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The past decades witnessed a proliferation of wireless systems research that has focused on designing more efficient communication and novel sensing applications. However, another well-known capability of wireless has arguably received less attention: the ability to heat, and more generally, provide energy. As an example, consider the microwave oven, a nearly 50-year-old invention that to this day continues to remain largely similar in capability, blasting energy blindly to re-heat food without advancing significantly in terms of fine-grained heating capabilities. Similarly, the existing energy delivery systems for powering battery-free IoT tags energize its surroundings blindly, constraining the battery-free tags to be detected only at specific checkpoints – a range of 5-15 meters at best. While precise control of wireless signals, also known as beamforming, has been an important solution in improving wireless communication systems’ throughput and signal-noise ratio, these systems have not directly translated to innovations in wireless systems for heating and energy delivery more broadly. In this dissertation, we build a suite of blind beamforming systems that deliver precisely controllable wireless energy to battery-free devices (e.g., RFID) and objects (e.g., pizza). First, this thesis describes PushID, a beamforming system that powers battery-free RFID tags at scale. Second, inspired by PushID, we present SDC, a redesigned microwave oven system to heat food in a software-defined and fine-grained thermal trajectory. Further, we build on the same heating principle to develop WASER, which moves electronics-free soft robots using wireless beamforming. Besides these, this thesis demonstrates novel battery-free soft materials that can efficiently harvest wireless energy and be capable of advanced sensing capabilities.

湖泊沉积物的重金属污染防治一直是环境领域的热点问题.本研究采用氨基生物炭作为覆盖材料，利用梯度扩散薄膜技术（DGT），研究了上覆水不同pH及水流扰动条件下Cu（Ⅱ）、Pb（Ⅱ）在沉积物水界面间的原位释放特征，以及氨基生物炭对湖泊沉积物重金属污染的原位修复效果.研究结果表明，在0 r/min或100 r/min水动力条件下，可移动态重金属离子有不断由沉积物向其他介质扩散的趋势，1.81 kg/m2的氨基生物炭覆盖强度可降低Cu（Ⅱ）、Pb（Ⅱ）释放通量达89%以上，有效减小了水环境中重金属的潜在生态风险.在pH=5的酸性及pH=9的碱性水环境中原位修复效果较差，水体中大量的H+或络合物均会削弱氨基生物炭对重金属离子的吸附，当上覆水在pH=7的中性条件时原位修复效果最佳.100 r/min水流扰动下的上覆水Cu（Ⅱ）、Pb（Ⅱ）含量在释放平衡时较0 r/min条件下高出0.036~0.096 μg/mL，说明高强度的水流扰动易造成覆盖材料的扬起和浮动，导致覆盖材料与重金属发生解吸.

Supplemental material, sj-docx-1-npx-10.1177_1934578X221095350 for Comparison of Chemical Compositions and Antioxidant Activities of Fresh and Dried Rosa roxburghii Tratt Fruit by Guanyu Yan, Peiyan Zheng, Shaoquan Weng, Yida Zhang, Wenliu Xu, Jiaying Luo, Jianjun Fei, Jingxian Wang, Hui Zhang, Haisheng Hu and Baoqing Sun in Natural Product Communications

Supplemental material, sj-docx-1-npx-10.1177_1934578X221095350 for Comparison of Chemical Compositions and Antioxidant Activities of Fresh and Dried Rosa roxburghii Tratt Fruit by Guanyu Yan, Peiyan Zheng, Shaoquan Weng, Yida Zhang, Wenliu Xu, Jiaying Luo, Jianjun Fei, Jingxian Wang, Hui Zhang, Haisheng Hu and Baoqing Sun in Natural Product Communications

Research exploring the mechanism of acupuncture has been a hot topic in medicine. Resting-state functional magnetic resonance imaging (rs-fMRI) research is a noninvasive and extensive method, which is aimed at the research of the mechanism of acupuncture. Researchers use fMRI technologies to inspect the acupuncture process. The authors reviewed the application of rs-fMRI in acupuncture research in recent 10 years from the aspects of studying acupoints, subjects, acupuncture methods, and intensities. The results found that the application of rs-fMRI in acupuncture research mainly includes research on the onset mechanism of acupuncture treatment; visual evidence of diagnosis and treatment of dominant diseases; efficacy assessments; physiological mechanism of acupoint stimulation; and specific visualization of acupoints.

The performance of a wave rotor refrigerator (WRR) is strongly affected by unsteady heat transfer between gas and tubes. In this work, the mechanism of the heat transfer and its effects on WRR were investigated numerically and experimentally. Results show that the heat absorption of wave rotor occurs in the process of shock wave propagation, and heat release happens in other processes. The unsteady heat transfer causes an uneven wall temperature. The temperature varies along the longitudinal direction, while the time variation can be neglected. Furthermore, the position of the bolts, which link the wave rotor and the shaft, has a great influence on WRR gaps. The closer the position of bolts to the high-pressure (HP) nozzle is, the less effect of gaps would be. The research is an important guiding significance to the improvement of WRR refrigeration performance and WRR design.

The gas wave ejector (GWE) is an efficient gas wave equipment using pressure waves to realize energy exchange. In this paper, a theoretical analysis of the limitation of application range and the factors affecting the performance of GWE was carried out by numerical simulation. And a complete experimental system including an adjustable GWE was employed to obtain the specific performance values in various working conditions. Such theoretical analysis showed that the device became inapplicable with a relatively high driving pressure ratio, resulting from the generation of supersonic flow at the outlet end of the passages. A relatively high supercharging ratio also limited the equipment application because of the weakening of the reflected expansion waves and the enhancement of the reversed compression wave. Furthermore, the mixing, vortex, viscosity, and other flow losses could also affect the equipment performance. Then, a complete performance map indicating the specific performance values in the application range was obtained by plenty of experiments. The performance map proved that GWE had excellent efficiency and broad applicability especially as the driving pressure ratio was lower than 2.6. The results are significant for practical application and performance improvement of GWE.

IrO2 and RuO2 are known as two of the best catalysts for the oxygen evolution reaction (OER) in acidic electrolyte. It is reported that RuO2 has higher OER catalytic activity, while IrO2 possesses better electrochemical stability during the OER process in acid. Therefore, many combined strategies have been proposed to utilize the advantages of both IrO2 and RuO2 catalysts in water electrolysis applications. In this article we describe how, by tuning the wet-chemical synthesis process in which the Ir precursor is added after the synthesis of RuO2 nanoparticles (NPs) (two-step), the Ru0.5Ir0.5O2 NPs have been synthesized to improve the OER catalytic activity in both acidic and alkaline media. In detail, the specific OER activity of the Ru0.5Ir0.5O2 NPs (with a particle size of ca. 10 nm) is 48.9 μA cm−2 at an overpotential ŋ = 0.22 V (vs. RHE) and 21.7 μA cm−2 at ŋ = 0.27 V (vs. RHE) in 0.1 M HClO4 and 0.1 M KOH, respectively. These values are higher than those for the one-step (Ir0.5+Ru0.5)O2 NPs (obtained by contemporaneously adding both Ru and Ir precursors), which are 19.5 and 15.5 μA cm−2 at the same measuring conditions, respectively. Additionally, with more IrO2 component distributed on the particle surface, the two-step Ru0.5Ir0.5O2 NPs show better OER catalytic stability than RuO2 NPs. Ministry of Education (MOE) National Research Foundation (NRF) This work was supported by the Singapore Ministry of Education Tier 1 Grant (RG131/14) and Tier 2 Grant (MOE2015-T2- 1-020) and the Singapore National Research Foundation under its Campus for Research Excellence And Technological Enterprise (CREATE) program.

Distributed localization is essential in many robotic collective tasks such as shape formation and self-assembly.Inspired by the statistical mechanics of energy transition, this paper presents a fully distributed localization algorithm named as virtual particle exchange (VPE) localization algorithm, where each robot repetitively exchanges virtual particles (VPs) with neighbors and eventually obtains its relative position from the virtual particle (VP) amount it owns. Using custom-designed hardware and protocol, VPE localization algorithm allows robots to achieve localization using sensor readings only, avoiding direct communication with neighbors and keeping anonymity. Moreover, VPE localization algorithm determines the swarm center automatically, thereby eliminating the requirement of fixed beacons to embody the origin of coordinates. Theoretical analysis proves that the VPE localization algorithm can always converge to the same result regardless of initial state and has low asymptotic time and memory complexity. Extensive localization simulations with up to 10000 robots and experiments with 52 lowcost robots are carried out, which verify that VPE localization algorithm is scalable, accurate and robust to sensor noises. Based on the VPE localization algorithm, shape formations are further achieved in both simulations and experiments with 52 robots, illustrating that the algorithm can be directly applied to support swarm collaborative tasks.

The widespread popularity of the smartphone and the increasing integrated sensors, make it possible to provide the location-based service for anyone at anytime, anywhere. The pedestrian location based on the smartphone becomes a kind of wonderful solution for indoor/outdoor positioning. A smartphone fusion location method optimized by the indoor/outdoor detection is proposed in this paper. The light sensor signal, the magnetic sensor signal, and the global navigation satellite system (GNSS) signal are integrated into the navigation algorithm to improve the accuracy of the location identification. When the device is detected indoors, the pedestrian dead reckoning algorithm based on the accelerometers and gyroscopes is applied, the initial location and the heading direction values are obtained with the help of the mobile image sensor and the indoor electronic map. When the device is detected outdoors, the GNSS and the magnetic sensor are introduced in the system to assist the inertial process of the navigation. The experiment results indicate that the continuity and the accuracy of the seamless position between the two environments are effectively improved. It is a no-blind area indoor/outdoor navigation with the help of the indoor/outdoor detection method proposed in the paper.

Chuanxu Cai,1,2,* Xiqing Bian,3,* Mingshan Xue,1 Xiaoqing Liu,1 Haisheng Hu,1 Jingxian Wang,4 Song Guo Zheng,5 Baoqing Sun,1 Jian-Lin Wu31Department of Allergy and Clinical Immunology, Guangzhou Institute of Respiratory Health, State Key Laboratory of Respiratory Disease, National Clinical Research Center of Respiratory Disease, First Affiliated Hospital of Guangzhou Medical University, Guangzhou, People’s Republic of China; 2Department of Laboratory Medicine, Shenzhen People’s Hospital, Shenzhen, People’s Republic of China; 3State Key Laboratory of Quality Research in Chinese Medicine, Macau Institute for Applied Research in Medicine and Health, Macau University of Science and Technology, Taipa, Macao, People’s Republic of China; 4Center for Tissue Engineering and Stem Cell Research, Guizhou Medical University, Guiyang, Guizhou, People’s Republic of China; 5Department of Internal Medicine, Ohio State University College of Medicine and Wexner Medical Center, Columbus, OH, USA*These authors contributed equally to this workBackground and objective: The prevalence of asthma is greater than 20% in patients previously diagnosed with COPD. Patients with asthma–COPD overlap (ACO) are at risk of rapid progression of disease and severe exacerbations. However, in some patients with ACO, a clear distinction from COPD is very difficult by using physiological testing techniques. This study aimed to apply a novel metabolomic approach to identify the metabolites in sera in order to distinguish ACO from COPD.Methods: In the study, blood samples were collected from patients with COPD, ACO, and healthy controls. Cholamine derivatization-ultrahigh performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF/MS) was used to investigate serum metabolites of eicosanoids.Results: A clear intergroup separation existed between the patients with ACO and those with COPD, while ACO tends to have higher serum metabolic levels of eicosanoids. A robust Orthogonal Projections to Latent Structures-Discriminant Analysis (OPLS-DA) model was found for discriminating between ACO and COPD (R2Y =0.81, Q2=0.79). In addition, there is a significant correlation between some metabolites and clinical indicators, such as hydroxyeicosatetraenoic acids (HETEs), hydroperoxyeicosatetraenoic acids (HPETEs) and FEV1/FVC. The higher values of area under the receiver operating characteristic curves (ROC) of HETEs, which were metabolized from HPETEs through lipoxygenase (LOX), indicated that they should be the potential biomarkers to distinguish ACO from COPD.Conclusion: Eicosanoids can clearly discriminate different biochemical metabolic profiles between ACO and COPD. The results possibly provide a new perspective to identify potential biomarkers of ACO and may be helpful for personalized treatment.Keywords: metabolomics, COPD, asthma–COPD overlap, cholamine derivatization-UHPLC-Q-TOF/MS

Fe oxides and (oxy)hydroxides are promising cost-effective catalysts for scalable water electrolysis. For an improvement in the understanding of the structural factors required by the most active Fe sites, the role of geometric tilting in determining the activity of the FeO6 octahedron for water oxidation was investigated. The catalytic performance of the FeO6 octahedron in a series of crystalline structures, i.e., perovskites AFeO3, spinel ZnFe2O4, and β-FeOOH, was found to be negatively correlated with their octahedral tilting degree. This correlation was rationalized through the Fe–O covalency, which is reflected by the O 2p band center as well as the charge-transfer energy obtained from ab initio calculations. Thus, it was disclosed that FeO6 octahedral tilting alters the activity for water oxidation through changing the covalency degree of Fe–O bonds. Ministry of Education (MOE) National Research Foundation (NRF) Accepted version This work was supported by the Singapore Ministry of Education Tier 2 Grant (MOE2017-T2-1-009), Tier 1 Grant (RG3/17(S)), and the Singapore National Research Foundation under its Campus for Research Excellence and Technological Enterprise (CREATE) programme.

The fiber ring resonator is the key component of resonator fiber optic gyros. The configuration of an air-core photonic bandgap fiber (air-core PBF) ring resonator is proposed based on a kind of free space coupling setup (FSCS). The Mathematical model of such kind of ring resonator is derived. With relevant model derivation, the effects of different parameters, including fiber coupling efficiency, alignment of fiber polarization axis and backscattering of fiber end faces, on the performance of ring resonator are simulated. It is clarified that the performance of air-core PBF ring resonator can be greatly influenced by radial linear alignment of air-core PBFs, angular alignment of air-core PBFs, the difference of incident polarization angles and the angle of air-core PBF end faces. According to the simulation, the theoretical model of the FSCS has been established. Furthermore, the solutions to three errors in the FSCS have been advanced, respectively.

TiN-based nanocomposite coatings were prepared using physical vapor deposition to deliver enhanced mechanical, tribological and thermal characters that can be exploited for superhard cutting tool surfacing. These properties are controlled by tailoring processing methods to tune the microstructure and microchemistry. This thesis examined three coating systems, which are Ti-Al-N, Ti-Al-Y-N and Ti-Si-N, configured variously as multilayer superlattices and nanocomposites to comprehensively correlate hardness, wear resistance and oxidation resistance with deposition parameters. Combining X-ray diffraction and transmission electron microscopy with physical-mechanical testing, over a wide range of coating configurations, enabled construction of a predictive process-performance matrix to guide the fabrication of hardened surfaces.In multilayer TiN/TixAl1-xN coatings prepared by cathodic arc deposition, the mechanical properties were controlled by the layer period that was adjusted by varying substrate rotation speed. A hardness of 39 ± 4 GPa was achieved for a superlattice period of 13 nm, where the coatings contain columnar textured rock salt – type crystals connected by low-angle grain boundaries. When yttrium was introduced to the multilayers, by adding a Y - metal target powered by DC magnetron sputtering, the morphology changed from columnar to acicular grains with smaller grain size. Specifically, by fixing the period at 5.5 nm and incorporating Y from 0 to 2.4 at% the grain size decreased (from 100-200 nm to 20-30 nm) and hardness increased (from 29 ± 7 GPa to 41 ± 3 GPa). The improved performance was a consequence of solid solution hardening that arises from the misfit strain field introduced by Y (element atomic radii 2.12 Å) substitution for Ti (1.76 Å) or Al (1.18 Å), and a nanosize effect, where finer grains result in a greater volume fraction of grain boundaries that block dislocation movement. Higher Y additions also retard oxidation as high temperature (800 ºC) annealing generates Ti2O3, rather than TiO2 as in Y-free coatings, and also affects Al oxidation. Adhesion and wear resistance were not compromised by higher Y contents demonstrating that TiN/TixAl1-xN coatings can enhance mechanical properties and thermal stability. Notably, this work employed a pure Y target, instead of a Ti-Al-Y alloy target, and substrate holder rotation speed was the critical parameter, where faster substrate rotation leads to smaller periods and more uniform Y distribution. However, an Y-rich layer became progressively thicker at slower rotation with the period increasing from 5.5 nm to 24 nm. These Y-rich regions seeded crystal nucleation that reduced coherency at layer interfaces and grain boundaries to significantly degrade mechanical properties (41 ± 3 GPa to 30 ± 5 GPa). Therefore, the period and Y content work in tandem in multilayered TiN/TixAl1-xN coatings and the optimized Y content was to be 2.4 at% at a period of 5.5 nm.Nanocrystallite TiN / amorphous (a)-Si3N4 nanocomposites were fabricated by high power impulse magnetron sputtering. The introduction of silicon by controlling the Si target current can be used to modify the coating structure, tailor mechanical properties, improve wear resistance and passivate oxidation. Smaller crystal sizes promoted at higher Si content lead to TiN / amorphous (a)-Si3N4 nanocomposites, with ~10 at% Si/(Si+Ti) yielding maximum hardness (41 ± 3 GPa). Compared to TiN, Ti0.903Si0.097N showed enhanced resistance to oxidation and wear resistance, however, the TiN crystallites were not completely encapsulated by a-Si3N4 intergranular films and further optimization of the structure and property relationship can be realised.; Afin d’obtenir des matériaux aux caractéristiques mécaniques, tribologiques et thermiques améliorées, nous avons élaboré des revêtements nanocomposites à base de TiN en utilisant une technique de dépôt physique en phase vapeur. Ces matériaux aux caractéristiques spécifiques peuvent être exploités pour le surfaçage d’outils de coupe de très haute dureté. En ajustant les processus d’élaboration dont dépendent la microstructure et la microchimie des revêtements, il est possible de contrôler les propriétés de ces matériaux. Cette thèse présente les résultats obtenus sur les trois systèmes de revêtement que sont Ti-Al-N, Ti-Al-Y-N et Ti-Si-N, configurés soit en réseaux superposés multicouche soit en nanocomposites. L’accent est mis sur l’étude systématique de la dureté et de la résistance à l’usure et à l'oxydation en fonction des paramètres de dépôt. En combinant la diffraction des rayons X et la microscopie électronique à transmission avec des tests physico-mécaniques sur une large gamme de configurations de revêtement, on établit une matrice processus-performance prédictive permettant de guider la fabrication de surfaces durcies.

The popularization of smartphone and continuous upgrading of configuration make the 4A target (anytime, anywhere, anybody and anything) for location service become possible. Pedestrian navigation based on smartphone is an ideal solution for indoor and outdoor seamless positioning. Mobile navigation electronic map is the basis of pedestrian navigation. A smartphone seamless positioning system based on outdoor and indoor mobile navigation electronic map is proposed in this paper. Indoor map adding seamless connection between indoor and outdoor geographic information, which is convenient for initial position determination and heading constraint. The inertial sensors and GNSS module are combined to complete the navigation solution, and the navigation software is designed in eclipse environment. The Baidu map software package is used to carry on the secondary development to support the solution and display. The experiment verified the feasibility of the smartphone seamless positioning system, which can real time display the navigation solution and work dead zone free.

Gas wave ejector (GWE) is an efficient injection and supercharging device. The rotational speed of wave rotor is an important parameter affecting the equipment performance. The influence of rotational speed on device performance was intensively studied by experiments and numerical simulations. The results suggest that there is an optimal speed to optimize the equipment performance with fixed pressure ports. Redundant compression waves are generated destroying the ideal wave system when the speed deviates from the optimal value. And the performance reduction induced by these redundant waves is different since the pressure, initial pressure ratio and reversed pressure ratio in the passages of stable pressure region are different in different working conditions. In addition, increasing rotational speed to a certain extent can reduce various types of loss in the passages. However, the viscous dissipation increases sharply if the speed is high enough. The propagation speed of shock wave increases with the increase of rotational speed, which should be taken for granted when designing the geometries of pressure ports. In the experimental conditions, the highest isentropic efficiency and ejection rate GWE can reach about 60% and 80% respectively in the experiments of this paper.

High-performance dynamic angle measurement is an intensively researched subject, which has wide applications in various fields, such as satellite antenna, long distance telescope, etc. However, few goniometers can fulfil all the requirements of wide input range, high precision and high dynamic. Non-Planar Four-Mode Differential Ring Laser Gyroscope (NP-FMDRLG) is the so-called "next-generation" of Ring Laser Gyroscope (RLG), which is of high-precision and has no mechanical dithering parts, meeting the needs of almost all the high-performance angle measuring fields. NP-FMDRLG has no mechanical dithering parts and therefore no reaction to the rotation axis of the unit under test, feathering very low non-linearity of the scale factor, and can fulfil the measurement needs of both large and small angle, both fast and slow rotation rates. Theoretically, this paper analyzes and concludes that the bias drift is the most significant factor to the high-dynamic and high-precision angle measurement. Angle measuring precision of less than 1 arc-second is theoretically verified and experimentally demonstrated with former error analysis and field experiments. Furthermore, utilizing the ultra-high-precision rotation table SCMS-107 of the National Metrology Institutes of China (NMI), a dynamic angle measuring precision of 0.121 arc-seconds is experimentally verified. Due to the advantages stated above, NP-FMDRLG is an ideal goniometer for all high-performance and high-dynamic angle measurement areas, such as numerically controlled machine tools, high-precision rotation tables, satellite antennas, long-distance telescopes, pointing applications, etc.

La teoría principal de este trabajo se basa en la teoría de la estrategia de marketing internacional. El objetivo de este trabajo consiste en analizar las estrategias que ha seguido la empresa a nivel internacional, más en concreto, en el mercado europeo. En primer lugar, el trabajo presente trata de introducir la información básica de la empresa Huawei, analizar la situación actual de Huawei, su entorno, se ha llevado a cabo el análisis de DAFO, y se ha analizado las características de los principales competidores de Huawei. En segundo lugar, el trabajo ha determinado el mercado objetivo en el extranjero de la compañía, centrándonos en el mercado europeo, desde varios aspectos, tales como el producto, el precio, la distribución, la promoción donde se ha formulado la estrategia de marketing detallado para Huawei. Por último, una introducción breve de la gestión de riesgos de mercado en el extranjero de Huawei. La implementación efectiva de la estrategia internacional de Huawei a través del fortalecimiento de la gestión de riesgos.

Using Cobb-Douglas production function to establish agricultural production function of Anhui province agriculture, this paper measures each input factor's influence on total agricultural output, and calculates the contribution rate of agricultural technology progress; meanwhile, this paper analyzes the existing problems and solutions for the problems