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This paper proposes an efficient thermoelectric temperature control system based on an improved proportional integral differential algorithm in which energy feedback technology is used to enhance thermoelectric cooling. In the proposed power management system, two groups of batteries are efficiently and alternatingly charged and discharged such that the information of the circuit can be monitored in real time. The PID algorithm is improved by using the idea of a state machine to control the thermoelectric coolers through an H-bridge circuit with pulse-width modulation. Finally, the energy feedback circuit combined with improved synchronous switching technology is designed to recycle the energy to drive the sensor. By inputting current of 3.1A, a wide range of temperature control from 1.437 to 60.187 was implemented. While targeting a temperature of 10 at an ambient temperature of 22, the proposed temperature control system had a control time of 30.5s, compared with 287s when using the conventional method, with an accuracy of 0.1, and an error of only 0.35. The results confirm that electric energy at a peak voltage of 1.2V and current of 24A can be recovered. The proposed energy feedback system can thus improve the efficiency of energy utilization of TEC from peripheral circuits.

A photovoltaic–thermoelectric (PV–TE) hybrid system can be used for efficient thermal energy utilization from the generated waste heat in PV devices. In this article, an efficient PV–TE hybrid system with intelligent power-track switching technique and thermal management based on energy conversion is proposed. To make the output power of PV–TE system stable and normalized, an incorporated stable voltage circuit is designed based on energy conversion. In addition, a control-and-monitoring strategy is launched in the system to realize the normal collecting for the output power of PV–TE system. Finally, a battery protection circuit is performed to ensure that the energy converted by the entire system is effectively stored. The experimental results show that more electrical energy about 84 034 J was obtained with our energy harvesting system than that of a single photovoltaic (PV) cell. Besides, the thermal gradient of PV cells is indirectly reduced the operation of the whole system, which is automatically monitored due to the proposed intelligent power-track switching technique.

Thermoelectric coolers (TECs) are widely used in state-of-the-art thermal management systems. Recently, there is a big trend to power TECs using thermoelectric generators (TEGs). Mainstream research efforts focus on attaining a higher figure of merit ( ZT ) of thermoelectric material, which now faces a great challenge. Alternatively, this article proposes a different approach to improve the performance of TEC, that is, integration of a TEG with a TEC. The TEG converts the collected heat energy into electric current, which reduces the power consumption and enhances the cooling capacity of the TEC. Using different methods of connecting the TEC and TEG, two thermoelectric collaborative cooling systems are proposed. Accurate SPICE models of the two cooling systems are established. The experimental results demonstrate that the discrepancy between the currents flowing through the TEC in the experiments and in the SPICE models is less than 4.8% on average. Based on the verified SPICE models, the proposed TEC-TEG collaborative cooling systems are assessed in terms of power consumption, cooling capacity, coefficient of performance, and cooling efficiency. Compared with a typical Peltier cooling system, the two collaborative cooling systems achieve significant performance improvements.

Transparent conductive electrodes (TCEs) have attracted considerable attentions as one of the essential components in optoelectronic devices. High conductivity, transmittance and flexibility are required for the practical applications of the TCEs in wearable and portable electronics. Here, a simple fabrication process of capillary force-induced printing has been developed to realize highly aligned silver nanowires (AgNWs) film with high flexibility, stretchability and conformability. Ultrathin and skin-attachable OLEDs have been realized based on the aligned AgNWs electrode. This work has proposed a low-cost and fast fabrication strategy to realize highly aligned AgNWs electrode for the flexible and stretchable optoelectronic devices.

With the development of high-power light-emitting diodes (LEDs), the heat flux density of devices has continued to increase, which, in turn, requires the development of increasingly effective methods of heat dissipation to control the working temperature of LEDs. Due to their impressive performance in solid refrigeration and energy harvesting, thermoelectric devices such as thermoelectric coolers (TECs) and thermoelectric generators (TEGs) have been used to develop the methods of heat dissipation, which have been applied to power components and electronic devices. This article proposes a delayed electrothermal collaborative cooling system based on a TEC–TEG system that uses an auxiliary charging technique for energy harvesting. In the designed delay circuit, two power source rails containing a TEG and a charged capacitor are switched automatically to supply energy to a TEC according to the charge on the capacitor and the discharge time of the delay circuit used for energy transmission. The results of experiments show that using the proposed scheme, the electromotive force can be increased by 21.6%, from 0.37 to 0.45 V, in the TEG module compared with the collaborative electrothermal cooling system without auto-delayed power rail switching. The switching time cost of the proposed system was only 0.8 s, and it could continuously supply enough electromotive force to drive the TEC and the overall cooling system. The proposed electrothermal collaborative cooling system with delayed power rail switching and auxiliary charging can improve energy utilization and reduce device cost, which helps to efficiently manage heat dissipation in high-power LEDs.

In this article, a comprehensive and efficient thermal management system is proposed to harvest and reuse the thermal waste of high-power light-emitting diodes (HP-LEDs) for the first time. Besides a conventional cooling system, including a thermoelectric (TE) cooler (TEC), a heatsink, and a fan, the proposed thermal management system also employs a TE generator (TEG), a temperature sensor, a voltage boost converter, and a microcontroller for thermal waste recycling. In this system, some of the thermal waste released by the HP-LED is harvested by the TEG and converted into electrical energy. With the help of a voltage boost converter, the harvested electrical power is used to power a temperature sensor for monitoring the surface temperature of the HP-LED. The entire system is regulated by the microcontroller. The system is elaborately established, tested, and the results are discussed. The experimental results show that the proposed system has an output electrical power of approximately $696.5~\mu \text{W}$ , which is used to power a temperature sensor as a demonstration. The sensor works well, and the discrepancy of the surface temperature of the HP-LED measured by the sensor and by a thermometer is less than 5.38%, which validates the proposed thermal management system.

Single-layer graphene (SLG) sheets can exhibit thermoelectric properties under the control of gate voltage. The controlled factors and regulation mechanism of SLG thermoelectric properties have become research hotspots. In this paper, a SLG thermoelectric parameter model considering carrier concentration and mobility with temperature and gate voltage is proposed. Based on the proposed model, the square resistance ( $R_{\mathrm {s}}$ ) and Seebeck coefficient ( $S$ ) of the SLG are calculated. The results show that the maximum value of $R_{\mathrm {s}}$ decreases from 5.8 $\text{K}\Omega $ to 3.2 $\text{K}\Omega $ at the Dirac voltage when the temperature increases from 100 K to 500 K. A large and stable $S$ can be obtained at high voltages and temperatures. The maximum value of $S$ can reach $161.3~\mu \text{V}$ /K at $T = 500$ K, exhibiting a more obvious thermoelectric characteristic. Simultaneously, the saturation law of the power factor ( $Q$ ) with the change of gate voltage and the amplitude regulation of $Q$ by temperature are obtained. This work can provide a theoretical basis for analyzing the thermoelectric characteristics of SLG.

A micro/nano structure on the metallic electrode is necessary to outcouple power lost to surface-plasmon polaritons (SPPs) in organic light-emitting devices (OLEDs). However, a simple and efficient method to integrate the micro/nano pattern onto the surface of the metallic film is still a challenge. In this work, thermal nanoimprint lithography has been employed to directly imprint periodic corrugation onto an ultrathin metallic film. Both surface morphology and conductivity of corrugated metallic film have been improved by the imprinting process, which is important for its use as electrode in optoelectronic devices. The photons that trapped in SPP modes associated at the organic-cathode interface in the OLEDs have been efficiently extracted by using the periodically corrugated ultrathin metallic film as anode of the OLEDs. A 56% enhancement of current efficiency was achieved compared with the planar device. The corrugated ultrathin anode is further applied to flexible OLEDs, and improved light extraction efficiency has been obtained.

An ultrathin metal film with high transmittance and conductivity has been demonstrated to be a promising transparent electrode for organic light-emitting devices (OLEDs). However, mediocre surface morphology and continuity of evaporated metal films and the surface plasmon-polaritons (SPPs) energy loss between the metal electrode and organic layer still limit the external quantum efficiency (EQE) of OLEDs. Here, nanoimprint lithography has been directly applied on the ultrathin Au film with underlying uncured photopolymer to fabricate the nanopillared anode. Both the conductivity and transmittance of the nanopillared ultrathin Au film have been improved due to the improvement of continuity and surface smoothness. As we expected, the SPPs mode has been coupled into photons and further extracted from OLEDs by using the nanopillared Au film anode. Finally, 19.2% and 70.1% enhancement of current efficiency were achieved compared to the planar device with ultrathin Au anode and ITO anode, respectively.

When light passes through the interface of two materials with different Seebeck coefficients (S), a temperature gradient will be occurred at the interface, causing photo-thermoelectric effect, which in turn produces photocurrent. Since photocurrent is positively correlated with the difference of Seebeck coefficient of the material and negatively correlated with the resistance of the material, a method for calculating the thermoelectric parameters of graphene with double-gate structure is proposed in this paper. Taking the back gate voltage as a global variable and the top gate voltage as a local variable, the resistance of graphene sheets in different regions is regulated. By solving the resistance of graphene sheets in two regions with top gate and without top gate, their Seebeck coefficients can be obtained. The results show that under the control of the global back gate voltage, a small range of fine adjustment of the top gate voltage can accurately achieve precise control of the resistance and Seebeck coefficient of different regions of the graphene sheet. This paper provides a theoretical basis for the subsequent study on the photoelectric characteristics of graphene.

The spherical indentation combined with acoustic emission was used to evaluate the local strength of glass, which is a nondestructive testing approach. However, stress time effect on the local strength of glass during spherical indentation has not been studied before. In the present work, stress time effect was investigated by examining the local strength of unstrengthened and strengthened glass at different loading rates. It is discovered that the local strength of glass increased greatly with the loading rate, which confirmed the time dependence of the fracture on glass. As a typical brittle material, the discreteness of strength date of glass measured by spherical indentation was also analyzed to evaluate the strength of glass correctly.

In order to utilize the thermal energy released during the working of high-power light emitting diode (LED), a method combining thermoelectric cooling with energy harvesting is proposed for comprehensively managing the heat energy. In this work, the thermoelectric generator (TEG) as an energy conversion device absorbs heat released by LED, and the thermoelectric cooler (TEC) is used to create a relatively low-temperature environment at the bottom side of TEG. Based on this method, the harvested thermal with induced thermal gradient will be converted into electrical energy. Experimental results demonstrate that the surface temperature of LED can be effectively reduced to 44.5 °C under room temperature of 25 °C with temperature difference of 15.5 K on two sides of TEG. On the basis of energy harvesting technology, the electric energy converted from this thermal energy by TEG can successfully provide long-term power for the blue diode.

We propose a plasmonic ultrathin metal grid electrode as a promising light outcoupling strategy in a flexible organic light-emitting device (OLED). The plasmonic ultrathin metal grid electrode consists of an ultrathin Au grid film incorporating with plasmonic subwavelength corrugations, which was fabricated by lithography and nanoimprint technologies, demonstrates excellent optical and electrical properties as the substitute of ITO transparent electrode in flexible OLED. The transmittance of the plasmonic ultrathin Au grid electrode is 88.5% at 550 nm and the sheet resistance is about 36 Ω/sq. The periodic subwavelength corrugations of the plasmonic ultrathin Au grid electrode excite the surface plasmon-polariton (SPP) resonance which is an adverse optical mode with power loss in OLED, and the photons trapped in SPP mode are effectively outcoupled and extracted by the plasmonic corrugations. Compared to the ITO-based device, OLED based on plasmonic ultrathin Au grid electrode realizes a desirable enhancement of 60.3% in current efficiency. In addition, the flexible OLED based on the proposed electrode also exhibits decent mechanical robustness and flexibility with stable electroluminescence performances.

Zirconium dioxide (ZrO2) nanocrystals were prepared by the microwave-assisted ionic liquid method using an ionic liquid of 1-n-butyl-3-methyl imidazolium tetrafluoroborate ([BMIM]BF4). The X-ray diffraction (XRD) patterns indicated that the crystal structure was monoclinic. The morphology of ZrO2 nanocrystals was characterized by field emission scanning electron microscopy (FESEM) and transimission electron microscopy (TEM), which showed uniform ZrO2 nanoparticles without aggregation. Thermogravimetry (TG) and Fourier transform infrared spectrometer (FTIR) curves confirmed the adsorption of organic compounds on the surface of ZrO2.

Optical tweezers play an important role in many domains, especially in life science. And optical gradient force is necessary for constructing optical tweezers. In this paper, the optical gradient force in the focal region of radial varying polarization Bessel- Gauss beam is investigated numerically by means of vector diffraction theory. Results show that the beam parameter and vary rate parameter that indicates the change speed of polarization rotation angle affect the optical gradient force pattern very considerably, and some novel force distributions may come into being, such as multiple force minimums, force ring, and force crust. Therefore, the focusing of radial varying polarization Bessel-Gauss beam can be used to construct optical traps.

Optical vortex has attracted much interest re-cently due to its novel properties and applica-tions. In this paper, the focusing properties of Gaussian beam containing one non-spiral opti-cal vortex are investigated by means of scalar diffraction theory. Simulation results show that topological charge of non-spiral optical vortex affects optical intensity distribution in focal re-gion considerably, and non-spiral focal pattern may also occur. Multiple intensity peaks may appear companying with center main focal spot under condition of higher topological charge. In addition, the number of weak intensity peak outside of the center main intensity peak is re-lated to the value of topological charge.

Focal shift of radially polarized Bessel-modulated Gaussian (QBG) beam by phase shifting is investigated theoretically by vector diffraction theory. The phase shifting distribution is the function of the radial coordinate. Calculation results show that intensity distribution in focal region can be altered considerably by the topological charge of QBG beam and the phase parameter that indicates the vary degree of the phase shifting along radial coordinate. Topological charge induces the focal shift in transverse direction, while phase parameter leads to the focal shift along optical axis of the focusing system. More interesting, the focal shift may be incontinuous in certain case.

After different frequency observed temperature data of Bohai sea marine observation stations was analyzed, results showed that daily average sea surface temperature value obtained from 3-hour-observations (08h, 14h, 20h) which was slightly lower than that from 24-hour-observations. The general gap was within 0.10°, while the value was 0.05° for the monthly mean temperature. Daily average sea surface temperature values of 3-hour-observations have a little effect both in statistical properties and the accuracy of statistical data, which does not affect the representativeness of the data. It can be used in studying long time series problems. Analyzing the trend of the SST data changes in 1960-2012 and the SAT data changes in 1965-2012 by using the linear tendency estimate and cumulative distance square method, it can prove that SST annual variation rate was 0.010°/a, with a total increase of 0.53° in last 53 years; and SAT annual variation rate was 0.043°/a, with a total increase of 2.06° in last 48 years. Although the long-term trend of these two factors is significantly increased, but there was a significant mutation around 1987. From 1960 to 1987, it had a downward trend, after 1987 it began to grow, the upward trend has not diminished until 2009.

目的 通过使用管道护理标识，降低管道不良事件风险，消除护理安全隐患。方法 在全院临床科室使用统一的管道护理标识。结果 住院患者管道不良事件发生例数、特殊用药错误或并发症等例数明显下降，有统计学意义（P < 0.01）。结论 管道护理标识有助于降低管道不良事件风险，提高护理质量。