充液成形设备双闭环控制分析

目的 研究先进充液成形设备的精度控制技术,以满足充液成形过程中对成形介质压力及侧推油缸位置的高精度控制要求,并确保模具型腔的密封性和零件成形的稳定性。方法 基于PLC控制器下的PID闭环控制功能,将速度闭环和位置或压力闭环进行集成,开发应用于液压系统的双闭环控制方法。结果 使用双闭环控制方法,可以调整侧推油缸的位置控制精度及响应速度,并将精度控制在0.1 mm以内,也可调整增压装置的输出端压力控制精度,使精度达到0.3MPa。结论 在利用充液成形设备进行液压成形的过程中,双闭环技术可以实现设备侧向密封的精确位置控制以及型腔内压力的精确控制。     

闭环色彩控制系统在商业轮转机上的应用研究

介绍了闭环色彩控制系统的产家和工作原理,详细介绍了唯一在中国使用的QTI公司的色彩控制系统(CCS)的构成、在线色彩控制和检测方法,探讨了它在商业轮转机上的应用,以及给生产带来的便利和有待改善的方面.     

闭环式电起爆网路参数的计算方法

文中详细介绍了大型瓣环式电起爆网路的参数计算问题，按照Ｋｉｒｃｈｈｏｆｆ定律及大型闭环式电卢爆网路的特点，给出了电参数方程组及其求妥的数学模型。并通过分析方程组的特点，采用ＦＯＲＴＲＡＮ语言设计开发了计算程序，方程组的构造与计算均由计算机自动完成，较好地解决了闭环式网路参数计算的难题；     

Tetragonal Single‐Crystalline Boron Nanowires with Strong Anisotropic Light Scattering Behaviors and Photocurrent Response in Visible‐Light Regime

Boron is a narrow‐bandgap (1.56 eV) semiconductor with high melting‐point, low‐density, large Young's modulus and very high refractive index (3.03) close to silicon. Therefore, boron nanostructures is expected to possess strong visible‐light scattering properties. However, photonic and optoelectronic properties of the boron nanostructures are seldom studied until now. In this paper, we have successfully prepared single‐crystalline boron nanowire (BNW) arrays with high‐density on Si substrate. All the BNWs are found to possess strong light‐scattering behaviors in the visible regime. Most of all, the scattered light is found to polarize along the longitudinal direction of the nanowire. They also have excellent second‐harmonic generation (SHG) properties under ultrafast laser irradiation. Further optoelectronic measurements show that an individual BNW device exhibits notable photocurrent responses in the visible‐light range at ambient conditions, which can be attributed to the strong coupling effect between individual BNW and the visible light. The maximum photoresponsivity of an individual BNW can reach up to 12.12 A W^–1 at a voltage of 10 V, and the response time is only 18 ms. Therefore, it unveils that the BNWs have a promising future in visible‐light communications and detections.     

Conditions for Sub-poissonian Photon Statistics and Squeezed States in Resonance Fluorescence

We study the conditions for sub-poissonian photon statistics and squeezed states in the field of resonance fluorescence of a two-state atom. These conditions as a function of the detuning from resonance, the linewidth and the Rabi frequency have some overlap, but they are largely complementary. Super-poissonian statistics arise for small linewidths and large detunings, irrespective of the Rabi frequency. Squeezed states require small linewidths and either low or moderate Rabi frequencies, or large detunings from resonance.     

基于不对称信息的闭环供应链激励机制

运用委托代理理论,分别对制造商能获得回收市场真实信息和无法获得真实信息两种情况,设计了提供给第三方的线性合同的,并基于报童模型给出了制造商的最优生产决策.最后用仿真试验研究了市场情况以及回收量与需求的波动对制造商利润的影响.     

喷墨数字印刷质量的闭环检测与色彩控制系统设计

以传统印刷质量检测与控制理论为基础,结合数字印刷技术特点,提出了基于CCD机器视觉技术的喷墨数字印刷质量检测与闭环控制系统及方法,采用色度颜色偏差理论与方法,分别从色差、灰平衡、网点扩大、均匀性及色域范围5个方面,对实验和数据进行了对比分析。结果表明,修正后的颜色偏差波动水平快速达到了目标状态,补偿后的印刷质量要明显优于未控制前,验证了系统方法的可行性和有效性,为高精度喷墨数字印刷质量自动在线检测与控制提供了解决方案。     

再制造闭环供应链回收策略研究

在一个生产商和两个互相竞争的零售商组成的闭环供应链中比较了两种不同的回收策略—奖金策略:回收时向零售商支付回收奖金;押金策略:销售时向消费者征收押金,并在消费者退还旧件时返还押金。构造了两个分散决策的闭环供应链模型(1)DF模型。生产商通过零售商收集旧件,并为每一个旧件支付一定的奖金;(2)DD模型。生产商通过零售商向消费者征收额外的押金,消费者只有退还旧件,才能拿回押金。在基本模型的基础上,还考虑了政策对制造商与零售商决策的影响,在惩罚机制下讨论了DF模型与DD模型中决策者对惩罚机制的反应。     

Numerical Investigation of the Effects of Orientation and Gravity in a Closed Loop Pulsating Heat Pipe

The Closed Loop Pulsating Heat Pipe (CLPHP) is a very promising passive two-phase heat transfer device for relatively high heat fluxes (up to 30 W/cm²) patented by Akachi (1990, 1993). Although the CLPHP has a simple structure, its working principles are very complex compared to the standard heat pipe with a porous wick. One of the most debated issues deals on how the thermal performance is affected by the inclination and by the action of different gravity fields (terrestrial, lunar, martian and microgravity). Even if the internal tube diameter satisfies the conventional slug flow regime requirement on the Bond number, gravity force still plays an important role on the PHP behaviour. Heat input and the number of turns are two of the most important indirect parameters linked to the gravity issue. A complete numerical campaign has been performed by means of a FORTRAN code at different inclination angles and gravity levels on various PHP. The numerical model is able to estimate both the hydrodynamic and the thermal performance of a CLPHP with different working fluids. The analysis shows that the effect of local pressure losses due to bends is important and must be taken into account, in particular in the horizontal operation which is the reference point for space applications. Numerical results are matched with the experimental data quoted in literature and both good qualitative and quantitative agreement have been found.     

Optical Joint of Optoelectronic Radiation Converters with Immersion Light Guides and Calculation of Their Characteristics

In the present work, equations are obtained that establish relationships between the optical characteristics of optoelectronic radiation converters and straight cylindrical immersion light guides with straight faces manufactured from isotropic and anisotropic materials with different refractive indices. Engineering procedures to calculate the schemes of optical joint of pyrometric converters with light guides that improve the metrological characteristics of the immersion light-guide thermometry of radiation are developed.     

Steady-State Photocurrent Characteristics in Sillenite Crystals

The steady-state photocurrent through Bi₁₂TiO₂₀, Bi₁₂GeO₂₀, and Bi₁₂SiO₂₀ crystals was measured as a function of temperature (77–300 K) and illumination. The four-level energy-band diagram inferred from the experimental data adequately describes the carrier generation, recombination, and photocurrent quenching processes in wide-gap sillenite semiconductors.     

量子阱光电子器件的发展与中国光电子器件产业的形成

光电子技术发展推动着信息时代的变革,作为其心脏的半导体光电子器件正带动着一个新兴产业--光电子产业。 量子阱激光器是半导体激光器发展的第三里程碑。因为其性能优越,成为一代理想的激光器,在光通信、光存储、光显示等方面得到应用。 目前,中国光电子产业已具雏形,已有多家光通信器件制造公司形成年产亿元以上产值。而以光存储、光显示为代表的非通信光电子器件发展势头极其迅猛。其国产化带动数字音像和数字存储产业、全色显示屏、汽车灯、交通灯以至固体白光灯等产业,年产值规模可望在百亿以上     

Predicting Deposition Rate and Closing the Loop on Aerosol Jet Printing with In-Line Light Scattering Measurements

Aerosol jet printing is a compelling noncontact, digital manufacturing technology for flexible, hybrid, and conformal electronics, but batch-to-batch variability and process drift inhibit systematic study and translation to production environments. Emerging measurement techniques for the aerosol volume fraction, a key parameter governing deposition rate, have shown promise for real-time response, including a recent demonstration of human-in-the-loop control. By integrating improved light scattering measurements with custom software, a robust environment for real-time monitoring is established and fully automated closed-loop control over the deposition rate during printing is enabled. The physical basis for scattering measurements as a feedback source is examined and the quantitative insight this provides for ink development and fundamental process studies is highlighted. Three candidate process variables for closed-loop control, namely the atomizer voltage, carrier gas flow rate, and print speed, are then evaluated. The atomizer voltage demonstrates the best extended duration validity because it addresses atomization variability directly, but carrier gas flow rate and print speed provide faster and more deterministic responses. This methodology is then demonstrated for electrical properties using a silver nanoparticle ink, maintaining 98% of printed patterns within 10% of the mean resistance value over 3 h of printing.     

AlInN光电薄膜的研究进展

AlInN三元合金是优良的Ⅲ-Ⅴ族氮化物半导体材料,具有优良的光学和电学性能,在光电子器件应用方面具有广阔的应用前景.详细评述了近年来AlInN薄膜材料在生长技术、晶体结构、表面形貌、热学特性、光电特性等方面的研究,为AlInN三元合金在光电方面的基础和应用研究提供了重要参考.     

光电成像跟踪系统的实时数据融合技术研究

光电成像跟踪系统需要保证不同目标的自适应识别,同时严格按照时间序列执行的图像处理又是一个强实时性过程。实时融合跟踪技术提出并行执行多个算法组以适应不同类型目标的识别,并通过像素级、特征级和决策级的同时融合处理保证了系统跟踪的稳定性,最后在嵌入式并行处理硬件平台上有效解决了对运动目标的自适应跟踪。文中详细阐述了实时融合跟踪技术的技术思想和技术路线,在剖析其并行结构的基础上完成了光电成像跟踪系统的嵌入式硬件并行平台的设计和实现,取得了显著的工程应用成果。     

Optoelectronic and nonlinear optical processes in low dimensional semiconductors

Spatial confinement of quantum excitations on their characteristic wavelength scale in low dimensional materials offers unique possibilities to engineer the electronic structure and thereby control their physical properties by way of simple manipulation of geometrical parameters. This has led to an overwhelming interest in quasi-zero dimensional semiconductors or quantum dots as tunable materials for multitude of exciting applications in optoelectronic and nonlinear optical devices and quantum information processing. Large nonlinear optical response and high luminescence quantum yield expected in these systems is a consequence of huge enhancement of transition probabilities ensuing from quantum confinement. High quantum efficiency of photoluminescence, however, is not usually realized in the case of bare semiconductor nanoparticles owing to the presence of surface states. In this talk, I will focus on the role of quantum confinement and surface states in ascertaining nonlinear optical and optoelectronic properties of II–VI semiconductor quantum dots and their nanocomposites. I will also discuss the influence of nonlinear optical processes on their optoelectronic characteristics.     

III-Nitride-Based Quantum Dots and Their Optoelectronic Applications

Nano-Micro Letters - During the last two decades, III-nitride-based quantum dots (QDs) have attracted great attentions for optoelectronic applications due to their unique electronic properties. In...     

数字光电跟踪系统定位时的自激振荡及其抑制

由于某些非线性的影响,数字光电跟踪系统定位精度大大降低,因此相应的非线性补偿方法研究势在,必行.本文以数字化光电跟踪系统为研究对象,首先进行了电视跟踪定位时影响定位精度的等效间隙非线性分析,给出了两种主要非线性的理论表达式,即量化非线性和光电探测器滞后非线性,然后采用描述函数法对实测定位自激振荡进行了定量分析,最后确定了双极工作模式的PWM功率驱动器.在实际的数字化光电跟踪系统定位实验研究中,定位误差的最大峰-峰值小于22.23",表明双极PWM驱动器的零位振颤特性,对数字控制系统的自激振荡起到了很好的抑制作用.