摘要：Large cutaneous wounds pose a severe medical problem and may be deadly in cases when regeneration is ***,topical stem cell therapy has been realized as a promising strategy for wound healing and skin ***,stem cells must be administrated uniformly to the wound area,otherwise treatment will be ineffective,which has been a limitation of current administration ***,the delivery pressure and nozzle features of most clinical cell spray devices are unknown,which may significantly affect the viability of sprayed cells and their capacity for ***,we developed a novel pneumatically assisted atomization device(PAAD)in which cell suspensions were uniformly atomized at a low delivery *** optimized the applied fluidic pressure and air pressure to maximize cell survival and function for the application of multiple cell types,while ensuring uniform dispersal across the wound ***,we found that the application of sprayed umbilical cord-derived mesenchymal stem cells to wound sites significantly accelerated wound healing and promoted appendage regeneration on an excisional cutaneous wound ***,the novel PAAD system delivered living cells uniformly and maintained the viability and differentiation of sprayed cells,strongly suggesting its potential for application in clinical cell therapy,especially for large,irregular,and severe skin wounds.

摘要：针对收割过程中通常只在开机时设置一次作业参数,不能经常停机观察籽粒的清洁度进而随时调节作业参数这一问题,需要研制一种能够自动获取联合收获机作业过程中含杂率数据的装置。但是,迄今为止,在收获过程中监测籽粒含杂率的研究还处于探索阶段。针对以上问题,结合联合收获机作业过程中谷物的流变特性,该文设计了一种谷物含杂率传感器,通过电磁铁(弹簧)控制挡板的伸出(复位),以使采样盒可视玻璃窗口前聚集(卸载)谷物,通过采样盒内CMOS相机获取数字图像,应用数字图像处理技术获得含杂率。依据图像直方图优化LED光源的照射及安装方法以获取高质量图像,分析了电磁铁提供的拉力和弹簧提供的推力、采样盒入口尺寸,采用全局阈值迭代算法,使用三个迭代步提取稻谷、茎秆和细柄连通域,计算每个连通域的像素,最终从形态上识别了谷物和杂质,同时测量稻谷千粒质量、茎秆面密度和细柄线密度,建立了计算谷物杂质质量的数学模型。结果表明:在采样盒内两侧各安装2个LED,间接照射视窗时获取的图像质量较好,有效避免了图像强度直方图中出现的峰值;额定拉力为60 N的电磁铁可以提供足够的拉力;采用线径为1 mm的弹簧能提供足够的推力,由于在收割过程中出现的短秸秆和细柄的长度在10 mm到30 mm之间,因此采样盒的设计高度为95.7 mm,宽度为76.5 mm,入口宽度为31.9 mm,视窗长度为57.1 mm,宽度为57.4 mm,如此稻谷、秸秆和细柄可以顺利流入采样盒,并且在视窗中可以看到约200粒谷粒。在不同含杂率下进行了籽粒含杂率传感器监测精度的台架试验,结果表明:该装置监测的籽粒含杂率与人工获得的籽粒含杂率具有一致的变化趋势,能够监测在0～2.88%范围内的籽粒含杂率。为了满足田间作业监测需求,同时设计了采样盒的防水防尘罩,为相机提供一个稳定抓取图像的工作环境。于2017年11月17日,在苏州九里湖进行了不同喂入量下含杂率监测试验,试验使用Yamma4LZ2.5联合收割机,结果表明,田间试验的相对误差在9.44%和19.67%之间。该研究可为田间收获过程中自动获取谷物含杂率提供参考。

摘要：In this paper, we present a three-dimensional（3D） vacuum packaging technique at a wafer level for a radio frequency micro-electromechanical system（RF MEMS） resonator, in which low-loss silicon vias is used to transmit RF ***–Sn solder bonding is adopted to provide a vacuum encapsulation as well as electrical conductions. A RF model of the encapsulation cap is established to evaluate the parasitic effect of the packaging, which provides an effective design solution of 3D RF MEMS encapsulation. With the proposed packaging structure, the signal-to-background ratio（SBR） of 24 dB is achieved, as well as the quality factor（Q-factor） of the resonator increases from 8000 to 10400 after *** packaged resonator has a linear frequency–temperature（ f –T） characteristic in a temperature range between 0℃ and 100℃. And the package shows favorable long-term stability of the Q-factor over 200 days, which indicates that the package has excellent hermeticity. Furthermore, the average shear strength is measured to be 43.58 MPa among 10 samples.

摘要：本文针对一类具有时变输出约束链式非完整系统的预设时间镇定问题,首先通过tan型障碍Lyapunov函数处理系统输出约束,然后基于所给的新型切换时变函数,直接应用于虚拟(实际)控制器设计,提出了系统状态反馈镇定的非缩放变换设计方案.本文所设计的控制器使得闭环系统状态不违反约束的同时,可在任意给定的有限时间内收敛到零点.与传统的基于缩放变换设计相比,本文所提出的控制策略既有效解决了控制器的计算奇异性问题,又减少了关于时变缩放函数的计算,使控制器设计更为简单.最后,通过仿真结果验证了所提设方法的有效性.

摘要：The rise in the cases of motor impairing therapy. Due to the current situation that the service illnesses demands the research for improvements in rehabilitation of the professional therapists cannot meet the need of the motorimpaired subjects, a cloud robotic system is proposed to provide an Internet-based process for upper-limb rehabilitation with multimodal interaction. In this system, therapists and subjects are connected through the Internet using client/server architecture. At the client site, gradual virtual games are introduced so that the subjects can control and interact with virtual objects through the interaction devices such as robot arms. Computer graphics show the geometric results and interaction haptic/force is fed back during exercising. Both video/audio information and kinematical/physiological data axe transferred to the therapist for monitoring and analysis. In this way, patients can be diagnosed and directed and therapists can manage therapy sessions remotely. The rehabilitation process can be monitored through the Internet. Expert libraries on the central server can serve as a supervisor and give advice based on the training data and the physiological data. The proposed solution is a convenient application that has several features taking advantage of the extensive technological utilization in the area of physical rehabilitation and multimodal interaction.

摘要：Contact engineering is of critical importance for two-dimensional(2D)transition metal dichalcogenide(TMD)-based ***,there are only a few solutions to overcome this obstacle because of the complexity of the TMD-contact *** this work,we propose a novel method using a soft plasma treatment followed by the seamless deposition of a metal electrode to reduce the contact resistance of MoS_(2)field effect transistors(FETs).The treated FETs exhibit three times higher mobility than the control FETs without plasma *** soft plasma treatment can remove the facial sulfur atoms and expose the middle Mo atoms so that they come into direct contact with the metal electrode,thus greatly improving the contact ***-principles calculation is also performed to support the experimental *** potentially scalable strategy can be extended to the whole family of TMD based FETs to provide a possible route of device processsing technology for 2D device application.

摘要：A 10 Gbit/s burst-mode preamplifier is designed for passive optical networks （PONs）. To achieve a high dynamic range and fast response, the circuit is DC coupled, and a feed-back type peak detector is designed to perform auto-gaincontrol and threshold extraction. Regulated cascade （RGC） architecture is exploited as the input stage to reduce the input impedance of the circuit and isolate the large parasitic capacitance including the photodiode capacitance from the determination pole, thus increasing the bandwidth. This preamplifier is implemented using the low-cost 0. 13 ixm CMOS technology. The die area is 425 μm × 475 μm and the total power dissipation is 23.4 mW. The test results indicate that the preamplifier can work at a speed from 1.25 to 10.312 5 Gbit/s, providing a high transimpedance gain of 64.0 dBΩ and a low gain of 54. 6 dBl2 with a dynamic input range of over 22.9 dB. The equivalent input noise current is 23. 4 pA/ Hz1/2. The proposed burst amplifier satisfies related specifications defined in 10G-EPON and XG-PON standards.

摘要：Natural anisotropic nanostructures occurring in several organisms have gained more and more attention because of their obvious advantages in sensitivity, stability, security, miniaturization, portability, online use, and remote monitoring. Due to the development of research on nature-inspired bionic structures and the demand for highly efficient, low-cost microfabrication techniques, an understanding of and the ability to replicate the mechanism of structural coloration have become increasingly significant. These sophisticated structures have many unique functions and are used in many applications. Many sensors have been proposed based on their novel structures and unique optical properties. Several of these bio-inspired sensors have been used for infrared radiation/thermal, pH, and vapor techniques, among others, and have been discussed in detail, with an intense focus on several biomedical applications. However, many applications have yet to be discovered. In this review, we will describe these nanostructured materials based on their sources in nature and various structures, such as layered, hierarchical, and helical structures. In addition, we discuss the functions endowed by these structures, such as superhydrophobicity, adhesion, and high strength, enabling them to be employed in a number of applications in biomedical fields, including cell cultivation, biosensors, and tissue engineering.

摘要：The novel jet self-priming centrifugal pump,as important modern irrigation equipment,is widely used in large-scale irrigation,mine drainage and so *** order to improve the profile streamline of blade,the inlet shape of impeller was designed as distorted and the outlet shape as cylindrical,which can not only improve the pump efficiency,but also shorten the self-priming ***,the novel jet self-priming system was proposed,by employing the jet nozzle and check valve to improve the velocity of ***,nine different structure jet nozzles were designed based on the orthogonal design method,and the relevant self-priming experiments were performed on I level accuracy test bench in jiangsu *** to the greycorrelational analysis,the influence of the nozzle geometry parameters on the self-priming performance was *** relationship between self-priming time and self-priming height was *** test results showed that the hydraulic design of jet self-priming centrifugal pump was reasonable;all indicators met the Chinese national standard;the head reached 21.04 m and efficiency was 72.8%under the design flow *** is more,the self-priming performance was obviously improved by adjusting the geometrical parameters of *** the height of the self-priming process was 5.3 m,the self-priming time reached 62 s,which was much shorter than the national ***,this research could provide reference for designing the structure of jet self-priming centrifugal pump.

摘要：Nanozymes,the functional nanomaterials with enzyme-like activities,have been widely explored for both in vitro and in vivo applications(Wei and Wang,2013;Wu et al.,2019;Huang et al.,2019;Liang and Yan,2019).Particularly,by modulating the levels of reactive oxygen species(ROS)in vivo,numerous therapeutic nanozymes have been developed to treat diseases,ranging from cancer to neurodegenerative diseases(Fan et al.,2018;Kwon et al.,2018).