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The near field of the probe beam after passing through the gain module is measured. The “streamer effect” is first discovered in the experiment, which is characterized as continuity in the flow direction and non-uniformity in the lateral direction with high spatial frequency. To explain the “streamer effect”, a fluid–solid coupling model and an unstable resonator oscillation model of the direct-liquid-cooled thin-disk laser are established. The simulation results show that the non-uniformity of the coolant along the width of the flow channel gives rise to the streamer effect. A feasible cooling channel to achieve a high uniformity coolant is proposed and experimentally verified. At CW pumping of 9.6 kW, the influence of coolant on the output beam quality can be controlled at β

Improving on product overlay is one of the key challenges when shrinking technology nodes in semiconductor manufacturing. Using information from non-lithography process steps can unleash overlay improvement potential.1 The challenge is to find intra-wafer signatures by measuring planar distortion. Several previous applications showed that using exposure tool wafer alignment data can improve overlay performance.2 With smart placement of alignment mark pairs in the X and Y direction, it is possible to determine intra-wafer distortion wafer-by-wafer. Both the measurement and modeled results are applied directly as a feed-forward correction to enable wafer level control. In this paper, the capability to do this is evaluated in a feasibility study.

To observe the effect of humanized nursing in the perioperative period of gastrointestinal tumor. A total of 118 cases of gastrointestinal tumor patients treated in our hospital from March 2021 to May 2021 were selected. Patients were randomly assigned to the routine care control group or humanized nursing intervention group according to their willingness. The gastrointestinal function, psychological status, postoperative complications and nursing satisfaction status of the two groups were compared after intervention. The recovery rate of gastrointestinal function was faster in the study group, that is, the time of initial anal exhaust and initial defecation was lower in the study group than in the control group, and the incidence of abdominal distension was lower in the study group (P

With the rapid development of the traditional inorganic semiconductor industry, the improvement of its electrical performance is gradually approaching to the limit. It is difficult to continue to improve the performance, lessen the size, and reduce the cost. Therefore, organic semiconductor materials and devices with simple process and low cost have been found and gradually become a new research hotspot. Although organic semiconductor materials and devices are developing rapidly, their electrical properties, such as carrier mobility, are considerably inferior to those of inorganic semiconductors, and their research direction and application prospect are relatively fixed and single. They are developed only in display, sensing, photoelectric conversion and other fields, but the researches on switching power devices, integrated circuits and other fields are still relatively blank. At the same time, power devices are used only in the field of inorganic semiconductors. Therefore, in order to expand the research direction of organic semiconductors and power devices at the same time, a novelsilicon on insulator lateral double-diffused metal oxide semiconductor (SOI LDMOS)power device is reported in this paper. Unlike the SOI LDMOS power devices in traditional inorganic semiconductors, this novel device can be used in the field of organic semiconductors by combining with insulated flexible substrates, which provides a new possibility for the research direction of organic semiconductors. In this paper, both simulation and experiment verify that specific on-resistance (RON,sp) and threshold voltage (VTH) do not change significantly when the conventional SOI LDMOS lacks the substrate electrode, but the breakdown voltage decreases by about 15% due to the absence of the substrate electrode or the longitudinal electric field. In response to this phenomenon, in this paper proposed is a novel SOI LDMOS power device that possesses surface substrate electrodes and drift zone oxide trenches. This novel device can provide electrodes for the substrate again, optimize the horizontal and vertical electric field, and significantly change neither of the RON,sp and the VTH. At the same time, the breakdown voltage (BV) of conventional SOI LDMOS is increased by 57.54%, which alleviates the adverse effects caused by the application in the field of organic semiconductors. This novel SOI LDMOS power device provides the possibility of applying traditional power semiconductors to the research of organic semiconductors, and has innovative significance for expanding the organic semiconductor research.

This paper investigates the rotor cavity positioning and the combination of stator slot and rotor effective slot number on the eddy-current loss for interior permanent-magnet/reluctance machines operating under deep field-weakening conditions. A new closed-form expression for the stator and rotor eddy-current loss is developed. The optimal barrier-positioning for the minimum total loss and the effect on the eddy-current loss of varying the stator slot and rotor effective slot number are investigated for one-, two-, three-, and full-layered rotors.

Field test and laboratory analog model test on the stress-relief effects of protective layer extraction are time-consuming and laborious. In this paper, on the basis of full consideration of rock heterogeinity and in combination with gas geology at Pingdingshan Mine 5, a numerical model was estalished with the gas-solid coupling rock failure process analysis system RFPA-Gas to simulate the stress variation law, roof and floor deformation, fracture evolution law, displacement in the protected seam, change in gas permeability and gas migration law during protective layer extraction. The simulation results repoduced stress variations in coal and rock strata, roof and floor deformation and fracture evolution process during protective layer extraction. The movement of rock strata were characterized by upper three zones and lower two zones: caving zone, fracture zone and bending subsidence zone in the vertical direction in the overlying strata; floor deformation and failure zone and elasto-plastic deformation zone in the vertical direction in the underlying strata. It showed that stress relief occurred in the protected seam, which led to vertical and horizontal displacements, significant increase in gas permeability, gas desorption and migration. Hence, the outburst threat in the protected seam was eliminated. Meanwhile, with comprehensive analysis of variaition of stress state, deformation characteristics and fracture distribution in coal seam and with consideration of changes in gas leakage rate, gas pressure and permeability, according to gas leakage rate, the floor strata of the protecive layer were divided into four leakage zones. They corresponded to four zones with different stress states and fracture development: original leakage zone - slow reducing leakage zone - dramatic increasing leakage zone- steady increasing leakage zone. This classification provides a clear direction for gas control in the protective layer. The simulation results are in good agreement with the stress-relief effects in field.

A direct-liquid-cooled Nd:YLF thin disk laser resonator is presented, which features the use of refractive index matching liquid (RIML) as coolant. Highly uniform pump intensity distribution with rectangular shape is realized by using metallic planar waveguides. Much attention has been paid on the design of the gain module, including how to achieve excellent cooling ability with multi-channel coolers and how to choose the doping levels of the crystals for realizing well-distributed pump absorption. The flow velocity of the coolant is found to be a key parameter for laser performance and optimized to keep it in laminar flow status for dissipating unwanted heat load. A single channel device is used to measure the convective heat transfer coefficient (CHTC) at different flow velocities. Accordingly, the thermal stress in the disk is analyzed numerically and the maximum permissible thermal load is estimated. Experimentally, with ten pieces of a-cut Nd:YLF thin disks of different doping levels, a linear polarized laser with an average output power of 1120 W is achieved at the pump power of 5202 W, corresponding to an optical-optical efficiency of 21.5%, and a slope efficiency of 30.8%. Furthermore, the wavefront aberration of the gain module is measured to be quite weak, with a peak to valley (PV) value of 4.0 μm when it is pumped at 5202 W, which enables the feasibility of its application in an unstable resonator. To the best of our knowledge, this is the first demonstration of kilowatt-level direct-‘refractive index matching liquid’-cooled Nd:YLF thin disk laser resonator.

The inertia of wind turbines causes a reduction in their output power due to their inability to operate at the turbine maximum co-efficient of performance point under dynamic wind conditions. In this paper, this dynamic power reduction is studied analytically and using simulations, assuming that a steady-state optimal torque control strategy is used. The concepts of the natural and actual turbine time-constant are introduced, and typical values for these parameters are examined. It is shown that for the typical turbine co-efficient of performance curve used, the average turbine speed can be assumed to be determined by the average wind speed. With this assumption, analytical expressions for the power reduction with infinite and then finite turbine inertia are determined for sine-wave wind speed variations. The results are then generalized for arbitrary wind speed profiles. A numerical wind turbine system simulation model is used to validate the analytical results for step and sine-wave wind speed variations. Finally, it is used with real wind speed data to compare with the analytical predictions. Copyright © 2012 John Wiley & Sons, Ltd.

The fiber coupled system based on mini-bars is an effective way of avoiding complex beam shaping to reduce costs and improve brightness. Forty mini-bars mounted on copper microchannel heatsink are arranged in two stacks to collimate the output beam of the stacks with the aspherical cylindrical lens and cylindrical lens array in fast and slow axis directions in this paper. For increasing the fill factor of the beams of the stacks, the beams are combined spatially in the fast axis direction. The combined beam could be coupled into the fiber of 800 m core diameter and 0.22 numerical aperture. The opto-optical efficiency of the fiber coupled module is about 58% and the maximum output power is 1360 W with the power density of 1.73105 W/cm2 at fiber output facet.

Coke-oven workers are exposed to many kinds of pollutants that can cause health damage even lead to carcinogenesis. Therefore, it is critical to identify biomarkers that predict early health damage in these exposed individuals in molecular epidemiological studies. We applied an artificial neural network (ANN) model to the identification of such predictors in a study of coke-oven workers. The study included 330 steel-factory workers who were exposed to different levels of polycyclic aromatic hydrocarbons (PAHs) in the workplace and their levels of early health damage were determined by cytokinesis-block micronuclei (CMN), heat shock protein 70 (Hsp70) expression, benzo(a)pyrene diolepoxide-albumin adduct (BPDE-AA), and olive tail moment (OTM). The ANN model was built to predict the early health damage index, and the receiver operating characteristic (ROC) curve was used to illustrate the judged criteria and the ANN model. Trend Chi-square modeling was also performed. We found that there were 55 subjects with early health damage among 330 workers based on the multibiomarker criteria using the 95 percentile of the control group as the cut-off value, while there were 22-35 positive subjects if screening by any single biomarker. The Cochran-Armitage trend test for these findings were statistically significant (Z = 3.21, P = 0.0013). Six variables were selected to simulate the ANN model. The area under ROC (AUROC) was 0.726 ± 0.037 (P < 0.001), and the predictors included workplace, cholesterol, waistline, and others. Therefore, collective using CMN frequency, Hsp70 level, BPDE-AA level, and OTM with equal weights to make an initial screening test for early health damage in coke-oven workers is feasible and superior to any single biomarker. The determinants of the effects of multibiomarker on early health damage screening can be identified by the ANN model and ROC curve method.

A large aperture tapered fused silica fiber phase conjugate mirror with a maximum 50.7% stimulated Brillouin scattering (SBS) reflectivity is presented, which is operated with 400 Hz pulse repetition rate and 36.5 mJ input pulse energy. To the best of our knowledge, it is the first time that over 50% SBS reflectivity is achieved by using solid-state phase conjugate mirror under such high pulse repetition rate and high pulse energy. With much higher pulse repetition rate of 500 and 1000 Hz, the maximum SBS reflectivity is 41.2% and 33.3%, respectively. A single-longitudinal-mode Nd:YAG laser is experimentally studied with master oscillator power amplifier (MOPA) scheme using such a tapered fiber as a phase conjugate mirror. A 101 mJ pulse energy is achieved at 400 Hz repetition rate, with a pulse width of 6 ns and a M 2 factor of less than 2. The corresponding peak power reaches 16.8 MW.

According to the rock failure damage theories and the gas-solid coupling method, used RFPA 2D -GasFlow soft code to study the characteristics of microseism in time and space for gassy coal sample in different confining pressure. It is shown that there is some microseism precursory before main shock. Basing on the characteristics of microseism precursory events amount in time can be warned in advance, and basing on the characteristics of microseism precursory events produced by tension stress in space,there is can divide potential failure danger zone. It is shown that the divided results for potential failure danger zone are exactly, and with the increment of confining pressure, the accuracy of divided results on potential failure danger zone become higher. It is found that the potential failure danger zone consistent with crack initiatory zone by contrasted potential failure danger zone to crack development process, and with the increment of confining pressure, the consistency become higher.

As a critical issue for the pavement’s quality service life, surface cracking of the pavement structure is an ongoing research topic which attracts many researchers. This paper presents a numerical study of the periodic cracks in surface layer of pavement structures based on the FEM method. The formation mechanism of the periodic cracks is analyzed and the evolving process is simulated. A parametric study, including effects of the layer thickness, tensile strength of surface layer and layer elastic modulus on the crack spacing is carried out. The numerical results indicate that the horizontal stress between two adjacent cracks decreases gradually as the crack spacing decreases. The horizontal stress transits from tensile to compressive when the crack spacing decreases to a certain value. Such a stress state transition leads to the periodic array of the surface cracks. The evolving process of the periodic cracks indicates that new cracks infill in sequence between two earlier formed adjacent cracks and the crack spacing decreases in half simultaneously. No more new crack can infill when the crack spacing reaches to a certain value even with the increasing of external load. Numerical simulations also show that the crack spacing is strongly dependent on the surface layer thickness, tensile strength of the surface layer and elastic modulus of the surface layer.

A continuous-wave-operation laser amplifier chain consisting of three multi-concentration-doped Yb:YAG slab gain modules (GMs) at room temperature is presented. The output power of 22.3 kW with the beam quality of 3.3 times the diffraction limit is achieved from this chain. To the best of our knowledge, based on a Yb:YAG slab at room temperature, the highest power to date while maintaining excellent beam quality laser output. An extraction efficiency of 36% from the single slab GM is obtained and can be further enhanced to 46% by optimizing the parameters of GM. These results have confirmed that the Yb:YAG slab has an excellent scaling performance and is suitable for the development of high-average-power lasers.

We demonstrate a master oscillator power amplifier (MOPA) architecture based on Yb:YAG amplifiers and adaptive optics (AO) systems with a high power and high beam quality laser output. With two conduction cooled, dual-end-pumped Yb:YAG zigzag-slab amplifiers at room temperature, the fiber laser of 300 W was scaled to 11.9 kW. Moreover, AO system positioned downstream was utilized to correct wavefront of amplified laser. The beam quality β at maximum output power was 2.8 times diffraction limited with closed-loop AO system.

In the paper, under 5.6 GPa and 1200-1400℃, the type Ib diamond single crystals on defect-free[111] -oriented seed crystals are synthesized in a cubic anvil under high pressure and high temperature when the crack problem of diamond single crystal appears frequently. Highpurity Fe-Ni-Co solvents are chosen as the catalysts. Highpurity graphite powder (99.99%, purity) is selected as a carbon source. The effects of cooling process on the qualities of Gem-diamond single crystals are studied carefully. First, in order to study the common crack defects of diamond single crystals, using scanning electron microscope (SEM), the surface morphologies of high quality diamond single crystals and crack crystals are obtained respectively. Our SEM test results show that the surfaces of the crack crystals and the high quality crystals are all very smooth. Therefore, the crack crystal problem is not directly caused by the unordered accumulation of carbon. Second, the concentrations of nitrogen in the high quality diamonds and crack crystals are measured by Fourier transform infrared. In our studies, the nitrogen content of the diamond single crystal with crack is similar to the nitrogen content of high quality single crystal, so the appearance of crystal crack is not caused by high impurity content. According to the test results and the regularity of the occurrence of crack crystals, the reasons for the occurrence of crack crystals are analyzed seriously. When the weather conditions such as seasonal change, wind, rain or snowfall are not very stable, the probability of crack crystal problem to appear will increase greatly. In our opinion, the decrease of diamond crystal quality caused by the fluctuation of external growth conditions is the internal cause of crack crystal problem appearing. After growing diamond crystals, choosing the traditional power failure mode and slowing cooling process respectively, the effect of cooling process on the quality of diamond single crystal is investigated. In the season of the crack problem occurring frequently, choosing power failure cooling process, cracks appear in both diamond crystals with 1.3 mm or 6.0 mm in diameter. With the slow cooling process, the synthetic diamond crystals with 1.2 mm or 5.8 mm in diameter are all high-quality single crystals with no cracks inside. The research results show that the slow cooling process can effectively restrain the occurrence of crack crystal problems. In addition, the mechanism problems of crack crystals and the mechanisms of the effects of slow cooling process on diamond crystal qualities are discussed in detail. We believe that the slow cooling process is effective in solving the crack crystal problem, which is mainly attributed to the following two aspects:on the one hand, the slow cooling makes the internal stress of diamond single crystal growing effectively released, which improves the compressive strength of the crystal and the crystal quality as well; on the other hand, the slow cooling makes the solidification process of the catalyst melt slowly, which provides enough time for the crystal to balance the external stress of the catalyst and the equipment, so that the crystals, which are not affected by the unbalanced external stress, are not cracked.

A spectral beam combination(SBC) system with dual Multi-Layer Dielectric(MLD) grating dispersion compensation configuration, which can combine multiple fiber lasers into a common aperture beam with high beam quality and relax the linewidth requirement of the individual fiber laser, has become gradually one of the most important technique route of fiber laser beam combining. The basic principle and the key technologies of the SBC system with dual-MLD-grating configuration were introduced and analyzed briefly. The recent progress of the main key technologies about high power beam combinable narrow linewidth fiber laser, high power high efficiency short wavelength narrow linewidth fiber laser, large dispersion high efficiency MLD grating and high integration dense beam combining were reviewed. The recent progress on the key technologies of SBC with dual-MLD-configuration in Institute of Applied Electronics, China Academy of Engineering Physics, were also presented. The potential of the SBC with dual-MLD-configuration was prospected.

For years information technology (IT) has helped companies improve organizational efficiency and effectiveness. Today’s IT plays a more strategic role in building capabilities for sustaining and creating competitive advantages. The increasing importance of IT has led many organizations to integrate it into their daily operations. To justify the ever-increasing spending on IT, organizations have been searching for evaluation methods to prove the business value of IT. However, this is a challenging undertaking, as there are contradictory answers to questions on whether it is worthwhile to pay substantial sums for IT. To gain insight into the reasons behind the contradictory answers, this paper first reviews conflicting research results of past studies on IT business value. It then explains the term IT productivity paradox. Last, it provides five reasons why IT business value is not fully reflected in the way business managers expect it to be.

For advanced lithography metrology, SCD (Scatterometry Critical Dimension) is a common metrology technique applied to control processes. SCD has the capability to report accurate data information such as CD (Critical Dimensions), photoresist SWA (Side Wall Angle) and photoresist HT (Height). The shape of photoresist correlates with inline process controllers, namely scanner focus and dose. However, SCD is a model-based metrology method. In order to decode the process controllers, it requires computation from a geometric model. Once the model extracts the resist shape information from the spectra, one needs further correlation of those geometric parameters with the process controllers for monitoring. Thus, information loss through multiple modeling is a major concern. Indeed, during data transformation, noise and model approximation can distort the signals, in other words, the critical parameters, focus and dose, may not be measured accurately. This study therefore seeks a methodology to monitor focus and dose with the least amount of information transformation. Signal Response Metrology is a new measurement technique that obviates the need for geometric modeling by directly correlating focus, dose or CD to the spectral response of a SCD-based metrology tool.

In this paper, based on the self-reproduction condition of laser wavefront curvature, the influences of disk defocus on laser parameters can be calculated. The laser-pumping overlapping efficiency will decrease by 9%; the magnification will rise to 2.3, and the intra-cavity loss will be high to 30% due to a laser beam size mismatch when each disk has focal length of -100 m in a positive-branch confocal unstable resonator containing four disks with magnification of 1.8. Therefore, the optical conversion efficiency and stability will be reduced significantly. Several methods defocus compensation of are compared, it can be found that inserting variable-focus lens in resonant is useful in large dynamic range. In experiment, the defocus values are measured in different pumping power. A lens group, used for compensate components according to the single pass probe, is carefully designed. Under this compensation, the pulse energy can be maintained in 10 J from 1 Hz to 100 Hz. The output power can be improved 2.33 times compared to non-compensation condition.

This paper describes an analytical approach for calculating the stator iron loss for multiple-barrier interior permanent magnet (IPM) machines with distributed windings, under open and short-circuit (deep field-weakening) conditions. It is based on using a lumped equivalent-circuit model to predict the rotor mmf and then the harmonic components of the airgap flux density. A “filter function” approach is used to calculate the stator tooth and yoke flux densities and hence iron loss components. It provides an insightful means for visualizing the effect of stator and rotor design changes on the stator iron losses. The analytical stator iron loss predictions for four IPM machine configurations are compared with finite element results.

The shower bars are still in an introductory stage of a product cycle in the current Taiwan market. It is still far behind the shower head in terms of the household penetration. For the increase of the local acceptance of the shower bars and development of the market, the key lies in the developers' understanding of the users' feelings about, needs for and expectations of the shower bars and the launch of the products meeting their requirements. This study explores the shower bar user groups through survey of lifestyles and analyzes the kansei values and preferences of each group based on the survey results. An open-ended questionnaire was provided to understand the inconveniences and problems the consumers experience when using the shower bar while the kansei descriptive terms for the shower bars are were collected. According to the analysis results, the lifestyles of the shower bar users include the following ten aspects: trendy fashion, kansei living, recreation-minded, challenge trying, routine following, care for society, active, busy, celibatarian and resolute. Through cluster analysis, the users were divided into the four major clusters: relaxed and self-centered, ordinary and stable, fashion pursuing and busy living. The kansei value needs and expectations of each group was discussed and analyzed based on their characteristics and the returned questionnaire was reviewed to come up with 46 kansei descriptive words and 4 major issues for improvement were summarized for reference in designing the shower bars.

It is necessary to achieve underwater moving target detection and tracking by sonar image sequences movement target segmentation. The AUV movement target detection arithmetic based on LIP model at static background is proposed. First of all, illumination segments based on human visual characteristics to sonar image, constructs optical flow equation and make the appropriate simplify the discrete processing to saturation region, Weber area, De Vries area of sonar image, at last, completes movement target detection by estimating the optical flow vector by LUCAS-KANADE method. The experiments show that the method can achieve movement target correct extract at static background.

The effect of changing the number of slots and poles on the performance of a particular surface permanent magnet (SPM) machine design is studied in detail using finite-element analysis. This includes examining the back-EMF, the open-circuit/full-load power losses, the cogging/ripple torque, and the field-weakening performance. The simulation results are compared with the expected relationships to provide electric machine designers useful insights on the effect of the number of slots and poles on the performance of surface PM machines.

A high power multi-pass diode-pumped solid-state MOPA system with large core diameter tapered quartz fiber as phase conjugator is experimentally investigated. The results of the effects of laser longitudinal mode characteristic, laser pulse width and fiber surface optical quality on SBS reflectivity are presented. Maximum SBS reflectivity of 69.7% is obtained with the repetition rate of 1000 Hz, input pulse energy of 38mJ and pulse width of 24 ns. The phase conjugator is made from a taper shaped quartz fiber with the diameter of 1mm at the input end and 0.4mm at the other end. It has good application prospects in improving the beam quality and compressing the pulse width for high power laser system with high repetition rate.

A model for describing laser-induced damage in optical materials by nanosecond laser pulses is investigated. The laser-damage critical fluence is obtained based on calculating the light absorption of nanoabsorbers by using Mie theory and solving the heat equation. Considering a power law distribution of nano-absorbers, we calculated the damage probability at the surface of fused silica including Pt particles. The theoretical results calculated with appropriate parameters are applied to fit the experimental data in order to identify the properties of nanodefects.