Aiming at the quality problems of the land cover classification data, such as missing update of changed spots, overrun of spot collection accuracy, incorrect spot classification, and inconsistencies between the filling of the change types of map spots and technical regulations, had been found during the quality inspection of the national geographic condition monitoring in China. This paper analyzed the key production factors, processes and causes that affect the process quality of the land cover classification data, and proposed the concept of the whole production quality control, and discussed the quality control measures to improve the land cover classification product. The research based on the new requirements of the whole-process quality control system in order to solve the quality problem-oriented production quality control method, could improve the quality of land cover classification product and provided reference for the quality control of the production process of related engineering projects in the future.

With the development of real 3D model production technology and the expansion of application field, people pay more and more attention to the quality of real 3D model. However, how to measure the quality of today's real 3D model have been bothering its producers and users. In this paper, we analysed the quality model of real scene 3D model based on oblique photography from the perspective of the third party. Our analysis is guided by the application requirements of real scene 3D model, combined with the existing production technology level. Our analysis is guided by the application requirements of real scene 3D model, combined with the existing production technology level, we established the quality framework of real scene 3D model. This quality framework of real 3D model includes nine quality elements. Using this quality framework, we made a quality evaluation test in Yingjing County, Sichuan Provence. The test results show that the quality framework can fully reflect the quality of the real scene 3D model. The quality framework of real scene 3D model established in this paper solves the problem that it is difficult to evaluate the quality of real scene 3D model. The quality framework provides a basis for comprehensive and objective evaluation of real scene 3D model quality.

Today's society has entered the era of big data, and the quality of surveying and mapping results has become the focus of government departments. As the statistical results of other industries, surveying and mapping results as one of the basic data sources provide data support for government decision-making, The status of surveying and mapping projects is constantly improving. This article introduces the ISO9001 quality management system implemented by the surveying and mapping production unit, the CMA quality management system implemented by the surveying and mapping quality inspection unit, and the first-level acceptance system for the two-level inspection of surveying and mapping products. Through the cause and effect diagram, taking the quality control of the fundamental geographical conditions monitoring of the national major surveying and mapping project as an example, the use method of the core tool 5M1E (Man, Machine, Material, Methods, Measurement, Environment) in the quality management system is demonstrated to prove that the quality management system plays an important role in the project. Provide reference experience for peers.

Two-stage 4 K pulse tube cryocooler is one of the most promising coolers for low temperature applications. However, an efficient and reliable method is still absent for pulse tube optimization in liquid helium temperatures due to complex heat and mass flow oscillation. In this study, a two-stage pulse tube cryocooler model was built with a commercially-available software, SAGE®. The DC flow effect on the performance was investigated and the filling ratio of second stage regenerator were numerically optimized. With the model, a no-load temperature of 2.7 K and a cooling capacity of 0.5 W at 4.2 K were achieved, which is well-matched with the experimental results.

Motivated by the observation of in-situ nanocrystallization in the surface layer of plasma nitrided steels, this work is carried out to establish a thermodynamic model that describes the Gibbs free energy of BCC-Fe solution using the quasi-binary solution model. The model is specifically developed for the nitriding process of the multi-component steels, whose composition is first converted to an Fe-Cr-eq-N ternary system using the concept of Cr equivalent through the relative elemental electronegativities with respect to nitrogen. With the thermodynamic model, the limit of stability of the BCC pseudo binary solution can be evaluated with temperatures and used to guide the selection of nitriding conditions. It has been recognized that the nitrogen-containing martensite is unstable and likely to decompose in the form of spinodal decomposition over a specific compositional/temperature range. 40CrNi steel is adopted in this work and plasma nitrided at 800 K for 8 h. Nano-scale FeN1/12 phase and high-nitrogen martensite phase have been experimentally observed in the nitrided surface layer, which embraces the thermodynamic predictions in terms of nanocrystallization via spinodal decomposition.

At present, in the inspection and acceptance of high spatial resolution remotly sensed orthophoto image, the horizontal accuracy detection is testing and evaluating the accuracy of images, which mostly based on a set of testing points with the same accuracy and reliability. However, it is difficult to get a set of testing points with the same accuracy and reliability in the areas where the field measurement is difficult and the reference data with high accuracy is not enough. So it is difficult to test and evaluate the horizontal accuracy of the orthophoto image. The uncertainty of the horizontal accuracy has become a bottleneck for the application of satellite borne high-resolution remote sensing image and the scope of service expansion. Therefore, this paper proposes a new method to test the horizontal accuracy of orthophoto image. This method using the testing points with different accuracy and reliability. These points’ source is high accuracy reference data and field measurement. The new method solves the horizontal accuracy detection of the orthophoto image in the difficult areas and provides the basis for providing reliable orthophoto images to the users.

High temperature superconducting (HTS) applications require high-capacity and high-reliability cooling solutions to keep HTS materials at temperatures of approximately 80 K. In order to meet such requirements, Sumitomo Heavy Industries, Ltd. (SHI) has been developing high cooling capacity GM-type active-buffer pulse tube cryocooler. An experimental unit was designed, built and tested. A cooling capacity of 390.5 W at 80 K, COP 0.042 was achieved with an input power of approximately 9 kW. The cold stage usually reaches a stable temperature of about 25 K within one hour starting at room temperature. Also, a simplified analysis was carried out to better understand the experimental unit. In the analysis, the regenerator, thermal conduction, heat exchanger and radiation losses were calculated. The net cooling capacity was about 80% of the PV work. The experimental results, the analysis method and results are reported in this paper.

Since 2012, a new, compact Gifford-McMahon (GM) cryocooler for cooling superconducting single photon detectors (SSPD) has been developed and reported by Sumitomo Heavy Industries, Ltd. (SHI). Also, it was reported that National Institute of Information and Communications Technology (NICT) developed a multi-channel, conduction-cooled SSPD system. However, the size and power consumption reduction becomes indispensable to apply such a system to the optical communication of AdHoc for a mobile system installed in a vehicle. The objective is to reduce the total height of the expander by 33% relative to the existing RDK101 GM expander and to reduce the total volume of the compressor unit by 50% relative to the existing CNA-11 compressor. In addition, considering the targeted cooling application, we set the design cooling capacity targets of the first and the second stages 1 W at 60 K and 20 mW at 2.3 K respectively. In 2016, Hiratsuka et al. reported that an oil-free compressor was developed for a 2K GM cryocooler. The cooling performance of a 2K GM expander driven by an experimental unit of the linear compressor was measured. No-load temperature less than 2.1 K and the cooling capacity of 20 mW at 2.3 K were successfully achieved with an electric input power of only 1.1 kW. After that, the compressor capsule and the heat exchanger, etc. were assembled into one enclosure as a compressor unit. The total volume of the compressor unit and electrical box was significantly reduced to about 38 L, which was close to the target of 35 L. Also, the sound noise, vibration characteristics, the effect of the compressor unit inclination and the ambient temperature on the cooling performance, were evaluated. The detailed experimental results are discussed in this paper.

To improve the efficiency of a cryocooler, it is vital to improve the regenerator. In general, the heat capacity of materials decreases as temperature decreases. Thus, when temperature is below 50 K, lead spheres are often used as a regenerator material. However, the pressure drop through a sphere regenerator is larger than that through a screen regenerator. To overcome this dilemma, a new, low pressure loss tin-plated screen is proposed. A comparison test was performed with a two-stage GM cryocooler by replacing part of the first stage regenerator material, bronze screens with tin-plated screens. Compared to a regenerator filled with bronze screens, the cooling capacity of the first stage increased by about 14% at 40 K and 90% at 30 K with such tin-plated screens. The ratio of the wire diameter before and after the deposition was also optimized. An optimum cooling capacity of 53.5 W at 40 K was obtained at a diameter ratio of about 1.4. The detailed experimental results are reported in this paper.

An effective way to improve the efficiency of a cryocooler is to improve the efficiency of the regenerator. In general, the heat capacity of materials decreases as temperature decreases. Thus, when temperature is below 40 K, lead or bismuth spheres are often used as regenerator materials. However, the pressure drop in a sphere regenerator is much larger than that in a screen regenerator. To overcome this dilemma, Xu et al. reported that cooling performance at the temperature of less than 40 K was improved when using tin-plated screens at the cold end of the regenerator. However, the reliability of tin at low temperatures is still not verified fully because of its phase transition from a normal β phase to an abnormal α phase, which may result in a significant reduction of the mechanical strength. In this paper, a zinc-plated screen is proposed as another potential alternative. A comparison test was performed with a two-stage GM cryocooler by replacing part of the first stage regenerator material, phosphorus bronze screens, with zinc-plated screens. Compared to a regenerator filled with bronze screens, the cooling capacity of the first stage increased by about 11% at 40 K and 60% at 30 K with these zinc-plated screens. The detailed experimental results are reported in this paper.

model.We investigated whether intrathecal (i.t.) ALX-1393 can inhibit the autonomic response during bladder HD in the IC/BPS rat model.METHODS: Animals Twelve Sprague-Dawley female white rats (200-250g) were divided into 2 groups (control, n¼12 and ALX-1393, n¼12, respectively).All rats received protamine sulfate (PS) 10mg/ml in the urinary bladder for 30 minutes followed by 750ug/ml lipopolysaccharide (LPS) instillation for 45 minutes.One week after the instillation, cystometry (n¼6, in both groups, respepctively) and HD (n¼6, in both groups) was performed.Hydrodistention and Cystometry Based on previous experiments, HD was performed at a pressure of 150-170 mmHg for 30 seconds with a 3 minute interval.Autonomic response was quantified as the difference of mean arterial pressure between baseline period prior to distension and during HD.Anesthesia was performed with Intraperitoneal injection of Zoletil (Tiletamine+Zolazepam) 0.1cc/100g and Rompun (Xylazine) 0.025~0.04/100g.After placing a PE-50 tubing into the bladder, awake cystometry was performed by infusing physiological saline at a slow infusion rate (0.04ml/min).Intrathecal administration of ALX-1393 Through the subarachnoid space, a polyethylene catheter was advanced and placed at L6-S1 spinal cord level.Saline (for control) or ALX-1393 was injected after 1st HD, and 2 more sessions were performed 5 and 30 minutes after saline or ALX-1393 injection.RESULTS: A significant increase in BP was consistently observed for 3 consecutive sessions of HD in control group (19.49AE5.50,13.63AE6.22and 17.18AE7.67mmH2O).In ALX-1393 group, minimal change of BP was observed during HD which was performed 5 minutes after ALX-1393 i.t.injection (4.22AE9.69mmH2O).The exaggerated autonomic response was observed 30 minutes after ALX-1393 i.t.injection (15.62AE8.60mmH2O).On cystometry, intercontraction interval (ICI) in control group demonstrated little change after saline i.t injection (12.17AE20.58,p¼0.207), while significantly prolonged ICI was seen immediately after ALX-1393 i.t injection (57.83AE24.86,p¼0.005).CONCLUSIONS: ALX-1393 inhibits the exaggerated autonomic responses during bladder HD and ameliorates detrusor overactivity in the IC/BPS rat model.These findings suggest that GlyT2 may be a novel therapeutic target for the treatment of IC/BPS.

The structure of plasma antenna is more complex than metal antenna to reach ideal gain, efficiency, matching, etc. Therefore, earlier plasma antenna prototypes were always featured with larger size and weight. The NSSC research team has developed new prototypes with equivalent performance as metal antenna. In recent research, we also optimized the antenna structure to reduce size and weight. The new plasma antenna prototype is much smaller than the former ones, and its power consumption is also reduced from more than 100 watts to about 30 watts.

Plasma antenna is a sort of ionized gaseous antenna, which can be reconfigurable by altering the input RF power. This article introduces the reconfigurable plasma antenna and antenna array prototype of the NSSC. Through HFSS simulation, we studied the frequency reconfigurable, EMC and antenna array performance of plasma antenna. According to this study, plasma antenna has very wide bandwidth, its insulating medium gas cavity has very low EMI/RCS, and it is very suitable to be used in antenna array, low RCS antenna and ultra-wide/frequency hopping communication.

A novel Gifford-McMahon (GM) cycle, called an asymmetric GM cycle, is proposed. In an asymmetric GM cycle, the displacer moves slowly when it is adjacent to the upper dead point but moves rapidly when it is adjacent to the lower dead point. Therefore, the expansion process is longer, while the discharging process is shorter than in a conventional GM cycle. Meanwhile, the duration of the charging process can be kept the same as that in a conventional GM cycle. Accordingly, the phase shift between the pressure and the displacement can be improved, and the mass flow rate into the expansion space can also be increased. Therefore, the P-V work and the cooling capacity can be increased. To implement the GM cycle, a novel Scotch yoke was invented. In the Scotch yoke, there is a concave part at the upper center of the slide groove and a convex part at the lower center of the slide groove. The effect of the Scotch yoke has been confirmed by numerical simulation and experimental investigation. With a conventional Scotch yoke, the cooling capacity was 44 W at 37.4 K at the first stage and 1.0 W at 3.94 K at the second stage. With a novel Scotch yoke, the cooling capacity was 44 W at 35.9 K at the first stage and 1.0 W at 3.96 K at the second stage. The cooling capacity at the first stage at 40 K was improved by about 10%, from 51.5 W to 57.3 W.

Large planar plasma sheets, generated by a linear hollow cathode in pulse discharge mode under magnetic confinement, can be used in the field of plasma antenna, plasma stealth, and simulation of a plasma layer surrounding vehicles traveling at hypersonic velocities within the Earth's atmosphere. Firstly, to investigate the propagation properties of electromagnetic waves at different frequencies and polarization, the transverse field transfer matrix method is introduced. Secondly, the measured electron density temporal and spatial distribution and the transverse field transfer matrix method are utilized to calculate the reflection, transmission and absorption of electromagnetic waves by large planar plasma sheets with different currents. Finally, 1 GHz (less than the critical cut-off frequency) electromagnetic waves and 4 GHz (greater than the critical frequency) electromagnetic waves are chosen to investigate the evolution of propagation properties during the pulsed discharge period. Results show that both the reflection and absorption of the electromagnetic waves are greater for their polarization direction parallel to that of magnetic field, and their frequencies lower than the critical cut-off frequency, and as the discharge currents rise, the reflection increases while the absorption decreases. However both the reflection and absorption of the electromagnetic waves with their polarization direction perpendicular to the magnetic field direction and their frequency greater than the critical cut-off frequency become less, and as the discharge currents rise, both the reflection and absorption will increase. For the electromagnetic waves with their polarization direction perpendicular to the magnetic field direction, there is an upper hybrid resonance absorption band near the upper hybrid resonance frequencies, in which the absorption is significant but the absorption peak value is not affected by the discharge current. The propagation characteristics of the electromagnetic waves with polarization direction perpendicular to the magnetic field direction are the same as that of the electromagnetic waves with the polarization direction parallel to the magnetic field direction, except the upper hybrid resonance absorption. During the pulse discharge period, the propagation characteristic of the electromagnetic waves experiences an unstable phase before reaching steady states. The transition time is about 100 s and increases as the discharge current rises. The upper hybrid resonance absorption is significant during the phase of steady state for waves with frequency lower than the critical cut-off frequency and polarization direction parallel to the magnetic field direction. For the applications of a large planar plasma sheet to reflect electromagnetic waves effectively and steadily, the pulse discharge period should be larger than 100 s, and its discharge current should be large enough to make the critical cut-off frequency greater than the frequency of incident wave, and its polarization direction should be parallel to the magnetic field direction.

Plasma column antenna is a new technology for UHF/VHF communication. Except for theoretical research, creating a prototype with considerable performance as metal antenna is really very difficult. The plasma antenna research team of National Space Science Center has created some techniques to make a practical plasma antenna prototype, it can reach the same antenna gain and radiation pattern as a common metal antenna with relatively small size and power consuming. This paper presents our experience and problem solutions on plasma antenna research and manufacture.

利用脉冲磁约束线形空心阴极放电装置,在15mT磁场约束下,产生了持续时间为200μs、峰值放电电流为3A、面积为60cm×60cm的大面积等离子体片。采用快帧法和旋转空心阴极法,在90~210Pa内,利用朗缪尔探针首次获得了不同气压的等离子体片的厚度向电子密度分布及其演化构成的二维分布图;研究了在同等峰值放电电流条件下,等离子体片达到最大厚度向峰值电子密度时,气压对所需放电时间、最大厚度向峰值电子密度及电子密度半高宽的影响。结果表明:在相同的峰值放电电流条件下,等离子体片达到最大厚度向峰值电子密度的时间随气压的降低而减小;气压越低,最大厚度向峰值电子密度越大,电子密度半高宽越小。

Plasma antenna is a kind of reconfigurable antenna, its antenna frequency and radiation pattern can both be quickly changed by altering the input ionizing power and turning on certain antenna array elements. This article introduce our HFSS analysis method in the study of plasma antenna and array. As a preliminary study, we simulate the reconfigurable performance of a two elements plasma antenna array.

Sumitomo Heavy Industries, Ltd. (SHI) has been continuously developing 4K GM-type pulse tube cryocoolers for cooling superconducting magnets and pre-cooling ultra-low temperature refrigerators, such as dilution refrigerators, etc. In a double-inlet or a 4-valve GM-type pulse tube cryocooler, there is a gas circulation, called DC flow, generated by the pulse tube, the regenerator and the orifice. The performance of a pulse tube cryocooler is strongly dependent on the rate of such kind of flow. It is possible to improve the performance by optimizing the rate. In order to optimize the rate, a bypass line with a small valve is installed between the warm end of the pulse tube and the low pressure side of the compressor. The second stage cooling capacity at 4.2 K was improved by about 0.25 W after optimization of the rate by adjusting the opening of the valve. The details of the experiment results will be reported in this paper.