资源类型

期刊论文 648

年份

2023 63

2022 58

2021 48

2020 42

2019 40

2018 37

2017 45

2016 28

2015 22

2014 26

2013 21

2012 17

2011 24

2010 27

2009 29

2008 34

2007 28

2006 13

2005 6

2004 6

展开 ︾

关键词

元胞自动机模型 2

固体氧化物燃料电池 2

应用 2

性能化 2

效果评估 2

目标识别 2

Tetrasphaera 1

AD9954 1

Al@AP/PVDF纳米复合材料 1

BNCT医院中子照射器 1

CAE 1

CAN总线 1

CCD影像 1

DQP漂白 1

EDI 1

Fluent 1

HDPE 1

HY-2 1

KP法制浆 1

展开 ︾

检索范围:

排序: 展示方式:

Numerical simulation and experiment research of radiation performance in a dish solar collector system

Yong SHUAI, Xinlin XIA, Heping TAN

《能源前沿(英文)》 2010年 第4卷 第4期   页码 488-495 doi: 10.1007/s11708-010-0007-z

摘要: The Monte Carlo ray-tracing method is applied and coupled with optical properties to predict the radiation performance of solar concentrator/cavity receiver systems. Several different cavity geometries are compared on the radiation performance. A flux density distribution measurement system for dish parabolic concentrators is developed. The contours of the flux distribution for target placements at different distances from the dish vertex of a solar concentrator are taken by using an indirect method with a Lambert and a charge coupled device (CCD) camera. Further, the measured flux distributions are compared with a Monte Carlo-predicted distribution. The results can be a valuable reference for the design and assemblage of the solar collector system.

关键词: Monte Carlo method     solar energy     radiation performance     cavity receiver    

Analysis of radiation heat transfer and temperature distributions of solar thermochemical reactor for

Bachirou GUENE LOUGOU, Yong SHUAI, Xiang CHEN, Yuan YUAN, Heping TAN, Huang XING

《能源前沿(英文)》 2017年 第11卷 第4期   页码 480-492 doi: 10.1007/s11708-017-0506-2

摘要: This paper investigated radiation heat transfer and temperature distributions of solar thermochemical reactor for syngas production using the finite volume discrete ordinate method (fvDOM) and P1 approximation for radiation heat transfer. Different parameters including absorptivity, emissivity, reflection based radiation scattering, and carrier gas flow inlet velocity that would greatly affect the reactor thermal performance were sufficiently investigated. The fvDOM approximation was used to obtain the radiation intensity distribution along the reactor. The drop in the temperature resulted from the radiation scattering was further investigated using the P1 approximation. The results indicated that the reactor temperature difference between the P1 approximation and the fvDOM radiation model was very close under different operating conditions. However, a big temperature difference which increased with an increase in the radiation emissivity due to the thermal non-equilibrium was observed in the radiation inlet region. It was found that the incident radiation flux distribution had a strong impact on the temperature distribution throughout the reactor. This paper revealed that the temperature drop caused by the boundary radiation heat loss should not be neglected for the thermal performance analysis of solar thermochemical reactor.

关键词: solar thermochemical reactor     incident radiation flux     temperature distribution     radiation absorptivity     radiation emissivity     thermal performance analysis    

Particle therapy for cancers: a new weapon in radiation therapy

null

《医学前沿(英文)》 2012年 第6卷 第2期   页码 165-172 doi: 10.1007/s11684-012-0196-4

摘要:

Particle irradiation started to draw attention in the past decade and has now become a hotspot in the radiation oncology community. This article reviews the most advanced developments in particle irradiation, focusing on the characteristics of proton and carbon ions in radiation physics and radiobiology. The Bragg peak of physical dose distribution causes proton and carbon beams to optimally meet the requirement for cancer irradiation because the Bragg peak permits the accurate concentration of the dose on the tumor, thus sparing the adjacent normal tissues. Moreover, carbon ion has more radiobiological benefits than photon and proton beams. These benefits include stronger sterilization effects on intrinsic radio-resistant tumors and more effective killing of hypoxic, G0, and S phase cells. Compared with the most advanced radiation techniques using photon, such as three-dimensional conformal radiation therapy and intensity-modulated radiation therapy, proton therapy has yielded more promising outcomes in local control and survival for head and neck cancers, prostate carcinoma, and pediatric cancers. Carbon therapy in Japan showed even more promising results than proton therapy. The local controls and overall survivals were as good as that treated by surgery in early stages of non-small cell lung cancer, hepatocellular carcinoma, prostate carcinoma, and head and neck cancers, especially for such highly resistant tumors as melanoma. The non-invasive nature of particle therapy affords more patients with chances to receive and benefit from treatment. Particle therapy is gradually getting attention from the oncology community. However, the cost of particle therapy facilities has limited the worldwide use of this technology.

关键词: radiation therapy     particle therapy     proton     carbon     cancer    

Security of solar radiation management geoengineering

Andrew LOCKLEY

《工程管理前沿(英文)》 2019年 第6卷 第1期   页码 102-116 doi: 10.1007/s42524-019-0008-5

摘要:

Solar Radiation Management (SRM) geoengineering is a proposed response to anthropogenic global warming (AGW) (National Academy of Sciences, 2015). There may be profound – even violent – disagreement on preferred temperature. SRM disruption risks dangerous temperature rise (termination shock). Concentrating on aircraft-delivered Stratospheric Aerosol Injection (SAI), we appraise threats to SRM and defense methodologies. Civil protest and minor cyberattacks are almost inevitable but are manageable (unless state-sponsored). Overt military attacks are more disruptive, but unlikely – although superpowers’ symbolic overt attacks may deter SRM. Unattributable attacks are likely, and mandate use of widely-available weapons. Risks from unsophisticated weapons are therefore higher. An extended supply chain is more vulnerable than a secure airbase – necessitating supply-chain hardening. Recommendations to improve SRM resilience include heterogeneous operations from diverse, secure, well-stocked bases (possibly ocean islands or aircraft carriers); and avoidance of single-point-of-failure risks (e.g. balloons). A distributed, civilian-operated system offers an alternative strategy. A multilateral, consensual SRM approach reduces likely attack triggers.

关键词: security     geoengineering     solar radiation ma-nagement     SRM    

Performance improvement of a pulse tube cryocooler with a single compressor through cascade utilization

Xuming LIU, Xiafan XU, Biao YANG, Xiaotong XI, Liubiao CHEN, Junjie WANG, Yuan ZHOU

《能源前沿(英文)》 2021年 第15卷 第2期   页码 345-357 doi: 10.1007/s11708-020-0708-x

摘要: The high-frequency pulse tube cryocooler (HPTC) has been attracting increasing and widespread attention in the field of cryogenic technology because of its compact structure, low vibration, and reliable operation. The gas-coupled HPTC, driven by a single compressor, is currently the simplest and most compact structure. For HPTCs operating below 20 K, in order to obtain the mW cooling capacity, hundreds or even thousands of watts of electrical power are consumed, where radiation heat leakage accounts for a large proportion of their cooling capacity. In this paper, based on SAGE10, a HPTC heat radiation calculation model was first established to study the effects of radiation heat leakage on apparent performance parameters (such as temperature and cooling capacity), and internal parameters (such as enthalpy flow and gas distribution) of the gas-coupled HPTC. An active thermal insulation method of cascade utilization of the cold energy of the system was proposed for the gas-coupled HPTC. Numerical simulations indicate that the reduction of external radiation heat leakage cannot only directly increase the net cooling power, but also decrease the internal gross losses and increase the mass and acoustic power in the lower-temperature section, which further enhances the refrigeration performance. The numerical calculation results were verified by experiments, and the test results showed that the no-load temperature of the developed cryocooler prototype decreased from 15.1 K to 6.4 K, and the relative Carnot efficiency at 15.5 K increased from 0.029% to 0.996% when substituting the proposed active method for the traditional passive method with multi-layer thermal insulation materials.

关键词: radiation heat leakage     active thermal insulation     cascade utilization     cold energy     performance improvement     cryocooler    

Distributed governance of Solar Radiation Management geoengineering: A possible solution to SRM’s “free-driver

Andrew LOCKLEY

《工程管理前沿(英文)》 2019年 第6卷 第4期   页码 551-556 doi: 10.1007/s42524-019-0055-y

摘要: Geoengineering (deliberate climate modification) is a possible way to limit Anthropogenic Global Warming (AGW) (Shepherd, 2009; National Research Council, 2015). Solar Radiation Management geoengineering (SRM) offers relatively inexpensive, rapid temperature control. However, this low cost leads to a risk of controversial unilateral intervention—the “free-driver” problem (Weitzman, 2015). Consequently, this creates a risk of counter-geoengineering (deliberate warming) (Parker et al., 2018), resulting in governance challenges (Svoboda, 2017) akin to an arms race. Free-driver deployment scenarios previously considered include the rogue state, Greenfinger (Bodansky, 2013), or power blocs (Ricke et al., 2013), implying disagreement and conflict. We propose a novel distributed governance model of consensually-constrained unilateralism: Countries’ authority is limited to each state’s fraction of the maximum realistic intervention (e.g., pre-industrial temperature). We suggest a division of authority based on historical emissions (Rocha et al., 2015)—noting alternatives (e.g., population). To aid understanding, we offer an analogue: An over-heated train carriage, with passenger-controlled windows. We subsequently discuss the likely complexities, notably Coasian side-payments. Finally, we suggest further research: Algebraic, bot and human modeling; and observational studies.

关键词: geoengineering     Solar Radiation Management     governance     decentralised    

Theoretical study on flow and radiation in tubular solar photocatalytic reactor

《能源前沿(英文)》 2021年 第15卷 第3期   页码 687-699 doi: 10.1007/s11708-021-0773-9

摘要: In this paper, based on the mixture flow model, an optimized six-flux model is first established and applied to the tubular solar photocatalytic reactor. Parameters influencing photocatalyst distribution and radiation distribution at the reactor outlet, viz. catalyst concentration and circulation speed, are also analyzed. It is found that, at the outlet of the reactor, the optimized six-flux model has better performances (the energy increase by 1900% and 284%, respectively) with a higher catalyst concentration (triple) and a lower speed (one third).

关键词: photocatalytic hydrogen photoreactor     nume- rical simulation     solar energy     flow model     radiation model    

A method of determining flame radiation fraction induced by interaction burning of tri-symmetric propane

Jie JI, Junrui DUAN, Huaxian WAN

《能源前沿(英文)》 2022年 第16卷 第6期   页码 1017-1026 doi: 10.1007/s11708-020-0716-x

摘要: The interaction of multiple fires may lead to a higher flame height and more intense radiation flux than a single fire, which increases the possibility of flame spread and risks to the surroundings. Experiments were conducted using three burners with identical heat release rates (HRRs) and propane as the fuel at various spacings. The results show that flames change from non-merging to merging as the spacing decreases, which result in a complex evolution of flame height and merging point height. To facilitate the analysis, a novel merging criterion based on the dimensionless spacing / was proposed. For non-merging flames ( / >0.368), the flame height is almost identical to a single fire; for merging flames ( / ≤0.368), based on the relationship between thermal buoyancy and thrust (the pressure difference between the inside and outside of the flame), a quantitative analysis of the flame height, merging point height, and air entrainment was formed, and the calculated merging flame heights show a good agreement with the measured experimental values. Moreover, the multi-point source model was further improved, and radiation fraction of propane was calculated. The data obtained in this study would play an important role in calculating the external radiation of propane fire.

关键词: flame interaction     air entrainment     flame height     multi-point source model     thermal radiation    

Design and analysis of Salisbury screens and Jaumann absorbers for solar radiation absorption

Xing FANG, C. Y. ZHAO, Hua BAO

《能源前沿(英文)》 2018年 第12卷 第1期   页码 158-168 doi: 10.1007/s11708-018-0542-6

摘要: Two types of resonance absorbers, i.e., Salisbury screens and Jaumann absorbers are systematically investigated in solar radiation absorption. Salisbury screen is a metal-dielectric-metal structure which overcomes the drawback of bulky thickness for solar spectrum. Such structures have a good spectral selective absorption property, which is also insensitive to incident angles and polarizations. To further broaden absorption bandwidth, more metal and dielectric films are taken in the structure to form Jaumann absorbers. To design optimized structural parameters, the admittance matching equations have been derived in this paper to give good initial structures, which are valuable for the following optimization. Moreover, the analysis of admittance loci has been conducted to directly show the effect of each layer on the spectral absorptivity, and then the effect of thin films is well understood. Since the fabrication of these layered absorbers is much easier than that of other nanostructured absorbers, Salisbury screen and Jaumann absorbers have a great potential in large-area applications.

关键词: thin films     admittance loci     solar absorber    

Gain-enhanced reconfigurable radiation array with mechanically driven system and directive elements

《机械工程前沿(英文)》 2022年 第17卷 第4期 doi: 10.1007/s11465-022-0716-0

摘要: In the artificial intelligence-driven modern wireless communication system, antennas are required to be reconfigurable in terms of size according to changing application scenarios. However, conventional antennas with constant phase distributions cannot achieve enhanced gains in different reconfigurable sizes. In this paper, we propose a mechanically reconfigurable radiation array (RRA) based on miniaturized elements and a mechanically reconfigurable system to obtain gain-enhanced antennas in compact and deployed states. A five-element RRA with a phase-reconfigurable center element is designed and analyzed theoretically. The experimental sample has been fabricated, driven by a deployable frame with only one degree of freedom to realize the size and phase distribution reconfiguration simultaneously to validate the enhanced gains of RRA. The proposed RRA can be tessellated into larger arrays to achieve higher gains in other frequency regimes, such as terahertz or photonics applications with nanometer fabrication technology.

关键词: mechanism     reconfigurable radiation array (RRA)     compact state     deployed state     enhanced gain    

脉冲中子、伽马探测系统性能表征与设计技术

欧阳晓平

《中国工程科学》 2009年 第11卷 第5期   页码 44-53

摘要:

探测系统是获取辐射场特征信息的核心器件,是实施脉冲辐射探测的关键和技术基础,其性能直接决定测试数据的质量和测试方法的选择。对影响脉冲辐射探测的性能指标进行系统描述、表征是探测系统设计、研制、实际应用和综合性能评价的基础。用于复杂能谱脉冲中子、伽马混合辐射场时间谱、强度谱测量的探测系统,主要性能包括探测灵敏度、时间响应、能量响应、线性电流和中子、伽马分辨能力等指标参数,这些参数的获得与实现,需要根据中子、伽马射线与物质相互作用的基本原理,构建相应的探测结构和技术原理。在设计上,综合权衡能量收集和电荷收集方式选择、几何效率完备和高信噪比结合、信号响应和直照响应分离、探测效率与时间特性兼顾、综合性能与使用可靠性一致等设计原则,综合应用这些原则构成了探测系统设计方法。

关键词: 中子、伽马混合场     脉冲辐射探测     探测系统     设计原理     性能参数    

The effect of orbital radiation therapy on thyroid-associated orbitopathy complicated with dysthyroid

null

《医学前沿(英文)》 2017年 第11卷 第3期   页码 359-364 doi: 10.1007/s11684-017-0528-5

摘要:

Thyroid-associated orbitopathy (TAO) is an inflammatory autoimmune disorder. The most serious complication of TAO is dysthyroid optic neuropathy (DON), which can lead to permanent vision loss because of volume expansion in the orbital apex. Orbital radiation therapy (ORT) is an anti-inflammatory treatment used in the treatment of active TAO. Clinical studies support radiotherapy as having a modest effect on DON, and early radiotherapy may protect against disease progression to DON. Current studies suggest that radiotherapy is generally safe. However, risks still exist in some cases. The possible effects of radiotherapy on TAO, especially complicated with DON, are reviewed. The effects of radiotherapy on DON are not completely known, and evidence from standardized, prospective, and multicenter clinical trials is still lacking.

关键词: thyroid-associated orbitopathy     dysthyroid optic neuropathy     orbital radiation therapy    

Analysis of the radiation heat transfer process of phase change for a liquid droplet radiator in space

Jinying YIN, Linhua LIU

《能源前沿(英文)》 2011年 第5卷 第2期   页码 166-173 doi: 10.1007/s11708-010-0105-y

摘要: The optimization of a space power system is greatly affected by the radiation heat transfer in a liquid droplet radiator (LDR). Radiation heat transfer in a two-dimensional bed of phase-change particle is modeled by solving the radiative transfer equation using the discrete ordinates method and the energy equation using the implicit finite difference method. The Mie theory is used to calculate the radiative properties of the droplet bed, whereas the effective medium theory is used to obtain the optical constants of partial solidification droplets. Multiple factors affect heat flux in the LDR, such as size distribution, flow velocity, phase change of droplets, layer thickness, droplet concentration in the layer, and material type of the work fluid; each of these must be analyzed. Calculations show that once size distribution is neglected, the relative error increases significantly. Size distribution has a remarkably strong effect on heat flux when the flow velocity of the working fluid is above 100 m/s. An increase in flow velocity leads to an increase in the total heat flux for the layer with a fixed volume fraction of droplets. The solidification zone occupies nearly half of the layer, and droplets of different sizes exhibit temperature differences to some extent due to local thermal non-equilibrium among them. Droplet concentration in the layer and the material type of the working fluid have strong effects on heat flux, whereas the thickness of the layer has a mild influence on heat flux.

关键词: radiation heat transfer     particle polydispersion     liquid droplet radiator     phase change    

Geoengineering and the blockchain: Coordinating Carbon Dioxide Removal and Solar Radiation Management

Andrew LOCKLEY, Zhifu MI, D’Maris COFFMAN

《工程管理前沿(英文)》 2019年 第6卷 第1期   页码 38-51 doi: 10.1007/s42524-019-0010-y

摘要:

Geoengineering is a proposed response to anthropogenic global warming (AGW). Conventionally it consists of two strands: Solar Radiation Management (SRM), which is fast-acting, incomplete but inexpensive, and Carbon Dioxide Removal (CDR), which is slower acting, more expensive, and comprehensive. Pairing SRM and CDR offers a contractually complete solution for future emissions if effectively-scaled and coordinated. SRM offsets warming, while CDR takes effect. We suggest coordination using a blockchain, i.e. smart contracts and a distributed ledger. Specifically, we integrate CDR futures with time and volume-matched SRM orders, to address emissions contractually before release. This provides an economically and environmentally proportionate solution to CO2 emissions at the wellhead, with robust contractual transparency, and minimal overhead cost.

关键词: Geoengineering     Solar Radiation Management     Carbon Dioxide Removal     futures markets     smart contracts     blockchain    

Nongray radiation from gas and soot mixtures in planar plates based on statistical narrow-band spectral

Huaqiang CHU, Qiang CHENG, Huaichun ZHOU, Fengshan LIU

《能源前沿(英文)》 2011年 第5卷 第2期   页码 149-158 doi: 10.1007/s11708-010-0124-8

摘要: The nongray behavior of combustion products plays an important role in various areas of engineering. Based on the statistical narrow-band (SNB) spectral model with an exponential-tailed inverse intensity distribution and the ray-tracing method, a comprehensive investigation of the influence of soot on nongray radiation from mixtures containing H O/N +soot, CO /N +soot, or H O/CO /N +soot was conducted in this paper. In combustion applications, radiation transfer is significantly enhanced by soot due to its spectrally continuous emission. The effect of soot volume fraction up to 1×10 on the source term, the narrow-band radiation intensities along a line-of-sight, and the net wall heat fluxes were investigated for a wide range of temperature. The effect of soot was significant and became increasingly drastic with the increase of soot loading.

关键词: soot     combustion     SNB model     nongray radiation    

标题 作者 时间 类型 操作

Numerical simulation and experiment research of radiation performance in a dish solar collector system

Yong SHUAI, Xinlin XIA, Heping TAN

期刊论文

Analysis of radiation heat transfer and temperature distributions of solar thermochemical reactor for

Bachirou GUENE LOUGOU, Yong SHUAI, Xiang CHEN, Yuan YUAN, Heping TAN, Huang XING

期刊论文

Particle therapy for cancers: a new weapon in radiation therapy

null

期刊论文

Security of solar radiation management geoengineering

Andrew LOCKLEY

期刊论文

Performance improvement of a pulse tube cryocooler with a single compressor through cascade utilization

Xuming LIU, Xiafan XU, Biao YANG, Xiaotong XI, Liubiao CHEN, Junjie WANG, Yuan ZHOU

期刊论文

Distributed governance of Solar Radiation Management geoengineering: A possible solution to SRM’s “free-driver

Andrew LOCKLEY

期刊论文

Theoretical study on flow and radiation in tubular solar photocatalytic reactor

期刊论文

A method of determining flame radiation fraction induced by interaction burning of tri-symmetric propane

Jie JI, Junrui DUAN, Huaxian WAN

期刊论文

Design and analysis of Salisbury screens and Jaumann absorbers for solar radiation absorption

Xing FANG, C. Y. ZHAO, Hua BAO

期刊论文

Gain-enhanced reconfigurable radiation array with mechanically driven system and directive elements

期刊论文

脉冲中子、伽马探测系统性能表征与设计技术

欧阳晓平

期刊论文

The effect of orbital radiation therapy on thyroid-associated orbitopathy complicated with dysthyroid

null

期刊论文

Analysis of the radiation heat transfer process of phase change for a liquid droplet radiator in space

Jinying YIN, Linhua LIU

期刊论文

Geoengineering and the blockchain: Coordinating Carbon Dioxide Removal and Solar Radiation Management

Andrew LOCKLEY, Zhifu MI, D’Maris COFFMAN

期刊论文

Nongray radiation from gas and soot mixtures in planar plates based on statistical narrow-band spectral

Huaqiang CHU, Qiang CHENG, Huaichun ZHOU, Fengshan LIU

期刊论文