bluuebunny/crossref_metadata_2025 huggingface dataset:
1 fm/Hz noise level low temperature Fabry-Pérot atomic force/magnetic force microscope operating in 4–300 K temperature range
Authors: Karc Özgür , Çelik Ümit , Oral Ahmet
Published: January 2020

In this publication, we describe the design of a new fiber Fabry-Pérot interferometer and employ this to a low temperature atomic force/magnetic force microscope (LT-AFM/MFM) operating in the 4–300 K temperature range. A multilayer dielectric mirror coated optical fiber is used to achieve unprecedented 1 fm/Hz noise level, while the shot noise limit is 0.51 fm/Hz. The cavity length is adjustable, and the fiber can be brought within a very close proximity of the cantilever using a dedicated 2 mm stroke piezonanopositioner integrated on the piezotube scanner. The same nanopositioner also is used to park the fiber at a safe parking location during cantilever exchange. We demonstrate the performance of the LT-AFM/MFM by imaging the ITO thin film at 300 K, atomic steps on HOPG at 300 K, magnetic bits on the hard disk at 15 K, and the Abrikosov vortex lattice in the BSCCO(2122) single crystal at 4 K.
Influence of pore morphology on the diffusion of water in triblock copolymer membranes
Authors: Aryal Dipak , Howard Michael P. , Samanta Rituparna , Antoine Segolene , Segalman Rachel , Truskett Thomas M. , Ganesan Venkat
Published: January 2020

Understanding the transport properties of water in self-assembled block copolymer morphologies is important for furthering the use of such materials as water-purifying membranes. In this study, we used coarse-grained dissipative particle dynamics simulations to clarify the influence of pore morphology on the self-diffusion of water in linear-triblock-copolymer membranes. We considered representative lamellar, cylindrical, and gyroid morphologies and present results for both the global and local diffusivities of water in the pores. Our results suggest that the diffusivity of water in the confined, polymer-coated pores differs from that in the unconfined bulk. Explicitly, in confinement, the mobility of water is reduced by the hydrodynamic friction arising from the hydrophilic blocks coating the pore walls. We demonstrate that in lamella and cylindrical morphologies, the latter effects can be rendered as a universal function of the pore size relative to the brush height of the hydrophilic blocks.
Electric control of exchange bias in Co/FeOx bilayer by resistive switching
Authors: Wei Lujun , Qu Jiangtao , Zheng Rongkun , Liu Ruobai , Yuan Yuan , Wang Ji , Sun Liang , You Biao , Zhang Wei , Xu Qingyu , Du Jun
Published: January 2020

Two types of electric control of exchange bias (EB) by resistive switching (RS), i.e. conductive-filament-RS (type I) and interface-barrier-RS (type II) were observed in the Si/SiO2Ti/Pt/FeOx/Co/ITO multilayer devices, which were fabricated by magnetron sputtering. It is difficult for the type I device to control EB, which may be due to that the quantity of conductive filaments is not enough to modify the antiferromagnetic structure of FeOx near the Co/FeOx interface. However, the electric control of EB can be accomplished in the type II device. Compared with low-resistance-state (LRS), the exchange bias field (HE) increases a little but the coercivity (HC) increases significantly at high-resistance-state (HRS). We consider that the migration of the oxygen vacancies under different voltages is able to mediate the interfacial barrier height, leading to the bipolar RS effect and the change of EB as well. This provides a way for designing new types of spintronic devices based on electric control.
Synthesis and resistivity of topological metal MoP nanostructures
Authors: Han Hyeuk Jin , Hynek David , Wu Zishan , Wang Lei , Liu Pengzi , Pondick Joshua V. , Yazdani Sajad , Woods John M. , Yarali Milad , Xie Yujun , Wang Hailiang , Cha Judy J.
Published: January 2020

Due to the increased surface to volume ratios, topological nanomaterials can enhance contributions from the topological surface states in transport measurements, which is critical for device applications that exploit the topological properties. It is particularly important for topological semimetals in which bulk carriers are unavoidable to make them into nanostructures to reveal the nature of the topological surface states, such as the Fermi arcs or nodal lines. Here, we report the nanostructure synthesis of the recently discovered triple-point topological metal MoP by direct conversion of MoO3 nanostructures and study their transport properties. We observe that the initial size of the MoO3 templates critically determines the crystalline quality of the resulting MoP nanostructures: large MoO3 flakes lead to porous MoP flakes, while narrow MoO3 nanowires lead to MoP nanowires without pores. The size-dependent porosity observed in MoP nanostructures is attributed to the volume change during the conversion reaction and nanoscale confinement effects. For MoO3 nanowires with diameters less than 10 nm, the resulting MoP nanowires are single crystalline. The resistivity values of MoP nanostructures are higher than the reported values of MoP bulk crystals owing to the porous nature. However, despite the high porosity present in MoP flakes, the residual resistance ratio is ∼2 and the temperature-dependent resistivity curves do not show any strong surface or grain-boundary scattering. Demonstration of the facile synthesis of MoP nanostructures provides opportunities for careful investigations of the surface states in transport measurements and exploration of future electronic devices, including nanoscale interconnects.
Statistical analysis of read-back signals in magnetic recording on granular media
Authors: Slanovc Florian , Vogler Christoph , Muthsam Olivia , Suess Dieter
Published: January 2020

The comprehensive simulation of magnetic recording, including the write and read-back process, on granular media becomes computationally expensive if the magnetization dynamics of each grain are explicitly computed. In addition, in heat-assisted magnetic recording, the writing of a single track becomes a random process since the temperature must be considered and thermal noise is involved. Further, varying grain structures of various granular media must also be taken into account to obtain correct statistics for the final read-back signal. Hence, it requires many repetitions of the write process to investigate the mean signal as well as the noise. This work presents a method that improves the statistical evaluation of the whole recording process. The idea is to avoid writing the magnetization to one of its binary states. Instead, we assign each grain its probability of occupying one of its stable states, which can be calculated in advance in terms of a switching probability phase diagram. In the read-back process, we combine the probabilities to calculate a mean signal and its variance. Afterwards, repetitions on different media lead to the final read-back signal. Using a recording example, we show that the statistical behavior of the evaluated signal-to-noise ratio can be significantly improved by applying this probability mapping method, while the computational effort remains low.
Cavity-shaped magnet for highly sensitive magnetic detection of magnetic nanoparticles in breast cancer patients
Authors: Kuwahata Akihiro , Kusakabe Moriaki , Chikaki Shinichi , Saito Itsuro , Sekino Masaki
Published: January 2020

Magnetic nanoparticles and their detection systems are widely applied to the diverse biomedical applications, and the more accurate detection techniques have been explored. Here, we propose the cavity-shaped magnet that enables the application of the highly sensitive magnetic sensor for the enhancement of the detection ability. The numerical simulations based on the finite element method revealed the wide area of the magnetic null point (B ∼ 0 and ∇B ∼ 0) of the cavity-shaped magnet. The strong gradient of magnetic fields of ∇BZ ∼ 160 mT/mm in the conventional column-shaped magnet reduces to approximately zero and the wider magnetic null area is obtained in the cavity-shaped magnet. The magnetic null area of the column- and cavity-shaped magnet are ∼0.1 × 0.05 mm2 and ∼0.25 × 0.6 mm2, respectively, indicating that the area expands to approximately 30 times larger. This scale-up of the magnetic null area in the proposed cavity-shaped magnet suggests the application of the highly sensitive magnetic sensor, thereby would be offering the more accurate magnetic nanoparticle detection for biomedical applications.
Combining sustainable stochastic resonance with high-energy orbit oscillation to broaden rotational bandwidth of energy harvesting from tire
Authors: Zhang Yunshun , Cai Yingfeng , Teng Xiaopeng , Zheng Rencheng , Nakano Kimihiko
Published: January 2020

The efficient harvesting of mechanical energy from ambient vibrations is an ongoing project. Recent research has shown that nonlinear energy harvesters can generally overcome many significant disadvantages of linear harvesters arising from their narrow bandwidth. This paper proposes an energy harvester within an automotive tire that boasts the advantages of nonlinear systems to increase the harvesting bandwidth by combining stochastic resonance with high-energy orbit oscillations. A major challenge in this automotive application is the wide variation in tire speeds over which harvesting can take place. Stochastic resonance has some benefits here, particularly at low speeds at which high-energy orbit oscillations may not otherwise occur. Thus, as the speed of the vehicle and, therefore, a high-energy orbit oscillation of the harvester can be stimulated, the operating frequency of the harvester increases due to the presence of stochastic resonance and can be maintained as the speed of the vehicle increases or decreases. The results of numerical simulations and laboratory experiments show that the effective bandwidth of energy harvesting increased from 31 rad/s to 129.4 rad/s and the maximum power generated reached 0.21 mW, with a mean value of 35.6 μW, entirely through a combination of sustainable stochastic resonance and high-energy orbit oscillations within the harvester. Thus, by combining these two phenomena, the efficient bandwidth of rotation can be further extended to enhance the overall capability of tire-based energy harvesting.
On the transition behavior of laminar flow through and around a multi-cylinder array
Authors: Tang Tingting , Yu Peng , Shan Xiaowen , Li Jianhui , Yu Shimin
Published: January 2020

We numerically investigated the transitional behavior of two-dimensional laminar flows through and around a square array of 100 circular cylinders. The solid fraction of the array ϕ ranged from 0.007 85 to 0.661 and the Reynolds number Re (based on the free-stream velocity and the side length of the array) varied from 40 to 200. Globally, the first transition appears at the onset of vortex shedding, where the critical Reynolds number Recr is estimated from the Stuart-Landau equation. The results show that Recr ranges from 40 to ∼45 for the investigated range of ϕ. It is found that Recr increases quadratically with ϕ and the critical Reynolds number for an individual cylinder (Rdcr) increases linearly with ϕ. The subsequent transitions largely depend on ϕ, as revealed from the total drag and lift coefficients, Strouhal number, and the instantaneous vorticity field. For sufficiently small ϕ at high Re, the global vortex shedding is suppressed due to the weakened interaction between cylinders in the array. Several more cases with ϕ of 0.007 85 for Re between 400 and 4000 are also calculated to visualize the suppression behavior. The global transition behaviors are closely related to the secondary frequency (SF) observed from the power spectra of the local velocity. It is highly possible that the SF results from the cylinder interaction in the array. The local instabilities induced by cylinder interactions would promote the onset of global vortex shedding at small Re. Also, the local instabilities still exist even though the global vortex shedding is suppressed at large Re.
Long-term digital frequency-stabilized laser source for large-scale passive laser gyroscopes
Authors: Zhang Fenglei , Liu Kui , Li Zongyang , Cheng Feihu , Feng Xiaohua , Li Ke , Lu Zehuang , Zhang Jie
Published: January 2020

We report on the development of a digitally controlled long-term frequency stabilized ultrastable laser source, which serves as an injection laser to stabilize the perimeter of a 3 m × 3 m heterolithic passive resonant gyroscope. We operate the gyroscope at two different cavity modes to reduce back-scattering coupling disturbance for gyroscope locking. This scheme increases the requirement for the injection laser frequency stability since we are using the wavelength of the laser as the length standard for the heterolithic gyroscope structure. The laser source is digitally locked to an ultrastable high-finesse Fabry-Perot cavity and a femtosecond optical frequency comb referenced to an active hydrogen maser simultaneously. The fractional frequency stability of the locked laser is better than 1.2 × 10−14 for averaging times from 0.1 s to 10 000 s. The short-term frequency stability is limited by the stability of the Fabry-Perot cavity, and the long-term frequency stability is limited by the stability of the frequency comb. The digital locking system enables the laser to run autonomously for weeks and can quickly relock itself within seconds to ensure continuous running of the gyroscope. The digital frequency stabilization technique can also fulfill the requirements of space gravitational waves detection and the next generation space gravity recovery mission.
Effect of Sn for the dislocation-free SiSn nanostructure formation on the vapor-liquid-crystal mechanism
Authors: Timofeev Vyacheslav , Mashanov Vladimir , Nikiforov Alexander , Skvortsov Ilya , Gavrilova Tatyana , Gulyaev Dmitry , Gutakovskii Anton , Chetyrin Igor
Published: January 2020

Structures with tin-rich island arrays on silicon pedestals were obtained by molecular beam epitaxy using Sn as a catalyst for the growth of nanostructures. A tin island array was used further to study the growth of nanostructures in the process of Si deposition on the surface with Sn islands. It was established that, during the growth on the vapor-liquid-crystal mechanism, tin-rich islands are formed on faceted pedestals. A nanostructured cellular surface was formed between the islands on pedestals. The analysis of the elemental composition of the obtained nanostructures was performed by the methods of energy dispersive X-ray spectroscopy and photoelectron spectroscopy. It is shown that tin-rich islands can contain up to 90% tin, whereas the pedestal consists of silicon. The transmission electron microscopy data demonstrated a distinct crystal structure of tin-rich islands and silicon pedestals, as well as the absence of dislocations in the structures with island arrays on the faceted pedestals. The facet tilt angle is 19° and corresponds to the (311) plane. The photoluminescence signal was observed with a photoluminescence maximum near the wavelength of 1.55 μm.
Bioinspired sonar reflectors as guiding beacons for autonomous navigation
Authors: Simon Ralph , Rupitsch Stefan , Baumann Markus , Wu Huan , Peremans Herbert , Steckel Jan
Published: January 2020

Sonar sensors are universally applied in autonomous vehicles such as robots and driverless cars as they are inexpensive, energy-efficient, and provide accurate range measurements; however, they have some limitations. Their measurements can lead to ambiguous estimates and echo clutter can hamper target detection. In nature, echolocating bats experience similar problems when searching for food, especially if their food source is close to vegetation, as is the case for gleaning bats and nectar-feeding bats. However, nature has come up with solutions to overcome clutter problems and acoustically guide bats. Several bat-pollinated plants have evolved specially shaped floral parts that act as sonar reflectors, making the plants acoustically conspicuous. Here we show that artificial sonar beacons inspired by floral shapes streamline the navigation efficacy of sonar-guided robot systems. We developed floral-inspired reflector forms and demonstrate their functionality in 2 proof-of-principle experiments. First we show that the reflectors are easily recognized among dense clutter, and second we show that it is possible to discern different reflector shapes and use this identification to guide a robot through an unfamiliar environment. Bioinspired sonar reflectors could have a wide range of applications that could significantly advance sonar-guided systems.
Effects of Kudoa septempunctata infections in a human intestinal epithelial model (Caco-2): a DNA microarray study
Authors: Yamamoto So , Kawano Fumi , Yokoyama Hiroshi , Kobayashi Shoko
Published: January 2020

Kudoa septempunctata

, a myxosporean parasite infecting the trunk muscles of olive flounder (Paralichthys olivaceus), is reported to cause food poisoning in humans. The molecular mechanisms underlying the toxicity of K. septempunctata spores remain largely unknown. In the present study, we examine the molecular basis of such toxicity using DNA microarray analysis of K. septempunctata-inoculated human colon adenocarcinoma cells (Caco-2). We observed that the transepithelial resistance of the K. septempunctata-inoculated Caco-2 cell monolayers decreased markedly. DNA microarray analysis revealed that the mRNA expression profiles of control and inoculated cells clearly differed. Inflammatory and bacteria-related pathways, such as interleukin-8 (IL-8) production and MAPK/NF-kappa B pathway, were enriched. The concentrations of IL-8 and serotonin (5-HT) were higher in inoculated cells than in controls. K. septempunctata invasion damages the human intestinal epithelium, causing increased production of IL-8 and 5-HT, which likely results in the vomiting associated with K. septempunctata invasion.

Abbreviations

AP-1: activator protein 1; DAVID: Database for Annotation, Visualization and Integrated Discovery; ENS: enteric nervous system; FARMS: Factor Analysis for Robust Microarray Summarization; FDR: false discovery rate; GO: Gene Ontology; 5-HT: 5-hydroxytryptamine; IL-8: Interleukin-8; KEGG: Kyoto Encyclopedia of Genes and Genomes; K. septempunctata: Kudoa septempunctata; NF-kappa B: nuclear factor-kappa B; TJ: tight junction; TER: transepithelial electrical resistance
Research on productivity effect of manufacturing capital accumulation——an empirical study based on data of manufacturing enterprises in Beijing, Tianjin and Hebei
Authors: Fan Xiaonan , Li Qiyue , Feng Chong
Published: January 2020

Based on the panel data quantile regression, the horizontal and vertical comparisons reveal the marginal effect of the capital accumulation of the Beijing-Tianjin-Hebei region on the growth of total factor productivity. Combined with the heterogeneity of regions and industries, this paper provides a theoretical basis for how to effectively invest and how the government solves the mismatch of capital. The study found that although the increase in investment has a positive effect on the technological progress of enterprises, the dividend of capital investment has gradually disappeared, and the overall trend is inverted U-shaped. In terms of sub-regions, increasing investment in quality is still the main problem that Hebei Province facing in the future. Different industries also present different characteristics. A few industries have shown an increase in investment increased the growth rate of total factor productivity.
Integrated preparation of long-life hydrogen storage alloy film/Ni foil composite electrode material
Authors: Chen Ying , Wen Zi
Published: January 2020

An integrated preparation method of a long-life hydrogen storage alloy film/Ni foil composite electrode material has been proposed in this paper. The hydrogen storage alloy film/Ni foil composite electrode material was prepared by magnetron sputtering. The prepared film composite electrode effectively reduces the electron/ion diffusion distance, increases the specific surface area of alloy, and reduces the contact resistance between the active material and the current collector. Furthermore, the integrated preparation of long-life hydrogen storage alloy film/Ni foil composite electrode material is realized by depositing method. This paper provides a simple and effective method for reducing the internal resistance and increasing the electrochemical reaction rate of the hydrogen storage alloy, and the prepared film composite could be a promising candidate for Ni-MH batteries.
Study on performance of integrated pipeline vibration isolator
Authors: Lao Xingsheng , Liu Yong , Dai Chunhui , Wu Jun , Lyu Weijian
Published: January 2020

For power machine pipeline, a pipeline isolator with integrated pipeline surrounding rubber and base vibration isolating rubber is designed. Adjusting the rubber parameters of the pipeline mainly changes the impedance of the isolator and adjusting the base rubber mainly changes the force transfer rate. Thus the optimal vibration isolation effect can be achieved by increasing the rubber hardness of the pipe surrouding rubber and reducing the rubber hardness of the base rubber. The analysis also shows that the base rubber structure has a decisive influence on the low-frequency vibration isolation performance of the integrated pipeline isolator compared to the pipeline rubber.
Preparation of pesticide microspheres based on polylactic acid: optimized by response surface methodology
Authors: Li Yan , Dai Jiakun , Cao Duo , Ma Yu , Zhen Lisha , Chang Fan
Published: January 2020

Polylactic acid, as a kind of environment-friendly material, has excellent biodegradability, biocompatibility and plasticity. In recent years, it has been widely used in medicine, packaging and other fields, but rarely in agriculture. In this study, the process of buprofezin - polylactic acid microsphere was optimized by response surface method. Changing parameters, especially the concentration of PLA and the PLA/drug ratio, can increase the encapsulation efficiency of buprofezin - PLA microspheres. Ultimately, the highest encapsulation efficiency reached to 96.47%. The result of FESEM and laser particle size distribution analyzer showed that the microspheres have smooth surface and good dispersion, with particle size of 34.2 μm.
Double-objective optimization simulation and orthogonal experiment of shredding roller for silage machine
Authors: Jiang Yingshuai , Li Guoping , Zhang Xiangfang
Published: January 2020

At present, the main factor affecting the quality of the silage of the silage machine is the shredding roller. Therefore, a theoretical model based on single-page hyperboloids and a shredding roller with a herringbone arrangement are designed. Then, the theoretical analysis of each key parameter was carried out. The consumption of energy and throwing height of the shredding roller can be targeted, and the orthogonal simulation was performed on each parameter combination. The optimal parameter combination was obtained as the rotational speed of 1426r/min, the rake angle is 53°, the sliding-cutting angle is 8°, and the influence of each factor and level on the consumption of energy and the throwing height is analyzed successively. The verification of experiment that the shredding loss rate was reduced by 5% compared with the pre-optimization, the optimized of broken stems is 25% higher than pre-optimization, the throwing height was 30mm higher than the pre-optimization, and the consumption of energy was reduced by 3.1% compared with the pre-optimization. The optimized of objective was within the prescribed range.
Analysis and Research of Molten Copper Sloshing in Mould of Anode Based on VOF Method
Authors: Zheng Jie , Li Guoping , Teng Xinyi , Qiu Zefeng
Published: January 2020

In the production process of anode, the quality of anode is affected by the sloshing of molten copper caused by casting wheel during operation. Therefore, it is significant to study the sloshing of molten copper and the motion model of casting wheel for improving the quality of anode. Using VOF method and UDF to study the sloshing of molten copper and the motion characteristics of casting wheel. Establishing the ΔH – a model through the method of FLUENT and MATLAB. The optimal motion model of casting wheel is S-model.
Research on path planning of locally added path factor dijkstra algorithm for multiple AGV systems
Authors: Wu Guorong , Sun Xuan
Published: January 2020

Aiming at the problem of relative encounter path conflict in multi-AGV systems under special working conditions, a path planning method is proposed to limit the running direction of AGV by adding path factor to Dijkstra algorithm. This method can realize simple traffic rule formulation. Effectively reduce the conflict of opposite encounter paths and achieve the purpose of orderly operation of multiple AGVs.
Analysis of circular steel tubular columns under the coupling of fire and impact
Authors: Yuan Tingwei , Li Chunting , Zhang Qiuyue
Published: January 2020

Aiming at the coupling of a pair of sliding circular steel tubular columns with one end fixed by fire and impact, this paper analyzes the model by finite element software ABAQUS. The impact load is applied to the mid-span of the test piece. Through the analysis of the displacement of the mid-section of the test piece, the following three points are clarified: 1) The circular steel pipe column absorbs energy through integral plastic deformation and local plastic deformation; 2) The displacement of the end of the circular steel tubular column and the displacement and displacement of the upper and lower surfaces of the span depend on the axial compression ratio, the impact velocity and the temperature; 3) Under the coupling of fire and impact, the safe area of the column member depends on the temperature. And axial compression ratio; the greater the temperature and axial compression ratio, the smaller the safety zone. In order to study the concrete-filled steel tube under the coupling of fire and impact.
The damping effect Analysis of viscous damper in eccentric concrete frame structure
Authors: Fang Zhou , Zhang Qiuyue , Wang Chongge , Liu Zhichuang
Published: January 2020

The application of viscous dampers in structures can effectively reduce the inter-layer displacement of structures, especially they can reduce the torsional effects of structures in earthquakes. We can simplify the eccentric structure into a series rigid plate model and divide it into three types: a model of the viscous dampers are provided at position 1 of the eccentric structure, and a model of the steel supports are set at position 1 of the eccentric structure and a original structural model . Then analyzing the earthquake resistance of a 13-layer eccentric concrete structure model using SAP2000, It is concluded that the model of setting the steel supports can effectively reduce the horizontal displacement of the structure compared with the original structural model, but the effect of reducing the torsional displacement is not obvious enough; the model of setting the viscous damper can not only effectively reduce the inter-layer displacement of the structure, but also effectively reduce the torsional displacement of the structure; Setting the viscous dampers can effectively reduce the inter-layer writhing displacement of the structure than setting the steel support model on the premise of reducing the same level of horizontal inter-layer displacement.
Green Intelligent Logistics Sorting System in Big Data Environment
Authors: Gao Xinyue , Liu Lei
Published: January 2020

By referring to the current sorting process of logistics sorting equipment, combined with emerging technologies, green concepts and big data statistics, it is possible to predict the trend of future sorting systems and integrate existing technologies. First, investigate and research existing logistics warehousing. Next, the intelligence and automation of existing intelligent sorting are investigated. After investigating, on the basis of the above, this study analyzes the trend of the future sorting system and combines with the concept of green logistics. It optimized classification under principles of green warehousing conceptual to make the classification more efficient, more space-saving and more convenient; it uses the big data statistics technology to collect logistics information, provides information to the logistics company to re-plan the sorting point, and feedback to the electronic merchants to obtain the location of different kinds of online shopping products in each region, and make it possible to purchase goods in a targeted manner.
Research on Bearing Fault Diagnosis of Submersible Pump Motor Based on LMD and SVDD
Authors: Yuan Zhengtao , Song Fangzhen , Dou Renjie
Published: January 2020

The motor is a key component of the submersible pump. The health of the motor would greatly affect the safety and efficiency of the submersible pump. The bearing fault is one of the most common faults in motors. Therefore, detection and diagnosis of bearing faults are essential in the condition monitoring of pumps. In this paper, the local average decomposition (LMD) method is used to analyze the bearing vibration signals of submersible pump motor and extract feature vectors. A fault diagnostic model is established by the support vector data description (SVDD) to determine whether the submersible pump motor is faulty. The developed model exhibits practical significance in condition monitoring of submersible pump motor bearings.
System Design of Small-scale Seawater Desalination Device
Authors: Feng Lingzhi , Zheng Yuanzhou , Zhang Aobo , Lu Tianfu , Miao Tongyao , Peng Yunhui
Published: January 2020

Water is of great significance to the subsistence and development of human beings. As we all know, fresh water issues have always been a major problem to the ocean navigation, as the existing desalination devices generally have the disadvantages of large volume, highenergy consumption, which would bring pollution to the environment. Basing on the study results in existence, this paper presents a new system design of small-scale seawater desalination device, which founds on the enhanced heat transfer processes of fluid phase change, including loop heat pipe technology, new type of heat-sink type spoiler evaporator and integrated soaking plate fin condenser to implement the low-power and low-temperature system. This system covers an area of only 1.8m2, as the energy consumption is 62.5% of the reverse osmosis desalination method and 20% of the multistage distillation desalination method under the same conditions. What’s more, the system consists of the loop heat pipe based on the phase change thermal principle, integrated soaking plate fin condenser and the new type of heat-sink type spoiler evaporator, improves the heat transfer efficiency, besides it has low pollution.
Study of pulping technology on disposable tableware using withered leaves as raw material
Authors: Liu Bo-Fan , Liu Ming-Dan , Jin Peng , Zhong Yi-Xin
Published: January 2020

Disposable tableware is widely used around world due to its advantages such as sanitation, thermal preservation and low price. However, more and more countries are restricting the use of disposable tableware due to its difficulties in recycling and degradation in the natural environment. If disposable tableware is made of photobiodegradable PP plastic or high-impact polystyrene (HIPS), it is difficult to degrade and has a great impact on the earth environment. In this study, four kinds of withered leaves were selected as raw materials and mechanical chemical pulping method and caustic soda pulping method were used for experiments. The main processes include pulp preparation, adsorption and drying. The experiment indicated that withered leaves of magnolia grandiflora was the best raw material for making recyclable tableware.
Fast wave front correction method of reception diversity laser communication based on the analysis of distorted wave front of different receivers
Authors: Xu Chenlu , Hao Shiqi , Wang Yong , Liu Yujie , Zhao Qingsong
Published: January 2020

Reception diversity laser communication can improve the channel capacity as well as weaken light intensity scintillation caused by atmospheric turbulence. However, it can’t reduce the wave front distortion. Wave front distortion is usually corrected by adaptive optics system, because that reception diversity laser communication has more than one receiver, it would take much more time as well as resources to correct the distortion of different receivers. Based on the analysis of wave front distortion of different receivers, we set the best correcting voltage of one receiver as the initial correcting voltage of the other receiver, it can be concluded from the simulation that using the method we propose need less iteration times than the traditional methods when achieving same correcting effect and it can also achieve higher correcting effect when setting same iteration times.
Study on damage of polyimide target irradiated by Pulsed CO2 Laser
Authors: Wu Jiacheng , Hu Yue , Wang Xi
Published: January 2020

In this paper, the PI damage caused by pulsed CO2 laser was simulated. The theoretical model of PI damaged by pulsed CO2 laser was established. The temperature and stress distribution in PI samples were numerically analyzed by finite element method. The simulation results show that under the condition of low incident laser energy, serious melting damage has occurred on the PI surface, and there exists thermal stress damage. The damage of PI by pulsed CO2 laser is mainly thermal damage, and the melting phenomenon will be obvious.
Measurement of raised pavement marker’s photometric performance
Authors: He Huayang , Leng Zhengwei , Xue Yingqi , Zhou Yishu
Published: January 2020

Large error exists in the photometric performance test of raised pavement marker. This paper reports a set of retroreflective measurement standard devices built to measure raised pavement markers based on the principle of direct measurement, and the photometric performance of the raised pavement markers was tested. The study also involved calibration of a portable meter using the standard device. According to the experimental comparison, the method proposed in this paper provides a new direction for the development of retroreflection measurement technology. The results measured by the proposed method showed high accuracy. This method can solve the large measurement error problems with indication errors of 2% at most.
Effective Backbone Network for 3D Object Detection in Point Cloud
Authors: Xu Jun , Ma Yanxin , He Songhua
Published: January 2020

Three-dimensional (3D) object detection is composed of object classification and object localization, and has been used in many applications, such autonomous driving and mobile robot. However, the accuracy of classification and localization is greatly affected by the depth of the network. Shallow networks tend to cause poor classification, but as the depth of the network increases, the network degradation will become more obvious, which is not conducive to the training of network. To solve this problem, a novel Backbone Network is proposed in this paper for 3D object detection in point cloud, which consists of multiple residual modules. Experimental results on the KITTI 3D object detection benchmarks show that Backbone Network proposed can effectively improve the accuracy of 3D object detection.
Small target detection and window adaptive tracking based on continuous frame images in visible light background
Authors: Wang Zheng , Zeng Jianping , Xie Xiaoli , Wu Wuming , Chang Shengli
Published: January 2020

Due to the difficulty in distinguishing the target and the noise in the visible light background and the loss of the target for a short period of time, a scheme of track association and target tracking for the small target in the sky is carried out. Multi-feature similarity is taken into account, such as the maximum intensity, the maximum brightness, the size and the moving speed. Firstly, the trajectory prediction is carried out by the least square prediction method. By updating the real-time data to deduce the trajectory parameters, the target position in the next frame image is predicted. Based on the trajectory confidence test, all current recorded trajectories are traversed. The over-confidence trajectory is detected and the trajectories of continuous lost points are deleted, as well as the trajectories below the threshold of confidence. For the trajectory of the over-confidence, the target trajectory without the significant motion feature is deleted by judging the magnitude of the moving speed, so that the effective trajectory can be displayed while the false target is eliminated. Then, the target tracking is carried out, which is based on the LOG filter and the constant false alarm rate segmentation. Considering the temporal and spatial continuity of the target trajectory and the randomness of the amplitude and position of the noise, the false alarm rate can be reduced by eliminating the high amplitude noise by using the difference between the two in terms of temporal and spatial correlation. Owing to that the setting of the division threshold is not less than 5 times the background variance of the window image, the generation of the noise by the constant false alarm rate segmentation can be avoid when there is no target. In addition, the target coordinates may be abrupt due to sudden changes in target speed and the jitter of the image acquisition equipment. Therefore, we propose a dynamic adjustment scheme for the tracking window size to enable window adaptive tracking, which can set the length and width of the rectangular window to k times of the original size according to actual needs. At the same time, the number of points of the relatively stationary target in each frame of the image can be counted in real time. Finally, the reliability of the method is verified by simulation experiments, and the running speed is relatively fast and the recognition accuracy is relatively high.
Security study of laser measuring methods on high explosives
Authors: Gao Zheng-Ming , Zhao Juan , Li Su-Ruo
Published: January 2020

Interaction activities between the laser photons and the molecular of high explosives were described; the threshold of the laser beams’ power on the surface of the high explosives is achieved limiting the interaction probability between molecules of the high explosive and the photons, their changes of properties with the mathematical norm commonly used in engineering. Research confirm the security of common active optical measuring methods on high explosives, and prove the capability of their wide applications in measuring the properties and state characteristics of high explosives.
Study on the Interaction between Channels of Image Intensifier
Authors: Xie Yuntao , Liu Yang , Sun Xiaoquan
Published: January 2020

The experiment of mutual interference between channels of the UV imager was carried out. The plateform consists of jamming light with large area and target light with small area was established. The curve of the gray value of target light in image intensifier with the intensity of interference light was measured. Experimental results show that there is mutual interference between channels when the UV imager is irradiated by continuous laser and the mutual effects will benefit to suppress the target signal by reducing the gain of the adjacent channels. Theoretical mechanism of this phenomenon was studied. The electrical coupling model between channels was established, and the influence of transverse resistance between adjacent channels on the gain characteristics of adjacent channels was studied by nodal analysis. Numerical simulation results show that the transverse resistance between channels is the main cause of mutual interference between channels, which greatly influence the gain of the adjacent channels.
Effects of Gradient Optimizer on Model Pruning
Authors: Zhang Yang , Zhu Bin , Ma Qi , Wang Huanan
Published: January 2020

Deep convolutional neural networks deploy in applications are hindered by their large parameters and high computational cost. In this paper, we test different gradient optimizer’s effect on YOLOv3 model pruning. This is achieved by enforcing channel-level sparsity in YOLOv3 network. The model trained with Adam optimizer get 5× reduction in model size only after training 60 epochs.
Research of photon correlation technology
Authors: Zou Lianying , Gao Ning , Xiao Qian
Published: January 2020

Photon correlation technology is an important technology in the field of nanoparticle measurement at present. This paper expounds the research significance of photon correlation technology, introduces the research background and basic concepts of this technology, and studies and analyzes the research status of the correlation algorithm of the new photon correlator. Finally, prospect and application development trend of this technology are analyzed, from the aspects of practicability, application environment and hardware conditions, the difficulties faced by the photon correlation technology are put forward. There are some difficulties when the photon correlator needs to meet the requirements of accuracy, small sampling interval and large dynamic range, this article presents some possible solutions.
Design and Research of Ground Control System of the UAV-borne Photoelectric Platform
Authors: Zhao Xinglong , Zhao Jingshan , Zheng Xing , Cheng Jian , Bao Chuanmei , Zhang Zhengwu , Fu Xiaojin , Liu Yun
Published: January 2020

According to the working principle of a UAV-borne photoelectric platform, as well as the main functions and characteristics of the photoelectric platform ground control system, the overall design scheme and target of this system are proposed with an introduction of its composition and working principle. On this basis, the design and research of the system are carried out from hardware and software. Specific schemes of the two aspects are given. Finally, the future of the photoelectric platform ground control system is predicted on the trend of UAV-borne photoelectric platform.
Simulation Study on Laser Damage of Iron Plate
Authors: Wang Tianyu , Bian Jintian , Ye Qing , Li Xin , Sun Xiaoquan
Published: January 2020

Studying laser damage effects are of great significance in the field of industrial production. In order to evaluate the damage effect of laser on iron, the process of pulsed laser and continuous laser irradiate an iron plate was simulated by using COMSOL. The relationship between temperature and surface energy absorptivity of iron plate was discussed. The initial simulation parameters were set as follows: the pulsed laser wavelength is 1064nm, the pulse width is 10ns, the pulse energy is changed from 2mJ to 8mJ, and the average power of continuous laser is 225mW. The simulation results show that pulsed laser can rise the surface temperature of iron plate very quickly, and improve surface energy absorptivity of the plate. Thus using pulsed laser to radiate an iron plate before using continuous laser can improve damage efficiency of continuous laser on an iron plate.
Research on Temperature and Humidity Decoupling Control of Constant Temperature and Humidity Test Chamber
Authors: Wang Liheng , Zhu Zhifeng
Published: January 2020

The temperature and humidity system is a system commonly used in industry and is recognized as one of the most complex systems. Temperature and humidity are important parameters for improving production quality in industrial production. To carry out effective control, factors such as nonlinearity, large hysteresis and real-time change must be considered, and there is mutual coupling between temperature and humidity. Temperature change will lead to humidity. The change of humidity and the same change of temperature will also affect the temperature change. The positional PID control can achieve satisfactory results. In this paper, through the analysis of the temperature and humidity system model, the feedforward decoupling compensation method is adopted for the characteristics of the temperature and humidity control system, which provides an effective way for the modeling and control of the temperature and humidity system. The simulation results show that the feedforward decoupling controller designed in this paper can achieve satisfactory results under various experimental conditions.
Effects of Typical Emission Waveform on Laser Reflective Tomography Imaging
Authors: Zhang Xin-Yuan , Hu Yi-Hua , Zhao Nan-Xiang , Xu Shi-Long
Published: January 2020

Laser reflective tomography imaging is a new imaging method of long distance and high resolution. The echo could be expressed as the convolution of incident waveform and the reflectance projection distribution, so the deconvolution effect of the echo obtained by different emission waveforms is also different. In order to explore the reflectance projection distribution obtained by deconvolution of different emission waveforms under the same SNR, we simulated four kinds of emission pulses and from the comparison of the RMS of Euclidean distance between deconvolution results and reality results, we found that Gaussian pulse could be selected as the most suitable emission waveform when the SNR was less than 40, and when the SNR was larger, Sawtooth pulse was the best choice.
Numerical calculation and analysis of infrared radiation characteristics of stratospheric airship
Authors: Feng Yunsong , Lu Yuan , Jin Wei
Published: January 2020

In order to estimate the spatial distribution of infrared radiation of stratospheric airship, the geometric model of stratospheric airship was firstly constructed in this paper. Then, considering the influence of environmental radiation, the one-dimensional heat conduction differential equation of airship skin was established, the equation was solved by backward difference method, and the temperature distribution of airship skin was numerically calculated. On this basis, the spatial distribution of airship infrared radiation was further calculated. The results show that the infrared radiation intensity of the airship in the sunny face is higher than that in the shadow face, and the infrared radiation intensity of the airship in the 8~14μm is obviously higher than that in the 3-5μm.
Recycle of vanadium from aluminum slag of ferrovanadium
Authors: Chen Wei-Sheng , Liu Tzu-Yu , Lee Cheng-Han
Published: January 2020

Vanadium is a rare chemical element and it primarily comes from the by-product of other minerals. In this study, the material source mainly comes from vanadium-rich aluminum slag. This experiment aims to separate vanadium and other impurities, such as aluminum and zirconium. First, the slag was dissolved in the sodium hydroxide solution at pH value 13, and part of the alumina was precipitated. After removing the precipitation, the strong acid cation exchange resin, Dowex® G26, was added to eliminate the remaining impurities. In this procedure, the parameter of reaction time, the mass of ion exchange resin and pH value were supplied. Moreover, the adsorption isotherms described by means of the Langmuir and Freundlich isotherms were used to investigate the ion-exchange behaviors of vanadium. To sum up, this study will provide the best conditions of ion exchange to get high purity about 95% of vanadate.
Cobalt−Citrate Metal−Organic-Framework UTSA-16 on TiO2 Nanoparticles
Authors: Tseng Mei-Yi , Su Yen-Hsun , Lai Yi-Sheng , Pan Fei , Kung Po-Yen
Published: January 2020

Over the past few decades, the multifunctional material, metal-organic frameworks(MOFs), has been distinguished for their unique properties such as reticular structure, permanent porosities, high surface area, straightforwardly self-assembly and crystalline nature. On a count of these potentialities, the applications of MOFs can be classified into separation, catalysis, sensing, and biomedicine these four fields. In our studies, we will concentrate on the fields of gas storage and separations, water splitting, CO2 reduction, and White-light emission and so on.