检索结果-南通市图书馆

Regulation of sporopollenin synthesis for pollen wall formation in plant

在线全文

学校读者我要写书评

暂无评论

Science China(Life Sciences) 2016年第12期59卷 1335-1337页

作者： Zhong-nan yang College of life and environmental sciences Shanghai Normal University

Pollen wall is the most complicated cell wall in plant. It is composed of outer exine and inner intine with the exine fiar- ther divided into sexine and nexine. The composition of in- tine layer is generally considered to be same as a plant cell wall which is mainly composed of cellulose. Nexine layer can only be observed under transmission electron microscope. Recent investigation suggested that the major composition of nexine is arabinogalactan proteins （Jia et al., 2015）.

关键词： pollen cellulose outer

Current status of intrahepatic cholangiocarcinoma

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2008年第41期14卷 6289-6297页

作者： Jian yang Lu-nan Yan Liver Transplantation Division Department of Surgery West China Hospital Sichuan University Chengdu 610041 Sichuan Province China

Intrahepatic cholangiocarcinoma (ICC) is a rare primary liver cancer with a global increasing trend in recent years. Symptoms tend to be vague and insidious in development, often are diagnosed at an advanced stage when only palliative approaches can be used with a median survival rate of months. Comparing with HCC, ICC tends to spread to lymph nodes early, and is rarely limited to the regional lymph nodes, with a frequent postoperative recurrence. Surgery is the only choice of curative therapy for ICC, but recently no consensus has been established for operation. Thus, more data from multiple centers and more cases are needed. Generally speaking, current adjunctive therapy cannot clearly improve survival. Further research is needed to find more effective radio- and chemotherapeutic regimens.

关键词： Intrahepatic cholangiocarcinoma Lymph node metastasis Liver transplantation Adjunctive therapy

Paraffin section observation of flower bud differentiation of Chimonanthus praecox in Kunming and comparison of the differentiation processes in different regions,China

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

Horticultural Plant Journal 2022年第2期8卷 221-229页

作者： Sijin Li nan yang Longqing Chen Southwest Engineering Research Center for Landscape Architecture(State Forestry and Grassland Administration) Yunnan Province Engineering Research Center for Functional Flower Resources and Industrialization TechnologySouthwest Forestry UniversityKunming 650224China

Chimonanthus praecox is an important ornamental plant and cut flower material in *** blooms in the freezing winter and its flower emits charming ***,in different region the flowering time is *** order to understand the flowering mechanism of *** in the winter,we studied the flower bud differentiation in Spring City-Kunming using paraffin sectioning method in the present *** we compared the differentiation process difference from different *** was found that the temperature is the key factor for its flower bud differentiation and blossom of *** the process of bud differentiation,the temperature 20℃was the optimum for inducing changes from vegetative axillary buds to reproductive buds and subsequent morphological differentiation in *** in the first three differentiation periods—tepal primordial stage,staminal primordial stage and pistil primordial stage,Kunming took the shortest time to finish the process due to very rapid temperature rise to 20℃,whereas,in Zhengzhou the time for these differentiations was the longest,which may be caused by the slow temperature *** May,the high temperature stress forced the flower buds into the first long dormant period in all regions except *** Kunming,the average temperature was only 20–25℃,so the flower bud continued to *** all regions,Kunming is the first to complete whole flower bud differentiation even on the early August,and started the second dormancy very early but very *** the other regions,the plants went through a shorter dormancy and the low temperature broke the dormancy *** the plants of Kunming spent a longer period for the low ***,the low temperature less than 10℃is a key factor to breaking the second *** the regular effects of temperature on flower bud differentiation and blossom is very helpful for florescence regulation of ***.

关键词： Chimonanthus praecox Flower bud differentiation Paraffin section Temperature

Perturbed magnetic field of an infinite plate with a centered crack

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2011年第2期27卷 259-265页

作者： Fei Qin yang Zhang Ya-nan Liu College of Mechanical Engineering and Applied Electronics Technology Beijing University of Technology 100124 Beijing China

Deforming a cracked magnetoelastic body in a magnetic field induces a perturbed magnetic field around the crack. The quantitative relationship between this perturbed field and the stress around the crack is crucial in developing a new generation of magnetism-based nondestructive testing technologies. In this paper, an analytical expression of the perturbed magnetic field induced by structural deforma- tion of an infinite ferromagnetic elastic plate containing a centered crack in a weak external magnetic field is obtained by using the linearized magnetoelastic theory and Fourier transform methods. The main finding is that the perturbed magnetic field intensity is proportional to the applied tensile stress, and is dominated by the displacement gradient on the boundary of the magnetoelastic solid. The tangential component of the perturbed magnetic-field intensity near the crack exhibits an antisymmetric distribution along the crack that reverses its direction sharply across its two faces, while the normal component shows a symmetric distribution along the crack with singular points at the crack tips.

关键词： Magnetoelasticity Crack Perturbed magnetic field Fourier transform method Nondestructive testing

Flexible,Light-Interacting,B-Shaped Structures for Computations

在线全文

学校读者我要写书评

暂无评论

Research 2023年第4期2023卷 453-462页

作者： nan yang Zheng Qian Huaxian Wei Yubo Zhang Intelligent Manufacturing Key Laboratory of the Ministry of Education College of EngineeringShantou UniversityShantou 515063China

Integrating mechanical computing functions into robotic materials,microelectromechanical systems,or soft robotics can improve their intelligence in stimulation-response *** mechanical computing systems exhibit limitations,including incomplete functions,unchangeable computing rules,difficulties in realizing random logic,and lack of *** overcome these limitations,we propose a straightforward method of designing mechanical computing systems—based on the logic expressions—for complex *** designed soft,B-shaped mechanical metamaterial units,and compressed them to render stress inputs;the outputs are represented by the light-shielding effects caused by the unit *** realized logic gates and corresponding combinations(including half/full binary adder/subtractor and addition/subtraction of 2 numbers with multiple bits)and provided a versatile solution for making a mechanical analog-to-digital converter to generate both ordered and disordered *** performed all of the computations within the elastic regions of the B-shaped units;thus,after one computation,the systems can return to the initial states for *** proposed mechanical computers will potentially enable robotic materials,microelectromechanical systems,or soft robotics to perform complex ***,one can extend this concept to systems that are based on other mechanisms or materials.

关键词： shaped limitations return

Identify real gravitational wave events in the LIGO-Virgo catalog GWTC-1 and GWTC-2 with convolutional neural network

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

Frontiers of physics 2022年第5期17卷 1-8页

作者： Meng-Qin Jiang nan yang Jin Li College of Physics Chongqing UniversityChongqing 401331China Department of Electronical Information Science and Technology Xingtai UniversityXingtai 054001China

In recent years,machine learning models have been introduced into the field of gravitational wave(GW)data *** this paper,we apply the convolutional neural network(CNN)to LIGO O1,O2,O3a data analysis to search the released 41 GW events which are emitted from binary black hole(BBH)mergers(here we exclude the events from binary neutron star(BNS)mergers,and the events that are not detected simultaneously by Hanford(H)and Livingston(L)detectors),and use time sliding method to reduce the false alarm rate(FAR).According to the results,the 41 confirmed GW events of BBH mergers can be classified successfully by our CNN ***,through restricting the number of consecutive prewarning from sequential samples intercepted continuously in LIGO O2 real time-series and vetoing the coincidences of noise from H and L,the FAR is limited to be less than once in 2 *** is helpful to promote LIGO real time data processing.

关键词： convolutional neural network gravitational wave events false alarm rate

Predictability and skill of convection-permitting ensemble forecast systems in predicting the record-breaking“21·7”extreme rainfall event in Henan Province,China

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2022年第10期65卷 1879-1902页

作者： Kefeng ZHU Chenyue ZHANG Ming XUE nan yang Key Laboratory of Transportation Meteorology of China Meteorological Administration Nanjing Joint Institute for Atmospheric SciencesNanjing 210041China Key Laboratory of Mesoscale Severe Weather/Ministry of Education and School of Atmospheric Sciences Nanjing UniversityNanjing 210093China Center for Analysis and Prediction of Storms and School of Meteorology University of Oklahoma Norman Oklahoma 73072USA

During 19–21 July 2021,an extreme rainfall event occurred in Henan Province,China,during which a recordbreaking maximum hourly rainfall of 201.9 mm was recorded in Zhengzhou at 09 UTC July *** this study,the predictability of this extreme rainfall event is investigated using two convection-permitting ensemble forecast systems(CEFSs):one initialized from NCEP GEFS(named CEFS_GEFS)and the other initialized from time-lagged ERA5 data(named CEFS_ERA).Both are able to reproduce the daily heavy rainfall along the Taihang Mountains,but most members have significant position biases for the extreme rainfall in *** the hourly rainfall,a few members are able to capture the evolution and propagation of extreme ***,all ensemble members underestimate the extreme hourly rainfall and have position errors of a few tens to a few hundreds of *** results suggest that the predictability of the extreme hourly rainfall at the accuracy of city scale in Zhengzhou is low,especially by deterministic forecasting models,and the occurrence of the extreme requires many favorable conditions to happen *** terms of the Brier score,CEFS_GEFS performs better than CEFS_*** latter lacks spread,especially in regions with scarce rain,resulting in less dispersion in precipitation distributions and larger probability forecast *** a neighborhood is applied,the probability of precipitation(POP)is significantly increased over *** the traditional POP shows almost no skill for hourly rainfall≥25 mm h-1,the neighborhood POP significantly improves the forecast skill score,for both daily and hourly rainfall,suggesting higher predictability when spatial error among the ensemble members is allowed.

关键词： Convective-permitting ensemble forecasts Neighborhood precipitation probability Extreme rainfall

In situ observation of the effect of Al N particles on bainitic transformation in a carbide-free medium carbon steel

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2020年第5期27卷 620-629页

作者： Xiao-jie Zhao Zhi-nan yang Fu-cheng Zhang State Key Laboratory of Metastable Materials Science and Technology Yanshan UniversityQinhuangdao 066004China National Engineering Research Center for Equipment and Technology of Cold Strip Rolling Yanshan UniversityQinhuangdao 066004China

The bainitic transformation of the steels with different mass fractions of N, ~0.002% and 0.021%, was observed in situ by using high-temperature metalloscope. Micrometer-and nanometer-sized aluminum nitride(AlN) particles were found in the steel with 0.021% *** boundaries, the interior of the grains, and Al N particles were used as initial nucleation sites of bainitic ferrite, and bainitic ferrite subunits served as new nucleation sites to induce secondary nucleation. The lengthening rate of bainitic ferrite varied at different nucleation sites, which was controlled by the repeated nucleation and growth of bainitic subunits. The Al N particles not only provided several nucleation sites, but also increased the autocatalytic effect on the transformation, further shortening the incubation period, promoting the bainitic transformation, and refining the bainitic microstructure.

关键词： bainitic steel In situ observation phase transformation aluminum nitride

Understanding Contact Electrification at Water/Polymer Interface

在线全文

学校读者我要写书评

暂无评论

Research 2022年第2期2022卷 323-332页

作者： yang nan Jiajia Shao Morten Willatzen Zhong Lin Wang Bijing Institute of nanocenergy and nantosystems Chinese Academny of SciencesBeijing 101400China School of nanosience and Techmology University of Chinese Academy of SciencesBeiing 100049China CUSTech Instiute WenzhouZhejiang 325024China School of Materials Science and Enginering Georgia Institute of TcnologrAtlantaGreorgia 30332-0245USA

Contact electrifcation(CE)involves a complex interplay of physical interactions in realistic material *** this reason,scientific consensus on the qualitative and quantitative importance of different physical mechanisms on CE remains a formidable *** CE mechanism at a water/polymer interface is a crucial challenge owing to the poor understanding of charge transfer at the atomic ***-principle density functional theory(DFT),used in the present work,proposes a new paradigm to address CE Our results indicate that CE fllows the same trend as the gap between the highest occupied and lowest unoccupied molecular orbitals(HOMO and LUMO)of *** transfer occurs at the outmost atomic layer of the water/polymer interface and is closely linked to the functional groups and atom *** the polymer chains are parallel to the water layer,most electrons are transferred;conversely,if they are perpendicular to each other,the transfer of charges can be *** demonstrate that a decrease in the inerface distance between water and the polymer chains leads to CE in quantitative agreement with the electron cloud overlap model.W'e finally use DFT calculations to predict the properies of CE materials and their potential for triboeletric nanogenerator energy harvesting devices.

关键词： occupied chains polymer