| 1 | Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) emissions from electric arc furnaces for steelmaking显示文摘The proportion of steel produced using electric arc furnaces(EAFs)is increasing.In this study,polychlorinated dibenzo-p-dioxins and dibenzofurans(PCDD/Fs)concentrations and patterns in stack gas samples from three typical EAFs in steelmaking plants were determined to allow the contributions of EAFs in steelmaking plants to PCDD/Fs emissions in China to be assessed.Samples collection was accomplished by adopting the automatic isokinetic sampling technique,then the PCDD/Fs congeners concentrations were analyzed qualitatively and quantitatively by isotope dilution high-resolution gas chromatography high-resolution mass spectrometry(HRGC-HRMS).The mean PCDD/Fs mass concentrations in stack gases emitted during the scrap preheating phase of plants E1,E2,and E3 were 0.48,385.55,and 0.34 ng Nm^-3,respectively,and the total toxic equivalent(WHO2005-TEQ)concentrations were 0.05,33.16,and 0.03 ng Nm^-3,respectively.The PCDD/Fs mass concentration in stack gases emitted during the melting phase at plant E3 was 0.12 ng Nm^-3(0.02 ng WHO2005-TEQ Nm^-3).The operational temperature of the bag filter of the preheating in the E2 EAF was as high as 230℃,which is conducive to the generation of PCDD/Fs,whether the temperature in the bag filter of E1(150℃)and E3(120℃)are not.Moreover,the bag filter temperature is suggested to be best controlled to below 150℃.The emission factors(EF)for PCDD/Fs released into the air during the scrap preheating phase for plants E1,E2,and E3 were 0.13,52,and 0.10 mg WHO2005-TEQ t1,respectively,and the EF for the smelting phase from plant E3 was 0.14 mg WHO2005-TEQ t1.The emission factor in E2 is 5 times higher than the highest current UNEP toolkit factor for EAFs(10 mg TEQ/tonne steel).Therefore,an update for the UNEP toolkit emission factor for a few case plants is suggested.Several congeners,including 2,3,7,8-TeCDF,1,2,3,4,6,7,8-HpCDF,and 1,2,3,4,6,7,8-HpCDD,were dominant during the preheating phase,while 2,3,7,8-TeCDF,1,2,3,7,8-PeCDF,and 2,3,4,7,8-PeCDF were dominant during the smelting phase.The monitoring data from the case plants helps to better understand the PCDD/Fs emissions of EAFs using preheating process stages.However,a more complete emission inventory requires more case investigations on the PCDD/Fs emissions from representative EAFs steelmaking plants. | Qiuting Yang Lili Yang Jia Shen Yuanping Yang Minxiang Wang Xiaoyun Liu Xuejing Shen Changliang Li Jia Xu Fengfeng Li Da Li Guorui Liu Minghui Zheng | 2020 | Emerging Contaminants2020，6，1： | 3 |
| 2 | The quantitative evaluation of application of hyperspectral data based on multi-parameters joint optimization显示文摘In order to evaluate the mineral identification of the hyperspectral data and make a trade-off of the imaging system parameters,a quantitative evaluation approach based on the multi-parameters joint optimization is proposed for the hyperspectral remote sensing.In the proposed approach,the mineral identification is defined as the number of the minerals identified and the key imaging parameters employed include ground sample distance(GSD)and spectral resolution(SR).Certain limitations are found among parameters that are used for analyzing the imaging processes.The constraints include the industrial manufacturing level,application requirements and the quantitative relationship among the GSD,the SR and the signal-to-noise ratio(SNR).Regression analysis is used to investigate the quantitative relationship between the mineral identification and the key imaging system parameters.Then,an optimization model for the trade-off study is established by combining the regression equation with the constraints.The airborne hyperspectral image collected by Hymap is applied to evaluate the performance of the proposed approach.The experimental results reveal that the approach can achieve the evaluation of the mineral identification and the trade-off of key imaging system parameters.The error of the prediction is within one kind of mineral. | LI Na HUANG Ping ZHAO HuiJie JIA GuoRui | 2014 | Science China(Technological Sciences)2014，57，11： | 1 |
| 3 | Synthesis and assembly of full-length cyanophage A-4L genome显示文摘Artificial cyanophages are considered to be an effective biological method to control harmful cyanobacterial bloom.However,no synthetic cyanophage genome has been constructed and where its obstacles are unclear.Here,we survey a stretch of 16 kb length sequence of cyanophage A-4L that is unclonable in Escherichia coli.We test 12 predicted promoters of cyanophage A-4L which were verified all active in E.coli.Next,we screen for eight ORFs that hindered the assembly of intermediate DNA fragments in E.coli and describe that seven ORFs in the 16 kb sequence could not be separately cloned in E.coli.All of unclonable ORFs in high-copy-number plasmid were successfully cloned using low-copy-number vector,suggesting that these ORFs were copy-number-dependent.We propose a clone strategy abandoned the promotor and the start codon that could be applied for unclonable ORFs.Last,we de novo synthesized and assembled the full-length genome of cyanophage A-4L.This work deepens the understanding of synthetic cyanophages studies. | Ting Zhang Bonan Xu Jia Feng Pingbo Ge Guorui Li Jiabao Zhang Jianting Zhou Jianlan Jiang | 2023 | Synthetic and Systems Biotechnology2023，8，1： | 0 |
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