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An investigation on patient dose in screen-film diagnostic radiology in Lhasa City, Xizang Autonomous Region, China

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《医学前沿（英文）》 2013年 第7卷 第4期   页码 506-509 doi: 10.1007/s11684-013-0294-y

摘要：

This study aimed to investigate patient dose in diagnostic screen-film radiographic examinations in the city of Lhasa, China. Seven out of the twenty-six hospitals registered with the Lhasa Health Bureau were included in the investigation. The entrance surface air Kerma (ESAK) of seven conventional screen-film radiology X-ray equipment in these hospitals was measured with a QA dosimeter in September 2012. The X-ray examinations were divided into three categories: PA (posterior-anterior) chest, upper/lower limb, and AP (anterior-posterior) lumbar spine. For each category, ESAKs were calculated and analyzed. The mean ESAK was 0.6 mGy for PA chest, 0.3 mGy for upper/lower limb, and 1.8 mGy for AP lumbar spine. In addition, the mean ESAK value recorded for PA chest X-ray examinations exceeded the corresponding value recommended by the International Atomic Energy Agency (0.4 mGy).

关键词： radiation dosage     radiology     radiation protection     radiography/statistics & numerical data    

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Online control of biofilm and reducing carbon dosage in denitrifying biofilter: pilot and full-scale

Xiuhong Liu, Hongchen Wang, Qing Yang, Jianmin Li, Yuankai Zhang, Yongzhen Peng

《环境科学与工程前沿（英文）》 2017年 第11卷 第1期 doi: 10.1007/s11783-017-0895-9

摘要： Online control of DNBF was studied in the pilot-scale and full-scale experiments. DNBF was controlled by the online monitored effluent nitrate and turbidity. The effluent nitrate lower than 3 mg·L and saving 18% of carbon were both achieved. Denitrifying biofilter (DNBF) is widely used for advanced nitrogen removal in the reclaimed wastewater treatment plants (RWWTPs). Manual control of DNBF easily led to unstable process performance and high cost. Consequently, there is a need to automatic control of two decisive operational processes, carbon dosage and backwash, in DNBF. In this study, online control of DNBF was investigated in the pilot-scale DNBF (600 m ·d ), and then applied in the full-scale DNBF (10 × 104 m3·d ). A novel simple online control strategy for carbon dosage with the effluent nitrate as the sole control parameter was designed and tested in the pilot-scale DNBF. Backwash operation was optimized based on the backwash control strategy using turbidity as control parameter. Using the integrated control strategy, in the pilot-scale DNBF, highly efficient nitrate removal with effluent TN level lower than 3 mg·L was achieved and DNBF was not clogged any more. The online control strategy for carbon dosage was successfully applied in a RWWTP. Using the online control strategy, the effluent nitrate concentration was controlled relatively stable and carbon dosage was saved for 18%.

关键词： Reclaimed water treatment     Denitrifying biofilter     Carbon dosage     Backwash control    

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Impact of food to microorganism ratio and alcohol ethoxylate dosage on methane production in treatment

Yulun Nie, Xike Tian, Zhaoxin Zhou, Yu-You Li

《环境科学与工程前沿（英文）》 2017年 第11卷 第6期 doi: 10.1007/s11783-017-0947-1

摘要： The effects of food to microorganism (F/M) ratio and alcohol ethoxylate (AE) dosage on the methane production potential were investigated in treatment of low-strength wastewater by a submerged anaerobic membrane bioreactor (SAnMBR). The fate of AE and its acute and/or chronic impact on the anaerobic microbes were also analyzed. The results indicated that AE had an inhibitory effect to methane production potential (lag-time depends on the AE dosage) and the negative effect attenuated subsequently and methane production could recover at F/M ratio of 0.088–0.357. VFA measurement proved that AE was degraded into small molecular organic acids and then converted into methane at lower F/M ratio (F/M<0.158). After long-term acclimation, anaerobic microbe could cope with the stress of AE by producing more EPS (extracellular polymeric substances) and SMP (soluble microbial products) due to its self-protection behavior and then enhance its tolerance ability. However, the methane production potential was considerably decreased when AE was present in wastewater at a higher F/M ratio of 1.054. Higher AE amount and F/M ratio may destroy the cell structure of microbe, which lead to the decrease of methane production activity of sludge and methane production potential.

关键词： Anaerobic membrane bioreactor AnMBR     F/M ratio     Surfactant     Wastewater     Methane production     Influence    

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Particle therapy for cancers: a new weapon in radiation therapy

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《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    

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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    

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Broadening of appropriate demulsifier dosage range for latex-containing wastewater by sulfate addition

Shengzhi Zheng, Yudong Song, Yiming Li, Lidong Sun, Bin Hu, Mingdong An, Yuexi Zhou

《环境科学与工程前沿（英文）》 2018年 第12卷 第6期 doi: 10.1007/s11783-018-1041-z

摘要：

The effect of latex concentration on appropriate demulsifier dosage was investigated.

The appropriate demulsifier dosage range was controlled by zeta potential.

Sulfate could broaden appropriate demulsifier dosage range and improve latex removal.

关键词： Demulsification     Polybutadiene latex wastewater     Polyaluminum chloride     Zeta potential     Sulfate addition    

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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    

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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    

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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    

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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    

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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    

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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    

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

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《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    

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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    

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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    

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标题 作者 时间 类型 操作

An investigation on patient dose in screen-film diagnostic radiology in Lhasa City, Xizang Autonomous Region, China

null

期刊论文

Online control of biofilm and reducing carbon dosage in denitrifying biofilter: pilot and full-scale

Xiuhong Liu, Hongchen Wang, Qing Yang, Jianmin Li, Yuankai Zhang, Yongzhen Peng

期刊论文

Impact of food to microorganism ratio and alcohol ethoxylate dosage on methane production in treatment

Yulun Nie, Xike Tian, Zhaoxin Zhou, Yu-You Li

期刊论文

Particle therapy for cancers: a new weapon in radiation therapy

null

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

Broadening of appropriate demulsifier dosage range for latex-containing wastewater by sulfate addition

Shengzhi Zheng, Yudong Song, Yiming Li, Lidong Sun, Bin Hu, Mingdong An, Yuexi Zhou

期刊论文

Security of solar radiation management geoengineering

Andrew LOCKLEY

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

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

null

期刊论文

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

Jinying YIN, Linhua LIU

期刊论文