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    题名 作者 年代 出处 被引量
1Precise Modifications of Both Exogenous and Endogenous Genes in Rice by Prime Editing显示文摘Dear Editor,Harnessing genetic diversity and the introduction of elite alleles from wild relatives or landraces into commercial cultivars has been a major goal in crop breeding programs.Precise modification of the plant genome through clustered regularly interspaced short palindromic repeat(CRISPR)/CRISPR-associated protein(Cas)(CRISPR/Cas)-mediated homology-directed repair(HDR)offers a great promise to introduce elite alleles from wild relatives or landraces into commercialized cultivars in the short term.Huiyuan Li Jingying Li Jilin Chen Lei Yan Lanqin Xia 2020Molecular Plant2020,13,5:30
2Super-hydrophobic characteristics of butterfly wing surface显示文摘Many biological surface are hydrophobic because of their complicated composition and surface microstructure. Eleven species (four families) of butterflies were selected to study their micro-, nano-structure and super-hydrophobic characteristic by means of Confocal Light Microscopy, Scanning Electron Microscopy and Contact Angle Measurement. The contact an- gles of water droplets on the butterfly wing surface were consistently measured to be about 150 ? and 100 ? with and without the squamas, respectively. The dust on the surface can be easily cleaned by moving spherical droplets when the inclining angle is larger than 3 ?. It can be concluded that the butterfly wing surface possess a super-hydrophobic, water-repellent, self-cleaning, or “Lotus-effect”characteristic. The contact angle measurement of water droplets on the wing surface with and without the squamas showed that the water-repellent characteristic is a consequence of the microstructure of the squamas. Each water droplet (diameter 2 mm) can cover about 700 squamas with a size of 40 m×80 m of each squama. The regular riblets with a width of 1000 nm to 1500 nm are clearly observed on each single squama. Such nanostructure should play a very important role in their super-hydrophobic and self-cleaning characteristic.CONG Qian, CHEN Guang-hua, FANGYan , REN Lu-quan Key Laboratory for Terrain-Machine Bionics Engineering (Ministry of Education, China), Jilin University, Changchun, 130022, P. R. China 1 2004Journal of Bionic Engineering2004,1,4:24
3Toward Precision Genome Editing in Crop Plants显示文摘Precision genome editing through homology-directed repair(HDR)in plants remains very challenging due to the innately low occurrence of HDR and obstacles in the delivery of sufficient donor repair template(DRT)into plant cells.For single-base substitution,cytidine or adenine base editors have been used successfully in crop plants in recent years.However,base editing is constrained by the distance between the targeted base and PAM motif and cannot install predefined transversion mutations or insertions and deletions(indels).Here,we briefly summarize the strategies reported so far for precision genome editing in plants.Based on the recently developed prime editing strategy,which enables gene replacement without double-strand breaks(DSBs)or DRT in both human cells and plants,we provide our perspectives on exploiting diverse strategies to achieve precise targeted gene/allele replacement toward crop improvement and resilience for sustainable agricultural development.Jingying Li Huiyuan Li Jilin Chen Lei Yan Lanqin Xia 2020Molecular Plant2020,13,6:13
4Effect of Zr modification on solidification behavior and mechanical properties of Mg–Y–RE (WE54) alloy显示文摘Magnesium alloys containing rare earth elements (RE) have received considerable attention in recent years due to their high mechanical strength and good heat-resisting performance. Among them, Mg–5%Y–4%RE (WE54) magnesium alloy is a high strength sand casting magnesium alloy for use at temperatures up to 300 ℃, which is of great interest to engineers in the aerospace industry. In the present work, the solidification behavior of Zr-containing WE54 alloy and Zr-free alloy was investigated by computer-aided cooling curve analysis (CA-CCA) technique. And the solidification microstructure and mechanical properties of them were also investigated comparatively. It is found from the cooling curves and as-cast microstructure of WE54 alloy that the nucleation temperature of α-Mg in WE54 alloy increases after Zr addition, and the as-cast microstructure of the alloy is significantly refined by Zr. While the phase constitution of WE54 alloy is not changed after Zr addition. These phenomena indicate that Zr acts as heterogeneous nuclei during the solidification of WE54 alloy. Due to refined microstructure, the mechanical properties of Zr-containing WE54 alloy is much higher than Zr-free WE54 alloy.Jilin Li Rongshi Chen Yuequn Ma Wei Ke 2013Journal of Magnesium and Alloys2013,1,4:13
5Geologic investigation and mapping of the Sinus Iridum quadrangle from Clementine, SELENE, and Chang’e-1 data显示文摘The objectives of lunar satellite remote sensing are to study lunar surface characteristics, inner structure, and its evolution history. The contents of TiO 2 and FeO are assessed from Clementine UV/VIS data for Sinus Iridum. The geologic stratigraphic units and crates are interpreted visually based on SELENE Terrain Camera (TC) images and the spatial resolution of which is up to 10 m. And the geologic ages of different stratigraphic units are calculated by the crater size-frequency distributions measurements. The gravity anomaly is generated from SELENE gravity model (SGM90d) to show its difference from Mare Imbrium. Furthermore, the thickness of lunar regolith is also derived from microwave radiometer data of Chang’e-1 satellite. Integrating these results, it shows that the Sinus Iridum is different from the Mare Imbrium in inner structure and surface sedimentation. And its history of subsidence, deposition, volcanism, and impact is described. It makes sense to the future soft-landing and sampling at potential Sinus Iridum by remote sensing geologic analysis.CHEN ShengBo , MENG ZhiGuo, CUI TengFei, LIAN Yi, WANG JingRan & ZHANG XuQing College of Geoexploration Science and Technology, Jilin University, Changchun 130026, China 2010Science China(Physics,Mechanics & Astronomy)2010,53,12:10
6Sliding resistance of plates with bionic bumpy surface against soil显示文摘The non-smooth surface morphology of dung beetle, Copris ochus, was analyzed. The bulldozing plates with bionic geometric non-smooth or the chemical uneven surface were designed for the soil sliding test based on the simulation of the bumpy surface of the dung beetle. Special black metals— with different contents of alloys of manganese, silicon, chromium, copper and rare earth— were developed for making geometric non-smooth and chemical uneven surfaces by means of surface welding at the surfaces of a middle carbon steel plate. Four metals, with different surface properties including hardness and water contact angle were used to make the bulldozing plates for measuring the soil sliding resistance. Test results of soil sliding resistance indicate that all the geometric non-smooth plates and the chemical uneven plates reducing soil friction. Considering the materials and surface morphology, the bionic plate can reduce the soil sliding resistance from 18.1 % up to 42.2%, compared to the traditional smooth bulldozing plate made from middle carbon steel. The test results also show that the smaller the normal load, the greater effect on resistance reduction by the bionic non-smooth surface plates.LI Jian-qiao1, SUN Jiu-rong2, REN Lu-quan1, CHEN Bing-cong1 1. Key Laboratory for Terrain-Machine Bionics Engineering (Ministry of Education, China), Jilin University, Changchun 130022, P. R. China 2. College of Life Science, Peking University, Beijing 100871, P. R. China 1 2004Journal of Bionic Engineering2004,1,4:9
7Characterization and Prediction of Microporosity Defect in Sand Cast WE54 Alloy Castings显示文摘In order to study the effect of Zr modification and riser size on microporosity defect distributions in WE54 alloy sand castings,the microporosity volume percentage in Zr-free and Zr-containing WE54 alloy plate castings was determined by density measurement based on Archimedes' principle,and the microstructure of the microporosity defects was observed by optical microscopy and scanning electron microscopy.Then by using Procast software,the Niyama criterion was calculated in order to investigate the validity of Niyama criterion on prediction of microporosity defects in WE54 alloy sand castings.It is found from the density measurement results that Zr addition does not affect the microporosity distributions in WE54 alloy castings.While the distribution area of microporosity defect in the plate castings decreases significantly as the riser size increases.Based on the experimental results,a riser selection principle for production of compact WE54 alloy castings is proposed that the solidification modulus of the riser should be greater than that of the casting by 30%,simply m_r > 1.3m_c.By comparing the experimental and simulating results,it is found that the predicted microporosity regions by Niyama criterion agrees well with experimental results,and a critical Niyama value of0.4 ℃^(0.5) s^(0.5) mm^(-1) is suggested for prediction of microporosity formation in WE54 alloy sand castings.Jilin Li Rongshi Chen Yuequn Ma Wei Ke 2014Journal of Materials Science & Technology2014,30,10:9
8Hot Tearing of Sand Cast Mg-5 wt.% Y-4 wt.% RE (WE54) Alloy显示文摘Hot tearing is a common and severe defect occurring during solidification of castings.The rational understanding of hot tearing formation mechanism is beneficial to the foundry process design.In the present research,a new developed instrumented'CRC'equipment was applied in characterization of hot tearing in sand cast Mg-5 wt.%Y-4 wt.%RE(WE54)alloy with and without Zr addition.Microstructure observation and thermal analysis were carried out to help analyzing the results.The results showed that hot tearing onset occurs at a relatively low solid fraction(fs)in WE54 alloy sand castings,which indicates the participation of remaining liquid during hot tearing formation.Microstructure observation of the hot tearing surface also proves the liquid film existence between solidifying dendrites.The contraction strain caused by casting solidification induces the flowing of remaining liquid between solidifying dendrites and results in formation of interdendritic liquid films.These liquid films are separated by sufcient contraction stress and form hot cracks.The addition of Zr in WE54 alloy significantly refines the alloy microstructure and increases the solid fraction at hot tearing onset,both of which result in increasing of the fracture stress of interdendritic liquid film.Thus the hot tearing susceptibility of WE54 alloy is weakened by Zr addition.Jilin LI Rongshi CHEN Yuequn MA Wei KE 2013Acta Metallurgica Sinica(English Letters)2013,26,6:9
9LICOM Model Datasets for the CMIP6 Ocean Model Intercomparison Project显示文摘The datasets of two Ocean Model Intercomparison Project(OMIP)simulation experiments from the LASG/IAP Climate Ocean Model,version 3(LICOM3),forced by two different sets of atmospheric surface data,are described in this paper.The experiment forced by CORE-II(Co-ordinated Ocean–Ice Reference Experiments,Phase II)data(1948–2009)is called OMIP1,and that forced by JRA55-do(surface dataset for driving ocean–sea-ice models based on Japanese 55-year atmospheric reanalysis)data(1958–2018)is called OMIP2.First,the improvement of LICOM from CMIP5 to CMIP6 and the configurations of the two experiments are described.Second,the basic performances of the two experiments are validated using the climatological-mean and interannual time scales from observation.We find that the mean states,interannual variabilities,and long-term linear trends can be reproduced well by the two experiments.The differences between the two datasets are also discussed.Finally,the usage of these data is described.These datasets are helpful toward understanding the origin system bias of the fully coupled model.Pengfei LIN Zhipeng YU Hailong LIU Yongqiang YU Yiwen LI Jirong JIANG Wei XUE Kangjun CHEN Qian YANG Bowen ZHAO Jilin WEI Mengrong DING Zhikuo SUN Yaqi WANG Yao MENG Weipeng ZHENG Jinfeng MA 2020Advances in Atmospheric Sciences2020,37,3:9
10The Effect of Tide on the Global Climate Change显示文摘The differential rotation between the solid and fluid spheres caused by tidal force could explain the 1500 to 1800-year cycle of the world's temperature. Strong tide increases the vertical and horizontal mixing of water in the oceans, drawing the cold Pacific water from the depths to the surface and the warm water from the west to the east, where it cools or warms the atmosphere above, absorbs or releases CO2 to decrease or increase greenhouse effect and to make La Nina or El Nino occur in the global. The moon's declination and obliquity of the ecliptic affect the tidal intensity. The exchange of tidal energy and tide-generating force caused by the sun, moon and major planets makes the earth's layers rotate in different speeds. The differenti-al rotation between solid and fluid of the earth is the basic reason for El Nino and global climate change.YANG Xuexiang, CHEN Zhen and CHEN Dianyou( College of Ceo - exploration Science and Technology, Jilin University, Changchun 130026, P. R. China)Qiao Qiyuan(National Astronomical Observatory, Chinese Academy of Science, Beijing 100012, P. R. China) 2002Global Geology2002,7,1:7
11Factors impacting nanoindentation testing results of the cuticle of dung beetle Copris ochus Motschulsky显示文摘The cuticle of dung beetle is a layered composite material in micro- or nano-scale. Dung beetle can fly, walk and dig. It can shovel and compact dung of mammals into balls. It use foreleg to walk, midleg and hindleg to hold and impel dung ball. Its two foreleges as digging legs are developed. The factors impacting the nanoindentation testing results of the femur cuticle of forelegs of dung beetle Copris ochus Motschulsky were examined. The nanomechanical test instrument used for the tests was Hysitron nanomechanical system. The results shown that the holding time and loading time are important factors im- pacting the accuracy of such indentation properties as reduced modulus (Er) and the harness ( H ) of the femur cuticle of the forelegs of dung beetle Copris ochus Motschulsky in nanoscale. There exists a threshold holding time of 20 s for the reduced modulus of the femur cuticle. The tests of nanoindentation creep property and the regression analysis of relationship between the depth increment at the maximum load and the time further confirmed the correction of the above threshold holding time. There exist visco-elastic-plastic behaviour and creep phenomenon in the femur cuticle during indenting. Its creep property during the holding procedure at maximum load can be regressed by a general logarithmic equation. The equation fitted by the testing data is ? h = 54.83452 ln(0.00723t +1.00486), where, ? h is the depth increment at the maximum load and t is the time.TONG Jin , SUN Ji-yu , CHEN Dong-hui , ZHANG Shu-jun 1 1 1 2 1. Key Laboratory for Terrain-Machine Bionics Engineering (Ministry of Education, China), Jilin University, 5988 Renmin Street, Changchun 130022, P. R. China 2. Department of Multi-media and Computing, University of Gloucestershire, Cheltenham, The Park, GL50 2QF, UK. 1 2004Journal of Bionic Engineering2004,1,4:7
12Characterization of 500 Chinese patients with cervical esophageal cancer by clinicopathological and treatment outcomes显示文摘Objective: There are no comprehensive studies on survival outcomes and optimal treatment protocols for cervical esophageal cancer(CEC), due to its rare clinical prevalence. Our objective was to determine the relationship between pathological characteristics, treatment protocols, and survival outcomes in Chinese CEC patients.Methods: A total of 500 Chinese CEC patients were selected from our 500,000 esophageal and gastric cardia carcinoma database(1973–2018). There were two main groups: patients treated with surgery, and patients receiving non-surgical treatments(radiotherapy, radiochemotherapy, and chemotherapy). The Chi-square test and Kaplan–Meier method were used to compare the continuous variables and survival.Results: Among the 500 CEC patients, 278(55.6%) were male, and the median age was 60.9 ± 9.4 years. A total of 496 patients(99.2%) were diagnosed with squamous cell carcinoma. In 171(34.2%) patients who received surgery, 22(12.9%) had undergone laryngectomy. In 322(64.4%) patients who received non-surgical treatments, 245(76.1%) received radiotherapy. Stratified survival analysis showed that only T stage was related with survival outcomes for CEC patients in the surgical group, and the outcomes between laryngectomy and non-laryngectomy patients were similar. It was noteworthy that the 5-year survival rate was similar in CEC patients among the different groups treated with surgery, radiotherapy, chemotherapy, or radiochemotherapy(P = 0.244). Conclusions: The CEC patients had similar survival outcomes after curative esophagectomy and radiotherapy, including those with or without total laryngectomy. These findings suggest that radiotherapy could be the initial choice for treatment of Chinese CEC patients.Peinan Chen Xueke Zhao Fuyou Zhou Xin Song Shoujia Hu Yan Jin Xianzeng Wang Xuena Han ZongminFan Ran Wang Bei Li Wenli Han Panpan Wang Jilin Li Lixin Wan Liguo Zhang Qide Bao Fubao Chang Yanru Qin Zhiwei Chang Jianwei Ku Haijun Yang Ling Yuan Jingli Ren Xuemin Li Lidong Wang 2020Cancer Biology & Medicine2020,17,1:6
13Microbiota in health and diseases显示文摘The role of microbiota in health and diseases is being highlighted by numerous studies since its discovery.Depending on the localized regions,microbiota can be classified into gut,oral,respiratory,and skin microbiota.The microbial communities are in symbiosis with the host,contributing to homeostasis and regulating immune function.However,microbiota dysbiosis can lead to dysregulation of bodily functions and diseases including cardiovascular diseases(CVDs),cancers,respiratory diseases.Kaijian Hou Zhuo-Xun Wu Xuan-Yu Chen Jing-Quan Wang Dongya Zhang Chuanxing Xiao Dan Zhu Jagadish B.Koya Liuya Wei Jilin Li Zhe-Sheng Chen 2022Signal Transduction and Targeted Therapy2022,7,5:6
14Long-term protection effects of national reserve to forest vegetation in 4 decades: biodiversity change analysis of major forest types in Changbai Mountain Nature Reserve, China显示文摘The Changbai Mountain Nature Reserve (CNR) was established in 1960 to protect the virgin Korean pine mixed hardwood forest, a typical temperate forest of northeast China. We conducted systematic stud- ies of vascular diversity patterns on the north slope of the CNR mountainside forests (800-1700 m a.s.l.) in 1963 and 2006 respectively. The aim of this comparison is to assess the long-term effects of the protection on plant biodiversity of CNR during the interval 43 years. The research was carried out in three types of forests: mixed coniferous and broad-leaved forest (MCBF), mixed coniferous forest (MCF), and sub-alpine coniferous forest (SCF), characterized by different dominant species. The alpha diversity indicted by species richness and the Shannon-Wiener index were found different in the same elevations and forest types during the 43-year interval. The floral composition and the diversity of vascular species were generally similar along altitudinal gradients before and after the 43-year interval, but some substantial changes were evident with the altitude gradient. In the tree layers, the dominant species in 2006 were similar to those of 1963, though diversity declined with altitude. The indices in the three forest types did not differ significantly between 1963 and 2006, and these values even increased in the MCBF and MCF from 1963 to 2006. However, originally dominant species, P. koraiensis for ex- ample, tended to decline, while the proportion of broad-leaved trees increased, and the species turn- over in the succession layers trended to shift to higher altitudes. The diversity pattern of the under canopy fluctuated along the altitudinal gradient due to micro-environmental variations. Comparison of the alpha diversity in the three forests shows that the diversity of the shrub and herb layer decreased with time. During the process of survey, we also found some rare and medicinal species disappeared. Analysis indicates that the changes of the diversity pattern in this region are caused by both nature and human factors. Meteorological records revealed that climate has changed significantly in the past 43 years. We also found the most severe human disturbance to the CNR forests in the process of another field survey that is the exploitation of herb medicines and Korean pine nuts. We hope this research would give some guidance to the future reserve management in Changbai Mountain area.BAI Fan1, SANG WeiGuo1, LI GuangQi1, LIU RuiGang1, CHEN LingZhi1 & WANG Kun2 1 State Key Laboratory of Vegetation and Environment Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China 2 Nature Reserve Bureau of Changbaishan, Jilin 210011, China 2008Science China(Life Sciences)2008,51,10:5
15Sodium Citrate: A Universal Reducing Agent for Reduction/ Decoration of Graphene Oxide with Au Nanoparticles显示文摘一个灵巧的方法为减少的 graphene 氧化物 nanosheets (RGONS ) 的合成被建议,使用 graphene 氧化物并且 Au 减少 nanoparticle 的 graphene 氧化物 nanosheet (Au-RGONS ) 混血儿材料(去) 作为先锋和钠柠檬酸盐作为 reductant 和 stabilizer。产生 RGONS 和 Au-RGONS 混血儿材料被紫外力的光谱学描绘, X 光检查光电子光谱学, Fourier 变换红外线的光谱学,拉曼光谱学,原子力量显微镜学,传播电子显微镜学,和 X 光检查衍射。RGONS 和 Au-RGONS 混血儿材料通过在剩余之间的氢契约形成了稳定的胶体的分散,这被发现 RGONS 的表面和钠柠檬酸盐的 hydroxyl/carboxyl 组上的包含氧的功能。到三种 biomolecules 的 RGONS 和 Au-RGONS 混合的修改材料的玻璃质的碳电极(GCE ) 的电气化学的回答被调查,并且所有相对赤裸的 GCE 在电气化学的性能他们显示出显著增加。Zhe Zhang Huihui Chen Chunyan Xing Mingyi Guo Fugang Xu Xiaodan Wang Hermann J. Gruber Bailin Zhang Jilin Tang 2011Nano Research2011,4,6:5
16Research on water ice content in Cabeus crater using the data from the microwave radiometer onboard Chang’e-1 satellite显示文摘The existence, formation and content of water ice in the lunar permanently shaded region is one of the important questions for the current Moon study. On October 9, 2009, the LCROSS mission spacecraft impacted the Moon, and the initial result verified the existence of water on the Moon. But the study on formation and content of water ice is still under debate. The existence of water ice can change the dielectric constants of the lunar regolith, and a microwave radiometer is most sensitive to the dielectric parameters. Based on this, in this paper, the radiation transfer model is improved according to the simulation results in high frequency. Then the mixture dielectric constant models, including Odelevsky model, Wagner and landau-Lifshitz model, Clau-sius model, Gruggeman-Hanai model, etc., are analyzed and compared. The analyzing results indicate that the biggest difference occurs between Lichtenecker model and the improved Dobson model. The values estimated by refractive model are the second biggest in all the models. And the results from Odelevsky model, strong fluctuation model, Wagner and Landau –Lifshitz model, Clausius model and Bruggeman-Hanai model are very near to each other. Thereafter, the relation between volume water ice content and microwave brightness temperature is constructed with Odelevsky mixing dielectric model and the improved radiative transfer simulation, and the volume water ice content in Cabeus crater is retrieved with the data from microwave radiometer onboard Chang’e-1 satellite. The results present that the improved radiative transfer model is proper for the brightness temperature simulation of the one infinite regolith layer in high frequency. The brightness temperature in Cabeus crater is 69.93 K (37 GHz), and the corresponding volume water ice content is about 2.8%.MENG ZhiGuo 1 , CHEN ShengBo 1* , Edward Matthew OSEI Jnr 2 , WANG ZiJun 1 & CUI TengFei 1 1 College of Geoexploration Science and Technology, Jilin University, Changchun 130026, China 2 Department of Geomatic Engineering, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana 2010Science China(Physics,Mechanics & Astronomy)2010,53,12:4
17Purification and Properties of Superoxide Dismutase(SOD) in Allium Sativum显示文摘Superoxide dismutases(SODs) were purified to homogeneity from Allium Sativum by means of ammonium sulfate precipitation and column chromatography with DEAE-cellulose(DE52) and Sephadex G-75. Based on sodium dodecyl sulfate\|polyacrylamide gel electrophoresis(SDS-AGE), Allium Sativum is predicted to contain four SODs. The molecular weights of the native SODs are 41 3 kD, 37 0 kD, 35 2 kD and 31 0 kD, which consist of subunits of 20 7 kD, 18 4 kD, 17 7 kD and 15 4 kD respectively. Because of their specific sensitivity to hydrogen peroxide, cyanogens potassium and chloroform\|alcohol, the SODs in Allium Sativum appear to be Cu, Zn-SOD isoenzymes. The isoelectric analysis indicates that three of the four isoenzymes are acidic proteins with isoelectric points at pH 3 5, 3 7 and 4 0, respectively, and the fourth one is a basic protein with isoeletric point at pH 8 5.TENG Li-rong, WANG Ya-jun, WU Min, HONG Shui-sheng, CHEN Jia Meng Qing-fan and LIU Lan-ying ** College of Life Science, Jilin University, Changchun 130023, P. R. China 2003Chemical Research in Chinese Universities2003,19,4:3
18Nonlinear analysis on the coupling process of electromagnetic vibrator and earth显示文摘The linear model based on the hydraulic pressure vibrator has been no longer adaptable to the electromagnetic vibrator. In order to realize the effective transmission of the limited energy from the vibrator to the ground, it is important to study the coupling model of the electromagnetic vibrator and the earth. In this paper, a nonlinear restore term was introduced to the coupling model because of the existence of a large amount of harmonics in the vibrator baseplate. The nonlinear vibration analysis was applied to the model by the multiscale method. In the course of energy transmission from the vibrator to the ground, ultraharmonic resonance was used to explain the generation of harmonics. An improved scheme was advanced to select the cross correlation reference signal in the vibrator seismic exploration. Good application results were obtained in field experiments.CHEN Zubin1,2, TENG Jiwen2, LIN Jun1, ZHANG Linhang1 & JIANG Zhongjin1 1. Institute of Intelligent Instrument & Measurement Control Technology, Jilin University, Changchun 130026, China 2. Institute of Geology & Geophysics, Chinese Academy of Sciences, Beijing 100029, China 2005Science China Earth Sciences2005,48,8:3
19Study on the technology for highway construction and engineering practices in permafrost regions显示文摘In order to systemically summarize and integrate technology of highway construction in permafrost regions on the Qinghai-Tibet Plateau,we studied disciplines and mechanisms of formation and development of problems and challenges in highway engineer-ing in high-altitude permafrost regions based on construction experiences for 50 years and on 30 years of research regarding the Qinghai-Tibet and Xikang highways.Embankments,pavements,bridges,and countermeasures for ecosystem protection in per-mafrost regions were the main study objects.We combined extensive analysis of key problems of engineering stability with inter-action between permafrost and highways,theoretical models,indoor tests,and field tests to reveal the interaction between em-bankments,pavements,bridge piles,and permafrost.In this paper,we propose a series of engineering measures for highway sta-bility,design parameters,key indexes for pavement durability in low temperature,relationships between re-freezing time of bridge-pile foundation and strength development as well as ecosystem recovery in high-latitude cold regions;these eventually form a construction technology package for permafrost regions.ShuangJie Wang JianBing Chen JiLin Qi 2009Research in Cold and Arid Regions2009,1,5:3
20Effect of Thermal Fatigue Loading on Tensile Behavior of H13 Die Steel with Biomimetic Surface显示文摘Biomimetic surface is an effective ways to promote the performance grade and applied range of materials without alteringtheir substrate.Many improved properties such as resisting fatigue,enduring wear,etc,have been achieved by applyingbiomimetic morphology or structure to some engineering material surfaces.In this paper,aiming to reveal the relationshipbetween thermal cracking behavior and mechanical properties of engineering materials with biomimetic surface,biomimeticspecimens were fabricated using laser technique by imitating the heterogeneous structure on the surface of plant leaves.Theeffect of thermal fatigue cycling on the tensile properties of H13 die steel specimens with different surfaces (several types ofbiomimetic surfaces and a smooth surface) was compared and investigated.As a result,due to the coupling effects of themorphological features on the surface and the microstructure characteristics within unit zone,these specimens with biomimeticsurface exhibit remarkably enhanced Ultimate Tensile Strength (UTS) and 0.2% Yield Strength (YS) compared with referencespecimens while corresponding ductility remains largely unaffected even heightened,whether the thermal fatigue loads or not.The relative mechanisms leading to these improvements have been discussed.Zhihui Zhang~1,Luquan Ren~1,Hong Zhou~2,Zhiwu Han~1,Xin Tong~3,Yu Zhao~1,Li Chen~1 1.Key Laboratory of Bionic Engineering (Ministry of Education,China),Jilin University,Changchun 130022,P.R.China 2.Key Laboratory of Automobile Materials (Ministry of Education,China),Jilin University,Changchun 130022,P.R.China 3.The Department of Materials Surface Engineering,Guangzhou Research Institute of Non-Ferrous Metals,Guangzhou 510651,P.R.China 2010Journal of Bionic Engineering2010,7,4:3
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