基于功效散度和成对约束的半监督聚类算法

现有成对约束半监督聚类算法(CE-sSC)克服了极大熵聚类(MEC)算法不能利用样本成对约束信息的缺点,但CE-sSC算法的惩罚项中各熵项之间相互干扰,不利于惩罚项系数的选择。为克服此问题,基于相对熵提出了一类新的半监督聚类算法(PD-sSC),并把表示成对约束样本信息(外部信息)的相对熵项推广到了功效散度(PD)族。此时,PD指标可取任意的实数,当成对约束数较少时,可通过调整PD散度指标来选择比对比算法表现更好的PD-sSC算法。实验结果显示了PD-sSC算法的优良性质,PD-sSC算法惩罚系数的选择也比CE-sSC算法简单且高效。

区域制造业信息化公共服务平台功效测度

本文通过借鉴专家学者关于功能模型的研究成果,就不同层次的网站类平台的功能特征,建立了网站类平台的功能层次模型。并根据该功能层次模型,结合制造业信息化需求的特点,建立功能评价指标体系,采用因子分析法,以已建有制造业信息化公共服务平台的1 5个省份为主要研究对象,开展了其功效测度与分析。

“一矿二面”集中开采模式的综合效能度分析

将系统的时间利用率（有效度）和能力利用率（功效度）相结合，提出了综合效能度的概念和计算方法，以检测矿井运行的总体效果，并建立了功效度和有效度计算模型．通过对常村煤矿“一矿二面”开采模式的计算分析，选出了合理的集中开采模式并找出了矿井生产的薄弱环节．综合效能度的分析是有效、实用的，其结果对生产具有指导意义．

基于功效函数法的风险投资项目功效评价

文中利用数理统计手段中的变异系数法,计算交易中心风险投资项目的功效和风险监控指标的权重,并采用功效函数法将各种指标统一为无量纲的单一指标,根据这些指标计算出总的功效函数值的大小,来评价交易中心风险投资项目的功效。案例表明,功效函数法可以直观评价功效和风险的高低。

基于广义帕累托分布稳健估计法的沪市VaR预测

针对金融收益序列的"高峰、厚尾"特征,本文将ARMA-GARCH模型和POT模型结合起来度量上证综指的VaR,用广义帕累托分布(GPD)对POT模型的超额阈值进行拟合得到VaR。考虑到GPD参数的极大似然估计非稳健性,本文使用了GPD参数的三种稳健估计法:最小密度功效散度、中位数和似然矩估计。动态回溯检验结果表明,使用稳健方法拟合GPD,可以得到更为稳健、精准的VaR度量,并得到GPD稳健估计优劣性的比较结果。

Highly efficient class-F power amplifier with digital predistortion for WCDMA applications

A digital predistorted class-F power amplifier （PA） using Cree GaN HEMT CGH40010 operating at 2. 12 GHz is presented to obtain high efficiency and excellent linearity for wideband code-division multiple access （ WCDMA ） applications. Measurement results with the continuous wave （CW） signals indicate that the designed class-F PA achieves a peak power-added efficiency （PAE） of 75. 2% with an output power of 39.4 dBm. The adjacent channel power ratio （ACPR） of the designed PA after digital predistortion （DPD） decreases from -28. 3 and -27. 5 dBc to -51.9 and -54. 0 dBc, respectively, for a 4-carrier 20 MHz WCDMA signal with 7. 1 dB peak to average power ratio （PAPR）. The drain efficiency （DE） of the PA is 37. 8% at an average output power of 33. 3 dBm. The designed power amplifier can be aoolied in the WCDMA system.

基于闭包准则和成对约束的半监督聚类算法

基于功效散度和成对约束的半监督聚类算法(PD-sSC)将相对熵推广到功效散度(PD)族,剔除了目标函数中不同惩罚熵项之间的干扰,提高了惩罚项系数的选择效率。但当成对约束数目相对较大时,PD-sSC算法聚类效果不够理想。为了解决这个问题,提出了一种基于闭包准则的成对约束打包算法(CCPC),该算法利用must-link约束对原样本组进行打包,再利用各个包的中心点替代整个包,从而得到一组新样本,最后利用PD-sSC算法对新样本进行聚类分析。实验结果表明,无论成对约束数目是大还是小,CCPC算法都有很好的表现。

Size-dependent behaviors of viscoelastic axially functionally graded Timoshenko micro-beam considering Poisson effects

A size-dependent continuum-based model is developed for the functionally graded(FG)Timoshenko micro-beams with viscoelastic properties,in which material parameters vary according to the power law along its axial direction.The size effect is incorporated by employing the modified couple stress theory and Kelvin-Voigt viscoelastic model,so that viscous components are included in the stress and the deviatoric segments of the symmetric couple stress tensors.The components of strain,curvature,stress and couple stress are formulated by combining them with the Timoshenko beam theory.Based on the Hamilton principle,the governing differential equations and boundary conditions for the micro-beam are expressed with arbitrary beam section shape and arbitrary type of loads.The size effect,FG effect,Poisson effect,and the influence of the beam section shape on the mechanical behaviors of viscoelastic FG micro-beams are investigated by taking the simply supported micro-beam subjected to point load as an example.Results show that the size effect on deflection,normal stress and couple stress are obvious when the size of the micro-beam is small enough,and the FG effects are obvious when the size of the micro-beam is large enough.Moreover,the Poisson ratio influences the size effect significantly and the beam section shape is also an important factor influencing the mechanical behavior of the micro-beam.

Thermo-mechanical Behaviors of Functionally Graded Shape Memory Alloy Timoshenko Composite Beams

This paper focuses on the thermo-mechanical behaviors of functionally graded(FG)shape memory alloy(SMA)composite beams based on Timoshenko beam theory.The volume fraction of SMA fiber is graded in the thickness of beam according to a power-law function and the equivalent parameters are formulated.The governing differential equations,which can be solved by direct integration,are established by employing the composite laminated plate theory.The influences of FG parameter,ambient temperature and SMA fiber laying angle on the thermo-mechanical behaviors are numerically simulated and discussed under different boundary conditions.Results indicate that the neutral plane does not coincide with the middle plane of the composite beam and the distribution of martensite is asymmetric along the thickness.Both the increments of the functionally graded parameter and ambient temperature make the composite beam become stiffer.However,the influence of the SMA fiber laying angle can be negligent.This work can provide the theoretical basis for the design and application of FG SMA structures.

Future Outlook of Artificial Cavity Application for Reducing Hydrodynamic Resistance of Containerships

Absolute commitment to reduce the impact of greenhouse gas emissions while increasing fuel efficiency and power density requires further enhancement of prime mover characteristics and special coatings, but mostly requires compliance with EEDI （energy efficiency design index） measures. For the container shipping industry this represents significant increases in fuel costs that can be mitigated above all by reduction of power demand, that is, of ship frictional resistance. In this respect, this paper discusses advantages attainable by application of the ACS （air cavity system） technology on the basis of recent KSRC （Krylov State Research Centre） studies Savings in operating costs yielded by the enhanced propulsion performance for ships fitted with this system are illustrated by a case study of a containership.

Energy Efficiency Building Codes for Egypt

This paper summarizes the results of energy simulation analysis to determine the effectiveness of building characteristics in reducing electrical energy consumption in residential buildings （conditioned and unconditioned） and commercial buildings （office ＆ hotel） in Egypt. Specifically, the impact on building envelope performance is investigated for different strategies such as window size, glazing type and building construction for two geographical locations in Egypt. This paper also studies the energy savings in residential and nonresidential buildings for different lighting power densities （LPD）, energy input ratios （EIR）, set point temperatures （SPT） and heating, ventilation, and air conditioning （I-WAC） systems. The study shows certain findings of practical significance, e.g. that a window-to-wall ratio of 0.20 and reasonably shaded windows lower the total annual electricity use for nonresidential buildings by more than 20% in the two Egyptian locations.

Efficacy of moxibustion by stimulating acupoints of Danzhong(CV 17) and Ganshu(BL 18) on hyperplasia of mammary gland in rats

OBJECTIVE: To evaluate the efficacy of moxibustion, through stimulating acupoints of Danzhong(CV 17) and Ganshu(BL 18) in rats with hyperplasia of mammary gland(HMG) which induced by estrogen and progestogen.METHODS: Thirty female Sprague-Dawley rats were randomly divided into saline control group,HMG model group, and HMG moxibustion group with 10 in each group. Saline control was the group injected by saline. HMG model were created by injection of estrogen and progestogen. Moxibustion group was also injected of estrogen and progesto-gen with moxibustion at the same time. The Changes of nipple diameter and height were measured.The rats' skin temperature was recorded by an infrared thermal camera at the nipples, mammary areas,Danzhong(CV 17) and Ganshu(BL 18). Pathological changes of mammary gland in rats were also observed under light microscope.RESULTS: The diameter and height of the nipples in model group were prominently bigger and higher than that in control group(P < 0.01). The diameter and height in moxibustion group were prominently smaller and lower than that in model group(P < 0.01), and there was no significant difference between moxibustion group and control group.Compared with control group, skin temperature of the nipples, mammary area, and acupoints Danzhong(CV 17) and Ganshu(BL 18) decreased prominently in model group(P < 0.01-0.05). Compared with model group, skin temperature of that in moxibustion group increased prominently(P <0.05).CONCLUSION: Treatment with moxibustion can effectively decrease the HMG rats' nipple diameter and height, and increase the skin temperature in HMG model rats at the nipples, mammary areas,Danzhong(CV 17) and Ganshu(BL 18). This study convinces the therapeutic effect of moxibustion on mammary gland hyperplasia.

light intensity at the return place and encirclement power ratio for the distorted reflected beam based on cat-eye effect

Based on the definition of second order moment and the approximate three-dimensional analytical formula for probe detected laser beam passing through a cat-eye optical lens with center shelter and oblique detector, the analytical expression of the encirclement power ratio of the cat-eye effect reflected light under far-field condition has been deduced. Variable laws of light intensity at the return place and encirclement power ratio are performed by numerical calculation, and are analyzed physically. The results show that the light intensity at the return place decreases monotonically with the increases of the diameter, incidence angle, tilted angle of the detector and the center shelter ratio, but the relationships between these parameters and the encirclement power ratio are all nonmonotonic. The reasonable choice of the focal shift size would result in the largest light intensity at the return place and the largest erirclenent power ratio.

Effects of spin-coating speed on the morphology and photovoltaic performance of the diketopyrrolopyrrole-based terpolymer

Polymer solar cells(PSCs) were fabricated by combining a diketopyrrolopyrrole-based terpolymer(PTBT-HTID-DPP) as the electron donor, and [6,6]-phenyl C_(61) butyric acid methyl ester(PC_(61)BM) as the electron acceptor, and the power conversion efficiency(PCE) of 4.31% has been achieved under AM 1.5 G(100 m W cm^(-2)) illumination condition via optimizing the polymer/PC_(61)BM ratio, the variety of solvent and the spin-coating speed. The impact of the spin-coating speed on the photovoltaic performance of the PSCs has been investigated by revealing the effects of the spin-coating speed on the morphology and the absorption spectra of the polymer/PC_(61)BM blend films. When the thickness of the blend films are adjusted by spin-coating a fixed concentration with different spin-coating speeds, the blend film prepared at a lower spin-coating speed shows a stronger absorption per unit thickness, and the correspond device shows higher IPCE value in the longer-wavelength region. Under the conditions of similar thickness, the blend film prepared at a lower spin-coating speed forms a more uniform microphase separation and smaller domain size which leads to a higher absorption intensity per unit thickness of the blend film in long wavenumber band, a larger short-circuit current density(J_(sc)) and a higher power conversion efficiency(PCE) of the PSC device. Noteworthily, it was found that spin-coating speed is not only a way to control the thickness of active layer but also an influencing factor on morphology and photovoltaic performance for the diketopyrrolopyrrole-based terpolymer.

Optimization and degradation of rubrene/C_(70) heterojunction solar cells

Small molecule organic solar cells （OSCs） with the structure of indium tin oxide （1TO）/molybdenum trioxide （MOO3） （5 nm）/rubrene （x nm）/fullerene （C70） （y nm）/2, 9-dimethyl-4, 7-diphenyl-1, 10-phenanthroline （BCP） （6 nm）/aluminum （A1） （150 nm） are fabricated. The thickness of active layer for the devices is investigated in details. The results show that the optimum thicknesses of rubrene layer and C70 layer are 30 nm and 25 nm, respectively. The degradation of the device is also investigated. The result indicates that the open-circuit voltage （Voo） does not change, while the short-circuit current density （Jsc）, fill factor （FF） and power conversion efficiency （PCE） decrease continuously with time. The degradation can be attributed to the oxygen in ambient diffusing and infiltrating into the active materials and reacting with C70 in cells, which can result in the increase of interfacial series resistance.

Triazolotriazine-based thermally activated delayed fluorescence materials for highly efficient fluorescent organic light-emitting diodes(TSF-OLEDs)

Thermally activated delayed fluorescence(TADF) sensitized fluorescent organic light-emitting diodes(TSF-OLEDs) have shown great potential for the realization of high efficiency with low efficiency rolloff and good color purity. However, the superior examples of TSF-OLEDs are still limited up to now.Herein, a trade-off strategy is presented for designing efficient TADF materials and achieving highperformance TSF-OLEDs via the construction of a new type of triazolotriazine(TAZTRZ) acceptor. The enhanced electron-withdrawing ability of TAZTRZ acceptor, fused by triazine(TRZ) and triazole(TAZ)together, enables TADF luminogens with small singlet-triplet energy gap(ΔE_(ST)) values. Meanwhile, the increased planarity from the TRZ-phenyl linkage(6:6 system) to the TAZ-phenyl linkage(5:6 system)can compensate the decrease of oscillator strength(f) while lowing ΔE_(ST), thus achieving a trade-off between small ΔE_(ST) and high f. As a result, the related TSF-OLED achieved an extremely low turn-on voltage of 2.1 V, an outstanding maximum external quantum efficiency(EQEmax) of 23.7% with small efficiency roll-off(EQE1000 of 23.2%;EQE5000 of 20.6%) and an impressively high maximum power efficiency of 82.1 lm W^(-1), which represents the state-of-the-art performance for yellow TSF-OLEDs.

Exploring the Scale Effects of Trade-offs and Synergies of Multifunctional Cultivated Land——Evidence from Wuhan Metropolitan Area

The purpose of this paper is to explore the trade-offs and synergies of multifunctional cultivated land(MCL) at multiple scales. The study area is Wuhan Metropolitan Area, China. The entropy method and the method of Spearman’s rank correlation were employed for the analysis of combined land use/cover data, administrative division data, population data and statistical yearbook data, from the multi-scale perspectives of cities, counties and townships. The results showed that:(1) The multi-functionality of cultivated land had obvious spatial differences and its overall spatial patterns were relatively robust, which did not change very much at the single scale.(2) At each single scale, the MCL’s trade-offs and synergies had spatial heterogeneity.(3) Scale effects existed in the MCL’s trade-offs and synergies. From the prefecture-level city scale, to the county scale, and to the township scale, the MCL’s trade-offs were changed to synergies, and some synergic relationships were enhanced. This article contributes to the literature by deepening the multiscale analysis of trade-offs and synergies of multifunctional cultivated land. The conclusions might provide a basis for helping policy-makers to implement protection measures for the multi-functionality of cultivated land at the right spatial scale, and to promote the higher-level synergies of multifunctional cultivated land to realize its sustainable use.

Novel internal photoemission in manganite/ZnO heterostructure

A novel photovoltaic phenomenon of internal photoemission was found in a low cost manganite La0.62Ca0.29K0.09MnO3 （LCKMO）/zinc oxide （ZnO） heterojunction bilayers grown on ITO substrate by pulsed laser deposition （PLD） at relative low growth temperature. The heterostructure ITO/LCKMO/ZnO/A1 exhibits reproducible rectifying characteristics and light cur- rent under continuous laser irradiation of 2 = 325 nm. We report here the influence of LCKMO/ZnO bilayers＇ thickness on the electrical and photoelectric properties of the heterostructure at room temperature. The power conversion efficiency （PCE） is achieved when the LCKMO and ZnO layers are thin enough or the full space charge layer is sufficient. We obtained the maximum value of PCE of 0.0145% when the thicknesses of LCKMO and ZnO layers are 25 and 150 nm, respectively. The open circuit voltage is 0.04 V under this condition due to the internal photoemission.

Hierarchical iridium-based multimetallic alloy with double-core-shell architecture for efficient overall water splitting

The overall water splitting for hydrogen production is an effective strategy to resolve the environmental and energy crisis. Here, we report a facile approach to synthesize the Ir-based multimetallic, hierarchical, double-coreshelled architecture(HCSA) assisted by oil bath reaction for boosting overall water splitting in acidic environment. The Ir Ni Cu HCSA shows superior electrocatalytic activity for hydrogen evolution reaction(HER) and oxygen evolution reaction(OER), which are comparable to commercial Pt/C and better than IrO2. The Ir Ni Cu HCSA exhibits remarkably catalytic efficiency as bifunctional catalyst for overall water splitting where a low cell voltage of 1.53 V is enough to drive a current density of 10 mA cm^-2 and maintains stable for at least 20 h. The presented work for the design and synthesis of novel Ir-based multimetallic architecture paves the way for highperformance overall water splitting catalysis.

Lanthanide-doped metal-organic frameworks with multicolor mechanoluminescence

Metal-organic frameworks(MOFs)and mechanoluminescent(ML)materials have been considered as two types of promising materials that have their own application fields.It would be amazing to endow one material with the advantages of ML and MOFs,thus broadening their applications.However,there are quite few investigations on this topic,and the ML mechanism in ML-MOFs remains unclear.In this study,we proposed a strategy for developing ML-MOFs by doping lanthanide ions into the non-centrosymmetric SBD([Sr(μ-BDC)(DMF)]∞)MOF,and successfully synthesized a series of lanthanide-doped MOFs Ln-SBD(Ln=Tb,Dy,Sm,Eu)and Tb1-xEux-SBD(x=0.2,0.4,0.6,0.8)with multicolor ML.The lanthanide ions were uniformly distributed in the matrix of the SBD-MOF,and occupied the Sr site.The MLMOFs exhibited intense multicolor ML emissions varying from green to yellow to red by changing the co-doping ratios and species of lanthanide ions.The similar ML and photoluminescence(PL)spectra indicated that the ML emission was assigned to the radiative transition from the excited states to the ground states of lanthanide ions.The radiative transition was induced by the electron bombardment process that originated from the piezoelectric effect of the non-centrosymmetric SBD host.In addition,a pioneering temperature sensing research based on ML was carried out,which is promising for realizing dual-functional detection of stress and temperature without excitation light sources.This study gives a unique insight for developing more versatile and interesting smart materials by combining the versatility of MOF with the ML emission,imparting additional values to both MOF and ML materials.Moreover,this study provides a general rule for selecting MOFs with an acentric structure as the host for ML materials.