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The reduction in the power cost of air supply systems has emerged as a critical challenge in the development of polymer electrolyte membrane fuel cells. This study proposes the use of dual-lead rotors to improve the performance of twin-screw expanders for the purpose of boosting expanders' recovery power and consequently lowering the power cost of the air supply subsystem, which is hardly investigated in previous publications. For this purpose, a mathematical model is built to assess the potential of improving the expander performance by means of the dual-lead rotors. And the influence of lead and length of the high-pressure rotor segment and overall rotor length are analyzed. The results demonstrate that the smaller lead and larger length of the high-pressure rotor segment result in better geometric characteristics and thus thermodynamic performance. For example, case #4 with dual-lead rotors exhibits a larger rotating angle at the suction end and a larger suction area than those of constant-lead rotors by 43° and 100%, respectively, which further lower the suction pressure loss. Compared with constant-lead rotors, the maximum increments in the mass flowrate and indicated power are observed as 45% and 25.4%, respectively. However, the dual-lead rotors could not effectively contribute to an increase in the isentropic indicated efficiency of twin-screw expanders due to the severe leakage, and hence, it becomes crucial to address the leakage issues in twin-screw expanders. [ABSTRACT FROM AUTHOR]

Purpose: Numerous modifications laparoscopic techniques have mushroomed in recent years. Here we describe a modified technique of extracorporeal ligation of processus vaginalis in children using a hernia crochet needle with a cannula. Methods: Processus vaginalis repair was carried out on patients diagnosed with inguinal hernia or hydroceles using this novel technique between June 2021 and June 2022. The processus vaginalis was closed extracorporeally using a hernia crochet needle with a cannula. In the presence of patent processus vaginalis, the same procedure would be performed on the contralateral side. The primary outcomes was the safety and efficiency of this modified procedure, and the secondary outcomes was the post operative complications. Results: A total of 212 (165 inguinal hernia and 47 hydroceles) children were corrected by this novel technique. The mean operation time was 27.49 min for unilateral inguinal hernia cases and 36.55 min for bilateral cases. The unilateral hydrocele median operation time was 27.83 min and that for the bilateral cases was 37.30 min. During the mean of 10.92 months of follow-up, there was only a boy subject to a metachronous contralateral occurrence of hernia 10 months after surgery, and no other complications (knot reactions, testicular atrophy, postoperative hydrocele or iatrogenic) have been observed yet. Conclusion: This study shown a unique procedure with using a hernia crochet needle with a cannula to be simple, safe, and effective in managing inguinal hernias and hydroceles in the pediatric population. [ABSTRACT FROM AUTHOR]

Due to the lack of oil injection cooling, it is usually necessary for dry twin-screw compressors to design cooling jackets to carry away the heat generated during operation. In order to investigate to what extent a cooling jacket can improve the performance of screw compressors, this study set up an experimental platform for a dry twin-screw compressor applied in fuel cell vehicles and used water as the working liquid in the cooling jacket. Then, the performance parameters of the screw compressor under different rotating speeds, discharge pressures, and cooling water flow rates were measured. It can be considered that the existence of a water cooling jacket is of great significance for improving the performance of dry screw compressors and improving extreme operating conditions. The research results may provide a reference for the development and improvement of dry twin-screw compressors in the future. [ABSTRACT FROM AUTHOR]

Haiyang-1D (HY-1D) is the second operational satellite in China's Haiyang-1 series of satellites, carrying the Chinese Ocean Color and Temperature Scanner (COCTS) to provide ocean color and temperature observations. The radiometric calibration is a prerequisite to guarantee the quality of the satellite observations and the derived products, and the radiometric calibration of the thermal emissive bands of HY-1D/COCTS can effectively improve the accuracy of sea surface temperature (SST) derived from the thermal infrared data. In this paper, a study on the regional cross-calibration of the COCTS thermal emissive bands is conducted for high-accuracy SST observations in the South China Sea. The Visible Infrared Imaging Radiometer Suite (VIIRS) on board the NOAA-20 satellite launched by the National Oceanic and Atmospheric Administration (NOAA) is selected as the calibration reference sensor, and a double-difference cross-calibration method is used for HY-1D/COCTS thermal infrared brightness temperature (BT) evaluation. The results show that the bias of the 11 µm and 12 µm thermal emissive bands of COCTS and VIIRS in the South China Sea are 0.101 K and 0.892 K, respectively, and the differences in BTs between the two sensors show temperature dependence. The cross-calibration coefficients are obtained and used to correct the BT of the COCTS thermal emissive bands. The bias of the BT of the 11 µm and 12 µm bands of COCTS are about 0.01 K after cross-calibration. To further validate the results, COCTS post-calibration data were examined using the NOAA-20 Cross-track Infrared Sounder (CrIS) data as a third-party source. The BT is calculated with the spectral response functions of the COCTS thermal emissive bands using the convolution calculation of the CrIS hyperspectral region observations. The comparison shows a small bias between the post-calibration COCTS thermal emissive band observations and CrIS, which is consistent with the comparison between VIIRS and CrIS. The accuracy of the post-calibration COCTS thermal emissive band BT data in the South China Sea has been significantly improved. [ABSTRACT FROM AUTHOR]

Since 2002, China has launched four Haiyang-1 (HY-1) satellites equipped with the Chinese Ocean Color and Temperature Scanner (COCTS), which can observe the sea surface temperature (SST). The planned new generation ocean color observation satellites also carry a sensor for observing the SST represented by the payload in this paper. We analyze the spectral brightness temperature (BT) difference between the payload and the Moderate Resolution Imaging Spectroradiometer (MODIS) onboard Terra for the thermal infrared channels (11 and 12 µm) based on atmospheric radiative transfer simulation. The bias and standard deviation (SD) of spectral BT difference for the 11 µm channel are −0.12 K and 0.15 K, respectively, and those for the 12 µm channel are −0.10 K and 0.03 K, respectively. When the total column water vapor (TCWV) decreases from the oceans near the equator to high-latitude oceans, the spectral BT difference of the 11 µm channel varies from a positive deviation to a negative deviation, and that of the 12 µm channel basically remains stable. By correcting the MODIS BT observation using the spectral BT differences, we produce the simulated BT data for the thermal infrared channels of the payload, and then validate it using the Infrared Atmospheric Sounding Interferometer (IASI) carried on METOP-B. The validation results show that the bias of BT difference between the payload and IASI is −0.22 K for the 11 µm channel, while it is −0.05 K for the 12 µm channel. The SD of both channels is 0.13 K. In this study, we provide the simulated BT dataset for the 11 and 12 µm channels of a payload for the retrieval of SST. The simulated BT dataset corrected may be used to develop SST-retrieval algorithms. [ABSTRACT FROM AUTHOR]

Inactivation is a crucial step in the production of postbiotics, with thermal inactivation being the prevailing method employed. Nevertheless, the impact of thermal treatment on bioactivity and chemical composition remains unexplored. The objective of this study was to assess the influence of heating temperature on the antioxidant, anti-inflammatory properties and the chemical composition of ET-22 and BL-99 postbiotics. The findings revealed that subjecting ET-22 and BL-99 to thermal treatment ranging from 70 °C to 121 °C for a duration of 10 min effectively deactivated them, leading to the disruption of cellular structure and release of intracellular contents. The antioxidant and anti-inflammatory activity of ET-22 and BL-99 postbiotics remained unaffected by mild heating temperatures (below 100 °C). However, excessive heating at 121 °C diminished the antioxidant activity of the postbiotic. To further investigate the impact of thermal treatments on chemical composition, non-targeted metabolomics was conducted to analyze the cell-free supernatants derived from ET-22 and BL-99. The results revealed that compared to mild inactivation at temperatures below 100 °C, the excessive temperature of 121 °C significantly altered the chemical profile of the postbiotic. Several bioactive components with antioxidant and anti-inflammatory properties, including zomepirac, flumethasone, 6-hydroxyhexanoic acid, and phenyllactic acid, exhibited a significant reduction in their levels following exposure to a temperature of 121 °C. This decline in their abundance may be associated with a corresponding decrease in their antioxidant and anti-inflammatory activities. The cumulative evidence gathered strongly indicates that heating temperatures exert a discernible influence on the properties of postbiotics, whereby excessive heating leads to the degradation of heat-sensitive active constituents and subsequent diminishment of their biological efficacy. [ABSTRACT FROM AUTHOR]

Single-rod magneto-rheological dampers (MRD) have the advantages of a simple mechanism, high reliability, and broad application range. They are widely used in various semi-active vibration control fields. However, their working mode requires a compensating mechanism to perform volume compensation on the rod, leading to additional stiffness for the system. Ignoring this point makes it tough to establish an accurate mechanical model to describe its performance in the design stage, affecting its application. To address this issue, this study proposes a multi-physics simulation model based on gas compensation for single-rod MRD to characterize their mechanical performance accurately. Firstly, the mechanism and mechanical model of the single-rod gas compensation MRD are introduced. Secondly, considering that its performance is affected by the coupling effect of multiple physical fields, including magnetic, flow, and solid mechanics fields, the control equations and boundary conditions of each field are analyzed separately, and a multi-physics coupling simulation model is established by COMSOL. In particular, the gas compensation unit is considered in the multi-physics simulation model. The effect of the compensating mechanism on the mechanical performance of the damper under different excitation speeds, currents, and initial pressures is analyzed. Finally, the accuracy of the proposed method is verified through the demonstration power test. The results show that the simulation can describe the additional stiffness in the damper. The average error between experimental value and simulation value is 7%. This demonstrates the degree of agreement between the experiment and simulation. [ABSTRACT FROM AUTHOR]

Hydrogen-rich compounds provide an efficient route to pre-compressing hydrogen molecules and facilitating the creation of metallic hydrogen at much reduced pressure. Motivated by the long-sought theoretically proposed calcium hydrides, we have performed high-pressure experiments on the Ca–H system in a laser-heated diamond anvil cell. The unconventional compound CaH4 with I4/mmm symmetry has been discovered to be stable above 25.5 GPa. Of particular significance is the crystal structure of CaH4, which has an elongated H2 molecular unit whose intramolecular bond strength changes with pressure. Below the dissociation pressure of pure hydrogen, the elongated H2 unit is likely to dissociate into an atomic one. Our findings indicate that the presence of Ca atoms causes a very positive chemical pre-compression effect to potentially prompt the dissociation of the H2 unit. [ABSTRACT FROM AUTHOR]

Background: Semantic segmentation of brain tumors plays a critical role in clinical treatment, especially for three-dimensional (3D) magnetic resonance imaging, which is often used in clinical practice. Automatic segmentation of the 3D structure of brain tumors can quickly help physicians understand the properties of tumors, such as the shape and size, thus improving the efficiency of preoperative planning and the odds of successful surgery. In past decades, 3D convolutional neural networks (CNNs) have dominated automatic segmentation methods for 3D medical images, and these network structures have achieved good results. However, to reduce the number of neural network parameters, practitioners ensure that the size of convolutional kernels in 3D convolutional operations generally does not exceed 7 × 7 × 7 , which also leads to CNNs showing limitations in learning long-distance dependent information. Vision Transformer (ViT) is very good at learning long-distance dependent information in images, but it suffers from the problems of many parameters. What's worse, the ViT cannot learn local dependency information in the previous layers under the condition of insufficient data. However, in the image segmentation task, being able to learn this local dependency information in the previous layers makes a big impact on the performance of the model. Methods: This paper proposes the Swin Unet3D model, which represents voxel segmentation on medical images as a sequence-to-sequence prediction. The feature extraction sub-module in the model is designed as a parallel structure of Convolution and ViT so that all layers of the model are able to adequately learn both global and local dependency information in the image. Results: On the validation dataset of Brats2021, our proposed model achieves dice coefficients of 0.840, 0.874, and 0.911 on the ET channel, TC channel, and WT channel, respectively. On the validation dataset of Brats2018, our model achieves dice coefficients of 0.716, 0.761, and 0.874 on the corresponding channels, respectively. Conclusion: We propose a new segmentation model that combines the advantages of Vision Transformer and Convolution and achieves a better balance between the number of model parameters and segmentation accuracy. The code can be found at https://github.com/1152545264/SwinUnet3D. [ABSTRACT FROM AUTHOR]

Mullite–cordierite ceramic saggar is a necessary consumable material used in the synthesis process of LiCoO2 that is easily eroded during application. In our study, we systematically investigated the characteristics and surface corrosion behavior of waste saggar samples. We divided the cross sections of waste saggar into the attached layer, hardened layer, permeability layer, and matrix layer. Then, we examined the high-temperature solid-state reactions between saggar powder and lithium carbonate or cobalt oxide to identify erosion reactants correlating with an increase in the number of recycled saggars. The results of time-of-flight secondary ion mass spectrometric analysis (TOF-SIMS) prove that the maximum erosion penetration of lithium can reach 2 mm. However, our morphology and elemental distribution analysis results show that the erosion penetration of cobalt was only 200 μm. When enough lithium carbonate reacted, lithium aluminate and lithium silicate were the main phases. Our X-ray computed tomography (X-ray CT) analysis results show that the change in phase volume before and after the reaction, including the generation of oxygen and carbon dioxide gas, led to the internal crack expansion of the material–saggar interface. Our results can contribute to improving saggar and upgrading waste saggar utilization technology. [ABSTRACT FROM AUTHOR]

We have performed high pressure-temperature Brillouin scattering measurements on single crystal hydrogen sulfide using externally heated diamond anvil cell techniques. The pressure dependences of the acoustic velocities, isothermal elastic constants, and moduli of single crystal hydrogen sulfide have been determined along four isotherms. Both elastic constants and moduli increase monotonously with pressure along each isotherm, while they show a decreased tendency with temperature elevated under the same pressure points. The experimental equation of state of single crystal hydrogen sulfide is obtained by fitting with a third-order Birch-Murnaghan and Tait equation. It is proposed that the effect of hydrogen bonds contributes to the unique tendency of elastic anisotropy in single crystal hydrogen sulfide. Through our work, we have extended the melting curve and phase diagram of hydrogen sulfide up to 12 GPa and 580 K. [ABSTRACT FROM AUTHOR]

Background: Immaturity of ganglia (IG) is an extremely rare disease and always requires surgical intervention in the neonatal period, but without guidelines to choose the ideal enterostomy procedure, the timing of stoma closure remains controversial. The aim of this study was to report our experience using Santulli enterostomy for the treatment of nine infants diagnosed with IG.Methods: Patients who underwent Santulli enterostomy and were diagnosed with IG in our center between 2016 and 2021 were retrospectively studied. Temporary stoma occlusion and a 24-h delayed film of barium enema (BE) were performed to evaluate intestinal peristalsis function to determine the timing of stoma closure. The demographic data, clinical and radiological findings, stoma occlusion and stoma closure results were explored.Results: A total of 9 infants underwent Santulli enterostomy and were diagnosed with IG postoperatively. Their median gestational age at birth was 36 weeks (range 31-42), and their median birth weight was 2765 g (range 1300-3400). All patients had symptom onset in the neonatal period, including abdominal distension and biliary vomiting. Eight patients showed obvious small bowel dilatation in the plain films, except for one patient's films that suggested gastrointestinal perforation with free gas downstream of the diaphragm. BE was performed in 6 patients, all of which had microcolons. The median age at operation was 3 days (range 1-23). Seven patients had an obvious transitional zone (TZ) during laparotomy, and the position of the TZ was 25-100 cm proximal above the ileocecal (IC) valve. Immature ganglion cells were present in the colon in 7 patients and the terminal ileum in 6 patients. The median age of successful stoma occlusion was 5 M (range 2-17) and 8 M (range 4-22) at ostomy closure. There was little or no barium residue in the 24-h delayed film of BE before stoma closure, and all patients were free of constipation symptoms during the follow-up.Conclusion: Santulli enterostomy appears to be a suitable and efficient procedure for IG, combined with temporary stoma occlusion and 24-h delayed film of BE to evaluate the recovery of intestinal peristalsis function. [ABSTRACT FROM AUTHOR]

The Chinese Ocean Color and Temperature Scanner (COCTS) onboard Haiyang-1 (HY-1) series satellites has two thermal infrared channels with the spectrum range of 10.30–11.40 and 11.40– $12.50 \ \mu \text{m}$ for sea surface temperature (SST) observations. To reprocess the Haiyang-1B (HY-1B) COCTS SST, the Bayesian cloud detection and optimal estimation (OE) SST retrieval were applied to COCTS data in this study. The Bayesian cloud detection algorithm that has been developed is based on Bayes’ theorem and uses a simulation of COCTS observations. The MODerate resolution atmospheric TRANsmission (MODTRAN) model was used for the simulation of COCTS brightness temperatures. SSTs were retrieved from COCTS by OE from 2009 to 2011 in the northwest Pacific. A comparison of COCTS OE SST with in situ SST showed that the COCTS SSTs are cooler than buoy measurements by −0.23 °C on average, and the standard deviation (SD) of differences was 0.51 °C. A large component of the mean difference is attributable to the cool skin effect at the ocean surface (typically −0.15 °C to −0.2 °C), with the remainder being attributable to simulation and calibration biases. The mean difference of COCTS OE SST with matched skin temperatures from the advanced along-track scanning radiometer (AATSR) is closer to zero, being −0.09 °C, with an SD of 0.49 °C. These validation results of COCTS OE SST demonstrate that Bayesian cloud detection and OE SST retrieval algorithm work well for improving COCTS SST accuracy and show the potential of these methods to help develop SST products for operational HY-1 satellites: HY-1C and HY-1D. [ABSTRACT FROM AUTHOR]

The visible and infrared scanning radiometer (VIRR) onboard the Fengyun-3C (FY-3C) meteorological satellite has 11 μm and 12 μm channels, which are capable of sea surface temperature (SST) observations. This study is based on atmospheric radiative transfer modeling (RTM) by applying Bayesian cloud detection theory and optimal estimation (OE) to obtain sea surface skin temperature ( SST skin ) from VIRR in the Northwest Pacific. The inter-calibration of FY-3C/VIRR 11 μm and 12 μm brightness temperature (BT) is carried out using the Moderate Resolution Imaging Spectroradiometer (MODIS) as the reference sensor. Bayesian cloud detection and OE SST retrieval with the calibration BT data is performed to obtain SST skin . The SST skin retrievals are compared with the buoy SST with a temporal window of 1 h and a spatial window of 0.01°. The bias is −0.12 °C, and the standard deviation is 0.52 °C. Comparisons of the retrieved SST skin with the AVHRR (Advanced Very High Resolution Radiometer) SST skin from European Space Agency Sea Surface Temperature Climate Change Initiative (ESA SST CCI) project show the bias of 0.08 °C and the standard deviation of 0.55 °C. The results indicate that the VIRR SST skin are consistent with AVHRR SST skin and buoy SST. [ABSTRACT FROM AUTHOR]

Background/purpose: To investigate the clinical manifestations, treatments of retrograde intussusception and summarize the experience.Methods: Children with retrograde intussusception treated in our hospital from January 2011 to January 2021 were retrospectively analysed. Demographics, clinical manifestations, preoperative colour Doppler ultrasound (CDU) findings, findings during surgery and follow-up results were collected.Results: A total of 4719 cases of intussusception were treated in our department, including 12 cases of retrograde intussusception (0.25%). There were 8 males and 4 females.The age ranged from 4.1 to 14.3 months, with an average of (8.3 ± 2.8) months.; The weight ranged from 5.5 to 12.6 kg, with an average of (9.4 ± 2.3) kg; The onset time ranged from 6 to 15 h, with an average of (10.0 ± 2.4) h. All the children received CDU examination before surgery, and in one case, the possibility of 2 intussusception masses was considered. Emergency surgical exploration was performed after the failure of air enema reduction. During the operation, multiple types of intussusception were found (coincidence of anterograde and retrograde intussusception). The pattern of anterograde intussusception was all ileo-ileo-colic variety and the retrograde intussusception was proximal sigmoid colon into descending colon. All the children were successfully reduced by manual reduction without intestinal necrosis or intestinal malformation. All children were discharged 6-7 days after surgery, and had no recurrence after 3-6 months of follow-up.Conclusions: Retrograde intussusception is easily misdiagnosed before surgery. During air enema, if the intussusception mass was fixed and did not move with increasing pressure, we should be aware of the possibility of retrograde intussusception, and the enema pressure should not be too large to avoid intestinal perforation. If the intraoperative position of the intussusception mass was not consistent with that of the preoperative enema, it was recommended to use bimanual examination to explore whether there was still a mass in the abdominal cavity to avoid misdiagnosis. [ABSTRACT FROM AUTHOR]

Background: Caudal block is one of the most preferred regional anesthesia for sub-umbilical region surgeries in the pediatric population. However, few studies are available on caudal block performed in laparoscopic-assisted Soave pull-through of Hirschsprung disease (HD). We aimed to compare general anesthesia (GA) and general anesthesia combined with caudal block (GA + CA) in laparoscopic-assisted Soave pull-through of HD. Methods: A retrospective review was performed in children with HD operated in our hospital between 2017 and 2020. Patients were divided into the GA and GA + CA group. The primary outcome was the duration of operation, and secondary outcomes included intraoperative hemodynamic changes, the Face, Legs, Activity, Cry, Consolability (FLACC) scale, dose of anesthetics, and incidence of side effects. Results: A total of 47 children with HD were included in the study, including 20 in the GA group and 27 in the GA + CA Group. The two groups were similar in age, gender, weight and type of HD (P > 0.05). The GA + CA group had significantly shorter duration of operation (especially the transanal operation time) (median 1.20 h vs. 0.83 h, P < 0.01) and recovery time (mean 18.05 min vs. 11.89 min, P < 0.01). The mean doses of sufentanil and rocuronium bromide during the procedure and FLACC scores at 1 h and 6 h after surgery were also lower in the GA + CA group (p < 0.01). The hemodynamic changes in the GA + CA group were more stable at time of t2 (during transanal operation) and t3 (10 min after transanal operation), but there was no significant difference in the incidence of postoperative side effects between the two groups (P = 1.000). Conclusion: General anesthesia combined with caudal block can shorten the duration of operation, and provide more stable intraoperative hemodynamics and better postoperative analgesia. [ABSTRACT FROM AUTHOR]

The scanning microwave radiometer (RM) onboard the Haiyang-2A (HY-2A) satellite has low-frequency channels with the capability of observing sea surface temperature (SST) from space. To improve the accuracy of the HY-2A RM SST data, the intercalibration of RM brightness temperature (BT) and SST retrieval were carried out. Based on the simulated BTs using the microwave radiative transfer model (RTM), the double-difference approach was applied to perform the intercalibration of RM BTs for the 10.7, 18.7, 23.8, and 37.0 GHz channels, with the Global Precipitation Measurement (GPM) Microwave Imager (GMI) as the reference. The RM 6.6-GHz BTs were corrected with the RTM modeled BT on account of a lack of the similar channel in GMI. The comparison of RM original BTs with GMI and modeled BTs showed large biases and the strong dependence on latitude. We obtained latitude-dependent coefficients using robust linear regression for RM BT correction and applied recalibrated RM BTs for the SST retrieval. The validation of the RM retrieved SST showed the bias of −0.12 °C and the robust standard deviation (RSD) of 1.10 °C compared with buoy SST in the region between 70°S and 70°N. In the tropical and subtropical regions, the bias was −0.12 °C and the RSD was 0.93 °C. In addition, the relationships between the SST difference and the sea surface and atmospheric parameters were investigated. Both statistics of validation results and error analysis indicated significant improvement of RM SST accuracy. [ABSTRACT FROM AUTHOR]

This study aimed to determine the environmental and ecological factors influencing the planktonic prokaryotic community profiles in the composite ecosystem comprising Taihu Lake, Taipu River and Jinze Reservoir in the Taihu Watershed in China. A total of 42 water samples were intermittently collected from different sites in 6 months across four seasons. Physicochemical characteristics of the ecosystem, bacterioplankton diversity and composition, the presence of co-occurrence patterns, and environmental predictors of ecological modules in the bacterioplankton network were determined. The central species played a more important role in regulating the structure and function of the bacterioplankton community and in responding to environmental contamination than the entire community. The relative abundance of the phylum Proteobacteria and the class Betaproteobacteria varied significantly between months and locations, which were identified as core functional taxa. A non-random co-occurrence pattern and function-driven modular structure were observed in the bacterioplankton co-occurrence network. Dissolved oxygen and ammonium nitrogen were the major and mutual environmental predictors of the bacterioplankton community composition, functional attributes and relative abundance of ecological modules. The results improve our understanding of the impact of anthropogenic contamination on bacterioplankton diversity and biogeochemical cycles and the formulation of strategies for bioremediation of the Taihu Watershed. [ABSTRACT FROM AUTHOR]

Palladium nanoparticles were prepared via solvothermal method using Na2PdCl4, AgNO3, and oleylamine. By choosing the optimal reaction time and reaction temperature, palladium nanoparticles with regular morphology and size within 10 nm were prepared. A vacuum freeze drying was applied to prevent aggregation of nanoparticles. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the causes and treatments of early complications involving laparoscopic radical resection of choledochal cyst and summarize the experience.Methods: Children with choledochal cyst treated by laparoscopy in the Department of Pediatric Surgery, Fujian Provincial Maternity and Children's Hospital, and Guangzhou Women and Children's Medical Centre, from March 2016 to May 2018, were retrospectively analysed. Demographics, causes and treatments of early complications, liver function analysis and ultrasonography were collected.Results: In total, 231 cases were included; 204 were Type I (156 Type Ia and 46 Type Ic) and 27 were Type IV. No mortality was observed, and 224 cases were successfully laparoscopically operated, while 7 cases were converted to open surgery. Fifteen cases of postoperative developed biliary fistula. There were jejunal Roux loop obstruction in 2 cases and multiple intussusception, anastomotic stenosis after hepaticojejunostomy, residual of choledochal cyst and pancreatic fistula in one each. Patients were followed up ranging from 4 months to 48 months (12.6 ± 0.3 months on average). Postoperative ALT, AST, GGT, TBIL and DBIL all returned to normal during this time. Ultrasonography indicated 5 cases of widened Glisson's sheath and 1 case of intrahepatic hyperdense shadow.Conclusion: Early complications of laparoscopic radical resection of choledochal cyst can be minimized by properly managing preoperative indications and contraindications, carefully interpreting the magnetic resonance cholangiopancreatography results and accumulating experience by the surgeons. [ABSTRACT FROM AUTHOR]

Abstract: Recently, the superconductivity in phosphine (PH3) has been discovered with the superconducting transition temperature Tc up to 203 GPa by using high pressure resistance measurements. However, the structural information of PH3 under high pressure remains elusive. Motivated by this, in this work, the behavior of PH3 under high pressure has been investigated by Raman spectroscopy at 298 K. The Raman spectra varied with pressure increasing, accompanying with the change of the sample color, which first became yellow, then red, and finally opaque. In the pressure range of 8.53–18.36 GPa, the decomposition of PH3 was observed, and the main decomposition products were P2H4 and element hydrogen (H2). Upon compression to higher pressure, the Raman signal of hydrogen vibration was observed to become stronger, indicating that PH3 or P2H4 further decomposed into element phosphorus and hydrogen. The original PH3 did not form again upon decomposition to ambient pressure. P2H4 and other decomposition products of compressed phosphine were considered as main products of the high temperature superconducting phase reported in experiment. [ABSTRACT FROM AUTHOR]

Pressure-induced molecular dissociation provides significant insights into chemical bonding, governing the physical properties of molecular solids. Here the typical molecular solids, selenium and tellurium, have been explored experimentally to unearth the process of pressure-induced molecular dissociation. Before molecular dissociation, both commensurately and incommensurately modulated structures have been observed in these two elements. Upon compression, the successive commensurate–incommensurate phase transitions are proved by the soft amplitude (AMP) mode. The fitted critical pressure suggests that the molecular dissociation of Te is inferred to occur at 26.1 GPa in agreement with our XRD and Raman data. The current precise structural studies before pressure-induced molecular dissociation demonstrated in the elements selenium and tellurium will help in clarifying the mechanisms of molecular dissociation in related molecular solids. [ABSTRACT FROM AUTHOR]

Haiyang-2 (HY-2) is the first marine dynamic environmental satellite of China, which was launched on August 16, 2011. The scanning microwave radiometer (RM) onboard HY-2 has low-frequency channels with the capability of observing sea surface temperature (SST) from space. In this paper, the Level 2A (L2A) SST products of HY-2 RM are evaluated. The global HY-2 RM L2A SST products are compared with the buoy SST measurements, WindSat SST, and National Oceanic and Atmospheric Administration Optimum Interpolation (OI) weekly SST products for the period from January 2012 to December 2014. The collocations of HY-2 RM, WindSat, and buoy SST data are generated with the spatial window of 0.25° and the temporal window of 0.5 h. The biases are −0.45 °C (RM minus buoy) and −0.41 °C (RM minus WindSat) and the corresponding standard deviations are 1.73 °C and 1.72 °C. The comparisons of the weekly averaged HY-2 RM and OI SST show that the biases of each week difference are from −1.06 °C to 0.48 °C with the mean value of −0.30 °C. The standard deviations of the SST difference are from 0.83 °C to 1.47 °C with the mean value of 1.05 °C. The relationships between SST difference and the sea surface and atmospheric parameters, such as wind speed, wind direction, SST, and water vapor are investigated. [ABSTRACT FROM PUBLISHER]

Powder transport ratio is defined as the mass ratio of powder particles fed into the molten pool to all powders transported in the process of laser cladding by lateral powder feeding. According to the law of mass conservation and kinematic equation in physics, a powder transport model for flow field with cylindrical distribution and a mathematical expression of powder transport ratio are proposed. For different process parameters, the cross-sectional area of the clad layer is calculated by the model. Theoretical and experimental results are compared. The variation tendency of the theoretical cross-sectional area agrees well with the experimental results. The results indicate that the powder transport model can be used for fundamental research of real powder flow field. [ABSTRACT FROM AUTHOR]

Screw machines, mainly including single-screw type and twin-screw type, have gone through significant development and improvement during the past decade. This paper reviews the relevant studies available in the open literature for acquiring insight into and to establish the state of the art of the research and application status of screw machines. The related research on different aspects, which would affect the performance and reliability of screw machines includes rotor profile and geometric characteristics, thermodynamic modelling, vibration and noise, lubrication and wear, control of capacity and built-in volume ratio, and liquid injection technology. In the aspect of thermodynamic modelling, the available methods, i.e., empirical or semi-empirical model, lump model, and 3D CFD model, adopted for the performance prediction and optimal design of screw machines are summarized. Then, the review covers the application status of screw machines in the fields of air compression and expansion, refrigeration and heat pump, organic Rankine cycle (ORC), and other popular applications, with an emphasis on the reported performance and progress in technologies of screw machines. Finally, conclusions and perspectives for future research in the area of screw machines are presented. The review provides readers with a good understanding of the research focus and progress in the field of screw machines. [ABSTRACT FROM AUTHOR]

Fengyun-3C (FY-3C) is a second-generation meteorological satellite of China that was launched on 23 September 2013. The on board Visible and Infrared Radiometer (VIRR) can be used to observe global sea surface temperature (SST). In this paper, the VIRR SST products are compared with MODIS SST products and buoy measurements from 2015 to 2019. The collocations of VIRR, MODIS, and buoy SST are generated separately during the day and night with the spatial window of 0.05° × 0.05°. The comparison results show that the biases of VIRR SST minus buoy SST during the day and night are −0.21 and −0.13 °C with a corresponding robust standard deviation (RSD) of 0.58 and 0.59 °C, respectively. The mean differences between VIRR and MODIS are −0.10 and 0.08 °C with RSDs of 0.53 and 0.58 °C for the daytime and nighttime, respectively. The consistency of VIRR SST accuracy from 2015 to 2019 and the dependence of VIRR SST error on SST and latitude are also investigated. [ABSTRACT FROM AUTHOR]

The Chinese Ocean Color and Temperature Scanner (COCTS) onboard the Haiyang-1C (HY-1C) satellite was launched in September 2018. Accurate and stable calibration is one of the important factors when deriving geophysical parameters with high quality. The first assessment of HY-1C COCTS thermal infrared calibration is conducted in this research. We choose the Infrared Atmospheric Sounding Interferometer (IASI) onboard the MetOp-B satellite as the reference instrument, mainly due to its hyper-spectral characteristic and accurate calibration superiority. The brightness temperatures (BTs) from the two HY-1C COCTS thermal infrared bands centered near 11 and 12 µm are collocated with the IASI in the spatial window of 0.12° × 0.12° and temporal window of half an hour. The homogeneity filtering of matchups is also carried out by setting the relative standard deviation (RSD) thresholds on each collocated grid and its neighboring grids. Based on the filtered matchups, the HY-1C COCTS BTs from the 11 and 12 µm channels are compared with IASI. The mean differences of COCTS minus IASI are 2.68 and 3.18 K for the 11 and 12 μm channels, respectively. The corresponding standard deviations (SDs) are also 0.29 and 0.28 K, respectively. In addition, the BT differences show latitude-dependence and BT-dependence. In order to correct the HY-1C COCTS thermal infrared BTs, the latitude-dependent coefficients are obtained to express the relationship between the BT differences and IASI BTs using the linear robust regression. After the BT correction, the biases and BT-dependence of the COCTS original BT minus IASI differences are removed. Further, the SDs decrease to 0.21 K for the 11 and 12 μm channels. Overall, the calibration of the HY-1C COCTS thermal infrared channels remains stable and the accuracy is around 0.2 K after inter-calibration. [ABSTRACT FROM AUTHOR]

The Chinese Ocean Color and Temperature Scanner (COCTS) on board the Haiyang-1B (HY-1B) satellite has two thermal infrared channels (9 and 10) centred near 11 μm and 12 μm, respectively, which are intended for sea surface temperature (SST) observations. To improve the accuracy of COCTS SSTs, inter-calibration of COCTS thermal infrared radiance is carried out. The Infrared Atmospheric Sounding Interferometer (IASI) on board MetOp-A satellite is used as inter-calibration reference owing to its hyperspectral nature and high-quality measurements. The inter-calibration of HY-1B COCTS thermal infrared radiances with IASI is undertaken for data from the Period 2009–2011 located in the northwest Pacific. Collocations of COCTS radiance with IASI are identified within a temporal window of 30 min, a spatial window of 0.12° and an atmospheric path tolerance of 3%. Matched IASI spectra are convolved with the COCTS spectral response functions, while COCTS pixels within the footprint of each IASI pixel are spatially averaged, thus creating matched IASI-COCTS radiance pairs that should agree well in the absence of satellite biases. The radiances of COCTS 11 and 12 μm channel are lower than IASI with relatively large biases, and a strong dependence of difference on radiance in the case of 11 μm channel. We used linear robust regression for four different detectors of COCTS separately to obtain the inter-calibration coefficients to correct the COCTS radiance. After correction, the mean values of COCTS 11 and 12 μm channel minus IASI radiance are −0.02 mW m−2 cm sr−1 and −0.01 mW m−2 cm sr−1, respectively, with corresponding standard deviations of 0.51 mW m−2 cm sr−1 and 0.57 mW m−2 cm sr−1. Striped noise is present in COCTS original radiance imagery associated with inconsistency among the four detectors, and inter-calibration is shown to reduce, although not eliminate, the striping. The calibration accuracy of COCTS is improved after inter-calibration, which is potentially useful for improving COCTS SST accuracy in the future. [ABSTRACT FROM AUTHOR]