On-Chip Micro Temperature Controllers Based on Freestanding Thermoelectric Nano Films for Low-Power Electronics

Multidimensional integration and multifunctional com-ponent assembly have been greatly explored in recent years to extend Moore’s Law of modern microelectronics.However,this inevitably exac-erbates the inhomogeneity of temperature distribution in microsystems,making precise temperature control for electronic components extremely challenging.Herein,we report an on-chip micro temperature controller including a pair of thermoelectric legs with a total area of 50×50μm^(2),which are fabricated from dense and flat freestanding Bi2Te3-based ther-moelectric nano films deposited on a newly developed nano graphene oxide membrane substrate.Its tunable equivalent thermal resistance is controlled by electrical currents to achieve energy-efficient temperature control for low-power electronics.A large cooling temperature difference of 44.5 K at 380 K is achieved with a power consumption of only 445μW,resulting in an ultrahigh temperature control capability over 100 K mW^(-1).Moreover,an ultra-fast cooling rate exceeding 2000 K s^(-1) and excellent reliability of up to 1 million cycles are observed.Our proposed on-chip temperature controller is expected to enable further miniaturization and multifunctional integration on a single chip for microelectronics.

Three-dimensionally oriented organization of hexagonal MIL-96 microplates toward superior film microstructure

Preferential orientation control of metal—organic framework(MOF)films is advantageous for maximizing pore uniformity and minimizing grain-boundary defects.Nonetheless,the preparation of MOF films with both in-plane and out-of-plane orientations remains a grand challenge.In this study,we reported the preparation of three-dimensionally oriented MIL-96 layers through combining morphology control of MIL-96 seeds with addition of polyvinylpyrrolidone surfactants and arachidonic acids.The three-dimensionally oriented MIL-96 film was readily obtained through in-plane epitaxial growth.It is anticipated that the aforementioned protocol can be effective for obtaining diverse MOF films with a three-dimensionally oriented organization.

Evaluation of Control Effects against Sugarcane Pests：A New Sustained-release and Long-lasting Pesticide and Convenient and Efficient Pesticide Application Technology

[Objective]The paper was to screen a new ideal sustained-release,long-lasting and low-toxic pesticide and convenient and efficient pesticide application technology for controlling Ceratovacuna lanigera and Baliathrips serratus. [Method]2% Imidacloprid GR were selected and applied in the soil for field efficacy trial. [Result] The optimum dosage of 2% imidacloprid GR was 30 kg/hm^2（ active ingredient 600 g）,which can be mixed with fertilizer（ 30 kg pesticide and 40-80 kg fertilizer per hm^2） once combined with sugarcane planting management or big ridging during February and June. The control effects against C. lanigera and B. serratus could be more than 98. 2% and 81. 1%,respectively. The actual yield and sugar content in various pesticide treatments were increased by 33 390 kg/hm^2 and 6. 6% respectively compared to blank control. [Conclusion]2% imidacloprid GR has good control effects on C. lanigera and B. serratus. It is a new pesticide with ideal sustained-release,long-lasting and low-toxin effects against C. lanigera and B. serratus. Therefore,it could be used alternatively with other pesticides,to delay production and development of drug resistance.

Controlled Microstructure and Photochromism of Inorganic-organic Thin Films by Ultrasound

A series of inorganic-organic thin films based on uniformly dispersed nanoparticles of polyoxometalates （POM）entrapped in polyacrylamide （PAM） matrix were prepared by ultrasonic method with different irradiation time.The microstructure, photochromic behavior and mechanism of the films were studied by transmission electron microscopy （TEM）, ultraviolet-visible spectra （UV-VIS） and Fourier transform-infrared spectroscopy （FT-IR）.The microstructure and photochromic properties of the hybrid thin films could be controlled by ultrasound.TEM image revealed that the average size of phosphotungstic acid （PWA） nanoparticles decreased from 20 to 10 nm with the ultrasound irradiation time from 30 to 60 min. After irradiated with ultraviolet light,the transparent films changed from colorless to blue and showed reversible photochromism. The hybrid film, with ultrasound irradiation for 60 min had higher photochromic efficiency and faster bleaching reaction than the one with ultrasound irradiation for 30 min. FT-IR spectra showed that the Keggin geometry of heteropolyoxometalate was still preserved inside the composites, and the interactions between polyanions and polymer matrix increased as the ultrasound time prolonged. It is suggested that the mechanism of the different photochromic properties for the inorganic-organic thin films is the variation of the microstructure and interfacial interactions induced by ultrasound.

Effect of ion-beam assisted deposition on the film stresses of TiO_2 and SiO_2 and stress control

Based on Hartmann-Shack sensor technique, an online thin film stress measuring system was introduced to measure the film stresses of TiO2 and SiO2, and comparison was made between the film stresses prepared respectively by the conventional process and the ion-beam assisted deposition. The effect of ion-beam assisted deposition on the film stresses of TiO2 and SiO2 was investigated in details, and the stress control methodologies using on-line adjustment and film doping were put forward. The results show that the film stress value of TiO2 prepared by ion-beam assisted deposition is 40 MPa lower than that prepared by conventional process, and the stress of TiO2 film changes gradually from tensile stress into compressive stress with increasing ion energy; while the film stress of SiO2 is a tensile stress under ion-beam assisted deposition because of the ion-beam sputtering effect, and the film refractive index decreases with increasing ion energy. A dynamic film stress control can be achieved through in-situ adjustment of the processing parameters based on the online film stress measuring technique, and the intrinsic stress of film can be effectively changed through film doping.

Nonlinear dynamic characteristics and optimal control of a giant magnetostrictive film-shaped memory alloy composite plate subjected to in-plane stochastic excitation

The nonlinear dynamic characteristics and optimal control of a giant magnetostrictive film （GMF）-shaped memory alloy （SMA） composite plate subjected to in-plane stochastic excitation are studied. GMF is prepared based on an SMA plate, and combined into a GMF-SMA composite plate. The Van der Pol item is improved to explain the hysteretic phenomena of GMF and SMA, and the nonlinear dynamics model of a GMF-SMA composite cantilever plate subjected to in-plane stochastic excitation is developed. The stochastic stability of the system is analyzed, and the steady-state probability density function of the dynamic response of the system is obtained. The condition of stochastic Hopf bifurcation is discussed, the reliability function of the system is provided, and then the probability density of the first-passage time is given. Finally, the stochastic optimal control strategy is proposed by the stochastic dynamic programming method. Numerical simulation shows that the stability of the trivial solution varies with bifurcation parameters, and stochastic Hopf bifurcation appears in the process; the system＇s reliability is improved through stochastic optimal control, and the first- passage time is delayed. A GMF-SMA composite plate combines the advantages of GMF and SMA, and can reduce vibration through passive control and active control effectively. The results are helpful for the engineering applications of GMF-SMA composite plates.

Controllable fabrication of self-organized nano-multilayers in copper–carbon films

In order to clarify the influence of methane concentration and deposition time on self-organized nano-multilayers,three serial copper-carbon films have been prepared at various methane concentrations with different deposition times using a facile magnetron sputtering deposition system. The ratios of methane concentration(CH4/Ar+CH4) used in the experiments are 20%, 40%, and 60%, and the deposition times are 5 minutes, 20 minutes, and 40 minutes, respectively.Despite the difference in the growth conditions, self-organizing multilayered copper-carbon films are prepared at different deposition times by changing methane concentration. The film composition and microstructure are investigated by x-ray photoelectron spectroscopy(XPS), x-ray diffraction(XRD), field emission scanning electron microscopy(FESEM), and high-resolution transmission electron microscopy(HRTEM). By comparing the composition and microstructure of three serial films, the optimal growth conditions and compositions for self-organizing nano-multilayers in copper-carbon film are acquired. The results demonstrate that the self-organized nano-multilayered structure prefers to form in two conditions during the deposition process. One is that the methane should be curbed at low concentration for long deposition time,and the other condition is that the methane should be controlled at high concentration for short deposition time. In particular, nano-multilayered structure is self-organized in the copper-carbon film with copper concentration of 10-25 at.%.Furthermore, an interesting microstructure transition phenomenon is observed in copper-carbon films, that is, the nanomultilayered structure is gradually replaced by a nano-composite structure with deposition time and finally covered by amorphous carbon.

MHD Stability Analysis and Flow Controls of Liquid Metal Free Surface Film Flows as Fusion Reactor PFCs

Numerical and experimental investigation results on the magnetohydrodynamics（MHD） film flows along flat and curved bottom surfaces are summarized in this study. A simplified modeling has been developed to study the liquid metal MHD film state, which has been validated by the existing experimental results. Numerical results on how the inlet velocity（V）, the chute width（W） and the inlet film thickness（d0） affect the MHD film flow state are obtained. MHD stability analysis results are also provided in this study. The results show that strong magnetic fields make the stable V decrease several times compared to the case with no magnetic field,especially small radial magnetic fields（Bn） will have a significant impact on the MHD film flow state. Based on the above numerical and MHD stability analysis results flow control methods are proposed for flat and curved MHD film flows. For curved film flow we firstly proposed a new multi-layers MHD film flow system with a solid metal mesh to get the stable MHD film flows along the curved bottom surface. Experiments on flat and curved MHD film flows are also carried out and some firstly observed results are achieved.

Active control scheme for improving mass resolution of film bulk acoustic resonators

High mass resolution of sensors based on film bulk acoustic resonators （FBARs） is required for the detection of small molecules with the low concentration. An active control scheme is presented to improve the mass resolution of the FBAR sen- sors by adding a feedback voltage onto the driving voltage between two electrodes of the FBAR sensors, The feedback voltage is obtained by giving a constant gain and a constant phase shift to the current on the electrodes of the FBAR sensors. The acoustic energy produced by the feedback voltage partly compensates the acoustic energy loss due to the material damping and the acoustic scattering, and thus improves the quality factor and the mass resolution of the FBAR sensors. An explicit expression relating to the impedance and the frequency for an FBAR sensor with the active control is derived based on the continuum theory by neglecting the influence of the electrodes. Numerical simulations show that the impedance of the FBAR sensor strongly depends on the gain and the phase shift of the feedback voltage, and the mass resolution of the FBAR sensor can greatly be improved when the appropriate gain and the phase shift of the feedback voltage are used. The active control scheme also provides an effective solution to improve the resolution of the quartz crystal microbalance （QCM）.

Analysis and Control of Soil Residual Film Pollution Load in Cotton Fields in the Yellow River Delta

[Objectives]This study was conducted to explore the characteristics of soil residual film pollution load in cotton fields in the Yellow River Delta,so as to effectively control soil film pollution.[Methods]Cotton field mulching film survey and residue monitoring were conducted in the Yellow River Delta area.[Results]The amount of mulching film residues in cotton fields in the Yellow River Delta was 37.7-128.7 kg/hm^(2),which had a significant increase compared with 5 years ago,and the differences between plots were large;and after straw was returned to the field,the soil residual film obviously gathered in the 20-30 cm soil layer.The residual film blocks with a size of more than 25 cm^(2) accounted for 62.6%,which was a relatively high proportion,indicating that soil pollution can be caused easily,and it is difficult to control.During a certain period of time,the soil residual film pollution may have a tendency to aggravate,and the ecological risk is higher.[Conclusions]This study has important theoretical and practical significance for improving soil quality in the region and ensuring the safety of cotton field ecosystem and environmental health.

Roughness Control of Layer-by-Layer and Alternative Spray Films from Congo Red and PAH via Laser Light Irradiation

Films from congo red (CR) alternated with poly(allylamine hydrochloride), PAH, were prepared by layer-by-layer and alternative spray techniques. In order to investigate the change of roughness induced by laser light irradiation (532 nm), both kinds of films were characterized by using UV-visible spectroscopy and atomic force microscopy (AFM). At dif- ferent irradiation times, layer-by-layer, LbL, films showed small changes in the roughness and irregular behavior, whereas spray films exhibited higher and a regular decreasing of roughness with increasing irradiation time. The higher roughness of spray films as compared with the LbL ones was attributed to different formation mechanisms of the films. The decreasing of the roughness as a function of the irradiation time (exhibited by the spray films) was associated to surface relaxation due to the interplay between photoisomerization of congo red dye and the heating of the sample during the laser light irradiation. The results suggested that the alternative spray technique is the best choose to control of roughness of the films by using light irradiation.

SOLUTION FOR PRESSURE DISTRIBUTION IN SQUEEZE FILM DAMPER WITH ELECTROHYDRAULIC ACTIVE CONTROL

Aiming at the problems existed in the squeeze film damper of the rotating machinery utilizing traditional passive dynamic pressure film bearing, a project of dynamic pressure and static pressure hybrid oil film bearing with piezoelectric crystal electrohydraulic active control supply orifice hole is proposed. For this kind of hybrid film bearing, the π film assumption can not hold true. In order to solve the pressure distribution, a new kind of solving method is proposed.

可见光减反射膜薄层控制误差的分析与性能优化

为提升光学镜头的成像质量,消除杂散光的影响,以K9玻璃为基底设计可见光波段平均反射率小于0.1%的减反射膜。采用电子束离子辅助沉积的制备方式,针对薄层敏感度高、光谱变化大等问题,通过建立稳定控制膜层厚度的数学模型来减小膜厚误差,提高制备精度和成膜稳定性。对减反射膜进行环测实验,优化调整工艺参数,侧重提高减反射膜的硬度和耐水煮能力。实验结果表明,最终制备出的减反射膜在420~680 nm波段内的平均反射率约为0.044%,最高反射率为0.0712%,克服了以MgF2为外层的减反射膜机械性能和化学稳定性较差的问题,满足工程应用低损耗、稳定可靠、高强度、可重复性制备的要求。

宽角度位相调控反射镜的设计与研制

宽角度位相调控反射镜是下一代中高轨量子通信系统中的核心元件,用于宽角度范围内信号光的高效传递与偏振态的精确调控。基于等效多层膜理论,采用介质反射膜堆加非规整位相调控膜的膜系结构,设计了一种宽角度位相调控反射镜。选择Nb2O5和SiO2分别作为高、低折射率薄膜材料,通过误差分析,优化沉积工艺,采用电子束蒸发结合离子辅助沉积的方式,在德国莱宝Lab900-plus设备上制备出该薄膜元件。研制结果表明,反射镜在780 nm处、45°±7.5°入射范围内,其反射率大于99.3%,位相差控制在3°以内,满足量子通信系统的反射率及位相差控制要求,且通过相关环境模拟实验,满足可靠性要求,为该类偏振调控薄膜元件在下一代中高轨量子卫星中的工程应用打下了坚实的基础。

粉细砂岩油藏硅烷基改性控砂剂性能评价与应用

微粒运移是影响粉细砂岩油藏开发效果的主要原因,常规抑砂剂难以达到有效控制微粒运移的要求。为进一步提高药剂稳定储层微粒的性能,文章在计算机分子模拟基础上,设计引入硅烷基改性的新型控砂剂,对合成的控砂剂进行了结构表征和性能测试。新型控砂剂体系含有酰胺基、硅烷基等功能性官能团,与储层微粒通过氢键、共价键作用相互吸附,形成稳定均匀的分子膜,原位固定地层粉细砂或黏土颗粒。性能评价表明:新型控砂剂体系耐冲刷排量达8 500 mL/h,远高于常用抑砂剂900 mL/h的指标,对不同粒径微粒均具有良好的控砂作用,储层原位控砂作用显著。截至目前,现场应用60井次,措施有效率95%,延长稳产期1年以上,取得了显著效果。该技术在全国疏松砂岩油藏具有推广示范意义。

智能化气垫带式输送机性能测试平台设计

该文设计了一种智能化气垫带式输送机性能测试平台,通过调节气室入口的风压、风速,气孔排布方式、孔径及孔间距,可探究气室气压、气膜边缘风速及气膜厚度的变化规律。平台基于可控文丘里装置的反馈系统控制气垫带式输送机的气流,实验平台可以反映输入气流参数与形成气膜参数之间的耦合关系,将抽象的相关知识具象化,加深学生对气垫式输送装备的理解。

有意义人类控制(MHC)在AI影视创作中的探索与应用

当前AI工具存在自动化程度过高、人类控制不足造成生成结果可控性差的问题,成为其应用于专业影视创作的主要壁垒。本文通过总结自主视频生成流程“墨池”(Inkstone)设计与应用中的经验,结合人工智能(AI)与自动化领域的有意义人类控制(Meaningful Human Con⁃trol,MHC)概念,对比了三种不同的自动化工具设计思路,分析了基于MHC的AI影视创作流程和工具开发具体方式,以及目前加强人类控制的若干可行技术路径。研究表明,加强AI训练和生成过程中的MHC,有望在发挥AI工具优势的前提下,对生成内容进行准确控制,从而使创作能够体现艺术家意图,适应专业影视创作需求。

纳米Cu/多糖复合抗菌膜的制备与表征及其对冬枣黑斑病的防治效果

本研究以明胶和海藻酸钠为成膜基质,采用共混法将绿色合成的纳米Cu掺入多糖膜液,采用流延法制备纳米Cu/多糖复合膜。通过场发射扫描电子显微镜、傅里叶变换红外光谱仪、热重分析仪、紫外-可见近红外分光光谱仪、质构仪以及电感耦合等离子体质谱仪表征纳米Cu及纳米Cu/多糖复合膜的结构,探究薄膜的透光性、理化性能。测定膜的抗真菌活性,并应用到冬枣黑斑病防治,及测定薄膜Cu^(2+)迁移量。结果显示,绿色合成纳米Cu粒径约为44 nm,明胶/海藻酸钠薄膜可作为纳米Cu的优良载体。并且复合膜具有良好的热稳定性、阻隔性和机械性能。此外探究不同质量浓度纳米Cu/多糖复合膜对链格孢菌、镰刀孢菌及灰霉的抑菌性能,最高抑菌率分别为87.80%、77.73%、81.96%,具有良好的抗真菌效果及广谱性。其中对链格孢菌生物量的半抑制浓度为0.25 g/L,在贮藏10 d时,该质量浓度纳米Cu/多糖复合膜对感染黑斑病冬枣的防治效果为52.53%,发病率可有效降低53.16%,且Cu^(2+)迁移量为0.018 7 μg/mL。综上,本实验制备出了一种具有抗真菌活性生物可降解包装膜,为纳米Cu的应用提供了新思路,可为新型抗真菌保鲜材料开发提供理论依据。

大面积有机–无机杂化钙钛矿薄膜及其光伏应用研究进展

有机–无机杂化钙钛矿太阳能电池具有制备成本低、光电转换效率(Photoelectric Conversion Efficiency,PCE)高的巨大优势,显示出广阔的商业化前景。经过十几年的深入研究,钙钛矿太阳能电池(Perovskite Solar Cells,PSCs)的实验室器件(<1 cm^(2))、大面积器件(1~10 cm^(2))、迷你模组级器件(10~800 cm^(2))和模组级器件(>800 cm^(2))的最高认证PCE已分别提升至26.10%、24.35%、22.40%和18.60%。随着PSCs面积扩大,PCE急剧下降,这主要是因为制备方法的局限性,难以获得高质量的大面积钙钛矿薄膜。实验室器件常采用的旋涂法难以应用到实际生产中,目前大面积钙钛矿薄膜的制备方法主要有刮涂法和狭缝涂布法,但其存在薄膜成核结晶过程难以精确控制等问题。本文从大面积有机–无机杂化钙钛矿薄膜的制备方法入手,介绍了大面积钙钛矿层成膜机制及薄膜质量提升策略。最后,对未来高PCE、高稳定性的大面积PSCs的制备技术和应用进行了展望,旨在对高性能的大面积PSCs研究提供有益参考。

马铃薯淀粉膜制备工艺优化及活性包装中百里香酚释放动力学

为提高食品包装中抑菌剂百里香酚(thymol,THY)的生物利用率以延长食品的货架期,该研究采用介孔二氧化硅(mobil composition of matter No. 41,MCM-41)作为THY的控释载体(THY-MCM-41),以马铃薯淀粉为原料制备马铃薯淀粉活性包装膜。利用L_(9)(3^(4))正交试验探究马铃薯淀粉、甘油、氯化钙和THY-MCM-41质量浓度对包装膜机械、物理以及水蒸气阻隔性能的交互影响,优化马铃薯淀粉活性包装膜最佳制备工艺参数,并在不同储存环境下对最优组合活性包装膜中百里香酚的释放动力学进行研究,构建百里香酚释放预测模型。结果表明,当马铃薯淀粉质量浓度为0.04 g/mL,甘油质量浓度为0.015 g/mL,氯化钙质量浓度为0.005 g/mL,THY-MCM-41质量浓度为0.005 g/mL时,制备的包装膜A综合性能最优,其抗拉强度、溶胀度、水蒸气透过率、透氧性和不透明度分别为7.16 MPa、89.23%、1.42×10^(-10)g/(m·s·Pa)、1.02×10^(-15)cm^(2)/(s·Pa)和1.16 mm^(-1)。电子扫描电镜和傅里叶红外光谱分析均证实了THY-MCM-41均匀地分散在马铃薯淀粉膜中,与马铃薯淀粉之间具有良好的相容性。马铃薯淀粉活性包装膜可控制百里香酚的释放速率,将百里香酚的有效作用时间延长到10 d。其中,百里香酚的释放规律符合一级释放模型(R^(2)> 0.980),其释放行为遵循菲克扩散定律。该研究为智能活性包装膜中活性物质的精准控释提供了理论基础。