资源类型

期刊论文 40

年份

2023 2

2022 2

2021 4

2020 2

2019 3

2018 1

2017 1

2016 2

2014 1

2012 1

2011 1

2010 2

2009 1

2008 9

2007 4

2004 2

2003 2

展开 ︾

关键词

力常数 2

狭义相对论 2

键能 2

键长 2

4D打印 1

光速不变公设 1

光量子 1

凸极同步电机 变速恒频 交流励磁 双馈 1

制造业 1

刺激响应材料 1

力矩反馈器 1

原子光谱 1

双馈型 1

变流器 1

变速恒频 1

并网逆变器；模型预测控制；直接功率控制；三矢量；恒定开关频率；功率误差 1

微机电系统 1

恒流/恒压转换；并联稳压器；无级功率重构；水下观测网 1

时间常数 1

展开 ︾

检索范围：

排序： 展示方式：

Research progress on low dielectric constant modification of cellulose insulating paper for power transformers

《化学科学与工程前沿（英文）》 2023年 第17卷 第8期   页码 991-1009 doi: 10.1007/s11705-022-2259-7

摘要： Because of the increase in the transmission voltage levels, the demand for insulation reliability of power transformers has increasingly become critical. Cellulose insulating paper is the main insulating component of power transformers. To improve the insulation level of ultrahigh voltage transformers and reduce their weight and size, reducing the dielectric constant of oil-immersed cellulose insulating paper is highly desired. Cellulose is used to produce power-transformer insulating papers owing to its excellent electrical properties, renewability, biodegradability and abundance. The dielectric constant of a cellulose insulating paper can be effectively reduced by chemical or physical modification. This study presents an overview of the foreign and domestic research status of the use of modification technology to reduce the dielectric constant of cellulose insulating papers. All the mentioned methods are analyzed in this study. Finally, some recommendations for future modified cellulose insulating paper research and applications are proposed. This paper can provide a reference for further research on low dielectric constant cellulose insulating paper in the future.

关键词： low dielectric constant     chemical and physical modification     cellulose insulating paper     transformer     nanomaterials.    

HTML PDF 收藏

Analysis and characterization of wind-solar-constant torque spring hybridized model

Shantanu ACHARYA,Subhadeep BHATTACHARJEE

《能源前沿（英文）》 2014年 第8卷 第3期   页码 279-289 doi: 10.1007/s11708-014-0312-z

摘要： Solar and wind are the most promising renewable energy resources. But their unpredictable and varying nature prevents them from being used as the sole resource for power generation. This paper presents a model of wind and solar thermal hybrid power plant with a spring storage system which is expected to play an efficient role in combating with the drawbacks related to renewable power generation. In the proposed scheme, wind energy is harnessed by a hybrid vertical axis wind turbine, solar energy is utilized by a Stirling engine, and the surplus energy is stored in a winding spring. The paper discusses the working methodologies and analyses the performance of such 2.6 kW hybrid power plant model. It has been observed that the plant is capable of consistently generating 50% of its rated capacity irrespective of limitations in solar and wind resources.

关键词： hybrid vertical axis wind turbine     Stirling engine     solar-thermal energy     wind energy     constant torque spring    

HTML PDF 收藏

Development of a fan-stirred constant volume combustion chamber and turbulence measurement with PIV

《能源前沿（英文）》 2022年 第16卷 第6期   页码 973-987 doi: 10.1007/s11708-021-0762-z

摘要： A fan-stirred combustion chamber is deve-loped for spherically expanding flames, with P and T up to 10 bar and 473 K, respectively. Turbulence characteristics are estimated using particle image velocimetry (PIV) at different initial pressures (P = 0.5–5 bar), fan frequencies (ω = 0–2000 r/min), and impeller diameters (D = 100 and 114 mm). The flame propagation of methanol/air is investigated at different turbulence intensities (u′=0–1.77 m/s) and equivalence ratios (φ = 0.7–1.5). The results show that u′ is independent of P and proportional to ω, which can be up to 3.5 m/s at 2000 r/min. LT is independent of P and performs a power regression with ω approximately. The turbulent field is homogeneous and isotropic in the central region of the chamber while the inertial subrange of spatial energy spectrum is more collapsed to –5/3 law at a high ReT. Compared to laminar expanding flames, the morpho-logy of turbulent expanding flames is wrinkled and the wrinkles will be finer with the growth of turbulence intensity, consistent with the decline of the Taylor scale and the Kolmogorov scale. The determined SL in the present study is in good agreement with that of previous literature. The SL and ST of methanol/air have a non-monotonic trend with φ while peak ST is shifted to the richer side compared to SL. This indicates that the newly built turbulent combustion chamber is reliable for further experimental study.

关键词： fan-stirred combustion chamber     turbulence characteristics     particle image velocimetry (PIV)     methanol     turbulent expanding flames    

HTML PDF 收藏

Solar photovoltaic fed dual input LED lighting system with constant illumination control

Kinattingal SUNDARESWARAN,Kevin Ark KUMAR,Payyalore Raman VENKATESWARAN,Sankaran PALANI

《能源前沿（英文）》 2016年 第10卷 第4期   页码 473-478 doi: 10.1007/s11708-016-0420-z

摘要： A dual input LED lighting scheme with constant illumination is proposed in this paper. The scheme employs a photovoltaic array as the first input and a battery as the second one. A microcontroller is programmed to operate a changeover switch as well as a DC-DC converter for uninterrupted and constant illumination in work place. The scheme is suitable for conference halls, laboratories, clean rooms, marriage halls, theaters, etc. The complete modeling, design and experimentation of the proposed scheme are explained and the economic viability of the scheme is justified.

关键词： photovoltaic     LED light     dual input     P&O algorithm    

HTML PDF 收藏

The energy consumption in a batch stripper and a batch rectifier

Xianbao CUI, Tianyang FENG, Ying ZHANG, Zhicai YANG,

《化学科学与工程前沿（英文）》 2009年 第3卷 第4期   页码 443-452 doi: 10.1007/s11705-009-0266-6

摘要： The energy consumption in a batch rectifier and a batch stripper was investigated with a shortcut mathematical model. The minimum energy consumption of a batch stripper was compared to that of a batch rectifier under “general constant reflux” and “general constant distillate composition” with the ratio of minimum energy consumption /. When the feed contains a large amount of light component, the product purity specification is low and the relative volatility is small, the minimum energy consumption of a batch stripper is less than that of a batch rectifier under “general constant reflux” and “general constant distillate composition”. When the feed contains a small amount of light component, the product purity specification is very high and the relative volatility is low, a batch stripper can also consume less energy only in the “general constant distillate composition” operation mode. In other cases, a batch rectifier can consume less energy.

关键词： constant reflux     feed     energy consumption     general constant     product purity    

HTML PDF 收藏

用经典力学计算氢分子的键长键能及力常数

陈景

《中国工程科学》 2003年 第5卷 第6期   页码 39-43

摘要：

氢原子中1 s电子的电子云呈球形，电子的最大几率密度分布出现在玻尔半径a0的球壳内，认为几率密度分布及电子云属统计规律，意味着已经使用了宏观时标，这样就使氢分子体系中能量和时间的作用量远大于普郎克常数；根据电子云的交叠，用经典力学计算了基态氢分子的结构常数，获得键长、键能及力常数的表达式分别为Re = 〓a0，De = ze/4〓a0,k = ze/2〓，采用原子单位（a.u.）时z、e及a0均为1，获得Re=1.414 a.u.，De=0.177 a.u.，k=0.354 a.u.，这些数值与实验值的相对误差分别<1%，<2%和<4%；成键模型直观，物理意义明确，计算中不含任何人为性参数。

关键词： 氢分子     键长     键能     力常数    

HTML PDF 收藏

新型双馈变速凸极同步电机

宁玉泉

《中国工程科学》 2004年 第6卷 第12期   页码 27-31

摘要：

提出一种新型双馈变速凸极同步电机，阐述了它的基本原理和结构，电机的转子采用分裂磁极和正交绕组, 结构简单、可靠。转子绕组由低频交流变频电源供电，使电机具有变速恒频的特性。通过原型样机的试验，验证了该项发明的正确性和实用性，它将在大型水电、风电中得到广泛应用。

关键词： 凸极同步电机 变速恒频 交流励磁 双馈    

HTML PDF 收藏

Constant temperature control of tundish induction heating power supply for metallurgical manufacturing

Yufei YUE, Qianming XU, Peng GUO, An LUO

《能源前沿（英文）》 2019年 第13卷 第1期   页码 16-26 doi: 10.1007/s11708-018-0572-0

摘要： The tundish induction heating power supply (TIHPS) is one of the most important equipment in the continuous casting process for metallurgical manufacturing. Specially, the constant temperature control is greatly significant for metallurgical manufacturing. In terms of the relationship between TIH load temperature and output power of TIHPS, the constant temperature control can be realized by power control. In this paper, a TIHPS structure with three-phase PWM rectifiers and full-bridge cascaded inverter is proposed. Besides, an input harmonic current blocking strategy and a load voltage feedforward control are also proposed to realize constant temperature control. To meet the requirement of the system, controller parameters are designed properly. Experiments are conducted to validate the feasibility and effectiveness of the proposed TIHPS topology and the control methods.

关键词： tundish induction heating power supply (TIHPS)     constant temperature control     input harmonic current blocking     load voltage feedforward    

HTML PDF 收藏

Seismic response of precast reinforced concrete wall subjected to cyclic in-plane and constant out-of-plane

《结构与土木工程前沿（英文）》 2021年 第15卷 第5期   页码 1128-1143 doi: 10.1007/s11709-021-0753-5

摘要： This paper provides insight into the seismic behavior of a full-scale precast reinforced concrete wall under in-plane cyclic loading combined with out-of-plane loading replicated by sand backfill to simulate the actual condition of basement walls. The tested wall exhibited flexural cracks, owing to the high aspect ratio and considerable out-of-plane movement due to lateral pressure from the backfill. The wall performed satisfactorily by exhibiting competent seismic parameters and deformation characteristics governed by its ductile response in the nonlinear phase during the test with smaller residual drift. Numerical analysis was conducted to validate experimental findings, which complied with each other. The numerical model was used to conduct parametric studies to study the effect of backfill density and aspect ratio on seismic response of the proposed precast wall system. The in-plane capacity of walls reduced, while deformation characteristics were unaffected by the increase in backfill density. An increase in aspect ratio leads to a reduction in in-plane capacity and an increase in drift. Curves between the ratio of in-plane yield capacity and design shear load of walls are proposed for the backfill density, which may be adopted to determine the in-plane yield capacity of the basement walls based on their design shear.

关键词： precast wall     basement wall     out-of-plane response     quasi-static test     sand backfill     seismic parameters    

HTML PDF 收藏

Convective heat transfer in helical coils for constant-property and variable-property flows with high

Yufei MAO, Liejin GUO, Bofeng BAI, Ximin ZHANG

《能源前沿（英文）》 2010年 第4卷 第4期   页码 546-552 doi: 10.1007/s11708-010-0116-8

摘要： Forced convection heat transfer of single-phase water in helical coils was experimentally studied. The testing section was constructed from a stainless steel round tube with an inner diameter of 10 mm, coil diameter of 300 mm, and pitch of 50 mm. The experiments were conducted over a wide Reynolds number range of 40000 to 500000. Both constant-property flows at normal pressure and variable-property flows at supercritical pressure were investigated. The contribution of secondary flow in the helical coil to heat transfer was gradually suppressed with increasing Reynolds number. Hence, heat transfer coefficients of the helical tube were close to those of the straight tube under the same flow conditions when the Reynolds number is large enough. Based on the experimental data, heat transfer correlations for both incompressible flows and supercritical fluid flows through helical coils were proposed.

关键词： convective heat transfer     helical coils     high Reynolds number     supercritical pressure     variable property    

HTML PDF 收藏

Deep eutectic solvent inclusions for high- composite dielectric elastomers

《化学科学与工程前沿（英文）》 2022年 第16卷 第6期   页码 996-1002 doi: 10.1007/s11705-022-2138-2

摘要： Recent advances in novel electroactive devices have placed new requirements on material development. High-performance dielectric elastomers with good mechanical stretchability and high dielectric constant are under high demand. However, the current strategy for fabricating these materials suffers from high cost or low thermal stability, which greatly hinders large-scale industrial production. Herein, we have successfully developed a novel strategy for improving the dielectric constant of polymeric elastomers via deep eutectic solvent inclusion by taking advantage of the low cost, convenient and environmentally benign synthesis process and high ionic conductivity from deep eutectic solvents. The as-prepared composite elastomers showed good stretchability and a greatly enhanced dielectric constant with a negligible increase in dielectric dissipation. Moreover, we have proven the universality of our strategy by using different types of deep eutectic solvents. It is believed that low-cost, easy-synthesis and environmentally friendly deep eutectic solvents including composite elastomers are highly suitable for large-scale industrial production and can greatly broaden the application fields of dielectric elastomers.

关键词： composite materials     deep eutectic solvent     dielectric elastomer     high dielectric constant    

HTML PDF 收藏

Removing ammonia from air with a constant pH, slightly acidic water　spray wet scrubber using recycled

Ahmad Kalbasi Ashtari, Amir M. Samani Majd, Gerald L. Riskowski, Saqib Mukhtar, Lingying Zhao

《环境科学与工程前沿（英文）》 2016年 第10卷 第6期 doi: 10.1007/s11783-016-0869-3

摘要： Slightly acidic solutions are a practical means of removing ammonia from air Scrubbed NH accumulates in solution as NH and should be an excellent fertilizer Increased air velocity decreased NH removal and increased NH collection Previous research on wet scrubbers has only studied highly acidic scrubbing solutions because of their high ammonia capture efficiencies; however, the high acidity created practical problems. Lower acidity solutions would reduce corrosion, maintenance, and cost; however, designers may need to use strategies for increasing scrubber effectiveness, such as using lower air velocities. The objective of this study was to determine if a spray scrubber with slightly acidic and higher pH scrubbing solution (pH from 2 to 8) could effectively remove NH from NH laden air (such as animal building exhaust air), and also collect this valuable resource for later use as a fertilizer. A bench-scale spray wet scrubber treated 20 ppmv NH /air mixture in a countercurrent contact chamber. First, the solution pH was varied from 2 to 8 while maintaining constant air velocity at 1.3 m·s . Next, air velocity was increased (2 and 3 m·s ) while solution pH remained constant at pH6. At 1.3 m·s , NH removal efficiencies ranged between 49.0% (pH8) and 84.3% (pH2). This study has shown that slightly acidic scrubbing solutions are a practical means of removing ammonia from air especially if the scrubber is designed to increase collisions between solution droplets and NH molecules. The NH removed from the air was held in solution as NH and accumulates over time so the solution should be an excellent fertilizer.

关键词： Ammonia     Spray wet scrubber     Slightly acidic scrubbing solution     Controlled pH     Removal efficiency    

HTML PDF 收藏

Pre-chamber turbulent jet ignition of methane/air mixtures with multiple orifices in a large bore constant

Xiang LI, Wenzheng ZHANG, Zhong HUANG, Dehao JU, Li HUANG, Mingzhi FENG, Xingcai LU, Zhen HUANG

《能源前沿（英文）》 2019年 第13卷 第3期   页码 483-493 doi: 10.1007/s11708-019-0631-1

摘要： Liquefied natural gas (LNG), mainly composed of methane, is in progress to substitute diesel fuel in heavy-duty marine engine for practical, economic, and environmental considerations. However, natural gas is relatively difficult to be ignited in a large bore combustion chamber. A combustion enhancement technique called pre-chamber turbulent jet ignition (TJI) can permit combustion and flame propagation in a large-bore volume. To investigate the effect of air-fuel equivalence ratio and pre-mixed pressure on pre-chamber TJI of methane/air mixtures with multiple orifices in a large bore volume, experimental tests and computational simulations were implemented to study the discharge of hot turbulent jets from six orifices of the pre-chamber. Different initial pressures and air-fuel equivalence ratios were considered to analyze the characteristics of TJI. The asymmetry of the turbulent jet actuated from six different orifices were found due to the asymmetric orientation of the spark plug, resulting in the inhomogeneous distribution of combustion in the constant volume chamber, which should be considered seriously in the marine engine design. Besides, as the premixed pressure increases, it has more effect on the flame propagation and plays a more important role, as it further increases.

关键词： marine engine     natural gas     methane     turbulent jet ignition (TJI)     pre-chamber    

HTML PDF 收藏

Biosorption of Cu(II) to extracellular polymeric substances (EPS) from

Xiangliang PAN, Jing LIU, Wenjuan SONG, Daoyong ZHANG

《环境科学与工程前沿（英文）》 2012年 第6卷 第4期   页码 493-497 doi: 10.1007/s11783-012-0416-9

摘要： Biosorption of extracellular polymeric substances (EPS) from sp. (cyanobacterium) with Cu(II) was investigated using fluorescence spectroscopy. Three fluorescence peaks were found in the excitation-emission matrix (EEM) fluorescence spectra of EPS. Fluorescence of peak A (Ex/Em= 275/452 nm) and peak C (Ex/Em= 350/452 nm) were originated from humic-like substances and fluorescence of peak B (Ex/Em= 275/338 nm) was attributed to protein-like substances. Fluorescence of peaks A, B, and C could be quenched by Cu(II). The effective quenching constants (lg K ) were 2.8–5.84 for peak A, 6.4–9.24 for peak B, and 3.48–6.68 for peak C, respectively. The values of lg K showed a decreasing trend with increasing temperature, indicating that the quenching processes were static in nature. The binding constants (lg K ) followed the order of peak A>peak B>peak C, implying that the humic-like substances in EPS have greater Cu(II) binding capacity than the protein-like substances. The binding site number, , in EPS-Cu(II) complexes for peaks A, B, and C was less than 1. This suggests the negative cooperativity between multiple binding sites and the presence of more than one Cu binding site.

关键词： biosorption     conditional binding constant     extracellular polymeric substances (EPS)     fluorescence quenching    

HTML PDF 收藏

Numerical investigation on side heat transfer enhancement in 300 kA aluminum reduction cell

WANG Changhong, ZHU Dongsheng, LEI Junxi, ZHOU Jiemin

《能源前沿（英文）》 2008年 第2卷 第3期   页码 256-260 doi: 10.1007/s11708-008-0051-0

摘要： Industrial test and numerical simulation were synchronously applied to analyze the side heat transfer process and enhance heat transfer in aluminum reduction cell. The 3D slice finite element model of aluminum reduction cell was developed, with which the sidewall temperature field of the cell was computed by using software ANSYS. The main influencing factors on heat dissipation were analyzed and some effective measures were proposed to enhance sidewall heat transfer. The results show that the shell temperature of the test cell and the common cell is respectively 312°C and 318°C and the ledge thickness is 16 cm and 15 cm when side coefficient of heat transfer between the shell and the surroundings is 70 W/(mK). With the increase of the side coefficient of heat transfer between the shell and the surroundings, the temperature of the shell decreases but the thickness of the side ledge increases when the electrolytic temperature, the ambient temperature, the coefficient of heat transfer between molten bath and ledge, the eutectic temperature and the thermo-resistance of the side lining are constant.

关键词： constant     ambient temperature     thickness     electrolytic temperature     transfer process    

HTML PDF 收藏

标题 作者 时间 类型 操作

Research progress on low dielectric constant modification of cellulose insulating paper for power transformers

期刊论文

Analysis and characterization of wind-solar-constant torque spring hybridized model

Shantanu ACHARYA,Subhadeep BHATTACHARJEE

期刊论文

Development of a fan-stirred constant volume combustion chamber and turbulence measurement with PIV

期刊论文

Solar photovoltaic fed dual input LED lighting system with constant illumination control

Kinattingal SUNDARESWARAN,Kevin Ark KUMAR,Payyalore Raman VENKATESWARAN,Sankaran PALANI

期刊论文

The energy consumption in a batch stripper and a batch rectifier

Xianbao CUI, Tianyang FENG, Ying ZHANG, Zhicai YANG,

期刊论文

用经典力学计算氢分子的键长键能及力常数

陈景

期刊论文

新型双馈变速凸极同步电机

宁玉泉

期刊论文

Constant temperature control of tundish induction heating power supply for metallurgical manufacturing

Yufei YUE, Qianming XU, Peng GUO, An LUO

期刊论文

Seismic response of precast reinforced concrete wall subjected to cyclic in-plane and constant out-of-plane

期刊论文

Convective heat transfer in helical coils for constant-property and variable-property flows with high

Yufei MAO, Liejin GUO, Bofeng BAI, Ximin ZHANG

期刊论文

Deep eutectic solvent inclusions for high- composite dielectric elastomers

期刊论文

Removing ammonia from air with a constant pH, slightly acidic water　spray wet scrubber using recycled

Ahmad Kalbasi Ashtari, Amir M. Samani Majd, Gerald L. Riskowski, Saqib Mukhtar, Lingying Zhao

期刊论文

Pre-chamber turbulent jet ignition of methane/air mixtures with multiple orifices in a large bore constant

Xiang LI, Wenzheng ZHANG, Zhong HUANG, Dehao JU, Li HUANG, Mingzhi FENG, Xingcai LU, Zhen HUANG

期刊论文

Biosorption of Cu(II) to extracellular polymeric substances (EPS) from

Xiangliang PAN, Jing LIU, Wenjuan SONG, Daoyong ZHANG

期刊论文

Numerical investigation on side heat transfer enhancement in 300 kA aluminum reduction cell

WANG Changhong, ZHU Dongsheng, LEI Junxi, ZHOU Jiemin

期刊论文