中国科学院机构知识库网格系统: 检索

Set-up effect of large-diameter open-ended thin-walled pipe piles driven in clay 期刊论文 OAI收割
COMPUTERS AND GEOTECHNICS, 2023, 卷号: 159
作者: Qin, Wei; Gao, Jiayu; Chang, Kuntan; Dai, Guoliang; Wei, Houzhen

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收藏 | 浏览/下载：19/0 | 提交时间：2023/08/02

Large -diameter open-ended thin -wall steel pipe piles Pore water pressure distribution Excess pore water pressure dissipation Bearing capacity Set-up effect

A corrected p-y curve model for large-diameter pile foundation of offshore wind turbine 期刊论文 OAI收割
OCEAN ENGINEERING, 2023, 卷号: 273, 页码: 114012
作者: Zhang, Xiao-ling; Zhou, Rui; Zhang, Guo-liang; Han, Yan

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收藏 | 浏览/下载：10/0 | 提交时间：2024/01/04

Offshore wind turbine Large diameter pile Size effect P -y curve model The pile -soil interaction

Statistical size scaling of compressive strength of quasi-brittle materials incorporating specimen length-to-diameter ratio effect 期刊论文 OAI收割
THEORETICAL AND APPLIED FRACTURE MECHANICS, 2019, 卷号: 104, 页码: 9
作者: Lei WS; Qian GA(钱桂安); Yu ZS; Berto F

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收藏 | 浏览/下载：141/0 | 提交时间：2020/03/11

Unconfined compressive strength Quasi-brittle materials Statistical size scaling Volume effect Length-to-diameter ratio effect

Diameter Effects on Cytotoxicity of Multi-Walled Carbon Nanotubes 期刊论文 OAI收割
JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY, 2009, 卷号: 9, 期号: 5, 页码: 3025-3033
作者: Wang, X.; Jia, G.; Wang, H.; Nie, H.; Yan, L.

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收藏 | 浏览/下载：21/0 | 提交时间：2019/04/09

Cytotoxicity Alveolar Macrophages (Am) Diameter-effect Apoptosis Multi-walled Carbon Nanotubes (Mwnts)

Dome design and coupled thermal-mechanical analysis of supersonic missile (EI CONFERENCE) 会议论文 OAI收割
2009 International Conference on Optical Instruments and Technology, OIT 2009, October 19, 2009 - October 22, 2009, Shanghai, China
Xing-qiao A.; Qun W.; Hong-guang J.

收藏 | 浏览/下载：60/0 | 提交时间：2013/03/25

A review of high-speed flow pressure and aerodynamic heating effect on Supersonic missile's dome is given. The dome should have excellent properties in optical mechanical and chemical characteristics. A design of dome on supersonic mode is described according to tactical guide line of a missile. The dome made of quartz which is about 8mm thick and 141mm in window diameter. To check up the reliability of the dome a reasonable finite element model (FEM) of dome is established and a thermal-mechanical Analysis to the dome by finite element software NASTRAN has carried on through these can obtained the distribution of temperature field and stress field when the speed is 2.3Ma. The results indicated that the stress was concentrated in the joint of the dome end and the Missile Section and the maximum stress was 16.4Mpa. The stress of other nodes was smaller than the allowable stress of quartz glass. Reference to the results of the analysis a lightweight revision to the dome structural dimension and a new method of dome fixing have put forward which can reduce the stress concentration. 2009 SPIE.

The synthesis and field emission property of carbon nanotubes on carbon fibers substrate (EI CONFERENCE) 会议论文 OAI收割
Technical Digest of the 20th International Vacuum Nanoelectronics Conference, IVNC 07, July 8, 2008 - July 12, 2008, Chicago, IL, United states
Leyong Z.; Weibiao W.; Jingqiu L.; Yuxue X.; Da L.; Song C.; Haifeng Z.

收藏 | 浏览/下载：33/0 | 提交时间：2013/03/25

Using ferrocene as catalyst precursor C2H2 as carbon source carbon nanotubes (CNTs) with uniform density were synthesized on carbon fibers substrate by floating catalyst method. The morphology and microstructure were characterized by field emission scanning electron microscope (FESEM) and high-resolution transmission electron microscopy (HRTEM). The observation showed that the length of CNTs is about 2 m the average space between adjacent CNTs is about 300 nm and the diameter of CNT is about 45 nm. The less dense "short and stubby" aligned CNTs films should have good electron field emission characteristics. The results of field emission showed that the emission current of CNTs/carbon fibers was 5 A at the field of 2.5 V/m and the emission current can be 280 A with a field of 7 V/m (the specimen area is 0.25 cm2 and the distance between cathode and anode is 200 m). The calculation based on the F-N plot indicated that the field enhancement factor of CNTs tip is 499122. Using the conductivity and chemical stability of carbon fibers and the uniform and sparse density distribution of CNTs on carbon fibers substrate the tip predominance of carbon nanotubes can be exerted and simultaneously the effect of screening effects between adjacent carbon nanotubes on the field emission performance can also be effectively decreased. The CNTs synthesized on carbon fibers substrate has many predominances for the fabrication of cold cathode devices. For example using the removability of carbon fibers the cathode of CNTs/carbon fibers can be arbitrarily moved enlaced or combined to form different patterns and the cathode of CNTs/carbon fibers can be also fabricated in large size. Therefore CNTs/carbon fibers may have potential application in field emission displays.

Research on the support structure of the primary mirror of large-aperture telescope (EI CONFERENCE) 会议论文 OAI收割
3rd International Symposium on Advanced Optical Manufacturing and Testing Technologies, AOMATT 2007: Large Mirrors and Telescopes, July 8, 2007 - July 12, 2007, Chengdu, China
Yang W.; Jingxu Z.

收藏 | 浏览/下载：28/0 | 提交时间：2013/03/25

Large-aperture telescope can be used in surveying battlefield researching landform searching object real-time monitoring imaging detecting and identifying spatial targets and so on. A large-aperture telescope for achieving high resolution power is designed to monitor spatial target and image in real time. Real-time monitoring plays an important role in military conflicts. The orbit parameter of object quantity geometrical shape parameter and so on can be obtained by detect spatial target. With the development of optical technology people require larger aperture in optics-electronic (OE) system. By increasing optical aperture the ability of collecting light and resolution power in the system can be enhanced. But the support structure of the primary mirror of large-aperture telescope will be a very difficult problem. With the increase of primary mirror aperture the weight of the primary mirror will become larger than before. The root mean square (rms) of the primary mirror is affected by many factors such as deadweight deformation of heat environment and so on. Due to the primary mirror of telescope is an important component of telescope system. By reducing the weight of primary mirror precision of the system is ensured. During the designing phase one can consider the supporting project of the primary mirror synthetically and analyze it roundly according to technical requirement of optical system and the effect factors. The final structural design can be reasonable. In an astronomical telescope the surface of reflector is an important part for collecting dark radiation of celestial bodies. Its surface shape will have an effect on collecting efficiency of telescope radiant energy directly. So the rms must be very high. Optical system of large aperture small wavelength and small focus can receive maximal light intensity. For ground-based optical astronomical telescope the design proposed in the paper can satisfy the requirement of the possible minimum atmosphere seeing at astronomical observatory site and exert the use efficiency of the telescope adequately. So the accuracy of the traditional surface of reflector can assure that 90% of all the light energy can be focused on within the angle diameter range of the minimum atmosphere seeing then 100% of light energy should be focused on the angle diameter range of minimum atmosphere seeing. Because the rms of mirror is very high precise surface machining and accurate the support of mirror are very important tasks during designing and manufacturing the telescope. In the paper various support techniques of a large-aperture telescope primary mirror are discussed and a 3.5 meter telescope system at the Starfire Optical Range (SOR) overviewed simply which was operated by the Directed Energy Directorate of the Air Force Research Laboratory Kirtland AFB NM USA from the ground-based O-E system for the observations of spatial target. We also analyze Theoretical elastic deformation of the Steward Observatory 2.3 meter mirror is analyzed.

Lateral motion and departure of vapor bubbles in nucleate pool boiling on thin wires in microgravity 会议论文 OAI收割
5th International Conference on Fluid Mechanics, Shanghai, PEOPLES R CHINA, AUG 15-19, 2007
作者:

收藏 | 浏览/下载：1433/98 | 提交时间：2009/07/23

Microgravity Nucleate Pool Boiling Lateral Motion Bubble Departure Diameter Marangoni Effect Heat-Transfer

High energy long duration frequency-doubled Nd:YAG laser and application to veins occlusion (EI CONFERENCE) 会议论文 OAI收割
High-Power Lasers and Applications III, November 8, 2004 - November 11, 2004, Beijing, China
作者: Li D.

收藏 | 浏览/下载：29/0 | 提交时间：2013/03/25

Laser treatment represents an attractive option to other methods of vessel diseases especially varicose veins. A long pulse (30-50ms) 532nm laser (Fig.1) is used in our experiments with the pulse duration matching the thermal relaxation time of the vessels and the green laser matching the absorption spectrum peak of the blood. Laser irradiates nude vein vessels directly or exterior skin to finish operation faster and to acquire the practical data for upper enteron varicose vein treatment in several animal experiments performed in vivo. The 5J-energy pulse allows us to finely occlude rabbit or dog's vein vessels up to 2 mm in diameter when irradiating them off external skin (Fig.2). Blood vessels are occluded at once and later biopsy specimens show the immediate and long-term lasting occlusion effect. While irradiating vessels directly (Fig.3) the vessels are usually irradiated to perforate detailed causes are still under investigation. Animal experiments show long pulse green laser therapy is a safe and effective solution to the vein's occlusion which promises such laser with high energy of each pulse and 30-50 ms duration is an ideal candidate for vessel diseases treatment.

Study on LD-pumped Nd:YAG laser cutter (EI CONFERENCE) 会议论文 OAI收割
ICO20: Lasers and Laser Technologies, August 21, 2005 - August 26, 2005, Changchun, China
作者: Zhang G.; Zhang G.; Zhang G.; Zhang J.; Zhang J.

收藏 | 浏览/下载：24/0 | 提交时间：2013/03/25

The theory of laser cutter and the technology neck is analyzed. We can conclude that it is almost impossible to deal with the waste thick silicon wafers which are yielded in producing silicon wafers by conventional eroding or diamond cutting when the cutting velocity equals 100mm/min while it is also unperfected with ecumenical laser cutter without good beam quality or precise laseroptics system. It is represented that high average power and high repetition rate laser with good beam quality and precise laseroptics system are pivotal to obtain excellent cutting effect such as thick groove depth double-layer 0.75mm thick silicon wafer can be penetrated.. The cross section is fine and the groove is narrow rapid cutting speed the cutting quality meets the expecting demand. fine kerf section without considering the effect of technique. Considering laser medium thermal lens effect and thermal focal length changing with pumping power using plano-convex high reflectivity mirror as the back cavity mirror to compensate the heat lens influence a /4 waveplate to compensate heat -induced birefraction utilize the Nd:YAG self- aperture effect more than 50 W average power 1.064 um IR output is obtained with beam quality factor (M2) equals 3.19. Through the LD-Pumped Nd:YAG laser cutter we developed with short focus length negative spherical aberration focusing lens double axis linear step motor positioning system suitable beam expander multiplying factor appropriate diameter of exit beam aperture proper repetition rate when the cutting velocity equals 400mm/min 0.75mm thick silicon wafer can be penetrated