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基于Stair−YOLOv7−tiny的煤矿井下输送带异物检测
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作者 梅晓虎 吕小强 雷萌 《工矿自动化》 CSCD 北大核心 2024年第8期99-104,111,共7页
针对现有煤矿井下输送带异物检测方法应对复杂场景适应性差、无法满足实时性和轻量化要求、处理尺寸差异较大异物时表现不佳的问题,基于轻量化YOLOv7−tiny模型进行改进,提出了一种Stair−YOLOv7−tiny模型,并将其用于煤矿井下输送带异物... 针对现有煤矿井下输送带异物检测方法应对复杂场景适应性差、无法满足实时性和轻量化要求、处理尺寸差异较大异物时表现不佳的问题,基于轻量化YOLOv7−tiny模型进行改进,提出了一种Stair−YOLOv7−tiny模型,并将其用于煤矿井下输送带异物检测。该模型在高效层聚合网络(ELAN)模块中添加特征拼接单元,形成阶梯ELAN(Stair−ELAN)模块,将不同层级的低维特征与高维特征进行融合,加强了特征层级间的直接联系,提升了信息捕获能力,增强了模型对不同尺度目标和复杂场景的适应性;针对检测头引入阶梯特征融合(Stair−fusion),形成阶梯检测头(Stair−head)模块,通过逐层融合不同分辨率的检测头特征,增强了中低分辨率检测头的特征表达能力,实现了特征信息的互补。实验结果表明:Stair−YOLOv7−tiny模型在输送带异物开源数据集CUMT−BelT上的检测效果优于CBAM−YOLOv5,YOLOv7−tiny及其轻量化模型,准确率、平均精度均值、召回率和精确率分别达98.5%,81.0%,82.2%和88.4%,检测速度为192.3帧/s;在某矿井下输送带监控视频分析中,Stair−YOLOv7−tiny模型未出现漏检或误检,实现了输送带异物的准确检测。 展开更多
关键词 输送带异物检测 YOLOv7−tiny 多尺度目标检测 Stair−fusion 高效层聚合网络 检测头
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The Whole Theory of This Universe—A Step Forward to Einstein. Part-4: “Concept Map of Rotating Universe”
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作者 Rehana Kousar 《Journal of Applied Mathematics and Physics》 2024年第5期1699-1724,共26页
The article collectively proposes a revolutionary perspective on the universe, intertwining concepts of time, spatial positioning, and cosmic dynamics. We introduce the idea of a rotating universe centered around Mega... The article collectively proposes a revolutionary perspective on the universe, intertwining concepts of time, spatial positioning, and cosmic dynamics. We introduce the idea of a rotating universe centered around Mega Central Energy Pools (MCEPs), where time varies relative to the distance from the universe’s center, potentially enabling time travel. This model challenges conventional notions of time and cosmology, suggesting that black holes and white holes act as cosmic recycling factories. Additionally, this model unveils a novel theory of dark matter, positing photons as its constituents and highlighting their role in energy transfer across the cosmos. Furthermore, the investigation into Venus’s unique day-length-to-year-length ratio unveils a microscopic mechanism involving swirling energy droplets, charged particles, and field interactions, offering insights into planetary dynamics on both micro and macro scales. 展开更多
关键词 Rotating Universe Time Stair Time Acceleration Time Dilations Accelerating Galaxies
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A Comparison of Pound's Poetic Ideas and Some Chinese Poetic Principles-Using the Translation of "The Jewel Stairs' Grievance" as a Case in Point
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作者 成婷 《海外英语》 2011年第9X期268-268,270,共2页
The prominent features of Li Bai's "The Jewel Stairs'Grievance" are precise diction;implicit meaning;an absent narrator;and a seamless unity of images and feelings.Pound's translation of it in Ca... The prominent features of Li Bai's "The Jewel Stairs'Grievance" are precise diction;implicit meaning;an absent narrator;and a seamless unity of images and feelings.Pound's translation of it in Cathay reveals some kind of connections between some Chinese poetic principals and Pound's individual poetics. 展开更多
关键词 POETIC PRINCIPALS POUND The Jewel stairs’Grievance
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Practical Use of Stairs to Assess Fitness, Prescribe and Perform Physical Activity Training
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作者 Jasem Ramadan Al Kandari Salman Mohammad +2 位作者 Ruqayyah Al-Hashem Girma Telahoun Mario Barac-Nieto 《Health》 CAS 2016年第13期1402-1410,共9页
Aim: Evaluating climbing stairs for prescription and implementation of physical activity regimes. Methods: Healthy females (F, n = 14), and males (M, n = 15) participated. By climbing 100 steps of stairs with 0.173 m ... Aim: Evaluating climbing stairs for prescription and implementation of physical activity regimes. Methods: Healthy females (F, n = 14), and males (M, n = 15) participated. By climbing 100 steps of stairs with 0.173 m height, Heart rate (HR) and oxygen uptake were measured throughout the floors;Blood pressure (BP) was measured at ground and the 5th floors only. Results: Energy increased from 2 to 7.6 was metabolic equivalents (METs = 3.5 ml O<sub>2</sub>/min.kg) at 17.3 m elevation in 2 min. at the 5th floor, and percent Heart Rate Reserve (%HRR) was 66.17% in F and 48.7% in M, proportional to their aerobic efforts. Average climbing efficiency was 15.8 ± 2.3% (n = 29). Aerobic capacity estimated dividing the highest work rate (17.3 Kg.m/2min.Kg × 0.00239 = 0.0207 Kcal/min.Kg), by fractional effort (F = 0.6617, M = 0.487) and fractional efficiency (0.158), at 5 Kcal/L O2 was 0.040 in F and 0.054 L O2/Kg.min in M. Minimum training intensity reached at the 3rd floor by F. In M the highest %HRR reached was 48.7% at the 5th floor, insufficient for training. Conclusions: Stairs used for submaximal evaluation of aerobic capacity and for target intensity prescription. Training, levels climbed, repetitions per day (if 5, 100 Kcal per day, ascending) and number of days/week are adjusted. Full regime requires up to 7.6 METs, a total of 532 and 140 MET.min/week ascending and descending, respectively. Intensities >7.6 MET, climbing rate should be >8.65 m/min. Limiting ascent to 1 (3.5 METs) or 2 (5.5 METs) floors or only descents (2 - 3 METs) may be used for unfit subjects. This method is useful for those with no access to sophisticated facilities. 展开更多
关键词 Stair Climbing DESCENT Heart Rate Reserve Aerobic Effort Oxygen Cost Work Output Efficiency Aerobic Capacity Exercise Prescription TRAINING
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Form Art and Function Analysis of Outdoor Stairs
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作者 MENG Lingshuai 《Journal of Landscape Research》 2021年第2期83-88,共6页
Stairs are an important structural component in the architectural space design.It not only serves as a link between landscapes,but also a highlight of the space.Interpretation of stairs can be carried out from the for... Stairs are an important structural component in the architectural space design.It not only serves as a link between landscapes,but also a highlight of the space.Interpretation of stairs can be carried out from the form and function of stairs.This paper mainly takes the outdoor stairs as the research object,which is a building component to solve the vertical traffic function of the building,and selects some stairs designs worldwide for the analysis.Focusing on architectural design,the study investigates the expression form of each component of the outdoor stairs,and explores the diversified designs of the stairs.The paper urges designers to pay close attention to the problems of stair design in essence,to deeply understand the forms and methods of stair expression,to expand the breadth of architectural design thinking,to pursue in-depth understanding of the inherent laws of building generation,and to improve the quality of architecture. 展开更多
关键词 Outdoor stairs Form art Form and structure
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Stair climbing,genetic predisposition,and the risk of incident type 2 diabetes:A large population-based prospective cohort study
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作者 Yuanjue Wu Mengyun Luo +1 位作者 Xiao Tan Liangkai Chen 《Journal of Sport and Health Science》 SCIE CSCD 2023年第2期158-166,共9页
Background:Cross-sectional evidence and small-scale trials suggest positive effects of stair climbing on cardiometabolic disease and glucose regulation.However,few studies have examined the long-term association betwe... Background:Cross-sectional evidence and small-scale trials suggest positive effects of stair climbing on cardiometabolic disease and glucose regulation.However,few studies have examined the long-term association between stair climbing and the incidence of type 2 diabetes(T2D).We aimed to prospectively evaluate the association of stair climbing with T2D and assess modifications by genetic predisposition to T2D.Methods:We included 451,699 adults(mean age=56.3±8.1 years,mean±SD;55.2%females)without T2D at baseline in the UK Biobank and followed up to March 31,2021.Stair climbing information was collected through the touchscreen questionnaire.Genetic risk score for T2D consisted of 424 single nucleotide polymorphisms.Results:During a median follow up of 12.1 years,14,896 T2D cases were documented.Compared with participants who reported no stair climbing,those who climbed stairs regularly had a lower risk of incident T2D(10-50 steps/day:hazard ratio(HR)=0.95,95%confidence interval(95%CI):0.89-1.00;60-100 steps/day:HR=0.92,95%CI:0.87-0.98;110-150 steps/day:HR=0.86,95%CI:0.80-0.91;>150 steps/day:HR=0.93,95%CI:0.87-0.99,p for trend=0.0007).We observed a significant interaction between stair climbing and genetic risk score on the subsequent T2D risk(p for interaction=0.0004),where the risk of T2D showed a downward trend in subjects with low genetic risk and those who reported stair climbing activity of 110-150 steps/day appeared to have the lowest overall T2D risk among those with intermediate to high genetic risk.Conclusion:A higher number of stairs climbed at home was associated with lower T2D incidence risk,especially among individuals with a low genetic predisposition to T2D.These findings highlight that stair climbing,as incidental physical activity,offers a simple and low-cost complement to public health interventions for T2D prevention. 展开更多
关键词 COHORT Genetic risk score Stair climbing Type 2 diabetes UK Biobank
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Oxygen uptake response to switching stairs exercise by non-parametric modeling
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作者 Hairong Yu Chenyu Zhang +2 位作者 Kai Cao Hamzah M.Alqudah Steven Weidong Su 《Control Theory and Technology》 EI CSCD 2024年第2期315-325,共11页
Oxygen uptake plays a crucial role in the evaluation of endurance performance during exercise and is extensively utilized for metabolic assessment. This study records the oxygen uptake during the exercise phase (i.e.,... Oxygen uptake plays a crucial role in the evaluation of endurance performance during exercise and is extensively utilized for metabolic assessment. This study records the oxygen uptake during the exercise phase (i.e., ascending or descending) of the stair exercise, utilizing an experimental dataset that includes ten participants and covers various exercise periods. Based on the designed experiment protocol, a non-parametric modeling method with kernel-based regularization is generally applied to estimate the oxygen uptake changes during the switching stairs exercise, which closely resembles daily life activities. The modeling results indicate the effectiveness of the non-parametric modeling approach when compared to fixed-order models in terms of accuracy, stability, and compatibility. The influence of exercise duration on estimated fitness reveals that the model of the phase-oxygen uptake system is not time-invariant related to respiratory metabolism regulation and muscle fatigue. Consequently, it allows us to study the humans’ conversion mechanism at different metabolic rates and facilitates the standardization and development of exercise prescriptions. 展开更多
关键词 Non-parametric modeling Interval stair training exercise Kernel method.Cardiorespiratory response Oxygen uptake
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瑞昌石化办公北楼,洛阳,河南,中国
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作者 王方戟 《世界建筑》 2016年第5期116-117,共2页
建筑以无象征性含义的悬浮之盒的形态介入城郊工业园区空旷的环境中。建筑立面上各个语言的尺度相差悬殊。经过特定的组合,它们将人们在形态上对建筑"楼层"的习惯性阅读瓦解了,取而代之的是人们对建筑形态更加自由的阅读。同时,立面... 建筑以无象征性含义的悬浮之盒的形态介入城郊工业园区空旷的环境中。建筑立面上各个语言的尺度相差悬殊。经过特定的组合,它们将人们在形态上对建筑"楼层"的习惯性阅读瓦解了,取而代之的是人们对建筑形态更加自由的阅读。同时,立面上各个语言也与具有不同使用含义的内部空间相对应。主楼梯不仅是交通空间,也是一个曲折、连贯的中庭空间,它将建筑的各个楼层在感知上连接在一起。 展开更多
关键词 建筑形态 中庭空间 交通空间 interior STAIR floating Floor FREEDOM BREAKING 监控室
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基于Stair模式的大学生创新创业教育实践探索 被引量:3
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作者 周燕 黎鸿雁 +3 位作者 贾柠宁 李静 张佳景 马波 《高教学刊》 2019年第3期43-45,共3页
萨提亚模式作为一种积极向上、自信统一、内外和谐的心理学模式,非常适合融入大学生创新创教育及训练指导,帮助大学生迈向身心统一、充满信心地创新实践锻炼,激发学生的创新创业热情,促进了大学生创新创业意识、创新创业能力的提高,帮... 萨提亚模式作为一种积极向上、自信统一、内外和谐的心理学模式,非常适合融入大学生创新创教育及训练指导,帮助大学生迈向身心统一、充满信心地创新实践锻炼,激发学生的创新创业热情,促进了大学生创新创业意识、创新创业能力的提高,帮助学生在创新创业实践活动中寻找到属于自己内心的力量、勇气、喜悦,建立更和谐的团队关系,为大学生职业规划及未来职业发展奠定了基础。 展开更多
关键词 萨提亚(Stair)模式 创新创业教育 创新实践 职业发展
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基于萨提亚模式的思政课大学生职业素质培养——以“思想道德修养与法律基础”为例 被引量:6
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作者 周燕 黎鸿雁 +1 位作者 贾柠宁 李亚青 《河北农业大学学报(社会科学版)》 2019年第2期76-80,共5页
育好时代新人是时代赋予思政课的任务。高校思政课要努力把握青年学子成长的自然律动,巧妙地将思想政治教育内容融入与大学生职业素质教育有机融合,帮助学生完善自我、勇担责任、和谐一致,健康成长。萨提亚(Stair)模式是一种以成长为取... 育好时代新人是时代赋予思政课的任务。高校思政课要努力把握青年学子成长的自然律动,巧妙地将思想政治教育内容融入与大学生职业素质教育有机融合,帮助学生完善自我、勇担责任、和谐一致,健康成长。萨提亚(Stair)模式是一种以成长为取向的积极心理学模式,注重心灵的联结和自我的成长力量的提升。实践证明,将思想政治教育与职业生涯教育有机结合,基于萨提亚(Stair)模式的应用,有助于拓宽职业生涯规划教育渠道,增强思政课职业素质教育的有效性。 展开更多
关键词 Stair模式 思想政治教育 职业素质教育 创新育人
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Stair evacuation simulation based on cellular automata considering evacuees' walk preferences 被引量:5
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作者 丁宁 张辉 +1 位作者 陈涛 Peter B.Luh 《Chinese Physics B》 SCIE EI CAS CSCD 2015年第6期687-693,共7页
As a physical model, the cellular automata (CA) model is widely used in many areas, such as stair evacuation. However, existing CA models do not consider evacuees' walk preferences nor psychological status, and the... As a physical model, the cellular automata (CA) model is widely used in many areas, such as stair evacuation. However, existing CA models do not consider evacuees' walk preferences nor psychological status, and the structure of the basic model is unapplicable for the stair structure. This paper is to improve the stair evacuation simulation by addressing these issues, and a new cellular automata model is established. Several evacuees' walk preference and how evacuee's psychology influences their behaviors are introduced into this model. Evacuees' speeds will be influenced by these features. To validate this simulation, two fire drills held in two high-rise buildings are video-recorded. It is found that the simulation results are similar to the fire drill results. The structure of this model is simple, and it is easy to further develop and utilize in different buildings with various kinds of occupants. 展开更多
关键词 building evacuation stair simulation cellular automata walk preferences
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Analyzing floor-stair merging flow based on experiments and simulation 被引量:2
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作者 Yu Zhu Tao Chen +1 位作者 Ning Ding Wei-Cheng Fan 《Chinese Physics B》 SCIE EI CAS CSCD 2020年第1期168-174,共7页
In most situations,staircase is the only egress to evacuate from high-rise buildings.The merging flow on the stair landing has a great influence on the evacuation efficiency.In this paper,we develop an improved cellul... In most situations,staircase is the only egress to evacuate from high-rise buildings.The merging flow on the stair landing has a great influence on the evacuation efficiency.In this paper,we develop an improved cellular automaton model to describe the merging behavior,and the model is validated by a series of real experiments.It is found that the flow rate of simulation results is similar to the drills,which means that the improved model is reasonable and can be used to describe the merging behavior on stairs.Furthermore,some scenarios with different door locations and building floor numbers are simulated by the model.The results show that(i)the best door location is next to the upward staircase;(ii)the total evacuation time and the building floor number are linearly related to each other;(iii)the pedestrians on upper floors have a negative influence on the evacuation flow rate. 展开更多
关键词 evacuation dynamics merging flow stair simulation cellular automaton high-rise buildings
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Comparison of gait properties during level walking and stair ascent and descent with varying loads 被引量:1
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作者 Tomohiro Demura Shin-ich Demura Sohee Shin 《Health》 2010年第12期1372-1376,共5页
This study aimed to compare gait properties during level walking and during stair ascent and descent with varying loads. Fifteen healthy young men (mean age: 22.1 ± 1.6 years) walked while holding four different ... This study aimed to compare gait properties during level walking and during stair ascent and descent with varying loads. Fifteen healthy young men (mean age: 22.1 ± 1.6 years) walked while holding four different loads relative to each subject’s body mass (0, 20, 40 and 60% of body mass: BM) on their backs. Stance time, swing time, and double support times were selected as gait parameters. All parameters showed a maximal value during stair ascent and a minimum value during level walking. Stance and double support times increased significan- tly with each load during level walking and during stair ascent and descent. In conclusion, st- air ascent and descent creates more unstable movement than level walking regardless of the weight of the load. The effect of loads on gait increases with the weight of the load and becomes obvious once the load exceeds 60% of BM. 展开更多
关键词 GAIT STAIR ASCENT STAIR DESCENT LOAD
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Discrete Differential Geometry of Triangles and Escher-Style Trick Art 被引量:2
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作者 Naoto Morikawa 《Open Journal of Discrete Mathematics》 2016年第3期161-166,共7页
This paper shows the usefulness of discrete differential geometry in global analysis. Using the discrete differential geometry of triangles, we could consider the global structure of closed trajectories (of triangles)... This paper shows the usefulness of discrete differential geometry in global analysis. Using the discrete differential geometry of triangles, we could consider the global structure of closed trajectories (of triangles) on a triangular mesh consisting of congruent isosceles triangles. As an example, we perform global analysis of an Escher-style trick art, i.e., a simpler version of “Ascending and Descending”. After defining the local structure on the trick art, we analyze its global structure and attribute its paradox to a singular point (i.e., a singular triangle) at the center. Then, the endless “Penrose stairs” is described as a closed trajectory around the isolated singular point. The approach fits well with graphical projection and gives a simple and intuitive example of the interaction between global and local structures. We could deal with higher dimensional objects as well by considering n-simplices (n > 2) instead of triangles. 展开更多
关键词 Discrete Differential Geometry Triangle Mesh Global Analysis Singular Point Penrose stairs
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APPLICATIONS OF STAIR MATRICES AND THEIR GENERALIZATIONS TO ITERATIVE METHODS
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作者 邵新慧 沈海龙 李长军 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2006年第8期1115-1121,共7页
Stair matrices and their generalizations are introduced. The definitions and some properties of the matrices were first given by Lu Hao. This class of matrices provide bases of matrix splittings for iterative methods.... Stair matrices and their generalizations are introduced. The definitions and some properties of the matrices were first given by Lu Hao. This class of matrices provide bases of matrix splittings for iterative methods. The remarkable feature of iterative methods based on the new class of matrices is that the methods are easily implemented for parallel computation. In particular, a generalization of the accelerated overrelaxation method (GAOR) is introduced. Some theories of the AOR method are extended to the generalized method to include a wide class of matrices. The convergence of the new method is derived for Hermitian positive definite matrices. Finally, some examples are given in order to show the superiority of the new method. 展开更多
关键词 stair matrices iterative method parallel computation generalization of the AOR method
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Simulation on spread of fire smoke in the elevator shaft for a high-rise building
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作者 Yunchun Xia 《Theoretical & Applied Mechanics Letters》 CAS 2014年第3期80-85,共6页
Spread of fire smoke in the elevator shaft of a high-rise building is influ- enced by many driving facts. We simulate smoke spreading in the elevator shaft, stair room, and pre-chamber with and without different suppl... Spread of fire smoke in the elevator shaft of a high-rise building is influ- enced by many driving facts. We simulate smoke spreading in the elevator shaft, stair room, and pre-chamber with and without different supplied pressurized air. The simulation shows that smoke moves very fast in the elevator shaft. When a 12 floor high-rise building is in fire, smoke can fill up the elevator shaft in less than 1.5 min after a fire started, temperature in the elevator shaft can be higher than 187℃ in 5 rain, and the concentration of CO can also reach a high level. The elevator shaft has a very low visibility in less than about 100 s. 展开更多
关键词 high-rise building elevator shaft stair room smoke spread
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助动词Will的理解与翻译
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作者 程席法 《上海翻译》 CSSCI 北大核心 1990年第3期29-30,共2页
在英语中,助动词will(过去式为would)是最普通、使用最频繁的词之一,因此,正确理解它在不同语言环境中的具体功能,进行正确的翻译,理应受到高度的重视。但令人遗憾的是,实际情况并非如此。其结果自然是在翻译中每每出现“习惯性错误”,... 在英语中,助动词will(过去式为would)是最普通、使用最频繁的词之一,因此,正确理解它在不同语言环境中的具体功能,进行正确的翻译,理应受到高度的重视。但令人遗憾的是,实际情况并非如此。其结果自然是在翻译中每每出现“习惯性错误”,使审校人员改不胜改。其中最常见的现象,是译者一遇到will,就将其译作“将”,而不是根据不同情况做具体分析,选择确切的词语。不但一般译者往往如此,即使是专门从事翻译研究的人也在所难免。请看下面的一个例子:“For Heaven’s sake,hurry down!You’ll not meet anyone on the frontstair.Do be quick;and stay among 展开更多
关键词 WILL 请看 选择词 NOTHING 令人 NEVER quick 同卵双生子 STAIR 伊德
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Design and Simulation of a Topology Aggregation Algorithm in Multi-Domain Optical Networks
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作者 Lei Wang Li Lin Li Du 《Communications and Network》 2017年第4期235-248,共14页
The aggregate conversion from the complex physical network topology to the simple virtual topology reduces not only load overhead, but also the parameter distortion of links and nodes during the aggregation process, t... The aggregate conversion from the complex physical network topology to the simple virtual topology reduces not only load overhead, but also the parameter distortion of links and nodes during the aggregation process, thereby increasing the accuracy of routing. To this end, focusing on topology aggregation of multi-domain optical networks, a new topology aggregation algorithm (ML-S) was proposed. ML-S upgrades linear segment fitting algorithms to multiline fitting algorithms on stair generation. It finds mutation points of stair to increase the number of fitting line segments and makes use of less redundancy, thus obtaining a significant improvement in the description of topology information. In addition, ML-S integrates stair fitting algorithm and effectively alleviates the contradiction between the complexity and accuracy of topology information. It dynamically chooses an algorithm that is more accurate and less redundant according to the specific topology information of each domain. The simulation results show that, under different topological conditions, ML-S maintains a low level of underestimation distortion, overestimation distortion, and redundancy, achieving an improved balance between aggregation degree and accuracy. 展开更多
关键词 TOPOLOGY AGGREGATION Multiline FITTING STAIR FITTING MUTATION Point DISTORTION
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A New Copper(Ⅰ) Iodide Coordination Polymer Incorporating Cu_2I_2 Double-stranded Stair: Synthesis, Crystal Structure and Luminescent Property
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作者 高兰 吴建炎 +6 位作者 李梦雅 章凌 张萍 吴强芳 蔡晓庆 陈锋涛 章世深 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2013年第6期885-889,共5页
A new coordination compound, [(CuI)(Btd)]n (1, Btd = 2,1,3-benzothiadiazole), was obtained at room temperature by the reaction of 2,1,3-benzothiadiazole with CuI and KI saturated aqueous solution. It was charact... A new coordination compound, [(CuI)(Btd)]n (1, Btd = 2,1,3-benzothiadiazole), was obtained at room temperature by the reaction of 2,1,3-benzothiadiazole with CuI and KI saturated aqueous solution. It was characterized by elemental analysis, IR spectroscopy, single-crystal X-ray diffraction analysis and photoluminescence. The complex crystallizes in the triclinic Pi space group, with a = 4.1620(6), b = 10.4590(15), c = 10.5052(15) A, a = 69.310(2), β = 83.608(2), γ = 78.873(2)°, V = 419.30(10) A3, Z = 2, C6H4N2SCuI, Mr = 326.61, Dc = 2.587 g/cm^3, F(000) = 304 and/^(MoKa) = 6.464 mm-1. The final R = 0.0418 and wR = 0.0936 for 1451 observed reflections with 1 〉 2σ(I) and R = 0.0422 and wR = 0.0939 for all data. In the complex, the Cu atoms are coordinated by one nitrogen atom and three iodine atoms to form a double-stranded stair, and such stairs are further linked to build a 2D framework via C-H…I interactions. 展开更多
关键词 copper(I) iodide double-stranded stair luminescent
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Helicoidal shell response to earthquake loads
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作者 Mohammed S. Al-Ansari 《Journal of Civil Engineering and Architecture》 2009年第3期16-22,共7页
This paper studies and analyzes the response of helical stairs as helicoidal shells in earthquake zones. The response of helical stairs under gravity loads was analyzed by both the membrane theory and finite element m... This paper studies and analyzes the response of helical stairs as helicoidal shells in earthquake zones. The response of helical stairs under gravity loads was analyzed by both the membrane theory and finite element methods. The non-linear response of helical stairs, when subjected to UBC (Uniform Building Code) dynamic and static equivalent earthquake loads, were obtained using finite element models. These responses were compiled and analyzed in order to draw recommendations for the preliminary design of helical stairs in earthquake zones. The analysis of the results obtained showed that helical stairs are stiffer and lighter than regular ones. 展开更多
关键词 helicoidal shells helical stairs earthquake response finite element earthquake loads
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