检索结果-南通市图书馆

Journal of Environmental Sciences 2024年第1期135卷 367-378页

作者： Xiaochen Li Yifan Wang ning Wang Mei Li Maomao bai Jingtao Xu Hongbo Wang School of Municipal and Environmental Engineering Shandong Jianzhu UniversityJinan 250101China Resources and Environment Innovation Institute Shandong Jianzhu UniversityJinan 250101China

In this study,a stepwise oxidation system of potassium ferrate(K_(2)FeO_(4))combined with ozone(O+3)was used to degrade ciprofloxacin(CIP).The effects of pH and pre-oxidation time of K_(2)FeO_(4) on the evolution of K_(2)FeO_(4) reduction products(iron(hydr)oxides)and CIP degradation were investigated.It was found that in addition to its own oxidation capacity,K_(2)FeO_(4) can also influence the treatment effect of CIP by changing the catalyst content.The presence of iron(hydr)oxides effectively enhanced the mineralization rate of CIP by catalyzing ozonation.The pH value can influence the content and types of the components with catalytic ozonation effect in iron(hydr)oxides.The K_(2)FeO_(4) pre-oxidation stage can produce more iron(hydr)oxides with catalytic components for subsequent ozonation,but the evolution of iron(hydr)oxides components was influenced by O_(3) treatment.It can also avoid the waste of oxidation capacity owing to the oxidation of iron(hydr)oxides by O_(3) and free radicals.The intermediate degradation products were identified by Fourier transform ion cyclotron resonance mass spectrometry(FT-ICR-MS).Besides,the degradation pathways were proposed.Among the degradation products of CIP,the product with broken quinolone ring structure only appeared in the stepwise oxidation system.

关键词： Potassium ferrate reduction products Catalytic ozonation Ciprofloxacin Potassium ferrate pre-oxidation time

A low-noise,high-gain,and large-dynamic-range photodetector based on a JFET and a charge amplifier

在线全文

学校读者我要写书评

暂无评论

Frontiers of Information Technology & Electronic Engineering 2024年第2期25卷 316-322页

作者： Jinrong WANG Shuang'e WU Chengdong MI Yaner QIU Xin'ai bai Department of Physics Lyuliang UniversityLvliang033001China Guangdong Provincial Key Laboratory of Fiber Laser Materials and Applied Techniques South China University of TechnologyGuangzhou510640China

We demonstrate a low-noise,high-gain,and large-dynamic-range photodetector(PD)based on a junction field-effect transistor(JFET)and a charge amplifier for the measurement of quantum noise in Bell-state detection(BSD).Particular photodiode junction capacitance allows the silicon N-channel JFET 2sk152 to be matched to the noise requirement for charge amplifier A250.The electronic noise of the PD is effectively suppressed and the signal-to-noise ratio(SNR)is up to 15 dB at the analysis frequency of 2.75 MHz for a coherent laser power of 50.08µW.By combining of the inductor and capacitance,the alternating current(AC)and direct current(DC)branches of the PD can operate linearly in a dynamic range from 25.06µW to 17.50 mW.The PD can completely meet the requirements of SNR and dynamic range for BSD in quantum optics experiments.

关键词： Quantum noise Bell-state detection(BSD) Photodetector(PD) Junction field-effect transistor(JFET) Charge amplifier

Chiral mesostructured hematite with temperature-independent magnetism due to spin confinement

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第3期17卷 2019-2024页

作者： baiwen Zhang Jing ai Yingying Duan Te bai Lu Han Shunai Che School of Physics Science and Engineering Tongji UniversityShanghai 200092China School of Chemistry and Chemical Engineering Tongji UniversityShanghai 200092China Wuxi Vocational College of Science and Technology Wuxi 214028China School of Chemistry and Chemical Engineering Frontiers Science Center for Transformative MoleculesState Key Laboratory of Metal Matrix CompositesShanghai Jiao Tong UniversityShanghai 200240China

Hematite(α-Fe_(2)O_(3))is known to undergo conversion from weak ferromagnetic to antiferromagnetic as the temperature decreases below the Morin temperature(TM=250 K)due to spin moment rotation occurring during the Morin transition(MT).Herein,we endowed hematite with mesostructured chirality to maintain weak ferromagnetism without MT.Chiral mesostructured hematite(CMH)nanoparticles were prepared by a hydrothermal method with glutamic acid(Glu)as the symmetry-breaking agent.The triangular bipyramidal CMH nanoparticles were composed of helically cleaved nanoflakes with twisted crystal lattice.Field-cooled(FC)magnetization measurements showed that the magnetic moments of CMH were stabilized without MT within the temperature range of 10–300 K.Hysteresis loop measurements confirmed the weak ferromagnetism of CMH.The enhanced Dzyaloshinskii–Moriya interaction(DMI)was speculated to be responsible for the temperature-independent weak ferromagnetism,in which the spin configuration would be confined with canted antiferromagnetic coupling due to the mesostructured chirality of CMH.

关键词： hematite chiral mesostructure Dzyaloshinskii–Moriya interaction weak ferromagnetism antiferromagnetic material temperature-independent magnetism

A Simplified Method for the Stress Analysis of Underground Transfer Structures Crossing Multiple Subway Tunnels

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & Sciences 2024年第6期139卷 2893-2915页

作者： Shen Yan Dajiang Geng ning Dai Mingjian Long Zhicheng bai College of Civil Engineering Tongji UniversityShanghai200092China China Construction 4th Engineering Bureau 6th Corp. Ltd.Shanghai201199China Department of Civil and Architecture Engineering Hubei Polytechnic UniversityHuangshi435003China

According to the design specifications,the construction of extended piles involves traversing the tunnel’s upper region and extending to the underlying rock layer.To address this challenge,a subterranean transfer structure spanning multiple subway tunnels was proposed.Deliberating on the function of piles in the transfer structure as springs with axial and bending stiffness,and taking into account the force balance and deformation coordination conditions of beams and plates within the transfer structure,we established a simplified mechanical model that incorporates soil stratification by combining it with the Winkler elastic foundation beam model.The resolved established simplifiedmechanicalmodel employed finite difference technology and the Newton-Simpsonmethod,elucidating the mechanical mechanism of the transfer structure.The research findings suggest that the load carried by the upper structural columns can be transferred to the pile foundation beneath the beams through the transfer structure,subsequently reaching the deep soil layer and ensuring minimal impact on adjacent tunnels.The established simplified analysis method can be used for stress analysis of the transfer structure,concurrently considering soil stratification,pile foundation behavior,and plate action.The pile length,pile section size,and beam section size within the transfer structure should account for the characteristics of the upper load,ensuring an even distribution of the beam bending moment.

关键词： Crossing tunnels transfer structure force mechanism simplify analysis layered soil mass

An aircraft brake control algorithm with torque compensation based on RBF neural network

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第1期37卷 438-450页

作者： ning bai Xiaochao LIU Juefei LI Zhuangzhuang WANG Pengyuan QI Yaoxing SHANG Zongxia JIAO School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China Science and Technology on aircraft Control Laboratory Beihang UniversityBeijing 100191China Key Laboratory of Advanced aircraft Systems(Beihang University) Ministry of Industry and Information TechnologyBeijing 100091China Research Institute for Frontier Science Beihang UniversityBeijing 100191China ningbo Institute of Technology of Beihang University Ningbo 315800China Tianmushan Laboratory Xixi Octagon CityYuhang DistrictHangzhou 310023China

The wheel brake system of an aircraft is the key to ensure its safe landing and rejected takeoff.A wheel’s slip state is determined by the brake torque and ground adhesion torque,both of which have a large degree of uncertainty.It is this nature that brings upon the challenge of obtaining high deceleration rate for aircraft brake control.To overcome the disturbances caused by the above uncertainties,a braking control law is designed,which consists of two parts:runway surface recognition and wheel’s slip state tracking.In runway surface recognition,the identification rules balancing safety and braking efficiency are defined,and the actual identification process is realized through recursive least square method with forgetting factors.In slip state tracking,the LuGre model with parameter adaptation and a brake torque compensation method based on RBF neural network are proposed,and their convergence are proven.The effectiveness of our control law is verified through simulation and ground experiment.Especially in the experiments on the ground inertial test bench,compared to the improved pressure-biased-modulation(PBM)anti-skid algorithm,fewer wheel slips occur,and the average deceleration rate is increased by 5.78%,which makes it a control strategy with potential for engineering applications.

关键词： aircraft landing Brakes Disturbance observer Neural networks Runway identification

Left ventricular thrombosis caused cerebral embolism during venoarterial extracorporeal membrane oxygenation support: A case report

在线全文

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2024年第5期12卷 973-979页

作者： Yao-Bang bai Feng Zhao Zhen-Hua Wu Guo-ning Shi Nan Jiang Intensive Care Unit Department of Cardiac SurgeryTianjin Chest HospitalTianjin 300222China Department of Cardiac Surgery Tianjin Chest HospitalTianjin 300222China

BACKGROUND Venoarterial(VA)extracorporeal membrane oxygenation(ECMO),an effective short-term circulatory support method for refractory cardiogenic shock,is widely applied.However,retrospective analyses have shown that VA-ECMO-assisted cases were associated with a relatively high mortality rate of approximately 60%.Embolization in important organs caused by complications of left ventricular thrombosis(LVT)during VA-ECMO is also an important reason.Although the incidence of LVT during VA-ECMO is not high,the consequences of embolization are disastrous.CASE SUMMARY A 37-year-old female patient was admitted to hospital because of fever for 4 d and palpitations for 3 d.After excluding the diagnosis of coronary heart disease,we established a diagnosis of“clinically explosive myocarditis”.The patient still had unstable hemodynamics after drug treatment supported by VA-ECMO,with heparin for anticoagulation.On day 4 of ECMO support,a left ventricular thro-mbus attached to the papillary muscle root of the mitral valve was found by transthoracic echocardiography.Left ventricular decompression was performed and ECMO was successfully removed,but the patient eventually died of multiple cerebral embolism.CONCLUSION LVT with high mobility during VA-ECMO may cause embolism in important organs.Therefore,a"wait and see"strategy should be avoided.

关键词： Venoarterial extracorporeal membrane oxygenation Left ventricular thrombosis Cerebral embolism Magnetic Resonance Imaging Therapy Case report

Simultaneous detection of flare-associated kink oscillations and extreme-ultraviolet waves

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2024年第5期67卷 1592-1601页

作者： LI Dong HOU ZhenYong bai XianYong LI Chuan FANG Matthew ZHAO HaiSheng WANG JinCheng ning ZongJun Key Laboratory of Dark Matter and Space Astronomy Purple Mountain ObservatoryChinese Academy of SciencesNanjing210023China Yunnan Key Laboratory of the Solar Physics and Space Science Kunming650216China School of Earth and Space Sciences Peking UniversityBeijing100871China National Astronomical Observatories Chinese Academy of SciencesBeijing100101China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing100049China School of Astronomy and Space Science Nanjing UniversityNanjing210023China Key Laboratory of Modern Astronomy and Astrophysics Ministry of EducationNanjing UniversityNanjing210023China Columbus Academy GahannaOhio43230USA Key Laboratory of Particle Astrophysics Institute of High Energy PhysicsChinese Academy of SciencesBeijing100049China Yunnan Observatories Chinese Academy of SciencesKunming650216China

Kink oscillations,which are frequently observed in coronal loops and prominences,are often accompanied by extreme-ultraviolet(EUV)waves.However,much more needs to be explored regarding the causal relationships between kink oscillations and EUV waves.In this article,we report the simultaneous detection of kink oscillations and EUV waves that are both associated with an X2.1 flare on 2023 March 03(SOL2023-03-03T17:39).The kink oscillations,which are almost perpendicular to the axes of loop-like structures,are observed in three coronal loops and one prominence.One short loop shows in-phase oscillation within the same period of 5.2 min at three positions.This oscillation could be triggered by the pushing of an expanding loop and interpreted as the standing kink wave.Time lags are found between the kink oscillations of the short loop and two long loops,suggesting that the kink wave travels in different loops.The kink oscillations of one long loop and the prominence are possibly driven by the disturbance of the coronal mass ejection(CME),and that of another long loop might be attributed to the interaction of the EUV wave.The onset time of the kink oscillation of the short loop is nearly same as the beginning of an EUV wave.This fact demonstrates that they are almost simultaneous.The EUV wave is most likely excited by the expanding loop structure and shows two components.The leading component is a fast coronal wave,and the trailing one could be due to the stretching magnetic field lines.

关键词： coronal loops solar flares solar prominence solar oscillations extreme-ultraviolet wave magnetohydrodynamic

Diabetes mellitus in patients with type 1 autoimmune pancreatitis at diagnosis and after corticosteroid therapy

在线全文

学校读者我要写书评

暂无评论

Hepatobiliary & Pancreatic Diseases International 2024年第4期23卷 393-398页

作者： Mei-Zi Li Tao Guo Yun-Lu Feng Sheng-Yu Zhang Xiao-Yin bai Xi Wu Kai Xu ai-Ming Yang Department of Gastroenterology State Key Laboratory of Complex Severe and Rare DiseasesPeking Union Medical College HospitalPeking Union Medical College and Chinese Academy of Medical SciencesBeijing 100730China Department of Radiology Peking Union Medical College HospitalPeking Union Medical College and Chinese Academy of Medical SciencesBeijing 100730China

Background:A high prevalence of diabetes mellitus(DM)coexisting with autoimmune pancreatitis(aiP)is observed.However,evidence on the circumstances under which corticosteroid therapy(CST)for aiP improves or worsens DM is scarce.This study aimed to demonstrate and identify predictors of DM control under the influence of CST.Methods:Patients diagnosed with type 1 aiP were enrolled from a prospectively maintained cohort and were classified into three groups according to the chronology in which aiP and DM were diagnosed:pre-existing DM(pDM),concurrent DM(cDM),and non-DM(nDM).The responses of DM to CST were assessed when corticosteroid was ceased or tapered to a maintenance dose and classified as‘improvement’and‘non-improvement’(including‘no change’and‘exacerbation’).Results:Among 101 patients with type 1 aiP,52(51.5%)patients were complicated with DM at the time of aiP diagnosis,with 36 patients in the cDM group and 16 patients in the pDM group.The incidences of diffuse pancreatic swelling(72.2%)and pancreatic body/tail involvement(91.7%)were significantly higher in the cDM group than in both the pDM and nDM groups.Of the 52 patients with DM,CST was administered in 48 cases.Multivariate logistic analysis identified that elevated serum gamma-glutamyl transferase(GGT)level at aiP diagnosis[odds ratio(OR)=0.032,95%confidence interval(CI):0.003-0.412,P=0.008]and pancreatic atrophy after CST(OR=0.027,95%CI:0.003-0.295,P=0.003)were negatively associated with DM control improvement.Conclusions:Patients with diffuse pancreatic swelling and pancreatic body/tail involvement in pancreatitis tended to be complicated with cDM at aiP diagnosis.CST exerted a beneficial effect on the clinical course of DM in nearly half of the aiP patients complicated with DM at diagnosis,particularly in those without elevated serum GGT levels at diagnosis and who did not experience pancreatic atrophy after CST.

关键词： Type 1 autoimmune pancreatitis Diabetes mellitus Corticosteroid therapy Predictive factor Pancreatic atrophy

Quantification of Central and Eastern China's atmospheric CH_(4) enhancement changes and its contributions based on machine learning approach

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2024年第4期138卷 236-248页

作者： Xinyue ai Cheng Hu Yanrong Yang Leying Zhang Huili Liu Junqing Zhang Xin Chen Guoqiang bai Wei Xiao College of Biology and the Environment Joint Center for sustainable Forestry in Southern ChinaNanjing Forestry UniversityNanjing 210037China Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD) Nanjing University of Information Science&TechnologyNanjing 210044China Guang’an Vocational&Technical College Guangan 638550China HuaNan Meteorological Administration Huanan 154400China

Methane is the second largest anthropogenic greenhouse gas,and changes in atmospheric methane concentrations can reflect the dynamic balance between its emissions and sinks.Therefore,the monitoring of CH_(4) concentration changes and the assessment of underlying driving factors can provide scientific basis for the government’s policy making and evaluation.China is the world’s largest emitter of anthropogenic methane.However,due to the lack of ground-based observation sites,little work has been done on the spatial-temporal variations for the past decades and influencing factors in China,especially for areas with high anthropogenic emissions as Central and Eastern China.Here to quantify atmospheric CH_(4) enhancements trends and its driving factors in Central and Eastern China,we combined the most up-to-date TROPOMI satellite-based column CH_(4)(xCH_(4))concentration from 2018 to 2022,anthropogenic and natural emissions,and a random forest-based machine learning approach,to simulate atmospheric xCH_(4) enhancements from 2001 to 2018.The results showed that(1)the random forest model was able to accurately establish the relationship between emission sources and xCH_(4) enhancement with a correlation coefficient(R^(2))of 0.89 and a root mean-square error(RMSE)of 11.98 ppb;(2)The xCH_(4) enhancement only increased from 48.21±2.02 ppb to 49.79±1.87 ppb from the year of 2001 to 2018,with a relative change of 3.27%±0.13%;(3)The simulation results showed that the energy activities and waste treatment were the main contributors to the increase in xCH_(4) enhancement,contributing 68.00% and 31.21%,respectively,and the decrease of animal ruminants contributed-6.70% of its enhancement trend.

关键词： TROPOMI Methane column concentrations Anthropogenic sources Random Forest model

Novel strategy of multidimensional information encryption via multi-color carbon dots aggregation-induced emission

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第6期17卷 5680-5687页

作者： Liu Ding Xilang Jin Yuchong Gao Shouwang Kang Haiyan bai Xuehao Ma Taotao ai Hongwei Zhou Weixing Chen Shaanxi Key Laboratory of Photoelectric Functional Materials and Devices Engineering Research Center of Light Stabilizers for Polymer Materials Universities of Shaanxi Province School of Materials and Chemical EngineeringXi’an Technological UniversityXi’an 710021China School of Material Science and Engineering Shaanxi University of TechnologyHanzhong 723000China Department of Materials Science and Engineering University of PennsylvaniaPhiladelphia 19104USA

Carbon dots(CDs)with aggregation-induced emission(aiE)have sparked significant interest in multidimensional anti-counterfeiting due to their exceptional fluorescence properties.However,the preparation of aiE CDs with multicolor solid-state fluorescence remains a formidable challenge due to its complicated construction.In the present work,a novel class of multicolor aiE CDs(M-CDs)were fabricated using selected precursor(salicylic acid,thiosalicylic acid,and 2,2'-dithiodibenzoic acid),with an eco-friendly,low-cost one-pot solvothermal method.In the dilute organic solution,M-CDs manifested blue emission,but upon aggregation in the presence of water,the red,yellow,green,and blue emissions were displayed due to the aiE effect.Structural analysis,coupled with theoretical calculations,revealed that the increase in the size of sp2 domains would lower the Eg and cause a red-shift emission wavelength.Significantly,the continuous emission of M-CDs from blue to red can be utilized as ink for multimode printing,enabling the creation of a variety of school badges and quick response codes.These findings hold promising implications for multi-information encryption applications.

关键词： aggregation-induced emission(aiE) luminescence mechanism multi-color emission information encryption.