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1.
《天津大学学报(英文版)》2018,(6)
A thioester-functionalized triphenylamine hole-transporting molecule(TPD-SAc) was synthesized and self-assembled to form a monolayer on an ultra-thin Au film supported on indium-tin oxide glass. The modified surface was characterized by aqueous contact angle, ellipsometer, atomic force microscopy, X-ray photoelectron spectroscopy, and ultraviolet photoelectron spectrometer to substantiate the formation of compact and pinhole-free monolayers. The modified organic light emitting diode device [indium-tin oxide/Au(5 nm)/self-assembled monolayers(SAM)/TPD(50 nm)/Alq_3(40 nm)/TPBI(15 nm)/LiF(1 nm)/Al(100 nm)] showed a luminance of 7303.90 cd/m~2 and a current efficiency of 8.49 cd/A with 1.78 and 2.29-fold increase, respectively, compared to the control device without SAM. The improvements were attributed to the enhanced compatibility of the organic–inorganic interface, matched energy level by introduction of an energy mediating step and superior hole-injection property of SAM molecules. 相似文献
2.
In order to compare two kinds of blue electroluminescent materials,we have investigated two kinds of blue OLEDs with the similar structure ITO/CuPc/NPB/JBEM:perylene/Alq/Mg:Ag[device(J)] and ITO/CuPc/NPB/DPVBi:perylene/Alq/Mg:Ag[device(D)].The difference of luminance and efficiency was not obvious for the two devices,However,there was remarkable difference for their lifetime.The device(J) achieved longer half lifetime of 1035h at initial luminance of 100 cd/m^2,and that of device(D) was only255h,According to their energy level diagrams,the differentce of their stability may originate from different host materials in the two devices.It may be attributed to the better thermal stability of JBEM molecues than that of DPVBi.It is shown that JBEM may be a promising blue organic electroluminescent material with great stability. 相似文献
3.
Three types of blue-violet light-emitting devices based on an exciton-confined structure have been prepared, in which different materials were used as emitting layers and hole-transporting layers. They had structures of ITO/CuPc/NPB/CPB/TPBi/Alq3/LiF/Al(DNC), ITO/CuPc/JO3/CBP/TPBi/Alq3/LiF/Al(DJC ) and ITO/CuPc/JO3/FNPD/TPBi/Alq3/LiF/Al(DJF). Here copper phthalocyanine (CuPc) acted as hole-injecting layer( HIL), N, N-bis-(1-naphthyl)-N, N-diphenyl-1. lbiphenyl-4-4-diamine(NPB) and J03 bole-transporting layers ( HTLs), 4,4‘-dicarbazolyl-1,1‘ -biphenyl (CBP) and FNPD as emitting layers( EMLs), N, arylbenzimidazoles (TPBi) as holeblocking layer ( HBL ), and tris(8-quinolinolato ) aluminium complex ( Alq3 ) as electron- transporting layer ( ETL). TPBi applied here is a good confinement to both charges and excitons, which make the devices emit blue-violet light originating from the emitter, CBP and FNPD. Their characteristics have also been investigated. The result shows that the device DNC based on NPB/CBP has the best performance among the three devices. The excellence of DNC is attributed to the better hole-transporting ability of NPB as compared with J03, and the better emitting ability of CBP as compared with FNPD, although the best matching of energy levels is found in the hole-transporting layer and emitting layer of the device DJP. 相似文献
4.
Cohesion is essential to the analysis and understanding of the discourse and is a significant device to help to realize the succinctness, coherence and the value of the language in the text. Cohesive devices are sorted into two types by Halliday and Hasan: lexical cohesion(repetition, synonymy and collocation) and grammatical cohesion(reference, ellipsis, substitution and conjunction). The present thesis intends to render insight into the internal structure of Hemingway's world-famous novel The Old Man and the Sea from a discourse-stylistic perspective by analyzing both the grammatical and lexical cohesive devices employed in it. Additionally, the thesis will consider the relationship between the employment of cohesive devices in Hemingway's classic profound language techniques and his gist of heroism that encompasses a trinity of roles ——Saint, Hero and Father. 相似文献
5.
A new blue electroluminescent material,distyrylarylene(DSA)derivative,4,4‘-bis[2,2-(1-naphthyl,phenyl)vinyl]-1,1-biphenyl(NPVBi)is designed and synthesized.The DSA derivative shows better thermal stability because of its high glass transition temperature.A blue organic light emitting diode(OLED0with the structure ITO/TPD/NPVBi/Alq/LiF/Al is studied.The electroluminescent(EL0spectrum of the OLED exhibits that light emission originates from NPVBi with a peak at 460nm,its Commission Internationale de l‘Eclairage(CIE)color coordinates are x=0.16,y=0.15,and showing independence of CIE color coordinates on current density.The new DSA derivative is expectable as a new candidate for blue light emitter in OLEDs. 相似文献
6.
The main purpose of the present research is to reveal features of the use of cohesive devices in English IM(Instant Message).In order to be accurate and explicit,Oxford WordSmith Tools(Version 4.0) is applied to investigate the frequency of each type of cohesive devices used by online-communicators.Cohesion in English IM is characterized by a number of distinguishing features:1) this genre of discourse makes abundant use of cohesive ties such as personal reference,lexical reiteration and ellipsis;2) substitution and comparative reference are rarely applied;3) The variety of conjunctions used is limited,and the most frequently used conjunctions are and,so,but and or.In analyzing the cohesive effect of each cohesive device,it is held that in order to overcome the limitations of the messaging systems and to achieve smooth communication,participants mainly adopt explicit cohesive ties which could achieve stronger force of cohesion in IM communication. 相似文献
7.
Failure Process and Energy Transmission for Single-Layer Reticulated Domes Under Impact Loads 总被引：5，自引：0，他引：5
No failure, moderate failure, severe failure, and slight failure are the four failure modes generalized observed in the dynamic response of the single-layer reticulated dome under vertical impact load on apex. TE (the time that the end of impact force) and TF (the time that members are broken) are two key times in the failure process. Characteristics of dynamic responses at the two key times are shown in order to make the failure mechanism clear. Then three steps of energy transfer are summarized, i.e. energy applying, energy loss and energy transfer, energy consump-tion. Based on the three steps, energy transfer process for the failure reticulated dome under once impact is introduced. Energy transmissibility and local loss ratio are put forward firstly to obtain EL F(the energy left in the main reticulated dome) from the initial kinetic energy of impactor. More-over, the distribution of failure modes is decided by EL F which leads to the maximum dynamic re-sponse of the reticulated dome, but not by the initial impact kinetic energy of impactor. 相似文献
8.
In the coke oven gas to methanol(CTM) process, boiling water(above 200 ℃) is generally used as the coolant in the methanol synthesis reactor, and thus, medium-pressure steam is generated as a by-product. In this paper, the influence of the coolant temperature on the CTM process is investigated from two aspects, which are the performance analyses of the reactor and the overall process and the energy integration of by-product steam. The results reveal that the coolant temperature plays a key role in the CTM process optimization. When the coolant temperature is reduced to 187 ℃, though low-pressure steam is generated, the techno-economic performance of the whole process is greatly improved: the energy/exergy efficiency is increased by 4-9%, energy cost is saved by 37.1%, income is increased by 5.4 M$/year, and the C02 emission is reduced by 21.3%. 相似文献
9.
Experimental investigation on system with combination of ground-source heat pump and solar collector
This paper presents the heating performance and energy distribution of a system with the combination of ground-source heat pump and solar collector or a solar-assisted ground-source heat pump system (SAGSHPS) by calculation and experiment.The results show that the average absolute error is less than 0.6 ℃ and the relative error is less than 5% under the pulse load when the analytical solution to the 2-D solid cylindrical source model is used for the SAGSHPS.The coefficient of performance (COP) of the SAGSHPS is 2.95-4.70.The average fluid temperature in the borehole heat exchanger can increase by 3 ℃ with the assistance of solar collector,which will improve the COP of the heat pump by approximately 10% from the experimental data.The energy contributions to the total heating load of soil,electricity and solar are 56.30%,36.87% and 6.83%,respectively. 相似文献
10.
English language(EL) and French language(FL) are very similar in their language attributes-lexicon,syntax and tenses.During FL acquisition,especially during the early acquisition stages,FL learners are strongly influenced by their EL forms.The essential point of this paper is to distinguish the differences and similarities of the EL and FL,then to suggest some strategies to restrain the negative transfer effectively,which would be helpful in third language acquisition. 相似文献
11.
Stabilization for a class of second-order switched systems with saturation constrains 总被引：1，自引：0，他引：1
This paper proposes a global stabilization method for a class of planar switched systems with input saturation constrains
by using a state feedback and switching strategy. This method is proved to be effective by analyzing the characteristics of
the trajectory of second-order linear systems with input saturation.
Project supported by the China Postdoctoral Science Foundation (Grant No.20070420643), the National Natural Science Foundation
of China (Grant No.60774059), and the Innovation Program of the Shanghai Municipal Science and Technology Commission (Grant
No.08DZ2272400) 相似文献
12.
Single phase Fe5C2 intermetallic compound was prepared by mechanical alloying method. The phase and crystal structure of sample were analyzed with X-ray differaction spectrum. The decomposing temperature of the Fe5C2 compound is 596.4℃ determined by the DSC curve. It is further shown that the size of nanometer crystal grain is an important condition for carrying out the solid state reaction at room temperature and normal pressure. 相似文献
13.
High frequency ultrasonic nondestructive testing was conducted using a direct contact method for SUS306 stainless steel treated
by high temperature and fracture tensile tests. Reflected ultrasonic echoes were analyzed. The relationships between the ultrasonic
attenuation coefficient, strength of backscattering wave and the elongation at break of the samples were obtained. The damages
were evaluated by using these results together with the analysis of microstructure and mechanics of the tested material.
Project supported by the National Natural Science Foundation of China (Grant No.60472102), and the Innovative Program of Shanghai
Municipal Education Commission (Grant No.07ZZ03) 相似文献
14.
In this paper, we discuss a class of piecewise linear hyperbolic maps on the 2-torus. These maps arise in the second-order digital fdter with two＇ s complement arithmetic. By introducing codings underlying the map operations, we give some admissibility conditions for symbolic sequences and find some periodic properties of these symbolic sequences. Then we use these conditions to check the admissibility of periodic symbol sequences. 相似文献
15.
The nonlinear Riemann problems were converted into nonlinear singular integral equations and the existence of the solution for the problem was proved by means of contract principle. 相似文献
16.
In the light of Ф-mapping method and the relationship between entropy and the Euler characteristic, the intrinsic topological structure of entropy of Kerr black holes is studied. From the Ganss-Bonnet-Chem theorem, it is shown that the entropy of Kerr black hole is determined by singularities of the Killing vector field of spacetime. These singularities naturally carry topological numbers, Hopf indices and Brouwer degrees, which can also be viewed as topological quantization of entropy of Kerr black holes. Specific results S = A/4 for non-extreme Kerr black holes and S = 0 for extreme ones are calculated independently by using the above-mentioned methods. 相似文献
17.
Batch processes have been increasingly used in the production of low volume and high value added products. Consequently, optimization
control in batch processes is crucial in order to derive the maximum benefit. In this paper, a run-to-run product quality
control based on iterative learning optimization control is developed. Moreover, a rigorous theorem is proposed and proven
in this paper, which states that the tracking error under the optimal iterative learning control (ILC) law can converge to
zero. In this paper, a typical nonlinear batch continuous stirred tank reactor (CSTR) is considered, and the results show
that the performance of trajectory tracking is gradually improved by the ILC.
Project supported by the Science Foundation of Shanghai Municipal Education Commission (Grant No.09Y208), and the Science
Foundation of Science and Technology Commission of Shanghai Municipality (Grant Nos.08DZ2272400, 09DZ2273400) and the “11th
Five-Year Plan” 211 Construction Project of Shanghai University 相似文献
18.
LI Gen guo 《上海大学学报(英文版)》1999,3(4):263-269
１ Ｉｎｔｒｏｄｕｃｔｉｏｎ Ｃｏｎｓｉｄｅｒｔｈｅｍｏｄｅｌｘ ¨＋ｘ（１－ｘ）（ｘ－ａ）＝０,（１）ｗｈｅｒｅａｉｓａｃｏｎｓｔａｎｔ．Ａｓａ＝－１,Ｅｑ．（１）ｒｅｄｕｃｅｓｔｏｔｈｅＤｕｆｆｉｎｇｅｑｕａｔｉｏｎｆｏｒｔｈｅｓｙｓｔｅｍｏｆｓｏｆｔｓｐｒｉｎｇｗｉｔｈｏｕｔｄａｍｐｉｎｇｘ ¨＋ｘ－ｘ３＝０．（２） ＴｈｅＤｕｆｆｉｎｇｓｙｓｔｅｍｈａｓｂｒｏａｄｅｎｇｉｎｅｅｒｉｎｇｂａｃｋｇｒｏｕｎｄ．Ｔｈｅｒｅａｒｅｐａｐｅｒｓ［１～４］ｒｅｌａｔｅｄｔｏｔｈｅｄｙｎａｍｉｃ… 相似文献
19.
Exchange coupling and magnetization reversal mechanism in two series of Co_xNi_(1-x)/CoO(30 nm)(x=0.2 and 0.4)bilayers are studied by vector magnetometer.Two components of magnetization are measured parallel and perpendicular to the applied field.At low temperatures,coercivity H_c∝(t_(FM))~(-n),n=1.5 and 1.38 for x=0.2 and 0.4,respectively,in agreement with the random field model.At room temperature,the coercivity is nearly proportional to the inverse FM layer thickness.In addition to the exchange field and the coercivity,the characteristic of the magnetization reversal mechanism was found to change with temperature.At temperatures below 180 K,magnetization reversal process along the unidirectional axis is accompanied only by nucleation and pinning of domain wall while magnetization rotation is also involved at high temperatures. 相似文献
20.
The big upper bound of typical van der Waerden number was investigated through calculating the van der Waerden number on a circle. And the van der Waerden number Wh (3,3) = 9, Wh (3,3,3)≥25 on a circle was calculated by computer. 相似文献