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Photodegradation of chromophoric dissolved organic matters in the water of Lake Dianchi, China

Yuan ZHANG,Chunming HU,Tao YU

《环境科学与工程前沿（英文）》 2015年第9卷第4期页码 575-582 doi: 10.1007/s11783-014-0664-y

摘要： Water samples were taken from Lake Dianchi, on the Yungui Plateau of southwest China, and experiments were conducted to simulate the photochemical degradation characteristic of chromophoric dissolved organic matter (CDOM) in the lake water. Three groups of experiments under different light conditions: ultraviolet (UV) light, visible light, and dark, were done and variations of fluorescence properties, UV absorbance, and dissolved organic carbon (DOC) concentrations during the experiments were analyzed to study the photodegradation process of CDOM with time. The result showed that light irradiation led to significant photochemical degradation of CDOM, resulting in changes in florescent properties, absorbance losses, decreases in aromaticity and average molecular weight, as well as decline in DOC concentration in the water. It was also observed that UV irradiation had greater effect than visible light did. However, various fluorophores had different sensitivities to the same irradiation condition, that is, protein-like fluorophore at the low excitation wavelengths is more sensitive to UV irradiation than the other fluorophores, and is more readily to undergo photo-degradation. In addition, visible light irradiation did not have significant impact on DOC in the water, with DOC concentration decrease by 5.57% –59.9% during the experiment time. These results may provide new knowledge on the environment behavior of CDOM in the water of Lake Dianchi.

关键词： chromophoric dissolved organic matter photodegradation ultraviolet radiation dissolved organic carbon

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Ambient photolysis frequency of NO

Qi Zou,Keding Lu,Yusheng Wu,Yudong Yang,Zhuofei Du,Min Hu

《环境科学与工程前沿（英文）》 2016年第10卷第6期 doi: 10.1007/s11783-016-0885-3

摘要： • Chemical actinometer (CA) was built for NO photolysis frequency, j(NO ), analysis. • CA data (10% accuracy) were compared with spectroradiometer (SR) data. • Long-term j(NO ) measurement was validated by comparison of CA and SR. • Dis-benefit of aerosol on j(NO ) due toparticulate matter (PM ) control on O . The photolysis frequency of NO , j(NO ), is an important analytical parameter in the study of tropospheric chemistry. A chemical actinometer (CA) was built to measure the ambient j(NO ) based on a high precision NO instrument with 1 min time resolution. Parallel measurements of the ambient j(NO ) by using the CA and a commercial spectroradiometer (SR) were conducted at a typical urban site (Peking University Urban Environmental Monitoring Station) in Beijing. In general, good agreement was achieved between the CA and SR data with a high linear correlation coefficient ( = 0.977) and a regression slope of 1.12. The regression offset was negligible compared to the measured signal level. The j(NO ) data were calculated using the tropospheric ultraviolet visible radiation (TUV) model, which was constrained to observe aerosol optical properties. The calculated j(NO ) was intermediate between the results obtained with CA and SR, demonstrating the consistency of all the parameters observed at this site. The good agreement between the CA and SR data, and the consistency with the TUV model results, demonstrate the good performance of the installed SR instrument. Since a drift of the SR sensitivity is expected by the manufacturer, we propose a regular check of the data acquired via SR against those obtained by CA for long-term delivery of a high quality series of j(NO ) data. Establishing such a time series will be invaluable for analyzing the long-term atmospheric oxidation capacity trends as well as O pollution for urban Beijing.

关键词： Photolysis frequency of nitrogen dioxide Chemical actinometer Spectroradiometer Tropospheric ultraviolet visible radiation model

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Ultraviolet exposure enhanced silicon direct bonding

Guanglan LIAO, Xuekun ZHANG, Xiaohui LIN, Canghai MA, Lei NIE, Tielin SHI,

《机械工程前沿（英文）》 2010年第5卷第1期页码 87-92 doi: 10.1007/s11465-009-0078-x

摘要： Ultraviolet (UV) exposure, as an additional technique following the traditional wet chemical activation processes, is applied to enhance hydrophilic silicon direct bonding. The effects of UV exposure on silicon wafers’ nano-topography and bonding strength are studied. It is found that the surface roughness of silicon wafers initially decreases and then increases with UV exposure time, and the bonding strength increases and then decreases accordingly. The correlations of annealing temperature and annealing time vs. bonding strength are experimentally explored. Results indicate that the bonding strength increases sharply then gently with increasing annealing temperature and annealing time using UV exposure. Besides, the reliability of silicon direct bonding with UV exposure enhancement after the high/low temperature cycle test, constant temperature and humidity test, vibration test and shock test is investigated. It follows from the results that the bonding strength of silicon wafer pairs with UV exposure decreases after the environmental tests, whereas the residual strength is still higher than that without UV exposure, and the variation trends of bonding strength vs. UV exposure time, annealing temperature and annealing time remain unchanged. Therefore, following the traditional wet chemical activation processes, appropriate UV exposure (about three minutes in this study) is effective and promising to enhance silicon direct bonding.

关键词： ultraviolet (UV) exposure silicon direct bonding bonding strength reliability

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Patterned wafer bonding using ultraviolet adhesive

Rui ZHUO, Guanglan LIAO, Wenliang LIU, Lei NIE, Tielin SHI

《机械工程前沿（英文）》 2011年第6卷第2期页码 214-218 doi: 10.1007/s11465-011-0130-5

摘要：

The process of patterned wafer bonding using ultraviolet (UV) adhesive as the intermediate layer was studied. By presetting the UV adhesive guide-layer, controlling the thickness of the intermediate layer (1– 1.5 μm), appropriate pre-drying temperature (60°C), and predrying time (6 min), we obtained the intermediate layer bonding of patterned quartz/quartz. Experimental results indicate that patterned wafer bonding using UV adhesive is achieved under room temperature. The process also has advantages of easy operation, low cost, and no plugging or leakage in the patterned area after bonding. Using the process, a microfluidic chip for red blood cell counting was designed and fabricated. Patterned wafer bonding using UV adhesive will have great potential in the fabrication of microfluidic chips.

关键词： ultraviolet (UV) adhesive intermediate layer patterned wafer bonding

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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

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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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Effects of design parameters on performance and cost analysis of combined ultraviolet-biofilter systems

Can WANG, Jinying XI, Hongying HU, Insun KANG

《环境科学与工程前沿（英文）》 2012年第6卷第4期页码 588-594 doi: 10.1007/s11783-012-0433-8

摘要： A conceptual mathematical model was used to evaluate the design parameters of a combined ultraviolet (UV)-biofilter system, and perform a cost analysis. Results showed that the UV light source strength and the gas residence times in the UV system (UVRT) and biofilter (EBRT) had positive effects on the overall chlorobenzene removal efficiency of the system. High ratio of UVRT to EBRT improved the removal efficiency, suggesting that the UV system has a greater effect on the overall performance of the system compared with the biofilter. Analysis of the capital and operating costs showed that the capital costs of the standalone biofilter system were much higher than those of the standalone UV system. However, the biofilter operating costs were lower than those of the UV system. The operating costs of the combined UV-biofilter system increased with increasing UVRT/EBRT ratio, whereas its capital costs decreased.

关键词： volatile organic compounds ultraviolet (UV) photodegradation biofilter modeling cost analysis

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Effect of ultraviolet irradiation and chlorination on ampicillin-resistant

Yuchen PANG,Jingjing HUANG,Jinying XI,Hongying HU,Yun ZHU

《环境科学与工程前沿（英文）》 2016年第10卷第3期页码 522-530 doi: 10.1007/s11783-015-0779-9

摘要： Antibiotic resistance is a serious public health risk that may spread via potable and reclaimed water. Effective disinfection is important for inactivation of antibiotic-resistant bacteria and disruption of antibiotic resistance genes. Ampicillin is a widely prescribed antibiotic but its effectiveness is increasingly undermined by resistance. In this study, changes in ampicillin resistance for ( ) CGMCC 1.1595 were analyzed after exposure to different doses of ultraviolet (UV) or chlorine, and damage incurred by the plasmid encoding ampicillin resistance gene was assessed. We reported a greater stability in ampicillin-resistant CGMCC 1.1595 after UV irradiation or chlorination when compared with previously published data for other strains. UV irradiation and chlorination led to a shift in the mortality frequency distributions of ampicillin-resistant when subsequently exposed to ampicillin. The ampicillin hemi-inhibitory concentration (IC ) without disinfection was 3800 mg·L , and an increment was observed after UV irradiation or chlorination. The IC of ampicillin-resistant was 1.5-fold higher at a UV dose of 40 mJ·cm , and was 1.4-fold higher when exposed to 2.0 mg·L chlorine. These results indicate that UV irradiation and chlorination can potentially increase the risk of selection for strains with high ampicillin resistance. There was no evident damage to after 1–10 mg Cl ·L chlorination, while a UV dose of 80 mJ·cm yielded a damage ratio for of approximately 1.2-log. Therefore, high UV doses are required for effective disruption of antibiotic resistance genes in bacteria.

关键词： antibiotic resistance Escherichia coli ampicillin resistance gene ultraviolet irradiation chlorination

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Toward better understanding vacuum ultraviolet–iodide induced photolysis via hydrogen peroxide formation

《环境科学与工程前沿（英文）》 2022年第16卷第5期 doi: 10.1007/s11783-021-1489-0

摘要：

• UV/VUV/I^– induces substantial H₂O₂ and IO₃^– formation, but UV/I^– does not.

关键词： Vacuum ultraviolet Hydrogen peroxide Iodate Hydroxyl radical Redox transition

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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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Experimental study on the temperature dependence of ultraviolet absorption cross-sections of sulfur dioxide

ZHANG Shiliang, ZHOU Jie, CHEN Xiaohu

《能源前沿（英文）》 2008年第2卷第2期页码 183-186 doi: 10.1007/s11708-008-0025-2

摘要： The photoabsorption cross-sections of sulfur dioxide were measured in the spectral regions of 200–230 nm and 275–315 nm at 298–415 K, using a grating monochromator with a resolution of 0.2 nm. The discrete absorption cross-section is directly correlated with the number of quantum excited from the base state. The absorption cross-sections at the peaks of discrete bands decreased linearly with the increase of temperature, which corresponded to the decrease in the population of vibrational and rotational transitions from the base level to higher excitation levels. The absorption cross-section peaks decreased linearly when the temperature increased from 298 to 415 K, with relative drops of 74.0% and 75.8% at 200–230 nm and 275–315 nm, respectively. Another distinctive feature of sulfur dioxide absorption spectra in the above two spectral regions was the quasiperiodic structure of the absorption peaks, whose equal wavelength intervals were 1.53 nm and 1.95 nm, respectively. Red and blue shifts were not found at the absorption peak positions.

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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