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The bottom-up approach to directly synthesizing low-dimensional materials with outstanding performance has extended the material basis for the next generation integrated circuit industry. All the low-dimensional semiconductors, metals, dielectrics, and their heterojunctions are very promising bricks to build faster and more efficient chips because of their atomically smooth surface and interfaces. The greatest challenge in the synthesis of nanomaterials is how to precisely control the structure, crystalline orientation, defects, dimensions, etc. In past decades, both the methodology and the mechanism of synthesis have been systematically investigated to improve the controllability. However, few studies focused on sensing the synthesis processes in situ and responding to the synthesis immediately. Here, we propose the concept of intelligent synthesis in which the final product can be automatically fine-controlled by a closed loop including in situ monitoring and real-time interventions. As a model system, a high-temperature-tolerant circuit is fabricated on the single-walled carbon nanotube (SWCNT) growth substrate for sensing and responding to the synthesis processes. As a result, either highly pure semiconducting (s-) SWCNT arrays or metallic-semiconducting (m-s) junction arrays with different junction positions is simply synthesized by programming the responding signal. The intelligent synthesis shows much higher efficiency and controllability compared to conventional methods and will lead to the next leap in nanotechnology.

The elderly may have unique, daily travel behaviour characteristics compared to other age groups, associated with age and physical ability. Defining these characteristics can inform urban infrastructure construction and planning. In this study, 20 elders aged between 60 and 70 years, living in the city centre of Tianjin, were selected to complete the survey. A total of 2232 hours of participant travel behaviour were collected via GPS equipment from July to August 2019. Data were used to create a space–time cube. Based on a statistical analysis of the GPS data, results indicated that the elderly mainly had six kinds of daily travel behaviours: visiting, shopping, outdoor exercise, eating out, going to the hospital and picking up and dropping off grandchildren. The main activity time was from 10:00 a.m. to 9:00 p.m. Their travel mode was mostly pedestrian-based, with an average single travel distance of about 1.01 km, and an average single travel time of about 0.5 hours. Using the space–time cube, characteristics of elderly daily travel behaviour were visualised. In addition, a typical space–time cube was summarised and presented. Data and methods from this study can provide reference and support for future-related research.

High-dose methotrexate (HDMTX) combined with leucovorin (LV) is the first-line drug therapy for many kinds of malignant tumors. However, the specific treatment plans, such as dosage and duration of administration, are usually formulated according to the clinician’s experience and therapeutic drug monitoring (TDM) of methotrexate in patients’ plasma, which are responsible for strong individual differences of drug usage. A large number of studies have shown that methotrexate targets the inside of the cell. The key cytotoxic component is the methotrexate polyglutamates (MTXPGs) in the cell. The concentration of methotrexate in plasma does not reflect the efficacy and side effects well. Based on mass spectrometry technology, we developed and validated an accurate, sensitive, and stable method to quantify the intracellular MTX (MTXPG1) and its metabolites MTXPG2–7 simultaneously. The lower limit of quantification was 0.100 ng/ml, and the run time was only 3 min. Moreover, our team has already developed two LC-MS/MS-based methods to respectively quantify methotrexate in plasma samples and two key proteins (γ-glutamyl hydrolase [GGH] and folylpolyglutamate synthetase [FPGS]) in peripheral blood mononuclear cells (PBMC). Through these highly sensitive and accurate approaches, we have gained a deep understanding of the whole pharmacokinetic process of MTX and explored the key factors affecting the accumulation process of intracellular active components (MTXPGs). Based on this research, it is possible to find a more effective way to provide an accurate reference for clinical drug use than traditional therapeutic drug monitoring (TDM).

This paper discusses the volcanic influence on the mineralogical and elemental geochemistry of No. 6 coal from Nanyangpo Mine in the Datong coalfield, north China. Sixteen samples (14 coal and 2 partings) were analyzed by different geochemical methods. The results revealed that the No. 6 coal is a medium–high volatility, highly calorific, bituminous coal with a low-ash and medium-sulfur content. The minerals mainly consisted of kaolinite, calcite, dolomite, and pyrite. In addition, traces of apatite, sphalerite, and anatase were also found. Calcite, dolomite, and pyrite in the coal samples were mainly derived from epigenetic hydrothermal solutions, whereas kaolinite and apatite originated from volcanic ash. Harmful trace elements including Pb, Cu, Mo, Tl, and Hg in the No. 6 coal samples were higher than those of common global coals. These harmful elements mainly occurred in sulfide minerals, which were probably influenced by hydrothermal inputs.

This article is devoted to the study of Japanese loanwords in Chinese and their classification. Particular attention is paid to the lexical units in writing in Chinese characters, coming from the Japanese language as graphic loanwords in modern Chinese and Japanese, popular on the Chinese-language Internet. The material of the study is loanwords of Japanese origin, selected from dictionaries and scientific works on this topic, as well as word usage in messages on Russian and Chinese Internet forums. We distinguish between two types of Japanese loanwords in Chinese according to how they are borrowed: phonetic and graphic borrowed words. Graphic borrowed from the Japanese language, including the actual Japanese words spelled in Chinese characters, and words created by the Japanese using Chinese characters to convey tokens of other languages, as well as the words of the ancient Chinese language, rethought by the Japanese to create terms, then returned back to modern Chinese language, constitute a characteristic group of graphic loanwords in Chinese.

Recently, lane detection has made great progress with the rapid development of deep neural networks and autonomous driving. However, there exist three mainly problems including characterizing lanes, modeling the structural relationship between scenes and lanes, and supporting more attributes (e.g., instance and type) of lanes. In this paper, we propose a novel structure guided framework to solve these problems simultaneously. In the framework, we first introduce a new lane representation to characterize each instance. Then a topdown vanishing point guided anchoring mechanism is proposed to produce intensive anchors, which efficiently capture various lanes. Next, multi-level structural constraints are used to improve the perception of lanes. In the process, pixel-level perception with binary segmentation is introduced to promote features around anchors and restore lane details from bottom up, a lane-level relation is put forward to model structures (i.e., parallel) around lanes, and an image-level attention is used to adaptively attend different regions of the image from the perspective of scenes. With the help of structural guidance, anchors are effectively classified and regressed to obtain precise locations and shapes. Extensive experiments on public benchmark datasets show that the proposed approach outperforms state-of-the-art methods with 117 FPS on a single GPU., Accepted by IJCAI 2021

In view of weak defect signals and large acoustic emission (AE) data in low speed bearing condition monitoring, we propose a bearing fault diagnosis technique based on a combination of empirical mode decomposition (EMD), clear iterative interval threshold (CIIT) and the kernel-based fuzzy c-means (KFCM) eigenvalue extraction. In this technique, we use EMD-CIIT and EMD to complete the noise removal and to extract the intrinsic mode functions (IMFs). Then we select the first three IMFs and calculate their histogram entropies as the main fault features. These features are used for bearing fault classification using KFCM technique. The result shows that the combined EMD-CIIT and KFCM algorithm can accurately identify various bearing faults based on AE signals acquired from a low speed bearing test rig.

Significance Spatial resolution can be electrically switched between high-resolution mode (HRM) and low-resolution mode in mixed-dimensional heterostructured photodetectors, and an interference fringe with 334 nm in period can be discriminated by setting at HRM. This can be attributed to the asymmetric geometry and the gate-tunable Fermi levels of these low-dimensional materials. It reveals great potential of the mixed-dimensional architectures in future nanoelectronics and nano-optoelectronics., Low-dimensional nanomaterials, such as one-dimensional (1D) nanomaterials and layered 2D materials, have exhibited significance for their respective unique electronic and optoelectronic properties. Here we show that a mixed-dimensional heterostructure with building blocks from multiple dimensions will present a synergistic effect on photodetection. A carbon nanotube (CNT)–WSe2–graphene photodetector is representative on this issue. Its spatial resolution can be electrically switched between high-resolution mode (HRM) and low-resolution mode (LRM) revealed by scanning photocurrent microscopy (SPCM). The reconfigurable spatial resolution can be attributed to the asymmetric geometry and the gate-tunable Fermi levels of these low-dimensional materials. Significantly, an interference fringe with 334 nm in period was successfully discriminated by the device working at HRM, confirming the efficient electrical control. Electrical control of spatial resolution in CNT–WSe2–graphene devices reveals the potential of the mixed-dimensional architectures in future nanoelectronics and nano-optoelectronics.

PURPOSE: This study aimed to investigate the prevalence, risk factors, and effects of primary nocturnal enuresis (PNE) on physical and mental health in young adults in mainland China.METHODS: An anonymous questionnaire was used to collect information including the sociodemographic characteristics, history of PNE, family history, daytime voiding symptoms, Pittsburgh Sleep Quality Index (PSQI) scores, Self-Esteem Scale (SES), and Self-Rating Depression Scale (SDS). A total of 22,500 university students from 23 provinces and 368 cities in mainland China were included.RESULTS: In total, 21,082 questionnaires were collected, and 20,345 of them qualified for statistical analysis. The PNE prevalence was 1.17%, and the distribution of monosymptomatic nocturnal enuresis (MNE) and nonmonosymptomatic nocturnal enuresis (NMNE) was 66.1% and 33.9%, respectively. In total, 28% of respondents with PNE reported bedwetting daily, 31.6% between 1 and 7 times weekly, and 40.4% between 1 and 4 times monthly; 80% of PNE cases had no history of treatment. The prevalence of PNE in patients with a family history, frequency, urgency, urinary incontinence, and recurrent urinary tract infections was significantly higher than in those without these conditions (PCONCLUSION: In mainland China, the PNE prevalence among young adults was found to be high, and PNE had significant effects on physical and mental health. Risk factors included a family history, daytime voiding symptoms, and lack of treatment.

Because of such advantages as light weight, small sizes, short launch cycle, the micro-satellite technology has been extensively used in military and civilian fields. To further improve the autonomous operation of a micro-satellite, and reduce intervention and control of the earth station, the author has controlled the autonomous operation of the cameras carried by the micro-satellite based on previously developed satellite service software. Also, the author has built a semi-physical simulation system for functional verification. The experiment result shows that this design is rational and reliable, which efficiently improves the autonomous operation ability of the micro-satellite.

Due to its advantages of light weight, small size and short launch period, etc., microsatellite is widely applied in military and civil fields. In order to further improve the data processing ability of microsatellite and optimize the integrated electronic system architecture, this paper presents a satellite CAN bus communication system which is suitable for microsatellite. Based on the FPGA module of SmartFusion2 chip, this design implements the IP core expansion of CAN bus, and carries out the dual redundancy design of two-stage bus, which can increase the integration of satellite system while improving the reliability and stability of communication network, and can be applied to the integrated design of satellite operation and attitude control. According to CAN communication protocol, CAN communication function is designed, which can be adopted for data polling, data processing, communication fault diagnosis and other operations. Finally, the rationality and reliability of the hardware and software design are verified by connecting the onboard computer with the real-time simulator to conduct joint simulation, thus meeting the design requirements.

This paper provides new geochemical data focusing on valuable elements in the coal, parting, and floor samples in the No. 5 coal seam of the Taiyuan Formation from the Wujiawan mine, Datong coalfield, northern China. The minerals mainly consist of kaolinite, calcite, and pyrite, as well as trace amounts of quartz and illite. The No. 5 coal is enriched in Li, Ga, high field strength elements (HFSEs), and rare earth elements and yttrium (REY) when compared with world hard coals. Of particular interest is the high average concentration of Li (67.66 &mu, g/g), which is around seven times higher than the value for world hard coals. Lithium, Ga, and HFSEs have strong inorganic affinities, whereas REY have organic affinities. The main carrier of Li, Ga, and HFSEs is aluminosilicate minerals, while REY appear to occur with organophosphorus. These HFSEs are enriched, both in the parting and in the adjacent coal samples. This suggests that these elements are likely to leach out during the diagenetic process. The distribution patterns of REY, along with the ratio of Al2O3/TiO2 and the figure of Zr/TiO2 vs. Nb/Y are suggestive of their derivation from felsic parent material. In the northern and eastern part of the Datong coalfield, there are several regions where the Li content is higher than the mineable grade, in particular in the northern Datong coalfield where there is a mine with an Li content of 294.6 &mu, g/g. This is significantly higher than the mineable grade. Therefore, there is a potential for financially viable recovery of Li in these coals of the Datong coalfield.

The Early Permian coal is of great value in the Tengxian Coalfield, Shandon Province, Eastern China. This work deals with the new data focusing on mineralogical characteristics in the Early Permian Shanxi Formation No. 3 coal from the Jinyuan Mine. The Jinyuan coal is a low ash and highly volatile A bituminous coal. Minerals in the No. 3 coal mainly comprise of kaolinite, ankerite, illite, calcite, siderite, and quartz, with varying compositions of trace amounts of pyrite, jarosite, bassanite, anatase, and rutile. According to mineral assemblage in the coal plies, three Types (A to C) can be identified in the No. 3 coal. The dominant minerals in Type A are poorly-ordered kaolinite, illite, quartz, pyrite, and jarosite. Type B is mainly composed of well-ordered kaolinite, illite, siderite, ankerite, and calcite. Type C, with just one sample (JY-3-7c), which contains high proportions of calcite (54%) and ankerite (34%). Terrigenous minerals are elevated in coal plies that typically have relatively high contents of ash yield. The formation of syngenetic pyrite was generally due to seawater, while the sulphate minerals (jarosite and coquimbite) were derived from the oxidation of pyrite. Epigenetic vein-like or fracture-fillings carbonate minerals (ankerite, calcite, and siderite), kaolinite, and pyrite, as well as authigenic quartz were derived from the influx of hydrothermal fluids during different periods, from the authigenic to epigenetic. The paragonite in the coal may have been formed by the precipitated from Na-rich hydrothermal fluids. No effects of magmatic intrusion on mineralogy were investigated in this research.

Carbon nanotubes (CNTs) are anticipated to be the successor of silicon in next-generation integrated circuits. However, one great challenge to the practical application of this concept is the need to grow horizontal semiconducting CNT arrays with very high purity. Here we show that this roadblock can be eliminated by switching the direction of an applied electric field during synthesis. This electro-renucleation approach twists the chirality of the CNTs to produce nearly defect-free s-CNTs horizontally aligned on the substrate with less than 0.1% residual metallic CNT. In principle, this residual percentage can be further reduced to less than 1 ppm simply by tuning the CNTs’ diameters to around 1.3 nm. Electro-renucleation thus offers a potential pathway to practical applications of CNT electronics and opens up a new avenue for large-scale selective synthesis of semiconducting CNTs and other nanomaterials. The main hurdle to the deployment of carbon nanotubes in the electronics industry is the requirement of obtaining pure semiconductor nanotube horizontal arrays. Here, a method is presented to prepare highly pure semiconductor nanotubes by switching the direction of an applied electric field during synthesis.

The company's data leakage has always been a very serious problem. Many of the leaked data is the user's personal privacy data, which will bring a lot of trouble to users. In order to improve the security of the storage and use of personal private information in the database, two methods of lightweight private information encryption and social engineering anonymization are proposed to protect database information. We compare the proposed method with the application layer encryption and pre encryption methods. The experimental results show that the proposed method can effectively protect the user's personal privacy data, and can detect and recover the privacy data when managers need it. The storage efficiency of the three methods is close. Therefore, it has good application value in privacy protection.

In this paper, a spherical film array structure based on vanadium dioxide (VO2) was designed and fabricated aimed to enhance the frequency response of transmittance in terahertz (THz) band of VO2 films. Vanadium dioxide and vanadium pentoxide composite spherical films were grown on the surface of two-dimensional single layer array of SiO2 sphere by magnetron sputtering and rapid thermal annealing method, and the frequency response of transmittance of spherical films was studied. The THz transmittance modulation depth (MD) of spherical films increased significantly in the 1.5–3 THz range as frequency increased, while MD of planar films only increased slightly throughout the frequency band. We attributed the frequency response of the MD of spherical films to the absorption by electric dipole resonance. The numerical simulations and electric field distributions illustrate that the regulating effect of resonance absorption would increase as the width of spherical gaps increase. When the width of the spherical gaps was 0 . 05 μ m , the absorptivity would increase by 120% from 1.5 to 3 THz, showing the possibility of further improving the THz MD of spherical films. This research would provide a good candidate material in the active modulation in terahertz band which broaden a path for dynamic terahertz radiation manipulation devices.

Springback, which occurs during stamping of shallow-drawn titanium alloy sheets, can negatively influence the stamping accuracy and reliability of follow-up assembly and welding of parts and restrict the application of titanium alloy sheets when high precision is a requirement. Therefore, accurate prediction and control of springback in titanium alloy sheets is an industrial problem that requires urgent attention. In this paper, a TA2M titanium alloy box formed via shallow drawing is used as the research object and springback control during stamping is attempted by varying the magnitude and mode of the blank holder force (VBHF) and height of a controllable drawbead. The influences of drawbead height, VBHF magnitude, and loading mode on the resulting sheet springback are determined by means of finite element simulation and experimentation to determine the best combination yielding the minimum springback. The results of this research provide a reliable reference for future efforts to form tough materials.

Zinc oxide thin film UV photodetectors based metal-semiconductor-metal structure were fabricated on Au interdigital electrodes by radio frequency magnetron sputtering. The performances of the UV photodetector under different annealing and testing temperatures from RT to 200 °C have been studied, obtaining optimized annealing temperature and suitable working temperature range. The detailed photoresponse mechanism has been discussed by analyzing competitive behaviors of several factors. The photodetector has good photoresponse linearity across a wide range of incident light intensity, and the response time, recovery time and responsivity were 0.82 ms, 0.64 ms and 124 A/W respectively under the 2.5 mW/cm 2 at 5 V applied bias. The low annealing temperature of ZnO film makes it be applied in flexible photodetector with great potential.

The accelerating urbanization and improvement of living standards have greatly increased the municipal solid waste (MSW) generation in China. Public private partnership (PPP) widely used in the field of waste-to-energy (WTE) industry can decrease the volume of MSW, generate power and address the serious environmental problems caused by MSW. The advantage of PPP model can be expressed in its inherent incentive, expanding product quality, improving capacity utilization, saving transaction costs, improving efficiency of WTE industry. We collect data of municipal solid waste disposal fee from 69 PPP WTE projects of 231 operating projects, covering 30% of all PPP WTE operating projects in 29 provinces from 1999–2016, the spatial-temporal model is built to analyze the waste-to-energy environmental efficiency in PPP waste-toenergy industry.

Background This study evaluated the minimal invasiveness, safety, and accuracy of robot-assisted pedicle screw placement procedure using a modified tracer fixation device. Methods Patients were randomly assigned to conventional fixation group (25 patients) and modified fixation group (27 patients). Results No baseline statistical difference was observed between the groups (P > 0.05). The length of unnecessary incision, amount of bleeding, and fixation duration for tracer fixation respectively were 6.08 ± 1.02 mm, 1.46 ± 0.84 ml, and 1.56 ± 0.32 min in the modified fixation group and 40.28 ± 8.52 mm, 12.02 ± 2.24 ml, and 5.08 ± 1.06 min in the conventional group. The difference between both groups was significant (P P > 0.05). Conclusions The modified minimally invasive procedure for tracer fixation results in minimal trauma and is simple, reliable, and highly safe. Additionally, the procedure does not compromise the accuracy of pedicle screw placement. Thus, it has great clinical applicable value. Trial registration Chinese Clinical Trial Registry: Registration number, ChiCTR1800016680; Registration Date, 15/06/2018.

It is common for major depressive disorder (MDD) to be accompanied by gastrointestinal (GI) symptoms, which are known to negatively impact the course and severity of the disease. Although previous studies have attempted to explore the neuropathology of MDD, few studies have focused on the pathogenesis of GI symptoms in MDD. In this study, we investigated the changes in regional gray matter volume (GMV) and regional homogeneity (ReHo) present in MDD accompanied by GI symptoms.The following images were obtained and analyzed: Structural and functional magnetic resonance images (MRI) of 36 patients with MDD accompanied by GI symptoms (GI symptoms group), 22 patients without GI symptoms (Non-GI symptoms group), and 27 healthy controls (HC. The 24-item Hamilton Depression Rating Scale (HAMD) was administered. A correlation analysis was used to identify the possible associations between altered regional GMV, ReHo symptoms, GI symptoms, and depressive symptoms.The total scores from the HAMD-24 in the GI symptoms group were significantly higher than in the Non-GI symptoms group (P0.05). Significant differences in both GMV and ReHo were observed among the three groups for the right parahippocampal gyrus, left precentral gyrus, left middle frontal gyrus, right superior frontal gyrus, right middle frontal gyrus, and left inferior orbitofrontal gyrus (AlphaSim correction, P0.001). The GI symptoms group exhibited significantly decreased GMV and ReHo in the left middle frontal gyrus, precentral gyrus, right superior frontal gyrus, and middle frontal gyrus. Additionally, the GI symptoms group exhibited increased ReHo in the left superior temporal gyrus at a higher level than the non-GI symptoms group. (AlphaSim correction, P0.001). These altered brain areas were correlated with GI symptoms (P0.001) but not depressive symptoms (P0.05).Patients with MDD accompanied by GI symptoms have more severe depressive symptoms. The structural and functional changes of the brain may be the pathogenesis for the GI symptoms in patients with MDD.

Considering the problems of randomness and fuzziness in evaluating indexes from maritime search and rescue response capability system, a novel method based on subjective-objective attribute weights integrated and center normal grey cloud method was presented. Firstly, cloud theory was introduced to transform the uncertainty of factors into quantitative digital features, to achieve the qualitative indicators of quantitative processing. Secondly, the improved analytic hierarchy process(IAHP) and criteria improved through inter-criteria correlation(CRITIC) were used respectively to determine the subjective and objective weights. The comprehensive weights were thus obtained through the relative information entropy principle. Thirdly, grey cloud method was used to make the second level evaluation indexs to get the assessment of maritime search and rescue response capability. And on the basis of that, the maritime search and rescue response capability evaluation results was obtained. Finally, the model was evaluated on three ports and the results showed the IAHP-CRITIC combination weighting method can effectively integrate the subjective and objective weights information. Compared with the other traditional models, our proposed model in this paper is closer to the actual situation which can comprehensively consider grey, fuzziness and randomness in the evaluation process. The above illustrative example analysis shows the effectiveness and feasibility of this method.

MUSTAFA, OZGUROGLU/0000-0002-8417-8628; CARCANO, FLAVIO M/0000-0002-0002-3507; Smirnov, Alexey/0000-0001-5361-8232; Sciarra, Alessandro/0000-0002-7899-8056; Chung, Byung Ha/0000-0001-9817-3660; Mosca, Alessandra/0000-0003-2538-8411 WOS:000474094900008 PubMed ID: 31150574 Background Apalutamide is an inhibitor of the ligand-binding domain of the androgen receptor. Whether the addition of apalutamide to androgen-deprivation therapy (ADT) would prolong radiographic progression-free survival and overall survival as compared with placebo plus ADT among patients with metastatic, castration-sensitive prostate cancer has not been determined. Methods In this double-blind, phase 3 trial, we randomly assigned patients with metastatic, castration-sensitive prostate cancer to receive apalutamide (240 mg per day) or placebo, added to ADT. Previous treatment for localized disease and previous docetaxel therapy were allowed. The primary end points were radiographic progression-free survival and overall survival. Results A total of 525 patients were assigned to receive apalutamide plus ADT and 527 to receive placebo plus ADT. The median age was 68 years. A total of 16.4% of the patients had undergone prostatectomy or received radiotherapy for localized disease, and 10.7% had received previous docetaxel therapy; 62.7% had high-volume disease, and 37.3% had low-volume disease. At the first interim analysis, with a median of 22.7 months of follow-up, the percentage of patients with radiographic progression-free survival at 24 months was 68.2% in the apalutamide group and 47.5% in the placebo group (hazard ratio for radiographic progression or death, 0.48; 95% confidence interval [CI], 0.39 to 0.60; P

Terahertz absorbers combined with phase-changing V O 2 are a class of stealth materials with adjustable absorptance. However, such absorbers still suffer from insufficient absorption bandwidth. We propose a three-layer terahertz (THz) absorber, consisting of an array of diagonally distributed double-sized V O 2 disks on a silica-coated gold film. We find this structure can generate the superposition of three resonant absorption peaks to broaden the absorption band. The finite element simulation (FES) results show that the absorption bandwidth can be adjusted from 2.63 to 5.04 THz by simply changing the sizes of the V O 2 disks. In addition, the peak absorptance can be continuously regulated from 9.8% to 96% by varying the conductivity of V O 2 . Finally, the absorber is polarization-insensitive and has wide-angle absorption. The wide absorption band and adjustable bandwidth of the absorbers have important applications potentially for intelligent stealth materials.

Femtosecond laser treatment has been widely used for modulating different kinds of materials as a convenient and efficient approach. In the process of laser modulation, the ionization caused by femtosecond laser irradiation may significantly affect the propagation and energy deposition of laser pulse inside the material, and thus finally influencing the surface morphology and optimizing the material properties. In this work, the ablation of WS2 is conducted in a wide range of laser fluence by single pulse. With the increase of injected energy, the expansion of craters goes through a process from rapid growth to stabilization both in the direction of diameter and in the depth direction. And a plasma model is proposed to track the dynamic response of the excited material and the transfer and deposition of the laser energy in the irradiation of WS2. The calculated results reveal that a great number of free electrons will generate after the incidence of laser pulse and leads the dense plasma zone to form. In this zone, the reflection on the surface and the absorption inside of WS2 are both enhanced due to the rapid increase of free electron density, which affects the injection and deposition of laser energy, thus resulting in the deposition of most energy in the shallow area below the surface. With the increasing of the laser fluence, the majority of laser energy is deposited on the surface of WS2, which leads the ablation crater to reach the saturation state. Meanwhile, a double-pulse train generated by temporal shaping is utilized to modulate the diameter of craters. By adjusting the pulse delay, the smallest diameter of the crater can be obtained at 0.7 ps. The results pave the way for potential applications of the effective method in controlling the material removal and improving the catalytic performance of pristine WS2.

In aerospace industry, metallic alloys are regularly used to manufacture various components ranging from stabilizers to engine shafts. These components must withstand foreign objective damage (FOD), which includes bird strikes, hail, ice, or any metal or concrete debris from the runway. In this current research, some selected aerospace grade alloys, namely, Al-2024-T3, Al-7075-T6, Ti-6Al-4V, and Inconel-718, which are regularly used to build potential aircraft components exposed to bird strike (otherwise known as soft impact) phenomena, is numerically tested to investigate their ability to resist the collision under two different impact velocities (117 m/s and 147 m/s). Finite element explicit code Ansys is adopted to run the test cases. Johnson-Cook flow stress and damage parameters are selected to model the alloy materials while Mooney-Rivlin parameters are utilized to represent the Lagrange bird model. From the investigation, it is found that the Inconel-718 plate is the best candidate to resist the bird impact and further analysis reveals that it can withstand an impact velocity of 327 m/s without being penetrated. Apart from Inconel-718 alloy, both Al-2024-T3 and Ti-6Al-4V plates are found to be damaged at the impact velocity of 147 m/s, while Al- 7075-T6 is completely penetrated even at a lower impact velocity, 117 m/s. Finally, some recommendations and future research directions are suggested based on numerical outcomes.

In order to improve performance of ejector refrigeration system, a booster is added before an ejector to enhance secondary flow pressure, which is called a booster assisted refrigeration system. Based on mass, momentum and energy conservation, a 1D model of ejector for optimal performance prediction was presented and validated with experimental data. A detailed study of working characteristics of the booster assisted ejector refrigeration system was carried out and compared against conventional ejector refrigeration system and compressor based refrigeration system, on the basis of first and second laws of thermodynamics. Effects of booster outlet pressure on COP th based on thermal energy and COP w based on work input, and also on entrainment ratio and area ratio of ejector were studied. The exergy destruction rates were also computed and analyzed for components of the booster-assisted ejector refrigeration system. Ways to reduce exergy destruction were discussed.

We report planar heterojunction perovskite solar cells with tetrafluoro-tetracyanoquinodimet-hane (F4-TCNQ) doped spiro-MeOTAD by solvent treatment as hole transport layer. The non-hygroscopic F4-TCNQ doped spiro-MeOTAD plays the same role as Li-bis (trifluoromethanesulfonyl) imide doped spiro-MeOTAD in perovskite solar cells, endowing the device both high efficiency and good stability. The F4-TCNQ dopant was optimized to enhance the conductivity and adjust the highest occupied molecular orbital of spiro-OMeTAD to match the valence band maximum of perovskite for efficient hole extraction, which results in a high fill factor, open circuit voltage and short current density, simultaneously. Device including the F4-TCNQ doped spiro-MeOTAD exhibits a power conversion efficiency of 10.59%, which is a 160% improvement relative to that of the control device with the pristine spiro-MeOTAD as hole transport layer. Time-dependent solar cell performance measurements revealed significantly improved air stability for perovskite solar cells with the F4-TCNQ doped spiro-MeOTAD hole transport layer.

A novel printed microstrip-fed ladder patch monopole antenna is presented for ultrawide band (UWB) application. The antenna consists of rectangular patch elements ladder arrayed at the both sides of the microstrip-fed line on a printed circuit board (PCB) and a rectangular ground plane. The antenna parameters of ladder number N , the rectangular patches geometry of ladder elements, the ladder step length and the length of ground plane are studied to obtain optimized antenna performances. The successfully designed, implemented and measured antenna has a compact size of 12 mm×12 mm and operation frequency band from 3.1 GHz to 10.6 GHz with voltage standing wave ratio (VSWR) less than 2. Using the ladder patch array in microstrip monopole antenna design makes antennas flexible in terms of controlling resonances, bandwidth, stable radiation patterns, and constant group delay.

A novel 4H-SiC trench MOSFET is presented and investigated by simulation in this paper. The device features an integrated Schottky barrier diode and an L-shaped P+ shielding region beneath the gate trench and aside one wall of the gate trench (S-TMOS). The integrated Schottky barrier diode works as a free-wheeling diode in reverse recovery and reverse conduction, which significantly reduces reverse recovery charge (Q rr) and reverse turn-on voltage (V F). The L-shaped P+ region effectively shields the coupling of gate and drain, resulting in a lower gate–drain capacitance (C gd) and date–drain charge (Q gd). Compared with that of conventional SiC trench MOSFET (C-TMOS), the V F and Q rr of S-TMOS has reduced by 44% and 75%, respectively, with almost the same forward output current and reverse breakdown voltage. Moreover, the S-TMOS reduces Q gd and C gd by 32% and 22%, respectively, in comparison with C-TMOS.

A novel ultralow loss 4H-SiC double trenches MOSFET is presented and its mechanism is investigated by simulation. The device features two integrated heterojunction diodes (HJD) consisting of a P-type polycrystalline Silicon (P-ploy Si) and SiC, a trench split gate (SG) and P+ region (PR) beneath the source trench. Both the SG and PR reduce the coupling effect between gate and drain, and transform part of gate-drain capacitance (CGD) into gate-source capacitance (CGS) and drain-source capacitance (CDS). Compared with the conventional trench MOSFET (Con-TMOS) and the HJD trench MOSFET (HJD-TMOS), the proposed double trenches MOSFET with integrated HJDs and SG (HJD-SG-DTMOS) decreases the CGD by 83% and 89%, respectively. Moreover, the integrated HJDs take the place of the parasitic body diode as a freewheel diode, and thus reduce the reverse turn-on voltage. As a result, not only the reverse turn-on voltage of the proposed device is decreased by 69% and 33%, but also the switching loss is reduced by 64% and 49%, compared with those of Con-TMOS and HJD-TMOS, respectively.