检索结果-南通市图书馆

Are Solar Active Regions Born with Neutralized Currents?

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2024年第7期24卷 79-88页

作者： Aiying Duan Yaoyu xing Chaowei jiang Planetary Environmental and Astrobiological Research Laboratory(PEARL) School of Atmospheric SciencesSun Yat-sen UniversityZhuhai 519000China Yunnan Key Laboratory of the Solar Physics and Space Science Kunming 650216China Key Laboratory of Tropical Atmosphere-Ocean System Sun Yat-sen UniversityMinistry of EducationZhuhai 519000China Institute of Space Science and Applied Technology Harbin Institute of TechnologyShenzhen 518055China

Solar active regions(ARs)are formed by the emergence of current-carrying magnetic flux tubes from below the *** for an isolated flux tube the direct and return currents flowing along the tube should balance with each other,it remains controversial whether such a neutralization of currents is also maintained during the emergence *** we present a systematic survey of the degrees of the current neutralization in a large sample of flux-emerging ARs which appeared on the solar disk around the central meridian from 2010 to *** vector magnetograms taken by Helioseismic and Magnetic Imager onboard Solar Dynamic Observatory are employed to calculate the distributions of the vertical current density at the *** on the main phase of flux emergence,i.e.,the phase in which the total unsigned magnetic flux is continuously increased,we statistically examined the ratios of direct to return currents in all the *** a large-sample statistical study suggests that most of the ARs were born with currents close to *** degree of current neutralization seems to be not affected by the active-region size,the active-region growing rate,and the total unsigned *** only correlation of significance as found is that the stronger the magnetic field nonpotentiality is,the further the AR deviates from current neutrality,which supports previous event studies that eruption-productive ARs often have non-neutralized currents.

关键词： Sun magnetic fields-Sun flares-Sun corona-Sun coronal mass ejections(CMEs)

Comparative analysis of DNA-SIP and magnetic-nanoparticle mediated isolation (MMI) on unraveling dimethoate degraders

在线全文

学校读者我要写书评

暂无评论

Frontiers of Environmental Science & Engineering 2024年第1期18卷 59-69页

作者： Luning Lian Yi xing Dayi Zhang Longfei jiang Mengke Song Bo jiang School of Energy and Environmental Engineering University of Science&Technology BeijingBeijing 100083China Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants University of Science&Technology BeijingBeijing 100083China National Environmental and Energy Science and Technology International Cooperation Base University of Science&Technology BeijingBeijing 100083China College of New Energy and Environment Jilin UniversityChangchun 130021China Guangzhou Institute of Geochemistry Chinese Academy of SciencesGuangzhou 510640China College of Natural Resources and Environment South China Agricultural UniversityGuangzhou 510642China National Engineering Laboratory for Site Remediation Technologies Beijing 100015China

Microorganisms are crucial in the bioremediation of organophosphorus pesticides. However, most functional microorganisms (> 99%) are yet to be cultivated. This study applied two cultivation-independent approaches, DNA-SIP and magnetic-nanoparticle mediated isolation (MMI), to identify the functional microorganisms in degrading dimethoate in agricultural soils. MMI identified five dimethoate degraders: Pseudomonas, Bacillus, Ramlibacter, Arthrobacter, and Rhodococcus, whereas DNA-SIP identified three dimethoate degraders: Ramlibacter, Arthrobacter, and Rhodococcus. Also, MMI showed higher resolution than DNA-SIP in identifying functional microorganisms. Two organic phosphohydrolase (OPH) genes: ophC2 and ophB, were involved in dimethoate metabolism, as revealed by DNA-SIP and MMI. The degradation products of dimethoate include omethoate, O,O,S-trimethyl thiophosphorothioate, N-methyl-2-sulfanylacetamide, O,O-diethyl S-hydrogen phosphorodithioate, O,O,O-trimethyl thiophosphate, O,O,S-trimethyl thiophosphorodithioate, and O,O,O-trimethyl phosphoric. This study emphasizes the feasibility of using SIP and MMI to explore the functional dimethoate degraders, expanding our knowledge of microbial resources with cultivation-independent approaches.

关键词： Stable isotope probing(SIP) Magnetic-nanoparticle mediated isolation(MMI) Dimethoate Biodegradation Cultivation-independent approach

Nonlinear Characteristic Analysis of Gas-Interconnected Quasi-Zero Stiffness Pneumatic Suspension System:A Theoretical and Experimental Study

维普期刊数据库评论

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 Mechanical Engineering 2024年第3期37卷 338-352页

作者： Xinwei jiang xing Xu Tianling Shi Vincent Akolbire Atindana Automotive Engineering Research Institute Jiangsu UniversityZhenjiang 212013China

Because of significantly changed load and complex and variable driving road conditions of commercial vehicles,pneumatic suspension with lower natural frequencies is widely used in commercial vehicle suspension *** ever,traditional pneumatic suspension system is hardly to respond the greatly changed load of commercial vehicles To address this issue,a new Gas-Interconnected Quasi-Zero Stiffness Pneumatic Suspension(GIQZSPS)is presented in this paper to improve the vibration isolation performance of commercial vehicle suspension systems under frequent load *** new structure adds negative stiffness air chambers on traditional pneumatic suspension to reduce the natural frequency of the *** can adapt to different loads and road conditions by adjusting the solenoid valves between the negative stiffness air ***,a nonlinear mechanical model including the dimensionless stiffness characteristic and interconnected pipeline model is derived for GIQZSPS *** the nonlinear mechanical model of GIQZSPS system,the force transmissibility rate is chosen as the evaluation index to analyze ***,a testing bench simulating 1/4 GIQZSPS system is designed,and the testing analysis of the model validation and isolating performance is carried *** results show that compared to traditional pneumatic suspension,the GIQZSPS designed in the article has a lower natural *** the system can achieve better vibration isolation performance under different load states by switching the solenoid valves between air chambers.

关键词： Pneumatic suspension Quasi-zero stiffness system Gas-interconnected system Nonlinear dynamic modeling

CO_(2) capture by modified clinoptilolite and its regeneration performance

在线全文

学校读者我要写书评

暂无评论

International Journal of Coal Science & Technology 2024年第2期11卷 81-90页

作者： Bo jiang Bo Zhang Xuqin Duan Yi xing School of Energy and Environmental Engineering University of Science and Technology BeijingBeijing 100083China Beijing Key Laboratory of Resource-Oriented Treatment of Industrial Pollutants University of Science and Technology BeijingBeijing 100083China YangQuan Coal Industry(Group)Co.Ltd. Yangquan 045000China School of Civil and Resource Engineering University of Science and Technology BeijingBeijing 100083China

This study focuses on CO_(2) capture by pressure swing adsorption(PSA),with modified clinoptilolite as the *** clinoptilolite is modified by roasting,by acid pickling,by a combination of acid pickling and roasting,and by ion *** by acid pickling-roasting and by ion exchange are found to give the highest CO_(2) adsorption capacities,of 730 mL/g and 876.7 mL/g,*** is found that regeneration of clinoptilolite by a combination of vacuum desorption and heating enables recovery of as much as 89%of its previous CO_(2) adsorption *** examine the CO_(2) adsorption capacity of clinoptilolite when applied to mixed gas,a simulated coking exhaust containing 12%CO_(2) and 4%O_(2) is used,and it is found that ion exchange modified clinoptilolite achieves a CO_(2) removal efficiency of 92.5%.A BET test reveals that acid pickling-roasting and Na^(+) modification enhance the porosity of clinoptilolite,thereby improving its adsorption *** work demonstrates the feasibility of applying modified clinoptilolite as an effective adsorbent for COO_(2)capture,providing a promising tool for dealing with greenhouse gases.

关键词： Clinoptilolite Carbon dioxide capture Pressure swing adsorption(PSA)

A hybrid WUDT-NAFnet for simultaneous source data deblending

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Petroleum Science 2024年第3期21卷 1649-1659页

作者： Chao-Fan Ke Shao-Huan Zu Jun-xing Cao Xu-Dong jiang Chao Li xing-Ye Liu Key Laboratory of Earth Exploration and Information Technology of Ministry of Education Chengdu University of Technology State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Chengdu University of Technology College of Geophysics Chengdu University of Technology

Simultaneous source technology,which reduces seismic survey time and improves the quality of seismic data by firing more than one source with a narrow time interval,is compromised by the massive blended ***,deblending algorithms have been developed to separate this ***,deep learning(DL)has been proved its great potential in suppressing the *** most popular DL method employs neural network as a filter to attenuate the blended noise in an iterative estimation and subtraction framework(IESF).However,there are still amplitude distortion and blended noise residual problems,especially when dealing with weak signal submerged in strong *** address these problems,we propose a hybrid WUDT-NAFnet,which contains two *** first network is a wavelet based U-shape deblending transformer network(WUDTnet),incorporated into IESF as a robust regularization term to iteratively separate the blended *** second network is a nonlinear activate free network(NAFnet)designed to recover the event amplitude and further suppress the weak noise residual in *** the hybrid network,the blended noise can be separated purposefully and *** using synthetic and field seismic data demonstrate that the WUDTNAFnet outperforms traditional curvelet transform(CT)based method and the deblending transformer(DT)model in terms of ***,for field applications,the data augmentation method of bicubic interpolation is applied to mitigate the feature difference between synthetic and field ***,the trained network exhibits strong signal preservation ability in numerical field example without requiring additional training.

关键词： Simultaneous-source Deblending Deep learning Transformer

Strength and ductility optimization of HPDC AlSi8MgCuZn2 alloys by modifying pre-aging treatment

在线全文

学校读者我要写书评

暂无评论

China Foundry 2024年第4期21卷 343-351页

作者： Yuan-hang jiang Hui-ting Zheng Fei Liu hai-dong Zhao National Engineering Research Center of Near-net Shape Forming for Metallic Materials South China University of TechnologyGuangzhou 510641China

Considering the components produced by high pressure die casting(HPDC)process usually with ultra-large sizes and complex morphologies,high temperature solid solution treatment is not a suitable method to further improve their mechanical *** this study,two-stage aging treatment with different pre-aging times was designed and employed to further improve the mechanical properties of HPDC Al8SiMgCuZn *** characteristics of precipitates were evaluated by a transmission electron microscope(TEM),and the precipitation strengthening mechanism was *** results reveal that the strengthening is mainly contributed by the precipitation ofβ″phase after two-stage aging,and the number density and size of the precipitates are significantly depended on the pre-aging *** number density of precipitates is increased with the pre-aging time prolonged from 0 h to 4 h,and then decreases with the further increase of pre-aging time from 4 h to 6 *** precipitates with the highest density and smallest size are observed after pre-aging for 4 *** pre-aged at 100℃for 4 h and then artificial aged at 200℃for 30 min,the yield strength of 207 MPa,ultimate tensile strength of 325 MPa and elongation of 7.6%are achieved.

关键词： high pressure die cast aluminum alloy microstructural heterogeneity mechanical properties precipitation strengthening two-stage aging

The effect of secondary phase on corrosion behaviors of the titanium–zirconium–molybdenum alloy

在线全文

学校读者我要写书评

暂无评论

Tungsten 2024年第2期6卷 342-354页

作者： Song-Wei Ge Ping Hu Jie Deng Shi-Lei Li hai-Rui xing Jia-Yu Han xing-jiang Hua Li Wang Jun-Zhou Yang Bo Jin Wen Zhang Kuai-She Wang School of Metallurgy Engineering Xi’an University of Architecture and TechnologyXi’an 710055China National and Local Joint Engineering Research Center for Functional Materials Processing Xi’an University of Architecture and TechnologyXi’an 710055China Western Xinxing Rare and Precious Metals Co. Ltd.Shangluo 726000China Northwest Institute for Non-Ferrous Metal Research Xi’an 710016China

As the range of applications for molybdenum and its alloys has expanded,the corrosive environment for molybdenum alloys has become more *** the past,the content of doping elements has been studied to investigate their infl uence on the corrosion performance of titanium–zirconium–molybdenum(TZM)*** this paper,it is considered that the second phase in the alloy is the main factor aff ecting the corrosion performance of TZM *** comparing the corrosion behavior of molybdenum metal and TZM alloy,the eff ect of the secondary phase on corrosion behaviors of TZM alloy has been *** results show that the second phase reduces the corrosion resistance of the TZM *** potential of the second phase is 73.7 mV higher than that of the Mo matrix,which contributes to the formation of microscopic electric *** the action of microscopic electric couples,pitting corrosion is preferentially formed at the interface between the second phase and the matrix,which accelerates the corrosion of the *** paper provides a theoretical basis for the application of TZM alloys in corrosive environments.

关键词： Secondary phase Electrochemical corrosion Titanium–zirconium–molybdenum(TZM) Galvanic corrosion Corrosion resistance

Association of interleukin-10 polymorphisms with risk of irritable bowel syndrome:A meta-analysis

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2013年第48期19卷 9472-9480页

作者： Shan-Yu Qin hai-xing jiang Dong-Hong Lu You Zhou Department of Gastroenterology the First Affiliated Hospital of Guangxi Medical University Minerva Foundation Institute for Medical Research FI-00290 Helsinki Finland

AIM:To clarify the current understanding of the association between interleukin-10(IL-10)polymorphisms and the risk of irritable bowel syndrome(IBS).METHODS:We searched for studies in any language recorded in PubMed,Embase and Cochrane library before August *** associations under allele contrast model,codominant model,dominant model,and recessive model were *** strengths of the association between IL-10 polymorphisms and IBS risk were estimated using odds ratios(OR)with 95%confidence interval(CI).Fixed effects model was used to pool the result if the test of heterogeneity was not significant,otherwise the random-effect model was ***:Eight case-control studies analyzing three single-nucleotide polymorphisms rs1800870(-1082 A/G),rs1800871(-819C/T),and rs1800872(-592A/C)of the IL-10 gene,which involved 928 cases and 1363 controls,were eligible for our *** results showed that rs1800870 polymorphisms were associated with a decreased risk of IBS(GG+GA vs AA:OR=0.80,95%CI:0.66-0.96),(AA+GA vs GG:OR=0.68,95%CI:0.52-0.90).Subgroup analysis revealed such association only existed in Caucasian ethnicity(AA+GA vs GG,OR=0.70,95%CI:0.55-0.89).The rs1800872 polymorphisms were associated with an increased risk of IBS in Asian ethnicity(CC vs GG:OR=1.29,95%CI:1.01-1.16).There were no associations between rs1800871 polymorphisms and the IBS ***:The results suggest that IL-10 rs1800870confers susceptibility to the risk of IBS in Caucasian ethnicity,and the rs1800872 may associate with IBS risk in ***,no significant associations are found between rs1800871 and IBS risk.

关键词： Interleukin-10 Irritable bowel syndrome Gene polymorphism Case-control Meta-analysis

Strengthening-softening transition and maximum strength in Schwarz nanocrystals

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Materials Science 2024年第3期6卷 320-328页

作者： Hanzheng xing Jiaxi jiang Yujia Wang Yongpan Zeng Xiaoyan Li Center for Advanced Mechanics and Materials Applied Mechanics LaboratoryDepartment of Engineering MechanicsTsinghua UniversityBeijing100084China Institute of High Performance Computing(IHPC) Agency for ScienceTechnology and Research(A*STAR)Singapore138632Singapore

Recently,a Schwarz crystal structure with curved grain boundaries(GBs)constrained by twin-boundary(TB)networks was discovered in nanocrystalline Cu through experiments and atomistic *** Cu with nanosized Schwarz crystals exhibited high strength and excellent thermal ***,the grainsize effect and associated deformation mechanisms of Schwarz nanocrystals remain ***,we performed large-scale atomistic simulations to investigate the deformation behaviors and grain-size effect of nanocrystalline Cu with Schwarz *** simulations showed that similar to regular nanocrystals,Schwarz nanocrystals exhibit a strengthening-softening transition with decreasing grain *** critical grain size in Schwarz nanocrystals is smaller than that in regular nanocrystals,leading to a maximum strength higher than that of regular *** simulations revealed that the softening in Schwarz nanocrystals mainly originates from TB migration(or detwinning)and annihilation of GBs,rather than GB-mediated processes(including GB migration,sliding and diffusion)dominating the softening in regular *** analyses of simulation data further showed that compared with those in regular nanocrystals,the GB-mediated processes in Schwarz nanocrystals are suppressed,which is related to the low volume fraction of amorphous-like GBs and constraints of TB *** smaller critical grain size arises from the suppression of GB-mediated processes.

关键词： Schwarz nanocrystal Curved grain boundary Atomistic simulation Grain size effect Maximum strength