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排序方式: 共有1156条查询结果,搜索用时 656 毫秒
1.
Eicosapentaenoic acid (EPA) production by an oleaginous fungus Mortierella alpina expressing heterologous the Δ17‐desaturase gene under ordinary temperature
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2.
研究开发出一种遥操作工程机器人系统,可以应用于诸如火灾现场的修复作业等广阔的领域.该系统由伺服控制的工程机器人、2根从远处操纵工程机器人的操纵杆、视频系统和6自由度运动模拟器组成.操作者坐于座椅上,座椅固定于运动模拟器的上方. 该系统需要解决的一个关键问题是如何使操纵者高质量地获得工作现场的临场运动感觉. 提出了一种6自由度临场运动感觉反馈方法,其信号源来自工程机器人上安装的6个加速度传感器. 该方法的有效性已为实验所证明,即应用6自由度运动模拟器不但可以高质量地模拟工程机器人单个自由度的运动:滚动、俯仰、转动以及前后、左右、上下的平移,而且可以高质量地模拟工程机器人的各种复合运动. 相似文献
3.
Mitsuho Yoshida Takako Sugiki Eiji ૿ sawa 《Fullerenes, Nanotubes and Carbon Nanostructures》1996,4(5):1019-1026
Application of our net algorithm to the generation of all possible IPR isomers for giant fullerenes Cn, n=102 to 120, missed nine out of 39,621 possible structures. Analysis revealed that the omission of too small and too large cap triangles was the reason. Within the range of fullerenes studied, the missed structures are of high-energy and do not affect the distribution of significantly low-energy isomers. 相似文献
4.
N Muto A Dota T Tanaka N Itoh M Okabe A Inada T Nakanishi K Tanaka 《Canadian Metallurgical Quarterly》1995,18(11):1576-1579
Hinokitiol, a constituent of the wood of Chamaecyparis taiwanensis, was found to induce differentiation of teratocarcinoma F9 cells. When examined by the agar-overlay method, in which expression of plasminogen activator as a differentiation marker protein was detected, this compound exhibited a dose- and time-dependent induction. Induction of differentiation by hinokitiol occurred irreversibly and required its addition for more than 12h. Among its structure-related compounds tested, tropolone and two colchicine-related compounds exerted potent activities comparable to that of hinokitiol. These findings indicate that free tropolone structure in the molecules plays an essential role in inducing differentiation of F9 cells. Hinokitiol showed a strong inhibitory effect of DNA synthesis in very early stages of culture, suggesting that this effect may be responsible for triggering differentiation of F9 cells. 相似文献
5.
Nobuhiro Kumada Nobuo Ozawa Nobukazu Kinomura Fumio Muto 《Materials Research Bulletin》1985,20(5):583-589
Pyrochlores of A1?xHxTaO3·nH2O (A=Na,K) were prepared under the hydrothermal conditions. The values of x for these compounds were increased from 0.3 to 0.5 for A=Na and from 0.2 to 0.5 for A=K by treatment with the distilled water. The compounds with x<0.5 were decomposed to a mixture of NaTaO3 and Na2Ta4O11 for A=Na, or to a mixture of KTaO3 and a tetragonal tungsten bronze phase, and those with x=0.5 to a single phase of A2Ta4O11 at elevated temperatures. Below the decomposition temperatures, defect pyrochlores with oxygen vacancies, , were produced. They were hygroscopic, and in the case of A=K and x=0.5 the original phase was recovered by leaving in air for several hours. 相似文献
6.
R. Kaji S. Adachi H. Sasakura S. Muto H. Kumano I. Suemune 《Journal of Superconductivity and Novel Magnetism》2007,20(6):447-451
We investigated optical pumping of nuclear spin polarizations in a single self-assembled In0.75Al0.25As/Al0.3Ga0.7As quantum dot. The nuclear spin polarization exhibits the abrupt jump and hysteresis in the excitation power dependence at
a particular excitation polarization. Measurement of circular polarization rate of the photoluminescence reveals that the
abrupt change of the nuclear spin polarization is created mainly by the spin flip-flop process between nuclei and an electron
of a positive charged exciton in this single quantum dot. Model calculation explains well the experimentally observed bistable
behavior in InAlAs quantum dot. By using this abrupt change, the sign and magnitude of electron and hole g-factors in z-direction are verified.
相似文献
7.
Sh ichi sawa Eiji sawa Yü ji Hirose 《Fullerenes, Nanotubes and Carbon Nanostructures》1995,3(5):565-585
Initial steps of thermal transformation from doubly bonded [2+2] (1) and [4+4] (2) dimers of C60 have been analyzed on the basis of computed structural features and Pople's energy partition scheme. Completely conjugated C120 structures 3 and 4 are found to be considerably stable and proposed to be important intermediates. The linkage patterns in 3 and 4 are also likely to appear in the repeating units of the metastable dimer and polymer phases of A1 crystals. 相似文献
8.
Eiji Takeda 《Microelectronics Reliability》1993,33(11-12)
A universal guideline and state-of-the-art hot-carrier effects in scaled MOSFETs are reviewed and discussed from the viewpoints of 1) DC and AC hot-carrier effects, 2) hot-carrier detrapping phenomena, 3) mechanical stress effects on hot-carrier phenomena, and 4) hot-carrier resistant device structures.In the deep-submicron region, the hot-carrier applicable voltage is less than 3 V, so AC hot-carrier effects from the dynamic operation of actual circuits should be taken into account. Despite much experimentation and analysis, there is still no universally accepted theory that explain the AC degradation mechanism. This is because the noise caused by the wiring inductance in ULSI circuits and in measurement systems screens the intrinsic AC hot-carrier effects.Here, AC hot-carrier degradation enhanced by gate pulse-induced-noise is analyzed experimentally and theoretically. After eliminating the noise problem, it is found that AC hot-carrier degradation in LDD (Lightly doped drain) and GOLD (gate-drain overlapped device) structures can be estimated based on DC degradation in terms of the effective stress time which takes the duty ratio into account. In addition, it is found that the noise is negligible when the wiring inductance is smaller that 80 nH (250 mω), which is important for future circuit design.Furthermore, hot-carrier detrapping effects, especially in p-channel MOS devices, and hot-carrier phenomena under mechanical stress are investigated experimentally to better understand the underlying hot-carrier physics. Finally, future hot-carrier resistant device structures are discussed. 相似文献
9.
A common-emitter current gain of 10 has been measured at 77 K for a 100 nm-base resonant-tunnelling hot-electron transistor (RHET) using a GaInAs/(AlGa)InAs heterostructure. The current gain for 25 nm-base RHETs has reached 25, which is the highest value yet reported for hot-electron transistors, and the collector current peak-to-valley ratio has reached 15.0 for the same device. 相似文献
10.
Eiji Hoashi Takehiko Yokomine Tomoaki Kunugi 《International Journal of Heat and Mass Transfer》2003,46(21):4083-4095
This paper presents a numerical simulation of wave-type heat transfer phenomena propagating in an aluminum thin foil irradiated by a pulsed laser using the cubic interpolated propagation method coupled with a thermo-convective model. We did not use the two-step model and dual-phase lag model, which are generally known as the non-Fourier heat conduction law, but wave-type heat transfer phenomena could be observed by our method. The main characteristic of the method is to solve the governing equation including the equation of continuity, the equation of motion, the equation of energy and the equation of state. It is found that when the pulse duration is under the order of picosecond, the pure heat conduction is hardly observed and heat transfer toward the inside of materials occurs only by a thermal shock wave. The heat conduction mode after pulse laser irradiation is strongly dependent upon the value of total incident laser energy density Ein and the threshold value for pure heat conduction is 5.0 × 104 J/m2 for an aluminum. 相似文献