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Science china(Technological {1.) 2005年第Z1期48卷 53-64页

作者： zhang.lei1,{1., liAN Zhenzhong1.{2., chinese academy of sciences, beij.ng.100080, china 2. Graduate School, chinese academy of sciences, beijing 1.0060, china institute of {1. Chinese Academy of Sciences Beijing 100080 China Graduate School Chinese Academy of Sciences Beijing 100060 China

This paper studies the effect of fissure water pressure in different fractures on the critical angle of landslide by laboratory investigation and numerical simulation in order to understand the mechanisms of fissure water pressure on landslide stability. Laboratory observations show that the effect of fissure water pressure on the critical angle of landslide is little when the distance between water-holding fracture and slope toe is three times greater than the depth of fissure water. These experimental results are also simulated by a three-dimensional face-to-face contact discrete element method. This method has included the fissure water pressure and can accurately calculate the critical angle of jointed slope when fissure water pressure in vertical sliding surface exists. Numerical results are in good agreement with experimental observations. It is revealed that the location of water-holding structural surface is important to landslide stability. The ratio of the distance between water-holding fissure and slope toe to the depth of fissure water is a key parameter to justify the effect of fissure water pressure on the critical angle of landslide.

关键词： jointed rock slope, discrete element method, fracture in vertical sliding surface, model experiment,fissure water pressure.

Stochastic structural model of rock and soil aggregates by continuum-based discrete element method

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Science china(Technological {1.) 2005年第Z1期48卷 95-106页

作者： wang yuannian1, ZHAO Manhong1, li {2. & J.G. wang2.. institute of mechanics, chinese academy of sciences, beij.ng.100080, china 2. Tropical Marine Science institute, National University of Singapore, 10 Kent Ridge Crescent, Singapore 1192.0 institute of {1. Chinese Academy of Sciences Beijing China Tröpical Marine Science institute National University of Singapore Singapore

This paper first presents a stochastic structural model to describe the random geometrical features of rock and soil aggregates. The stochastic structural model uses mixture ratio, rock size and rock shape to construct the microstructures of aggregates, and introduces two types of structural elements (block element and jointed element) and three types of material elements (rock element, soil element, and weaker jointed element) for this microstructure. Then, continuum-based discrete element method is used to study the deformation and failure mechanism of rock and soil aggregate through a series of loading tests. It is found that the stress-strain curve of rock and soil aggregates is nonlinear, and the failure is usually initialized from weaker jointed elements. Finally, some factors such as mixture ratio, rock size and rock shape are studied in detail. The numerical results are in good agreement with in situ test. Therefore, current model is effective for simulating the mechanical behaviors of rock and soil aggregates.

关键词： CDEM, rock and soil aggregate, mixture ratio.

Effect of rock mass structure and block size on the slope stability——Physical modeling and discrete element simulation

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Science china(Technological {1.) 2005年第Z1期48卷 1-17页

作者： li shihai1, liAN Zhenzhong1,2.& J. G. {2.3 1. {2. of mechanics, chinese academy of sciences, beij.ng.100080, china 2. Graduate School, chinese academy of sciences, beijing 100060, china 3. Tropical Marine Science {2., National University of Singapore, Singapore 1192.0 institute of {1. Chinese Academy of Sciences Beijing 100080 China Graduate School Chinese Academy of Sciences Beijing 100060 China Tropical Marine Science institute National University of Singapore Singapore 119260 Singapore

This paper studies the stability of jointed rock slopes by using our improved three-dimensional discrete element methods (DEM) and physical modeling. Results show that the DEM can simulate all failure modes of rock slopes with different joint configurations. The stress in each rock block is not homogeneous and blocks rotate in failure development. Failure modes depend on the configuration of joints. Toppling failure is observed for the slope with straight joints and sliding failure is observed for the slope with staged joints. The DEM results are also compared with those of limit equilibrium method (LEM). Without considering the joints in rock masses, the LEM predicts much higher factor of safety than physical modeling and DEM. The failure mode and factor of safety predicted by the DEM are in good agreement with laboratory tests for any jointed rock slope.

关键词： rock masses, slope stability, DEM simulation, block size effect, joints configuration effect, limit equilibrium method.

Exploring centimeter-sized crystals of bismuth-iodide perovskite toward highly sensitive X-ray detection

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chinese Chemical Letters 2024年第6期35卷 185-188页

作者： Xin Dong Jing liang Zhijin Xu Huajie Wu {1. wang {2. You Junhua Luo lina li College of Chemistry Fuzhou UniversityFuzhou 350116China State Key Laboratory of Structure Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China University of chinese academy of sciences Beijing 100049China

Lead-halide perovskites exhibit outstanding performance in X-ray detection due to their intrinsic features such as high charge carrier mobility,large atomic number,and long carrier lifetime,but the toxicity of lead is regarded as the major factor hindering their ***,we introduce organic molecule(R)-(-)-2.methylpiperazine(R-MPz)into the bismuth-based structure to synthesize lead-free(R)-(H_(2.MPz)BiI_(5)(R-MBI).The high-quality centimeter-sized single crystals have been obtained,which show a low dark current and superior environmental ***,the single-crystal device of R-MBI exhibits a highμτproduct up to 1.88×1.^(-4)cm^(2./V and a low trap density of 1.2.×1.^(1.)cm^(-3).Further,the detector displays excellent detection sensitivity of 2.3.58μC Gy_(air)^(-1.cm^(-2.and a favorable low detection limit of 4.35μGyair/s,both of which meet the requirement for medical *** findings shed light on the exploration of innovative bismuth-based hybrid perovskites for high-performance X-ray detection.

关键词： Perovskite Lead-free Bismuth-based X-ray detection Sensitivity

Experimental and discrete element numerical analysis of side slope instability induced by fissure water underlying impervious bed

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Science china(Technological {1.) 2005年第Z1期48卷 65-80页

作者： liU Bingshan1, li shihai1, zhang.lei1,{2. {2. Jianguo31. institute of mechanics, chinese academy of sciences, beij.ng.100080, china 2. Graduate School, chinese academy of sciences, beijing 100060, china 3. Tropical Marine Science institute, National University of Singapore, 10 Kent Ridge Crescent, Singapore 1192.0 institute of {1. Chinese Academy of Sciences Beijing 100080 China Graduate School Chinese Academy of Sciences Beijing 100060 China Tropical Marine Science institute National University of Singapore 10 Kent Ridge Crescent Singapore 119260 Singapore

When the sliding mass contains impervious bed, rainfall can infiltrate into mountain via crevices and form higher artesian aquifer at impervious bed inferior. This will decrease slip resistance and increase sliding forces of the sliding mass, thus lowering the safety factor, and inducing landslide disasters. In this paper, a landslide experimental apparatus is designed for experimental studies on the mechanism of this type of landslides. Meanwhile, the non-dimensional parameters in the model experiment are taken into account using dimensional analysis. The experimental results show that (1. the ratio of the cleft water pressure to the overlying pressure is a crucial parameter affecting the stability of the slope; (2. when the shut-in pressure reaches 80% of the normal component of the pressure on the slip surface made up of rock and soil, landslide will occur; (3) the whole slope will start to slide when the shut-in pressure is equal to the normal component of the pressure formed by the overlying rock and soil on the upper 30% area. In this article, a discrete element method simulation is used to investigate the influence of cleft water pressure and shearing strength on the landslide stability. It can be concluded that the critical value of Ccr, ?cr, which determines the slide mass stability, increases with the increase of the water pressure; if the water pressure reaches a high level, the stability of the slide mass depends mainly on C, while the influence of ? becomes smaller than C.

关键词： impervious bed, rainfall infiltration, pore water pressure, landslide experiment, displacement monitor, discrete element method.

Discovery of immune related factors in Fenneropenaeus chinensis by annotation of ESTs

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Progress in Natural Science:Materials International 2004年第1期14卷 48-55页

作者： SHEN Yaoqing 1,2. , XIAng Jianhai 1*, wang Bing 1,2. , li Fuhua 1 and TOng Wei 3(1. Experimental Marine Biology Laboratory, institute of Oceanology,{2., Qingdao 2.6071,china 2. Graduate School of the{2., beijing 100039, china 3. Genomics & Bioinformatics institute,{2., beijing 101300, china) chinese Acad Sci Inst Oceanol Expt Marine Biol Lab Qingdao 266071 Peoples R China chinese Acad Sci Grad Sch Beijing 100039 Peoples R China chinese Acad Sci Geonom & Bioinformat Inst Beijing 101300 Peoples R China

A total of 1.446 expressed sequence tags (ESTs) are obtained by a large scale sequencing of a cDNA library from cephalothorax of adult Fenneropenaeus chinensis . An EST analysis platform was built up based on local computers and bioinformatic techniques were used to annotate these ESTs in order to promptly find possible functional genes, especially for immune related factors. About 4% of the ESTs show similarity to the coding sequences of such factors, including lectin, serine protease, serpin, lysozyme, etc. These ESTs provide a partial profile of the immune system in F. chinensis and useful information for further study on these genes.

关键词： Fenneropenaeus chinensis bioinformatics ESTs immune factors

light-driven sextuple theranostics:nanomedicine involving second near-infrared AIE-active Ir(Ⅲ)complex for prominent cancer treatment

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Science china Chemistry 2024年第7期67卷 2314-2324页

作者： Xue liu Jiangao li Fei zhang Dingyuan Yan lei {2. Dong {2. Ben Zhong Tang Center for AIE Research Shenzhen Key Laboratory of Polymer Science and TechnologyGuangdong Research Center for Interfacial Engineering of Functional MaterialsCollege of Material Science and EngineeringShenzhen UniversityShenzhen 518060China College of Physics and Optoelectronic Engineering Shenzhen UniversityShenzhen 518060China School of Science and Engineering Shenzhen Institute of Aggregate Science and TechnologyThe Chinese University of Hong KongShenzhen(CUHK-Shenzhen)Shenzhen 518172China

light-driven cancer theranostics has shown inexhaustible and vigorous vitality by virtue of its high efficacy,prominent controllability and *** of an all-round theranostic material simultaneously affording both multimodal diagnosis imaging and synergistic phototherapy would be an appealing yet significantly challenging ***,a novel nanomedicine Ir@PPEG-MeEPO was ingeniously constructed by integrating beforehand1.2.charged amphiphilic polymer and well-tailored Ir(Ⅲ)complex IrDPTP,which was featured by second near-infrared(NIR-Ⅱ)aggregation-induced emission(AIE)tendency,efficient reactive oxygen species(ROS)generation,good photothermal conversion efficiency and high-performance hydrogen gas *** the best of our knowledge,IrDPTP held the longest emission wavelength among all reported AIE Ir(Ⅲ)***,Ir@PPEG-MeEPO was capable of controllably releasing ROS via triggered photothermal effect upon NIR irradiation,making it well-adapted to hypoxic environment of *** distinctive characteristics of Ir@PPEG-MeEPO endowed it with unprecedented performance on sextuple theranostics comprised of NIR-Ⅱfluorescence-photoacoustic-photothermal trimodal imaging and photodynamic-photothermal-hydrogen trimodal therapy,witnessed by the precise tumor diagnosis and complete tumor *** study would open up new perspectives for the exploration of superior nanomedicine for practical cancer theranostics.

关键词： aggregation-induced emission NIR-II emission cancer theranostics multimodal diagnosis imaging multimodal therapy

Generation of surface electrons in femtosecond laser-solid interactions

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Science china(Physics,{1. & Astronomy) 2006年第3期49卷 335-340页

作者： XU Miaohua1. li Yutong1. YUAN Xiaohui1.{1. ZHEng Zhiyuan1. liAng Wenxi1. YU Quanzhi1. zhang Yi1. wang Zhaohua1. WEI Zhiyi1.& zhang Jie1.1. Key Laboratory of Optical Physics, institute of Physics, chinese academy of sciences, beij.ng.100080, china {1. State Key Laboratory of Transient Optics Technology, chinese academy of sciences, Xi’an 71.068, china Key Laboratory of Optical Physics Institute of Physics Chinese Academy of Sciences Beijing China State Key Laboratory of Transient Optics Technology Chinese Academy of Sciences Xi’an China

The characteristics of hot electrons produced by p-polarized femtosecond laser-solid interactions are studied. The experimental results show that the outgoing electrons are mainly emitted in three directions: along the target surface, the normal direction and the laser backward direction. The electrons flowing along the target surface are due to the confinement of the electrostatic field and the surface magnetic field, while the electrons in the normal direction due to the resonant absorption.

关键词： hot electrons,surface magnetic field,femtosecond laser pulses

Morphologies of Fe-66.7 at.%Si alloy solidified in a drop tube

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Science china(Physics,{1. & Astronomy) 2005年第6期48卷 658-666页

作者： wang Haiyan1,2. liU Riping1, MA Mingzhen1, JIng Qin1, li Gong1, SUN liling2.& wang Wenkui1,2.1. Key Laboratory of Metastable Materials Science & Technology, Yanshan University, Qinhuangdao 066004,{2. 2. institute of Physics, chinese academy of sciences, beij.ng.100080,{2. Key Laboratory of Metastable Materials Science & Technology Yanshan University Qinhuangdao China institute of Physics Chinese Academy of Sciences Beijing China

Solidification of 0.1.1.0 mm diameter droplets of Fe-66.7 at.%Si alloy was achieved in a 3 m drop tube. The XRD, EDS, and SEM measurements reveal that all the droplets are composed of the primary phase α and the α+ε eutectic. With decreasing droplet diameter, the growth mode of the primary phase α changes from faceted to nonfaceted growth and the eutectic changes from needle-like to anomalous eutectic. In addition, the width of the primary phase α decreases with decreasing droplet size. The different cooling rates and undercooling levels corresponding to the samples with different sizes are responsible for the morphology changes. The cooling rates of the samples with different diameters during free fall were calculated and their effects on the microstructure formation were discussed. This kind of transition is also found inside the same sample, which is due to the larger cooling rate on the surface than at the center.

关键词： Fe-Si alloy, solidification, drop tube, undercooling.

Compression behavior of Zr_(41.Ti_(1.)Cu_(1.0}5)Ni_(1.)Be_(2..5) bulk metallic glass up to 2. GPa

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Science china(Physics,{1. & Astronomy) 2005年第3期48卷 319-324页

作者： li Gong 1, 2., ZHAN Zaiji 2., liU Jing 3 , YUN Jinku 1 , SUN liling 2., liU Riping 1 , zhang Jun 2.& {2. Wenkui 1, 2.1. Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004,{2. 2. Center for Condensed Matter Physics, institute of Physics, chinese academy of sciences, beij.ng.100080,{2. 3. BSRF, institute of High Energy Physics, chinese academy of sciences, beijing 100039,{2. Key Laboratory of Metastable Materials Science and Technology Yanshan University Qinhuangdao China Center for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences Beijing China BSRF Institute of High Energy Physics Chinese Academy of Sciences Beijing China

The compression of a Zr41.i1.Cu1.0}5Ni1.Be2..5 bulk metallic glass (BMG) is investigated at room temperature up to 2. GPa using in-situ high pressure energy dispersive X-ray diffraction with a synchrotron radiation source. The pressure-induced structural relaxation is exhibited. It is found that below about 8 GPa, the existence of excess free volume contributes to the rapid structural relaxation, which gives rise to the rapid volumetric change, and the structural relaxation results in the structural stiffness under higher pressure.

关键词： bulk metallic glass, high pressure, structural relaxation, synchrotron radiation.