By considering the thermo poroelastic effects of rock,the constitutive relationship of fatigue deterioration of rock under cyclic loading,elastic-brittle failure criteria and wellbore stress superposition effects,a th... By considering the thermo poroelastic effects of rock,the constitutive relationship of fatigue deterioration of rock under cyclic loading,elastic-brittle failure criteria and wellbore stress superposition effects,a thermal-hydraulic-mechanicalfatigue damage coupled model for fracture propagation during soft hydraulic fracturing in hot dry rock(HDR)was established and validated.Based on this model,numerical simulations were conducted to investigate the fracture initiation and propagation characteristics in HDR under the combined effects of different temperatures and cyclic loading.The results are obtained in three aspects.First,cyclic injection,fluid infiltration,pore pressure accumulation,and rock strength deterioration collectively induce fatigue damage of rocks during soft hydraulic fracturing.Second,the fracture propagation pattern of soft hydraulic fracturing in HDR is jointly controlled by temperature difference and cyclic loading.A larger temperature difference generates stronger thermal stress,facilitating the formation of complex fracture networks.As cyclic loading decreases,the influence range of thermal stress expands.When the cyclic loading is 90%pb and 80%pb(where pb is the breakdown pressure during conventional hydraulic fracturing),the stimulated reservoir area increases by 88.33% and 120%,respectively,compared to conventional hydraulic fracturing(with an injection temperature of 25℃).Third,as cyclic loading is further reduced,the reservoir stimulation efficiency diminishes.When the cyclic loading decreases to 70%pb,the fluid pressure far away from the wellbore cannot reach the minimum breakdown pressure of the rock,resulting in no macroscopic hydraulic fractures. 展开更多
关键词 hot dry rock soft hydraulic fracturing thermal-hydraulic-mechanical-fatigue damage coupling thermal stress fatigue deterioration fracture propagation
在线阅读 下载PDF
软土地区挡土墙地基加固技术研究 被引量:1
11
作者 王飞 《科学技术创新》 2025年第3期129-132,共4页
为了处理软土地区挡墙与地基的大位移与大变形问题,通过选取某工程作为研究背景,对已施工区域的挡墙位移、地基中PHC预应力管桩垂直度、地表位移及深层土体位移进行了监测与分析,根据挡墙地基产生病害的原因提出了相应的应急措施,结合... 为了处理软土地区挡墙与地基的大位移与大变形问题,通过选取某工程作为研究背景,对已施工区域的挡墙位移、地基中PHC预应力管桩垂直度、地表位移及深层土体位移进行了监测与分析,根据挡墙地基产生病害的原因提出了相应的应急措施,结合施工特点采取了旋喷桩和水泥土搅拌桩相结合的加固措施,解决了软土地基的变形问题和挡墙的大位移问题,取得了显著的加固效果,本研究可为软土地区的挡墙与地基的设计施工提供技术参考。 展开更多
关键词 软土 挡墙 地基变形 加固效果
在线阅读 下载PDF
深埋高应力隧道软岩大变形开挖补偿控制研究
12
作者 陶志刚 许闯 +2 位作者 李勇 王祥 王欢 《西安科技大学学报》 北大核心 2025年第1期86-97,共12页
随着中国西部地区隧道工程建设的蓬勃发展,深埋、高应力、高海拔隧道的软岩大变形灾害愈发严重,已经成为隧道灾害控制领域的研究重点和难点。位于横断山脉的大亮山公路隧道因其埋深大、断层多、突涌水、围岩强度低、地应力高等特点,隧... 随着中国西部地区隧道工程建设的蓬勃发展,深埋、高应力、高海拔隧道的软岩大变形灾害愈发严重,已经成为隧道灾害控制领域的研究重点和难点。位于横断山脉的大亮山公路隧道因其埋深大、断层多、突涌水、围岩强度低、地应力高等特点,隧道围岩大变形现象十分严重。为了探索这种类型隧道围岩大变形控制策略,提出了一种基于NPR材料的深埋隧道软岩大变形开挖补偿控制对策,为了验证其可行性和科学性,通过现场观测、室内物理模型试验与数值模拟进行深入研究。结果表明:NPR锚索可承受的最大动力冲击荷载为284.811 kN,抗冲击性能最高约为Q235锚杆的2倍,非线性吸能效果显著;NPR锚索开挖补偿控制体系能够有效调节围岩应力分布特征,及时为受开挖扰动的围岩提供补偿支护力,约束围岩塑性区扩展并吸收围岩释放的变形能;在正常与超载条件下,分别将软岩隧道围岩变形量控制在3 mm与5.8 mm以内,且无明显应力集中区域;NPR锚索开挖补偿支护体系可有效约束隧道围岩位移,最大水平位移量控制在3.35 mm以内,最大竖向位移量控制在15.21 mm以内。NPR锚索补偿开挖支护体系能够有效控制深埋高应力隧道软岩大变形灾害。 展开更多
关键词 NPR锚索 软岩隧道 大变形灾害 物理模型试验
在线阅读 下载PDF
采用谐振电感复用的LCL-T/LLC谐振变换器
13
作者 方炜 王帅 +2 位作者 康国杭 刘宿城 刘晓东 《电子科技大学学报》 北大核心 2025年第1期13-22,共10页
LLC谐振变换器有着转换效率高、软开关特性好等显著优点。但在储能系统充电的应用场合中,宽电压增益输出要求LLC谐振变换器工作频率在较大范围内变化,从而引起转换效率明显降低、磁性元件设计困难、轻载调节有限等问题。研究了一种采用... LLC谐振变换器有着转换效率高、软开关特性好等显著优点。但在储能系统充电的应用场合中,宽电压增益输出要求LLC谐振变换器工作频率在较大范围内变化,从而引起转换效率明显降低、磁性元件设计困难、轻载调节有限等问题。研究了一种采用谐振电感复用的LCL-T/LLC谐振变换器,可用于电动汽车的车载充电。将谐振电感置于变压器副边,构建LCL-T谐振腔使得变换器工作在恒流充电阶段,LCL-T谐振变换器的恒流特性可以显著减小变换器的工作频率范围;通过辅助开关改变谐振支路,该谐振电感也可参与LLC谐振,使变换器工作在恒压充电阶段,提供稳定的充电电压。由于谐振电感位于变压器副边,减少了死区时间内的磁芯损耗,提高了转换效率。详细分析了该变换器的工作模式和直流增益特性,给出了关键参数设计原则。最后,搭建了一台3.3 kW、400 V/330 V的实验样机,验证了变换器拓扑和控制方案的有效性。 展开更多
关键词 直流充电 LCL-T/LLC谐振变换器 软开关运行 电动汽车
在线阅读 下载PDF
煤矿深部巷道大变形分步联合控制研究
14
作者 李培涛 刘泉声 +2 位作者 朱元广 高峰 范利丹 《岩土力学》 北大核心 2025年第2期591-612,共22页
深部巷道大变形已成为深部煤炭安全高效开采的关键制约因素。为实现深部软弱围岩稳定性控制,提出了基于深部巷道大变形演化过程的分步联合支护方案及其理论分析模型。结果表明,深部软弱围岩呈破裂碎胀变形-损伤扩容变形-连续变形的分布... 深部巷道大变形已成为深部煤炭安全高效开采的关键制约因素。为实现深部软弱围岩稳定性控制,提出了基于深部巷道大变形演化过程的分步联合支护方案及其理论分析模型。结果表明,深部软弱围岩呈破裂碎胀变形-损伤扩容变形-连续变形的分布特征。分步联合支护后,围岩极限承载力随锚杆和锚索等效支护力增大呈线性增大趋势,但随注浆修复系数呈指数增大趋势。锚杆和锚索支护设计时应以极限承载力所需的注浆修复系数等于1.0时的等效支护力临界条件为基准。深浅孔注浆支护时须同时考虑注浆修复系数和围岩破裂区半径。不同支护措施的协同支护参数可由破裂修复区围岩极限承载平衡条件确定。数值模拟和工程应用分析表明,分步联合支护可实现深部软弱围岩碎胀大变形控制,具有较高的工程推广应用价值。 展开更多
关键词 深部软弱围岩 大变形 分步联合支护 承载平衡 协同控制
在线阅读 下载PDF
强震下基础隔震结构软碰撞防护研究
15
作者 金建敏 刘彦辉 +1 位作者 陈鹏 周惠蒙 《世界地震工程》 北大核心 2025年第1期165-174,共10页
针对基础隔震结构在超罕遇地震的强震作用下隔震层位移超限问题,采用已有弹性软碰撞防护装置和所研发的弹塑性软碰撞防护装置。考虑上部结构非线性,建立设置两类软碰撞防护装置的基础隔震结构模型,进行不同地震设防水准地震作用下设置... 针对基础隔震结构在超罕遇地震的强震作用下隔震层位移超限问题,采用已有弹性软碰撞防护装置和所研发的弹塑性软碰撞防护装置。考虑上部结构非线性,建立设置两类软碰撞防护装置的基础隔震结构模型,进行不同地震设防水准地震作用下设置两类软碰撞防护装置的基础隔震结构的非线性时程分析,研究不同防护距离、不同力学性能参数的弹性及弹塑性软碰撞防护装置对隔震层限位效果及上部结构地震响应的影响。结果表明:在超罕遇地震的强震作用下,两类软碰撞防护装置均可起到限制隔震层位移的作用;与仅能为隔震层附加刚度的弹性软碰撞装置相比较,能够为隔震层同时附加刚度和阻尼力的弹塑性软碰撞防护装置,隔震层限位效果和上部结构层间位移角响应控制效果均较优。合理设置弹性及弹塑性软碰撞防护装置,在将隔震层位移限制在规范限值以内的同时,上部结构最大加速度可限制在地震波输入峰值50%以下,确保基础隔震结构发挥正常的隔震功能。 展开更多
关键词 基础隔震结构 隔震层位移 软碰撞防护 限位效果 地震响应
在线阅读 下载PDF
多调制方式兼容的BCH概率软译码器的FPGA实现
16
作者 庞宇 张洋 +1 位作者 李国权 杨家斌 《微电子学与计算机》 2025年第3期75-83,共9页
为实现在复杂环境下多种人体体征参数的高可靠性传输,设计了一种基于现场可编程逻辑门阵列(Field Programmable Gate Array,FPGA)的BCH概率软译码器。译码器利用概率计算的方式替换Chase算法中的大量排序运算,并利用8位循环冗余校验(Cyc... 为实现在复杂环境下多种人体体征参数的高可靠性传输,设计了一种基于现场可编程逻辑门阵列(Field Programmable Gate Array,FPGA)的BCH概率软译码器。译码器利用概率计算的方式替换Chase算法中的大量排序运算,并利用8位循环冗余校验(Cyclic redundancy check,CRC-8)实现迭代译码。译码器包括信道信息输入模块、软解映射模块、概率比特序列生成模块、BCH硬译码模块、以及CRC-8提前终止判决模块,可同时满足二进制相移键控(Binary Phase Shift Keying,BPSK)、π/4-四相相对相移键控(π/4-Differential Quadrature Phase Shift Keying,π/4-DQPSK)两种调制方式的BCH译码。MATLAB仿真表明,在误块率为10^(−2)情况下,译码器与现有的Chase算法和硬译码算法相比分别有约0.9 dB、1.4 dB的性能增益。完成了基于FPGA的硬件设计。译码器使用全并行处理,逻辑结构简单,在相同译码速度条件下硬件消耗资源较Chase算法降低约20%。 展开更多
关键词 BCH码 软译码 概率计算 FPGA
在线阅读 下载PDF
软通道微创对高血压性脑出血患者的影响
17
作者 古选民 杨晋生 贾云玲 《成都医学院学报》 2025年第1期140-143,153,共5页
目的分析软通道微创治疗对高血压性脑出血患者的影响。方法选取2021年1月至2024年2月于河南科技大学第一附属医院神经外科收治的104例高血压性脑出血患者为研究对象,根据治疗方案不同,将其分为软通道组(接受软通道微创治疗,n=50)和硬通... 目的分析软通道微创治疗对高血压性脑出血患者的影响。方法选取2021年1月至2024年2月于河南科技大学第一附属医院神经外科收治的104例高血压性脑出血患者为研究对象,根据治疗方案不同,将其分为软通道组(接受软通道微创治疗,n=50)和硬通道组(接受硬通道微创治疗,n=54)。比较两组术中抽吸血肿量及体积比等血肿相关指标;比较两组术前、术后7 d血清可溶性髓系细胞触发受体-1(sTREM-1)、水通道蛋白4(AQP4)、细胞纤维连接蛋白(cFN)等水平;比较两组预后[格拉斯哥预后评分(GOS)]、神经功能[美国国立卫生研究院卒中量表(NIHSS)评分]及日常生活能力[日常生活活动能力量表(ADL)]。结果与硬通道组相比,软通道组术中抽吸血肿量及体积比均较低,且术后血肿排空、脑脊液恢复正常时间较短,差异有统计学意义(P<0.05)。与术前比较,术后7 d两组血清sTREM-1、AQP4、cFN水平均降低,且软通道组低于硬通道组(P<0.05)。术后1个月,两组GOS、ADL评分均升高,且软通道组高于硬通道组(P<0.05)。术后1个月,两组NIHSS评分均降低,且软通道组低于硬通道组(P<0.05)。结论软通道微创治疗可改善高血压性脑出血患者血肿吸收,降低血清sTREM-1、AQP4、cFN水平。 展开更多
关键词 高血压 脑出血 软通道 微创 血肿
在线阅读 下载PDF
黔西矿区软硬分层煤温度-压力耦合影响瓦斯解吸试验
18
作者 黄良 李希建 +1 位作者 刘钰 陈守坤 《工矿自动化》 北大核心 2025年第1期156-162,170,共8页
煤层瓦斯解吸特性对矿井瓦斯涌出规律和煤层气开发有重要影响,煤层温度和压力变化对软硬分层煤瓦斯解吸有明显控制作用。贵州黔西矿区煤层大多属于高瓦斯近距离突出煤层群,软硬结合较多,且煤层透气性低。为进一步明确该地区煤层瓦斯解... 煤层瓦斯解吸特性对矿井瓦斯涌出规律和煤层气开发有重要影响,煤层温度和压力变化对软硬分层煤瓦斯解吸有明显控制作用。贵州黔西矿区煤层大多属于高瓦斯近距离突出煤层群,软硬结合较多,且煤层透气性低。为进一步明确该地区煤层瓦斯解吸特性,以贵州黔西典型矿区小屯煤矿和青龙煤矿软硬分层煤为研究对象,利用HCA型高压容量法吸附装置对软硬分层煤进行不同温度、压力下的瓦斯解吸特征试验研究,对比分析温度、压力耦合变化对软硬分层煤瓦斯解吸特征的影响。结果表明:同一煤样温度、压力越高,瓦斯解吸初速度越大,对于0~120 s内的初始瓦斯解吸,瓦斯压力不占主导作用;软分层煤初始瓦斯解吸速率大于硬分层煤,硬分层煤累计瓦斯解吸量大于软分层煤,硬分层煤累计瓦斯解吸量最快在540 s内超过软分层煤;煤体暴露后60 s内含煤瓦斯解吸量变化最剧烈,且软分层煤前60 s解吸量所占比例大于硬分层煤,解吸更“活跃”;瓦斯解吸速率随压力的增加而升高,解吸速率可划分为3个阶段,即0~60 s为“解吸爆炸期”,60~1500 s为“解吸跳跃期”,1500~7200 s为“解吸稳定期”;软分层煤中值解吸时间受温度、压力影响大于硬分层煤,软分层煤瓦斯解吸主要集中在煤炭暴露后1800 s内。 展开更多
关键词 构造煤 软硬分层 瓦斯解吸速率 瓦斯解吸量 温度-压力耦合影响
在线阅读 下载PDF
深厚软土覆盖层固结特性对面板堆石坝安全的影响
19
作者 岑威钧 魏江梁 +2 位作者 郑长海 彭凯 石含鑫 《河海大学学报(自然科学版)》 北大核心 2025年第2期39-46,97,共9页
以某抽水蓄能电站上水库百米级深厚软土覆盖层上的沥青混凝土面板堆石坝为例,选择主沟覆盖层最深处断面,采用Biot固结理论计算分析了大坝填筑期及蓄水运行期坝体和坝基应力变形特性,重点研究了坝基固结变形分布规律和超静孔隙水压力消... 以某抽水蓄能电站上水库百米级深厚软土覆盖层上的沥青混凝土面板堆石坝为例,选择主沟覆盖层最深处断面,采用Biot固结理论计算分析了大坝填筑期及蓄水运行期坝体和坝基应力变形特性,重点研究了坝基固结变形分布规律和超静孔隙水压力消散情况,同时针对饱和软黏土覆盖层坝基,施工期采用“φ=0”总应力法开展坝基深层抗滑稳定分析。结果表明:坝体填筑过程中覆盖层中超静孔隙水压力增长、扩散和消散同步发生,其此消彼长的过程与地层的渗透系数密切相关,当坝体填筑到约1/3坝高时,覆盖层中超静孔隙水压力达到峰值,上层碎石黏土覆盖层相对偏大的渗透性使得坝体施工完成时覆盖层超静孔隙水压力大部分已消散,并在工后5a覆盖层基本完成固结;由于坝体填筑过程中及大坝蓄水后碎石黏土覆盖层孔压消散较快,深层饱和黏土附加应力较小,大坝工后沉降增量仅为-7.35cm(不计流变),约占最终稳定沉降量-337.58cm的2.18%;采用总应力法和有效应力法及相应参数计算得到的竣工期、蓄水期和库水位变动下大坝坝坡及坝基深层抗滑稳定安全系数均大于相应规范允许值,坝坡失稳可能性小。 展开更多
关键词 深厚覆盖层 BIOT固结 孔隙水压力 应力变形 稳定性分析
在线阅读 下载PDF
基于坐标注意力和软化非极大值抑制的密集安全帽检测
20
作者 尹向雷 苏妮 +1 位作者 解永芳 屈少鹏 《现代电子技术》 北大核心 2025年第2期153-161,共9页
为解决现有的安全帽检测算法对密集小目标的检测精度低的问题,提出一种基于坐标注意力和软化非极大值抑制的安全帽检测算法。引入坐标注意力机制,聚焦训练安全帽相关目标特征以提高准确率。采用软化非极大值抑制算法对候选框的置信度进... 为解决现有的安全帽检测算法对密集小目标的检测精度低的问题,提出一种基于坐标注意力和软化非极大值抑制的安全帽检测算法。引入坐标注意力机制,聚焦训练安全帽相关目标特征以提高准确率。采用软化非极大值抑制算法对候选框的置信度进行优化,提升模型对密集小目标的检测精度。通过WIoU优化边界框损失函数,使得模型聚焦于困难样例而减少简单示例对损失值的贡献,提升模型的泛化性能。实验结果表明:与基准模型YOLOv5s相比,所提算法的mAP@0.5达到88.4%,提升了3.0%;mAP@0.5:0.95达到65.6%,提升了6.8%;在召回率和准确率上分别提升了2.4%和0.5%。所提算法为密集小目标的检测提供了一定参考。 展开更多
关键词 安全帽检测 坐标注意力机制 软化非极大值抑制 YOLOv5s WIoU 边界框损失函数
在线阅读 下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部