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Journal of Future Foods 2024年第4期4卷 369-375页

作者： Meirong Cao Jing Wang Mengtian Wang Xiaoxuan Yuan Xu zhang Junzhan Ma yan zhang qiang Li Hebei Food Safety Key Laboratory Key Laboratory of Special Food Supervision Technology for State Market RegulationHebei Engineering Research Center for Special Food Safety and HealthHebei Food Inspection and Research InstituteShijiazhuang 050227China Hebei Key Laboratory of Forensic Medicine College of Forensic MedicineHebei Medical UniversityShijiazhuang 050017China

To effectively assess the extent of the mycotoxin contamination of grapes,a method was developed to analyze 22 mycotoxins by ultra-high-performance liquid chromatography coupled with quadrupole/orbitrap high-resolution mass spectrometry(UPLC-Q-Orbitrap HRMS).Samples were extracted and purified using the QuEChERS(quick,easy,cheap,effective,rugged,and safe)*** extracts were separated on a BEH Shield C18 column(100 mm×2.1 mm,1.7μm),using methanol and water with 0.1%formic acid solution and 2 mmol/L ammonium acetate as the mobile *** quantification was performed according to a matrix-matched external standard *** was a good linear relationship within the respective mass concentration ranges of 22 mycotoxins;the correlation coefficients were not less than *** limit of quantification was 0.3-10.0μg/*** recovery ranged from 68.6%to 109.0%,with a relative standard deviation of 1.28%-12.80%.The method is simple,rapid,highly sensitive,and accurate,making it useful for screening grapes for common and emerging mycotoxins.

关键词： Mycotoxins Ultra-high-performance liquid chromatography-quadrupole/orbitrap high-resolution mass spectrometry Grape

Attribution of Biases of Interhemispheric Temperature Contrast in CMIP6 Models

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Advances in Atmospheric Sciences 2024年第2期41卷 325-340页

作者： Shiyan zhang Yongyun HU Jiankai zhang yan XIA Laboratory for Climate and Ocean-Atmosphere Studies Department of Atmospheric and Oceanic SciencesSchool of PhysicsPeking UniversityBeijing 100871China College of Atmospheric Sciences Lanzhou UniversityLanzhou 730000China School of Systems Science Beijing Normal UniversityBeijing 100875China

One of the basic characteristics of Earth's modern climate is that the Northern Hemisphere(NH) is climatologically warmer than the Southern Hemisphere(SH). Here, model performances of this basic state are examined using simulation results from 26 CMIP6 models. Results show that the CMIP6 models underestimate the contrast in interhemispheric surface temperatures on average(0.8 K for CMIP6 mean versus 1.4 K for reanalysis data mean), and that there is a large intermodel spread, ranging from -0.7 K to 2.3 K. A box model energy budget analysis shows that the contrast in interhemispheric shortwave absorption at the top of the atmosphere, the contrast in interhemispheric greenhouse trapping, and the crossequatorial northward ocean heat transport, are all underestimated in the multimodel mean. By examining the intermodel spread, we find intermodel biases can be tracked back to biases in midlatitude shortwave cloud forcing in AGCMs. Models with a weaker interhemispheric temperature contrast underestimate the shortwave cloud reflection in the SH but overestimate the shortwave cloud reflection in the NH, which are respectively due to underestimation of the cloud fraction over the SH extratropical ocean and overestimation of the cloud liquid water content over the NH extratropical *** that underestimate the interhemispheric temperature contrast exhibit larger double ITCZ biases, characterized by excessive precipitation in the SH tropics. Although this intermodel spread does not account for the multimodel ensemble mean biases, it highlights that improving cloud simulation in AGCMs is essential for simulating the climate realistically in coupled models.

关键词： interhemispheric temperature contrast energy balance shortwave cloud forcing ITCZ CMIP6 AGCM

Weak Graph Map Homotopy and Its Applications

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Chinese Annals of Mathematics,Series B 2024年第2期45卷 235-252页

作者： Conglei zhang yanying WANG Zhiguo zhang yan ZHAO School of Mathematical Sciences Hebei Normal UniversityShijiazhuang 050024China Department of Basic Science Shanxi Agricultural UniversityJinzhang 030801ShanxiChina Center for Topology and Geometry based Technology School of Mathematical SciencesHebei Normal UniversityShijiazhuang 050024China School of Mathematical Sciences Hebei Normal UniversityTaiyuan 030031China School of Mathematics and Computer Science Shanxi Normal UniversityShijiazhuang 050024China School of Mathematics and Science Hebei GEO UniversityShijiazhuang 050031China

The authors introduce a notion of a weak graph map homotopy(they call it M-homotopy),discuss its properties and *** prove that the weak graph map homotopy equivalence between graphs coincides with the graph homotopy equivalence defined by Yau et al in *** difference between them is that the weak graph map homotopy transformation is defined in terms of maps,while the graph homotopy transformation is defined by means of combinatorial *** discuss its advantages over the graph homotopy *** its applications,they investigate the mapping class group of a graph and the 1-order M P-homotopy group of a pointed simple ***,they show that the 1-order M P-homotopy group of a pointed simple graph is invariant up to the weak graph map homotopy equivalence.

关键词： Weak graph map homotopy Trivial vertex Strong deformation retract Mapping class group MP-Homotopy group

Effects of formal credit on pastoral household expense: Evidence from the Qinghai-Xizang Plateau of China

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Journal of Integrative Agriculture 2024年第5期23卷 1774-1785页

作者： yan zhang Yi Huang Fan zhang Zeng Tang State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems College of Pastoral Agriculture Science and TechnologyLanzhou UniversityLanzhou 730020China

Formal credit is critical in agricultural production,allowing more expenditure and productive input,thereby improving farmers'*** pastoral China,formal financial institutions are gradually ***,a limited understanding remains of how formal credit affects herders'household *** on a survey of 544 herders from the Qinghai-Xizang Plateau of China,this study adopted the propensity score matching approach to identify the effect of formal credit on herders'total household expenses,daily expenses,and productive *** results found that average age,grassland mortgage,and other variables significantly affected herders'participation in formal *** credit could significantly improve household expenses,especially productive expenses.A heterogeneity analysis showed that formal credit had a greater impact on the household total expense for those at higher levels of wealth;however,it significantly affected the productive expense of herders at lower wealth ***,the mediating effect indicated that formal credit could affect herders'household income,thus influencing their household ***,this study suggests that policies should improve herders'accessibility to formal credit.

关键词： formal credit herders expense Qinghai-Xizang Plateau

Generation and regulation of electromagnetic pulses generated by femtosecond lasers interacting with multitargets

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Nuclear Science and Techniques 2024年第1期35卷 96-107页

作者： Ya-Dong Xia De-Feng Kong qiang-You He Zhen Guo Dong-Jun zhang Tong yang Hao Cheng Yu-Ze Li yang yan Xiao Liang Ping Zhu Xing-Long Xie Jian-qiang Zhu Ting-Shuai Li Chen Lin Wen-Jun Ma Xue-Qing yan State Key Laboratory of Nuclear Physics and Technology and Key Laboratory of HEDP of the Ministry of EducationCAPTPeking UniversityBeijing 100871China Beijing Laser Acceleration Innovation Center Beijing 101407China Institute of Guangdong Laser Plasma Technology Guangzhou 510540China National Laboratory on High Power Laser and Physics Shanghai Institute of Optics and FineChinese Academy of SciencesShanghai 201800China School of Materials and Energy University of Electronic Science and Technology of ChinaChengdu 611731China

Ultrashort and powerful laser interactions with a target generate intense wideband electromagnetic pulses(EMPs).In this study,we report EMPs generated by the interactions between petawatt(30 fs,1.4×10^(20) W/cm^(2))femtosecond(fs)lasers with metal flat,plastic flat,and plastic nanowire-array(NWA)*** analyses are conducted on the EMPs in terms of their spatial distribution,time and frequency domains,radiation energy,and *** results indicate that EMPs from metal targets exhibit larger amplitudes at varying angles than those generated by other types of targets and are enhanced significantly for NWA *** a plastic target holder and increasing the laser focal spot can significantly decrease the radiation energy of the ***,the composite shielding materials indicate an effective shielding effect against *** simulation results show that the NWA targets exert a collimating effect on thermal electrons,which directly affects the distribution of *** study provides guidance for regulating EMPs by controlling the laser focal spot,target parameters,and target rod material and is beneficial for electromagnetic-shielding design.

关键词： Electromagnetic pulses Laser plasma interaction Electromagnetic shielding Electron distribution

Atomic-scale mechanism of effect of co-separation of elements at interface of ferrite and austenite on Cr-depleted zone of duplex stainless steel

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Journal of Iron and Steel Research International 2024年第3期31卷 710-718页

作者： yan-hui Hou Ze-kun Xu Shi-long Zhou Guang-qiang Li The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081HubeiChina Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education Wuhan University of Science and TechnologyWuhan 430081HubeiChina

Three-dimensional atom-probe tomography and first-principles calculation combined with density functional theory were used to study the effect of the co-segregation of different elements formed during the solidification process of S32205 duplex stainless steel on the Cr-depleted zone at the interface between ferrite and *** was found that the co-segregation of different elements formed during the solidification process of duplex stainless steel can also form Cr-depleted zone at the interface between ferrite and ***,Mo,Si,B,C and P atoms promote co-segregation with Cr atoms,which promotes the formation of Cr-depleted zone at the interface between ferrite and austenite in duplex stainless *** and Si strongly promote the segregation of Cr at the interface between ferrite and austenite,thereby promoting the formation of Cr-depleted zone.B,C and P elements also promote the segregation of Cr element at the interface between ferrite and austenite and the formation of Cr-depleted zone,but their effect is weaker than that of Mo and Si *** conclusions provide a new theoretical basis for improving the intergranular corrosion performance of duplex stainless steel.

关键词： Duplex stainless steel Cr-depleted zone Intergranular corrosion Co-segregation First-principles calculation

Purification performance on molten steel of novel Al_(2)O_(3)-based ceramic filter prepared from microporous powder and nano-Al_(2)O_(3) powder

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Journal of Iron and Steel Research International 2024年第6期31卷 1535-1546页

作者： Zhe Chen Wen yan Ying Liu Guang-qiang Li Shao-song Hong Nan Li The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081HubeiChina Jiangsu Shengnai New Materials Co. Ltd.Taizhou 225534JiangsuChina

Reticulated ceramic foam filters provide an effective way to purify molten steel by removing non-metallic *** proposed a novel strategy to improve the purification performance of Al_(2)O_(3)-based ceramic filters by using microporous corundum-spinel raw materials to replace dense raw *** kinds of Al_(2)O_(3)-based ceramic filters fabricated from dense α-Al_(2)O_(3) micro-powder or microporous corundum-spinel powder were selected to carry out the immersion tests with molten *** the one hand,the higher surface roughness of the filter skeleton prepared from microporous raw materials increased the adsorption capacity of skeleton surface on inclusions in molten *** the other hand,the higher apparent porosity and larger pore size of the filter skeleton were more beneficial to the penetration of molten steel in the micropores of *** reaction process at the solid-liquid interface also improved the wettability of the interface between skeleton and molten steel,resulting in a larger penetration depth and a better adsorption effect on the *** summary,the novel Al_(2)O_(3)-based ceramic filter prepared with microporous corundum-spinel powder and addition of 5 wt.% nano-Al_(2)O_(3) powder reduced the total oxygen content of the steel from 40.2×10^(-4) to 12.7×10^(-4) wt.% by 68.4% and the Al content from 0.46 to 0.18 wt.% by 60.9% after immersion test,presenting the most excellent purification performance on molten steel.

关键词： Al_(2)O_(3)-based ceramic filter Microporous corundum-spinel powder Non-metallic inclusion-Microstructure Molten steel purification

Viscosity and structure of CaO-BaO-SiO_(2)-Al_(2)O_(3)-based mold slags for continuous casting of high titanium steel with different Tio2 absorption

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Journal of Iron and Steel Research International 2024年第8期31卷 1936-1946页

作者： Ya-tao Cui Xue-you Wang Xu-bin zhang qiang-qiang Wang Sheng-ping He College of Materials Science and Engineering Chongqing UniversityChongqing 400044China

The effect of TiO_(2) absorption into two different CaO-BaO-SiO_(2)-Al_(2)O_(3)-based mold slags from the steel plant on the viscosity,melting performance and microstructure of slags was investigated through the measurement of the viscosity-temperature relationship,melting temperature and Raman *** parameter of the number of non-bridging oxygen per tetrahedrally-coordinated atom(NBO/T)was also calculated to explain the microstructure variation of molten slags with different TiO_(2) *** variation of the actual slag consumption and the depth of the liquid slag in mold was explained through the comparison of the viscosity and the melting temperature of two different *** viscosity of mold slags(basicity=0.6)decreased from 1.1 to 0.68 Pa s with the increase in the Ti0_(2) absorption from 0 to 10%,while that of slags(basicity=0.7)decreased from 0.76 to 0.56 Pa s with the Ti0_(2) absorption from 0 to 6%.The activation energy of both two groups of slags had the tendency to decrease with the increasing TiO_(2) *** network structure of both two groups of slags measured by the Raman spectra showed that the fraction of complex structure units(Q^(1),Q^(2),Q^(3) and A1-O-Al)decreased and simple structure units(Al-O-and Q^(0))increased with the increase in TiO_(2) ***/T also increased with the increase in the TiO2 absorption,indicating that the absorption of TiO_(2) into slags resulted in the destruction of silicate/aluminate ***,the absorption of TiO_(2) into the current CaO-BaO-SiO_(2)-Al_(2)O_(3) mold slags decreased the degree of polymerization of these slags and then led to the decrease of viscosity.

关键词： Mold slag Viscosity Melting temperature Slag consumption Liquid slag depth Structure

Analytical Models of on-Chip Hardware Trojan Detection Based on Radiated Emission Characteristics

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Chinese Journal of Electronics 2024年第2期33卷 385-392页

作者： Fan zhang Dongrong zhang qiang REN Aixin CHEN Donglin SU School of Electronics and Information Engineering Beihang University Zhongguancun Laboratory The Research Institute for Frontier Science Beihang University

Since many third parties involved in integrated circuit(IC) manufacturing, hardware Trojans malicious implantation have become a threat to the IC industry. Therefore, varieties of reliable hardware Trojan detection methods are needed. Since electromagnetic radiation is an inherent phenomenon of electronic devices, there are significant differences in the electromagnetic radiated characteristics for circuits with different structures and operating states. In this paper, a novel hardware Trojan detection method is proposed, which considers the electromagnetic radiation differences caused by hardware Trojan implantation. Experiments of detecting hardware Trojan in field programmable gate arrays show that the proposed method can effectively distinguish the ICs with Trojan from the ones without Trojan by the radiated emission.

关键词： Electromagnetic radiation Propagation losses Hardware System-on-chip Registers Manufacturing Trojan horses

Carbon Emission Effects Driven by Evolution of Chinese Dietary Structure from 1987 to 2020

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Chinese Geographical Science 2024年第1期34卷 181-194页

作者： ZHU Yuanyuan zhang yan ZHU Xiaohua Key Laboratory of Geographic Process Analysis&Simulation Hubei Province Central China Normal UniversityWuhan430079China Institute of Geographic Sciences and Natural Resources Research Chinese Academy of SciencesBeijing100101China

Exploring carbon emission effects based on the evolution of residents’ dietary structure to achieve the carbon neutrality goal and mitigate climate change is an important *** study took China as the research object(data excluding Hong Kong,Macao and Taiwan) and used the carbon emission coefficient method to quantitatively measure the food carbon emissions from 1987–2020,then analyzed the carbon emission effects under the evolution of dietary *** results showed that during the study period,the Chinese dietary structure gradually changed to a high-carbon consumption *** dietary structure of urban residents developed to a balanced one,while that of rural residents developed to a high-quality *** the study period,the per capita food carbon emissions and total food consumption of Chinese showed an increasing *** per capita food carbon emissions of residents in urban and rural showed an overall upward *** total food carbon emissions in urban increased significantly,while that in rural increased first and then *** influence of beef and mutton on carbon emissions is the highest in dietary *** with the balanced dietary pattern,the food carbon emissions of Chinese residents had not yet reached the peak,but were evolving to a high-carbon consumption pattern.

关键词： dietary structure structural evolution carbon emission effects carbon neutrality China