检索结果-南通市图书馆

New steelmaking process based on clean deoxidation technology

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2024年第6期31卷 1249-1262页

作者： Zhongliang Wang Yanping bao State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China

After the converter steelmaking process,a considerable number of ferroalloys are needed to remove dissolved oxygen from the molten steel,but it also forms a lot of oxide inclusions that cannot be completely removed.At the same time,it increases the carbon emis-sions in the steel production process.After years of research,our team have developed a series of clean deoxidation technologies,includ-ing carbon deoxidation,hydrogen deoxidation,and waste plastic deoxidation of molten steel to address the aforementioned issues.In this study,thermodynamic calculations and laboratory experiments were employed to verify that carbon and hydrogen can reduce the total oxygen content in the molten steel melt to below 5×10^(-6) and 10×10^(-6),respectively.An analysis of the deoxidation mechanisms and ef-fects of polyethylene and polypropylene was also conducted.In addition,the applications of carbon deoxidation technology in different steels with the hot-state experiment and industrial production were discussed carefully.The carbon deoxidation experimental results of different steels were as follows:(1)the oxygen content of bearing steel was effectively controlled at 6.3×10^(-6) and the inclusion number density was lowered by 74.73%compared to aluminum deoxidized bearing steel;(2)the oxygen content in gear steel was reduced to 7.7×10^(-6) and a 54.49%reduction of inclusion number density was achieved with almost no inclusions larger than 5μm from the average level of industry gear steels;(3)a total oxygen content of M2 high-speed steel was as low as 3.7×10^(-6).In industrial production practice,car-bon deoxidation technique was applied in the final deoxidation stage for non-aluminum deoxidized bearing steel,and it yielded excellent results that the oxygen content was reduced to below 8×10^(-6) and the oxide inclusions in the steel mainly consist of silicates,along with small amounts of spinel and calcium aluminate.

关键词： clean deoxidation carbon deoxidation hydrogen deoxidation waste plastics deoxidation

Development and prospects of molten steel deoxidation in steelmaking process

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2024年第1期31卷 18-32页

作者： Zhongliang Wang Yanping bao State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China

In the long traditional process of steelmaking,excess oxygen is blown into the converter,and alloying elements are used for deoxidation.This inevitably results in excessive deoxidation of products remaining within the steel liquid,affecting the cleanliness of the steel.With the increasing requirements for steel performance,reducing the oxygen content in the steel liquid and ensuring its high cleanliness is necessary.After more than a hundred years of development,the total oxygen content in steel has been reduced from approximately 100×10^(-6)to approximately 10×10^(-6),and it can be controlled below 5×10^(-6)in some steel grades.A relatively stable and mature deoxidation technology has been formed,but further reducing the oxygen content in steel is no longer significant for improving steel quality.Our research team developed a deoxidation technology for bearing steel by optimizing the entire conventional process.The technology combines silicon–manganese predeoxidation,ladle furnace diffusion deoxidation,and vacuum final deoxidation.We successfully conducted industrial experiments and produced interstitial-free steel with natural decarbonization predeoxidation.Non-aluminum deoxidation was found to control the oxygen content in bearing steel to between 4×10^(-6) and 8×10^(-6),altering the type of inclusions,eliminating large particle Ds-type inclusions,improving the flowability of the steel liquid,and deriving a higher fatigue life.The natural decarbonization predeoxidation of interstitial-free steel reduced aluminum consumption and production costs and significantly improved the quality of cast billets.

关键词： steel deoxidation deoxidizer metallurgical equipment bearing steel IF steel

Adaptation of Ocular Opponency Neurons Mediates Attention-Induced Ocular Dominance Plasticity

在线全文

学校读者我要写书评

暂无评论

Neuroscience Bulletin 2024年第3期40卷 339-349页

作者： Fangxing Song Lili Lyu Min bao CAS Key Laboratory of Behavioral Science Institute of PsychologyChinese Academy of SciencesBeijing100101China Department of Psychology University of Chinese Academy of SciencesBeijing100049China Institute of Neuroscience Key Laboratory of Primate NeurobiologyCAS Center for Excellence in Brain Science and Intelligence TechnologyChinese Academy of SciencesShanghai200031China

Previous research has shown that ocular dominance can be biased by prolonged attention to one eye.The ocular-opponency-neuron model of binocular rivalry has been proposed as a candidate account for this phenomenon.Yet direct neural evidence is still lacking.By manipulating the contrast of dichoptic testing gratings,here we measured the steady-state visually evoked potentials(SSVEPs)at the intermodulation frequencies to selectively track the activities of ocular-opponency-neurons before and after the“dichoptic-backward-movie”adaptation.One hour of adaptation caused a shift of perceptual and neural ocular dominance towards the unattended eye.More importantly,we found a decrease in the intermodulation SSVEP response after adaptation,which was significantly greater when high-contrast gratings were presented to the attended eye than when they were presented to the unattended eye.These results strongly support the view that the adaptation of ocular-opponency-neurons contributes to the ocular dominance plasticity induced by prolonged eye-based attention.

关键词： Attention Ocular dominance Opponency neuron Adaptation Steady-state visually evoked potential

Global warming strengthens the association between ENSO and the Asian-Australian summer monsoon

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

Science China Earth Sciences 2024年第1期67卷 309-312页

作者： bao YANG Minhui HE School of Geography and Ocean Science Nanjing UniversityNanjing 210093China Key Laboratory of Desert and Desertification Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China

Previous studies have widely reported the linkages between Asian-Australian monsoon and the ENSO(Wu,2008;Azad and Rajeevan,2016;Chen et al.,2020;Shekhar et al.,2022;Zhang J et al.,2022;Chen et al.,2023;Hau et al.,2023;Heidemann et al.,2023).It is well accepted that the monsoon is weaker during the El Niño phase and stronger during the La Niña phase.For example,an anomalously strong western Pacific subtropical high in 2020,related to the La Niña event.

关键词： event monsoon Asian

Three-dimensional forest foodscape in large herbivores’habitat based on UAV with LiDAR detection

在线全文

学校读者我要写书评

暂无评论

Integrative Zoology 2024年第2期19卷 343-346页

作者： Heng bao Guangshun JIANG College of Wildlife and Protected Area Northeast Forestry UniversityHarbinChina Feline Research Center of National Forestry and Grassland Administration HarbinChina Research Center for Northeast Asia Biodiversity Conservation HarbinChina

Traditionally,wildlife habitat research mainly extracts two-dimensional habitat factors.However,they live in three-dimensional space,and the three-dimensional structure of the forest ecosystem is an important factor affecting the composition of the mammal community(Fig.1a,b),and the three-dimensional structure of the forest also determines the behavior pattern of wildlife multidimensional habitat selection or use(Flaspohler et al.2010;Palminteri et al.2012;Müller et al.2014).For instance,forest structure determines the vertical distribution of annual edible shoots,fruits,or seed nuts resources in space,providing additional ecological niches for frugivores,rodents,and other species,and then leading to niche differentiation of wild animals in vertical space utilization,thus increasing species coexistence(e.g.Li et al.2023).

关键词： habitat forest dimensional

Hybrid tri-memristor hyperchaotic map and application in Wasserstein Generative Adversarial Nets

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

Science China Technological Sciences 2024年第6期67卷 1855-1865页

作者： GU Yang bao Han YU XiHong HUA ZhongYun bao BoCheng XU Quan School of Microelectronics and Control Engineering Changzhou University School of Computer Science and Technology Harbin Institute of Technology

Inspired by basic circuit connection methods, memristors can also be utilized in the construction of complex discrete chaotic systems. To investigate the dynamical effects of hybrid memristors, we propose two hybrid tri-memristor hyperchaotic(HTMH)mapping structures based on the hybrid parallel/cascade and cascade/parallel operations, respectively. Taking the HTMH mapping structure with hybrid parallel/cascade operation as an example, this map possesses a spatial invariant set whose stability is closely related to the initial states of the memristors. Dynamics distributions and bifurcation behaviours dependent on the control parameters are explored with numerical tools. Specifically, the memristor initial offset-boosting mechanism is theoretically demonstrated, and memristor initial offset-boosting behaviours are numerically verified. The results clarify that the HTMH map can exhibit hyperchaotic behaviours and extreme multistability with homogeneous coexisting infinite attractors. In addition, an FPGA hardware platform is fabricated to implement the HTMH map and generate pseudorandom numbers(PRNs)with high randomness. Notably, the generated PRNs can be applied in Wasserstein generative adversarial nets(WGANs) to enhance training stability and generation capability.

关键词： memristor hybrid tri-memristor map spatial invariant set hyperchaos extreme multistability generative adversarial nets

Spatiotemporal changes of gross primary productivity and its response to drought in the Mongolian Plateau under climate change

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Arid Land 2024年第1期16卷 46-70页

作者： ZHAO Xuqin LUO Min MENG Fanhao SA Chula bao Shanhu bao Yuhai College of Geographical Science Inner Mongolia Normal UniversityHohhot 010022China Inner Mongolia Key Laboratory of Remote Sensing and Geographic Information Systems Hohhot 010022China

Gross primary productivity(GPP)of vegetation is an important constituent of the terrestrial carbon sinks and is significantly influenced by drought.Understanding the impact of droughts on different types of vegetation GPP provides insight into the spatiotemporal variation of terrestrial carbon sinks,aiding efforts to mitigate the detrimental effects of climate change.In this study,we utilized the precipitation and temperature data from the Climatic Research Unit,the standardized precipitation evapotranspiration index(SPEI),the standardized precipitation index(SPI),and the simulated vegetation GPP using the eddy covariance-light use efficiency(EC-LUE)model to analyze the spatiotemporal change of GPP and its response to different drought indices in the Mongolian Plateau during 1982-2018.The main findings indicated that vegetation GPP decreased in 50.53% of the plateau,mainly in its northern and northeastern parts,while it increased in the remaining 49.47%area.Specifically,meadow steppe(78.92%)and deciduous forest(79.46%)witnessed a significant decrease in vegetation GPP,while alpine steppe(75.08%),cropland(76.27%),and sandy vegetation(87.88%)recovered well.Warming aridification areas accounted for 71.39% of the affected areas,while 28.53% of the areas underwent severe aridification,mainly located in the south and central regions.Notably,the warming aridification areas of desert steppe(92.68%)and sandy vegetation(90.24%)were significant.Climate warming was found to amplify the sensitivity of coniferous forest,deciduous forest,meadow steppe,and alpine steppe GPP to drought.Additionally,the drought sensitivity of vegetation GPP in the Mongolian Plateau gradually decreased as altitude increased.The cumulative effect of drought on vegetation GPP persisted for 3.00-8.00 months.The findings of this study will improve the understanding of how drought influences vegetation in arid and semi-arid areas.

关键词： gross primary productivity(GPP) climate change warming aridification areas drought sensitivity cumulative effect duration(CED) Mongolian Plateau

Basic Research Advances in China on Embryo Implantation,Placentation,and Parturition

在线全文

学校读者我要写书评

暂无评论

Maternal-Fetal Medicine 2024年第1期6卷 37-49页

作者： Haili bao Haibin Wang Fujian Provincial Key Laboratory of Reproductive Health Research Department of Obstetrics and GynecologyThe First Affiliated Hospital of Xiamen UniversitySchool of MedicineXiamen UniversityXiamen 361102China State Key Laboratory of Vaccines for Infectious Diseases Xiang An Biomedicine LaboratorySchool of MedicineXiamen UniversityXiamen 361102China

This review aimed to summarize the major progress in maternal-fetal medicine achieved by Chinese scientists in recent years.PubMed was systematically searched from January 2020 to November 2023.Publications that reported the progress in embryo implantation,placentation,and parturition made by Chinese scientists in the last 3 years were selected.The milestone events during gestation,embryo implantation,endometrial decidualization,placentation,and parturition are pivotal to a successful pregnancy.Embryo implantation requires intricate interactions between implantation-competent blastocysts and receptive endometrium.To adapt to pregnancy,endometrial stromal cells transform into specialized decidual cells,which occur spontaneously under the influence of ovarian hormones in humans but require the presence of embryos in mice.With embryonic development,the placenta forms to support fetal growth until parturition.The maternal-fetal interface is composed of diverse cell types,including endometrial decidual cells,placental trophoblast cells,endothelial cells,and various immune cells,a sophisticated interplay among which contributes to the maintenance of pregnancy.Near term,the uterus transitions from quiescence to contractility,in preparation for delivery.Disruptions to these events lead to pregnancy-related disorders such as repeated implantation failure,recurrent pregnancy loss,preeclampsia,fetal growth restriction,preterm birth,and infertility.In recent years,Chinese scientists have made prominent achievements in basic research on the aforementioned pregnancy events.Chinese scientists have made remarkable contributions to reproductive biology and maternal-fetal medicine research in recent years,highlighting future research directions in this field.

关键词： Embryo implantation Decidualization Placentation Maternal-fetal interface Parturition

Research progress of slippage characteristic and gas film stability enhancement methods on biomimetic hydrophobic surfaces

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2024年第1期36卷 87-101页

作者： Meng-zhuo Zhang Hai-bao Hu Liu-zhen Ren Lu-yao bao Jun Wen Luo Xie School of Marine Science and Technology Northwestern Polytechnical UniversityXi’an710072China Research and Development Institute of Northwestern Polytechnical University in Shenzhen Shenzhen518063China

The biomimetic hydrophobic surface is a potentially efficient underwater drag reduction method and the drag reduction mechanism of this kind of surface comes from the interfacial slippage.For now,it is a hotspot to grasp the slippage characteristic and explore slippage enhancement strategies.This paper not only summarizes our numerical simulation and experimental results of slippage characteristic at the solid-liquid interface(SLI)of hydrophobic surfaces(HS)and the gas-liquid interface(GLI)of superhydrophobic surfaces(SHS)in recent years,but also introduces some innovative methods that can effectively improve the gas film stability and drag reduction effect of SHS.First,we used the molecular dynamics(MD)simulation method to figure out the effect of the solid-liquid interaction strength,the system temperature and the shear rate on the slippage of SLI,and expound their action mechanism from molecular scale.Then,by MD and multibody dissipative particle dynamics(MDPD)method,the slippage behavior at the GLI was studied under the influence of the microstructure size and the flow driving velocity.We proposed a new kind of hybrid slip boundary condition model to describe the slippage characteristic on GLI.In addition,we found through experiment that a three-dimensional backflow will appear on the GLI under the interfacial adsorption of surfactants,and the backflow direction will reverse with the change of GLI morphology.Finally,we put forward the wettability step structure and gas injection method to enhance the stability and drag reduction effect of the gas film on SHS.

关键词： Hydrophobic surface superhydrophobic surface interfacial slip underwater drag reduction