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期刊论文 34

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PEDOT:PSS 1

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低角估计；甚高频雷达；复杂场景；多径效应；高度估计 1

体积应变 1

剪切带 1

剪切应变 1

单站；结构总体最小二乘；逆迭代；到达角（AOA）；到达时间（TOA）；到达频率（FOA）；多源 1

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太赫兹通信；反射系数建模；入射角；建筑材料；菲涅耳模型 1

岩爆 1

弦切面 1

微角度检测；差分电容结构；转子式陀螺 1

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Performance, emission and combustion characteristics of CI engine fuelled with diesel and hydrogen

R. Senthil KUMAR,M. LOGANATHAN,E. James GUNASEKARAN

《能源前沿（英文）》 2015年 第9卷 第4期   页码 486-494 doi: 10.1007/s11708-015-0368-4

摘要： Hydrogen (H ) is being considered as a primary automotive fuel and as a replacement for conventional fuels. Some of the desirable properties, like high flame velocity, high calorific value motivate us to use hydrogen fuel as a dual fuel mode in diesel engine. In this experiment, hydrogen was inducted in the inlet manifold with intake air. The experiments were conducted on a four stroke, single cylinder, water cooled, direct injection (DI), diesel engine at a speed of 1500 r/min. Hydrogen was stored in a high pressure cylinder and supplied to the inlet manifold through a water-and-air-based flame arrestor. A pressure regulator was used to reduce the cylinder pressure from 140 bar to 2 bar. The hydrogen was inducted with a volume flow rate of 4l pm, 6l pm and 8l pm, respectively by a digital volume flow meter. The engine performance, emission and combustion parameters were analyzed at various flow rates of hydrogen and compared with diesel fuel operation. The brake thermal efficiency (BTE) was increased and brake specific fuel consumption (BSFC) decreased for the hydrogen flow rate of 8l pm as compared to the diesel and lower volume flow rates of hydrogen. The hydrocarbon (HC) and carbon monoxide (CO) were decreased and the oxides of nitrogen (NO ) increased for higher volume flow rates of hydrogen compared to diesel and lower volume flow rates of hydrogen. The heat release rate and cylinder pressure was increased for higher volume flow rates of hydrogen compared to diesel and lower volume flow rates of hydrogen.

关键词： hydrogen     brake thermal efficiency     crank angle     compressed ignition (CI)    

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Reliability analysis of kinematic accuracy for the elastic slider-crank mechanism

TUO Yaofei, CHEN Jianjun, ZHANG Chijiang, CHEN Yongqin

《机械工程前沿（英文）》 2007年 第2卷 第2期   页码 214-217 doi: 10.1007/s11465-007-0037-3

摘要： This paper deals with the static and dynamic output kinematic accuracy of a group of elastic slider-crank mechanisms with the same design parameters by taking the bar length, the joint-gaps, the mass density, and the sectional and the physical parameters as random variables. According to the principle of linear pile-up of small displacement, the static and dynamic output kinematic errors are synthesized, and the reliability model of the kinematic accuracy of the mechanism is built. Through an example, a study of the influencing factors on the reliability of the output kinematic accuracy of the mechanism is made. The results obtained reveal the following facts: with the increase of the crank s rotating speed, the dynamic elastic deformation of the mechanism becomes the principal factor that greatly affects the reliability of the output kinematic accuracy of the mechanism.

关键词： output kinematic     group     slider-crank     kinematic accuracy     displacement    

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Precise semi-analytical inverse kinematic solution for 7-DOF offset manipulator with arm angle optimization

《机械工程前沿（英文）》 2021年 第16卷 第3期   页码 435-450 doi: 10.1007/s11465-021-0630-x

摘要： Seven-degree-of-freedom redundant manipulators with link offset have many advantages, including obvious geometric significance and suitability for configu-ration control. Their configuration is similar to that of the experimental module manipulator (EMM) in the Chinese Space Station Remote Manipulator System. However, finding the analytical solution of an EMM on the basis of arm angle parameterization is difficult. This study proposes a high-precision, semi-analytical inverse method for EMMs. Firstly, the analytical inverse kinematic solution is established based on joint angle parameterization. Secondly, the analytical inverse kinematic solution for a non-offset spherical–roll–spherical (SRS) redundant manipulator is derived based on arm angle parameterization. The approximate solution of the EMM is calculated in accordance with the relationship between the joint angles of the EMM and the SRS manipulator. Thirdly, the error is corrected using a numerical method through the analytical inverse solution based on joint angle parameterization. After selecting the stride and termination condition, the precise inverse solution is computed for the EMM based on arm angle parameterization. Lastly, case solutions confirm that this method has high precision, and the arm angle parameterization method is superior to the joint angle parameterization method in terms of parameter selection.

关键词： 7-DOF redundant manipulator     inverse kinematics     semi-analytical     arm angle     link offset    

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Evaluating the material strength from fracture angle under uniaxial loading

Jitang FAN

《结构与土木工程前沿（英文）》 2019年 第13卷 第2期   页码 288-293 doi: 10.1007/s11709-018-0480-8

摘要： The most common experimental methods of measuring material strength are the uniaxial compressive and tensile tests. Generally, shearing fracture model occurs in both the tests. Compressive strength is higher than tensile strength for a material. Shearing fracture angle is smaller than 45° under uniaxial compression and greater than 45° under uniaxial tension. In this work, a unified relation of material strength under uniaxial compression and tension is developed by correlating the shearing fracture angle in theory. This constitutive relation is quantitatively illustrated by a function for analyzing the material strength from shear fracture angle. A computational simulation is conducted to validate this theoretical function. It is full of interest to give a scientific illustration for designing the high-strength materials and engineering structures.

关键词： strength     fracture     mechanics    

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Computation of the protein molecular mechanism using adaptive dihedral angle increments

Mikel DIEZ, Victor PETUYA, Mónica URIZAR, Erik MACHO, Oscar ALTUZARRRA

《机械工程前沿（英文）》 2013年 第8卷 第1期   页码 104-108 doi: 10.1007/s11465-013-0360-9

摘要：

Protein motion simulation is still a troublesome problem yet to be solved, especially due to its high computational requirements. The procedure presented in this paper makes use of the proteins’ real degrees of freedom (DOFs). The procedure makes no use of any intermediate energy minimization processes that may alter the motion path or result in very high computational cost requirements. In order to reduce the computational cost, presented algorithms make use of the balls and rods approach for protein structure modelization. Also, structures are normalized in order to minimize inaccuracies introduced by experimental methods, providing a more efficient but still accurate structure for motion simulation.

关键词： kinematics     serial robot     proteins     folding     molecular mechanism    

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CFD simulation on shell-and-tube heat exchangers with small-angle helical baffles

Minhua ZHANG,Fang MENG,Zhongfeng GENG

《化学科学与工程前沿（英文）》 2015年 第9卷 第2期   页码 183-193 doi: 10.1007/s11705-015-1510-x

摘要： Shell-and-tube heat exchanger with helical baffles is superior to that with segmental baffles in reducing pressure drop, eliminating dead zone and lowering the risks of vibration of tube bundle. This paper focused on the small-angle helical baffles that have been merely reported in open literature. These baffles are noncontinuous helical baffles with a helix angle of 10° to 30°, and their shapes are 1/4 ellipse, 1/4 sector and 1/3 sector. To assess the integrative performance, /? is employed, and the calculated results show that among the three baffle shapes the heat exchangers with a 1/4 sector helical baffle have the lowest pressure drop. At = 10° and 20°, 1/4 sector helical baffle heat exchangers show the best integrative performance; at = 30°, 1/4 ellipse and 1/4 sector helical baffle heat exchangers perform almost the same. For the study of helix angles, we found that 30° has the best integrative performance at low mass flow rate, almost the same as 20° at high mass flow rate.

关键词： heat transfer     pressure drop     helical baffle     CFD    

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Effects of Boundary Condition and Helix Angle on Meshing Performance of TI Worm Gearing

SUN Yue-hai, DUAN Lu-qian, WANG Shu-ren, ZHANG Ce

《机械工程前沿（英文）》 2006年 第1卷 第1期   页码 90-95 doi: 10.1007/s11465-005-0006-7

摘要：

To exactly describe the contact state and contact area of tooth surface of toroidal involute (TI) worm gearing, the authors introduced boundary condition into contact line analysis.With helix angle chosen as parameter, the criterion for the existence of meshing boundary line on the surface of TI worm gearing is derived. Results show that there can be four situations for meshing boundary line on the tooth surface of gear, namely, inexistence of meshing boundary line, a unique line, two lines, and two coincident lines. If the helix angle is equal to or slightly smaller than the bigger angle, which makes two meshing boundary lines superpose, a preferable meshing performance is obtained. Computer simulation proves the validity of the above conclusion.

关键词： preferable     inexistence     Results     validity     boundary condition    

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Industrial-scale investigations on effects of tertiary-air declination angle on combustion and steam

Xiaoguang LI, Lingyan ZENG, Hongye LIU, Yao LI, Yifu LI, Yunlong ZHAO, Bo JIAO, Minhang SONG, Shaofeng ZHANG, Zhichao CHEN, Zhengqi LI

《能源前沿（英文）》 2021年 第15卷 第1期   页码 132-142 doi: 10.1007/s11708-020-0803-z

摘要： Industrial-scale experiments were conducted to study the effects of tertiary air declination angle (TDA) on the coal combustion and steam temperature characteristics in the first 350-MW supercritical down-fired boiler in China with the multiple-injection and multiple-staging combustion (MIMSC) technology at medium and high loads. The experimental results indicated that as the TDA increased from 0° to 15°, the overall gas temperature in the lower furnace rose and the symmetry of temperature field was enhanced. The ignition distance of the fuel-rich coal/air flow decreased. In near-burner region, the concentration of O decreased while the concentrations of CO and NO increased. The concentration of NO decreased in near-tertiary-air region. The carbon in fly ash decreased significantly from 8.40% to 6.45% at a load of 260 MW. At a TDA of 15°, the ignition distances were the shortest (2.07 m and 1.73 m) at a load of 210 MW and 260 MW, respectively. The main and reheat steam temperatures were the highest (557.2°C and 559.4°C at a load of 210 MW, 558.4°C and 560.3°C at a load of 260 MW). The carbon in fly ash was the lowest (4.83%) at a load of 210 MW. On changing the TDA from 15° to 25°, the flame kernel was found to move downward and the main and reheat steam temperatures dropped obviously. The change of TDA has little effect on NO emissions(660–681 mg/m at 6% O ). In comprehensive consideration of the pulverized coal combustion characteristics and the unit economic performance, an optimal TDA of 15° is recommended.

关键词： supercritical down-fired boiler     industrial-scale experiment     tertiary air declination angle     coal combustion     steam temperature    

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A Miniature Meta-Optical System for Reconfigurable Wide-Angle Imaging and Polarization-Spectral Detection

Fei Zhang,Minghao Liao,Mingbo Pu,Yinghui Guo,Lianwei Chen,Xiong Li,Qiong He,Tongtong Kang,Xiaoliang Ma,Yuan Ke,Xiangang Luo,

《工程（英文）》 doi: 10.1016/j.eng.2023.07.008

摘要： Wide-angle imaging and spectral detection play vital roles in tasks such as target tracking, object classification, and anti-camouflage. However, limited by their intrinsically different architectures, as determined by frequency dispersion requirements, their simultaneous implementation in a shared-aperture system is difficult. Here, we propose a novel concept to realize reconfigurable dual-mode detection based on electrical-control tunable metasurfaces. As a proof-of-concept demonstration, the simultaneous implementation of wide-angle imaging and polarization-spectral detection in a miniature shared-aperture meta-optical system is realized for the first time via the electrical control of cascaded catenary-like metasurfaces. The proposed system supports the imaging (spectral) resolution of approximately 27.8 line-pairs per millimeter (lp·mm−1; ∼80 nm) for an imaging (spectral) mode from 8 to 14 μm. This system also bears a large field of view of about 70°, enabling multi-target recognition in both modes. This work may promote the miniaturization of multifunctional optical systems, including spectrometers and polarization imagers, and illustrates the potential industrial applications of meta-optics in biomedicine, security, space exploration, and more.

关键词： Metasurfaces     Reconfigurable     Imaging     Spectral    

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一种新型转子式陀螺的分辨率为0.47″的转子微偏转角度检测方法 Article

Hai LI, Xiao-wei LIU, Rui WENG, Hai-feng ZHANG

《信息与电子工程前沿（英文）》 2017年 第18卷 第5期   页码 591-598 doi: 10.1631/FITEE.1500454

摘要： 差分电容检测被广泛应用于振动陀螺仪质量块的位移测量，然而由于结构、理论以及接口电路等因素的限制其在转子式陀螺所需的转子偏转角度检测方面还尚未取得较高分辨率。本文提出了一种差分电容检测结构，用以测量一种新型转子式陀螺转子的偏转角度。本文建立了结构电容与转子偏转角度之间关系的数学模型，分析了差分电容与结构参数之间的关系，并获得了初步优化的尺寸参数。设计了一款低噪声读出接口电路将差分电容的变化转换为电压信号。对陀螺仪的转台测试结果表明，该角度检测结构的最小可分辨的偏转角度小于0.47″（0.00013°），三次多项式补偿后检测结构的非线性可达0.33%，并可进一步提高。结果表明该检测结构和电路有助于实现该陀螺仪的高精度。

关键词： 微角度检测；差分电容结构；转子式陀螺    

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Effect of placement angles on wireless electrocoagulation for bipolar aluminum electrodes

Zhenlian Qi, Jinna Zhang, Shijie You

《环境科学与工程前沿（英文）》 2018年 第12卷 第3期 doi: 10.1007/s11783-018-1034-y

摘要： We in our previous study reported the wireless electrocoagulation (WEC) based on bipolar electrochemistry for water purification. One of the most important advantages of WEC is the omission of ohmic connection between bipolar electrode (BPE) and power supply, and thus the electrochemical reactions on BPE are driven by electric field in solution induced by driving electrodes. In this study, the impact of placement angle of bipolar aluminum electrode on WEC was investigated to provide a detailed analysis on the correlations between the bipolar electrode placement angle and bipolar electrocoagulation reactions. The results showed that the WEC cell with a horizontal BPE placed at 0° produced the maximum dissolved aluminum coagulant, accounting for 71.6 % higher than that with a vertical one placed at 90°. Moreover, the finite element simulations of current and potential distribution were carried out along the surface of BPE at different placement angles, revealing the mechanism of different BPE placement angles on aluminum dissolution rates in WEC system.

关键词： Bipolar electrochemistry     Wireless electrocoagulation     Placement angle    

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Synthesis and properties of polybenzazoles containing flexible methylene in backbone

XU Xiaohui, LIU Xiaoyun, ZHOU Chengjun, ZHUANG Qixin, HAN Zhewen

《化学科学与工程前沿（英文）》 2008年 第2卷 第4期   页码 412-416 doi: 10.1007/s11705-008-0073-5

摘要： A novel series of polybenzazoles with rigid-rod benzoxazole cycle and soft methylene segment was designed and synthesized via solution condensation polymerizations from 4,6-diamino-1,3-benzenediol diphosphate, terephthalic acid and aliphatic dicarboxylic acid. The structures of polybenzazoles were characterized by means of FT-IR, H NMR and Wide-angle X-ray diffraction (WAXRD). All the polymers show excellent thermal stability and the s was above 471°C. The intrinsic viscosities [] of the polymers ranged from 0.8 to 0.9. The UV-Vis absorption peaks of the polymers in MSA were blue-shifted from 429 nm for PBO to 291 nm for PBOC7, and the Stokes shifts in PL spectra enlarged.

关键词： condensation     Wide-angle     absorption     excellent     diffraction    

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Effect of UAV prewetting application during the flowering period of cotton on pesticide droplet deposition

Weixiang YAO, Xianju WANG, Yubin LAN, Ji JIN

《农业科学与工程前沿（英文）》 2018年 第5卷 第4期   页码 455-461 doi: 10.15302/J-FASE-2018232

摘要：

Prewetting process can reduce the contact angle between the droplet and the leaf blade, so that the droplet can more easily wet and spread, thereby increasing the quantity of deposition. To improve the effectiveness of pesticides on cotton leaves, prewetting by single-rotor electric unmanned aerial vehicles (UAV) was studied, focusing on the effects of pesticide deposition on cotton leaves during the flowering period. Cotton leaves in 0°–30°, 30°–60°, 60°–90° leaf blade angle ranges (angle between the leaf blade and the horizontal plane) were examined. In the first experiment, four different prewetting volumes (0, 1.6, 3.2 and 4.8 L) were sprayed by a single-rotor electric UAV on four cotton plots (plots A to D) each with an area of 120 m , and then each area was sprayed with a 0.8% (w/v) ponceau 2R solution by another single-rotor electric UAV. The results revealed that with no prewetting, droplet deposition quantity decreased with increasing leaf blade inclination. After prewetting, the mean droplet deposition quantity on plots B, C and D increased by 39.8%, 9.7% and 24.9%, respectively. The prewetting rate of 1.6 L per 120 m had the most significant effect on improving the deposition of droplets. It was also found that the mean droplet deposition quantity in each leaf blade angle range increased after prewetting. For the leaf blade angle range 60° to 90°, this increase was the most pronounced, with 0.043, 0.062, 0.057 and 0.048 L·cm in plots A–D, respectively. Also, droplet deposition uniformity in the leaf blade angle range 60°–90° was better after prewetting. These results should provide a valuable reference for future research and practice to improve the effectiveness of pesticides applied to cotton by aerial applications.

关键词： aerial spray     cotton     deposition     flowering period     leaf angle     prewetting     UAV    

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Seasonal variations in leaf capturing of particulate matter, surface wettability and micromorphology in urban tree species

Huixia WANG, Hui SHI, Yangyang LI, Ya YU, Jun ZHANG

《环境科学与工程前沿（英文）》 2013年 第7卷 第4期   页码 579-588 doi: 10.1007/s11783-013-0524-1

摘要： The seasonal changes in leaf particulate matter (PM) accumulation, surface wettability and micromorphology in urban tree species, including ( . ), ( . ) and ( . ), were studied during a single growing season. The three species showed distinct seasonal trends in PM accumulation, increasing from spring to autumn (or winter) even during the rainy season, but at different rates. During the study, the leaf PM retention amount of , a species with ridged leaf surfaces, was significantly higher than that of and , species with waxy leaf surfaces. The contact angles of water droplets on leaves decreased with leaf age except on the abaxial surface of , which remained non-wettable or highly non-wettable throughout the growing season; the decrease in the contact angle on adaxial surface of was greater when compared with and . A significant and negative relationship existed between leaf PM retention amounts and contact angles on adaxial surface of leaves of all three species. The increase in wettability, probably caused when epicuticular wax was destroyed by mechanical and chemical abrasion, seemed to be the main factor leading to seasonal variations in leaf PM accumulation.

关键词： contact angle     particulate matter     retention amount    

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广角均匀照明效果的灯具设计

顾伟,雷威,张晓兵,杨国栋,吴永强,方庆华

《中国工程科学》 2007年 第9卷 第3期   页码 71-75

摘要：

设计了圆环型的灯心结构，在期望张角处布置反射光线照度峰值的办法，得到了表达所期望镜面的一 阶二次微分方程。经过数值求解和函数拟合，确定了球冠结构的反射侧面。当在球冠下方加装圆锥型镜面之后， 进一步提高了广角内的照度均匀度。设计方案将90°张角内的照度不均匀度从设计前的65％改善到了±15％之内。

关键词： 均匀照度分布     灯具     镜面    

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标题 作者 时间 类型 操作

Performance, emission and combustion characteristics of CI engine fuelled with diesel and hydrogen

R. Senthil KUMAR,M. LOGANATHAN,E. James GUNASEKARAN

期刊论文

Reliability analysis of kinematic accuracy for the elastic slider-crank mechanism

TUO Yaofei, CHEN Jianjun, ZHANG Chijiang, CHEN Yongqin

期刊论文

Precise semi-analytical inverse kinematic solution for 7-DOF offset manipulator with arm angle optimization

期刊论文

Evaluating the material strength from fracture angle under uniaxial loading

Jitang FAN

期刊论文

Computation of the protein molecular mechanism using adaptive dihedral angle increments

Mikel DIEZ, Victor PETUYA, Mónica URIZAR, Erik MACHO, Oscar ALTUZARRRA

期刊论文

CFD simulation on shell-and-tube heat exchangers with small-angle helical baffles

Minhua ZHANG,Fang MENG,Zhongfeng GENG

期刊论文

Effects of Boundary Condition and Helix Angle on Meshing Performance of TI Worm Gearing

SUN Yue-hai, DUAN Lu-qian, WANG Shu-ren, ZHANG Ce

期刊论文

Industrial-scale investigations on effects of tertiary-air declination angle on combustion and steam

Xiaoguang LI, Lingyan ZENG, Hongye LIU, Yao LI, Yifu LI, Yunlong ZHAO, Bo JIAO, Minhang SONG, Shaofeng ZHANG, Zhichao CHEN, Zhengqi LI

期刊论文

A Miniature Meta-Optical System for Reconfigurable Wide-Angle Imaging and Polarization-Spectral Detection

Fei Zhang,Minghao Liao,Mingbo Pu,Yinghui Guo,Lianwei Chen,Xiong Li,Qiong He,Tongtong Kang,Xiaoliang Ma,Yuan Ke,Xiangang Luo,

期刊论文

一种新型转子式陀螺的分辨率为0.47″的转子微偏转角度检测方法

Hai LI, Xiao-wei LIU, Rui WENG, Hai-feng ZHANG

期刊论文

Effect of placement angles on wireless electrocoagulation for bipolar aluminum electrodes

Zhenlian Qi, Jinna Zhang, Shijie You

期刊论文

Synthesis and properties of polybenzazoles containing flexible methylene in backbone

XU Xiaohui, LIU Xiaoyun, ZHOU Chengjun, ZHUANG Qixin, HAN Zhewen

期刊论文

Effect of UAV prewetting application during the flowering period of cotton on pesticide droplet deposition

Weixiang YAO, Xianju WANG, Yubin LAN, Ji JIN

期刊论文

Seasonal variations in leaf capturing of particulate matter, surface wettability and micromorphology in urban tree species

Huixia WANG, Hui SHI, Yangyang LI, Ya YU, Jun ZHANG

期刊论文

广角均匀照明效果的灯具设计

顾伟,雷威,张晓兵,杨国栋,吴永强,方庆华

期刊论文