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OBJECTIVE: This study aims to evaluate the diagnostic efficiency of diffusion-weighted imaging (DWI) in patients with placenta accreta spectrum (PAS). MATERIALS AND METHODS: The present study searched on PubMed, Embase, OVID, Cochrane, Scopus and CNKI, Chinese Bio-Medical Literature, VIP, Wanfang, Duxiu, databases for studies related to the diagnostic performance of DWI for PAS from inception to December 2022. The pooled sensitivity, the pooled specificity, positive likelihood ratio (LR+), negative likelihood ratio (LR-), and diagnosis odds ratios (DOR) were calculated by Meta-disc 1.4 and STATA 16.0. RESULTS: A total of 11 studies met the criteria and were included in the meta-analysis. The effect indexes of DWI in combined PAS were as follows. The pooled sensitivity was 0.670 (0.619-0.719). The pooled specificity was 0.720 (0.661-0.773). The pooled LR+ was 2.161 (1.454-3.211). The pooled LR-was 0.413 (0.280-0.609). The pooled AUC was 0.7841, and Q* was 0.7221. The pooled diagnostic ratio DOR was 6.713 (2.981- 15.118). Subgroup analysis showed that four studies used T2-weighted imaging (T2WI) + DWI to diagnose PAS, and the pooled AUC was 0.9822. CONCLUSIONS: The results showed that DWI had high sensitivity and specificity in the diagnosis of PAS. Furthermore, T2WI+DWI has higher diagnostic efficacy than DWI alone in the diagnosis of PAS. Therefore, it is necessary to set T2WI+DWI as a routine sequence for PAS, and T2WI+DWI should be a routine method for the daily diagnosis of PAS. [ABSTRACT FROM AUTHOR]

A synthetic electron cyclotron emission (ECE) diagnostic is used to interpret ECE signals from preset plasma equilibrium profiles, including magnetic field, electron density, and electron temperature. According to the simulation results, the electron temperature (Te) profile covering the harmonic overlap region can be obtained by receiving ECE signals at the high field side (HFS) of the HL-2M plasma. The third harmonic ECE at the low field side (LFS) cannot pass through the second harmonic resonance layer at the HFS unless the optical thickness (τ) of the second harmonic becomes gray (τ ≤ 2). In addition, the impact of the relativistic frequency down-shift has been evaluated and corrected. The measurable range of the HFS ECE has been calculated by scanning different parameters (electron density, temperature, and magnetic field). Higher plasma parameters allow a wider radial range of electron temperature measurements. The minimum inner measurable position can reach R = 120 cm (r/a = −0.89) when the product of core temperature (Te0) and density (ne0) is greater than 35 × 1019 keV m−3, which is extended by more than 30 cm inward compared with that of the LFS measurement. The HFS ECE will greatly improve the diagnostic ability of ECE systems on the HL-2M tokamak. [ABSTRACT FROM AUTHOR]

Frequent freezing injury greatly influences winter wheat production; thus, effective prevention and a command of agricultural production are vital. The freezing injury monitoring method integrated with '3S' (geographic information systems (GIS), global positioning system (GPS) and remote sensing (RS)) technology has an unparalleled advantage. Using HuanJing (HJ)-1A/1B satellite images of a winter wheat field in Shanxi Province, China plus a field survey, crop types and winter wheat planting area were identified through repeated visual interpretations of image information and spatial analyses conducted in GIS. Six vegetation indices were extracted from processed HJ-1A/1B satellite images to determine whether the winter wheat suffered from freezing injury and its degree of severity and recovery, using change vector analysis (CVA), the freeze injury representative vegetation index and the combination of the two methods, respectively. Accuracy of the freezing damage classification results was verified by determining the impact of freezing damage on yield and quantitative analysis. The CVA and the change of normalized difference vegetation index (ΔNDVI) monitoring results were different so a comprehensive analysis of the combination of CVA and ΔNDVI was performed. The area with serious freezing injury covered 0.9% of the total study area, followed by the area of no freezing injury (3.5%), moderate freezing injury (10.2%) and light freezing injury (85.4%). Of the moderate and serious freezing injury areas, 0.2% did not recover; 1.2% of the no freezing injury and light freezing injury areas showed optimal recovery, 15.6% of the light freezing injury and moderate freezing injury areas showed poor recovery, and the remaining areas exhibited general recovery. [ABSTRACT FROM AUTHOR]

Impurity effects on trapped electron modes (TEMs) in tokamak plasmas with inverted electron density profile (IEDP) are numerically investigated with a gyrokinetic integral eigenmode equation. It is found that different from the negative gradient of normal electron density profile, the positive gradient of the IEDP has a stabilizing effect on TEM in the presence of impurity ions. The electron temperature gradient threshold for TEM excitation increases not only with the increasing absolute value of IEDP but also with increasing impurity content. Furthermore, the effects of different impurity species and different impurity peaking profiles on TEMs with the IEDP are analyzed in detail. It is shown that there is a transition point of impurity density profile, on both sides of which the impurity has opposite effects on TEM. The dependence of such a transition point on electron temperature and density gradients is obtained numerically. Besides, the synergistic effects of ion temperature gradient and impurity density gradient are studied, in which a similar transition point of the ion temperature gradient is also identified in the case of outwardly peaked impurity density profile. In addition, impurity effects on the characteristics of mode structure and on the radial transport coefficients in positive and negative magnetic shear regions are discussed as well based on quasi-linear mixing length estimation. [ABSTRACT FROM AUTHOR]

OBJECTIVE: Growing evidence has revealed that circular RNAs (circRNAs) play important roles in the development of cancers, including colorectal cancer (CRC). In this study, we mainly focused on the expression of circ_0056618 and potential functions of circ_0056618 in CRC patients. PATIENTS AND METHODS: RT-PCR was performed to detect circ_0056618 and miR-206 expressions in CRC tissues and adjacent non-tumor tissues. Correlation analysis was used to analyze the correlation between circ_0056618 and miR- 206. Kaplan-Meier method was conducted to analyze the overall survival (OS) for CRC patients. Moreover, CCK-8 assay was used to measure cell proliferation ability and transwell assay was performed to detect cell migration ability. Besides, tube formation assay was performed to measure cell angiogenesis capacity. Western blot (WB) was performed to measure protein levels of tissues samples and CRC cell lines. Notably, the Luciferase reporter assay was performed to prove the binding sites in circ_0056618 with miR-206, miR- 206 with CXCR4 and VEGF-A. RESULTS: We found that circ_0056618 was elevated in CRC tumor tissues and CRC cell lines, which was related to poor diagnosis for CRC patients. MiR-206 was reduced in CRC tissues, which was negatively related with circ_0056618. Protein levels of CXCR4 and VEGF-A were elevated in CRC tumor tissues, which were negatively related with miR-206. Circ_0056618 inhibition inhibited proliferation, angiogenesis and migration of HT29 cells, and repressed protein levels of Cyclin D1, VEGF-A and N-cadherin and increased E-cadherin. Notably, Luciferase reporter assay indicated that circ_0056618 could sponge with miR-206, which could directly target at CXCR4 and VEGF-A. Finally, we proved a pathway that circ_0056618 promoted cell proliferation, migration and angiogenesis through sponging with miR-206 and removing the repressing effects of miR-206, thereby upregulating CXCR4 and VEGF-A in CRC. CONCLUSIONS: Above all, this study revealed that circ_0056618 was increased in CRC tissues, which was related with the poor OS of CRC patients. We found that circ_0056618 could promote cell proliferation, migration and angiogenesis through sponging with miR-206 and upregulating CXCR4 and VEGF-A in CRC, which might provide a novel potential therapeutic target for treating CRC. [ABSTRACT FROM AUTHOR]

A new algorithm (FYVOLC) for the automated detection of volcanic hot spots using data obtained from China's new-generation satellite FY-4A is developed and tested. FYVOLC improves the detection ability of the Volcanic Anomaly SofTware (VAST) algorithm by incorporating a Normalized Brightness Temperature Difference Index (NBTDI) to reduce the influence of 'cold' cloud. In addition, FYVOLC introduces a mid-infrared brightness temperature criterion to identify volcanic hot spots by making calculations based on the image itself without artificially determining any parameters. To test the volcanic hot-spot detection performance of FYVOLC, FY-4A Advanced Geostationary Radiation Imager data were used for eruptions from four volcanoes: Mayon Volcano in the Philippines (25–26 January 2018), and Bromo (1–2 September 2018), Lawu (3–4 September 2018), and Soputan volcanoes (3–4 October 2018) in Indonesia. A total of 147 images of the above four volcanoes were used, and the results obtained using the FYVOLC algorithm were compared with those from three existing volcanic hot-spot detection algorithms: the simplified contextual, VAST, and HOTSAT algorithms. It is shown that the simplified contextual and VAST algorithms are prone to generating false alerts (with a maximum false alert rate of up to 41% and 48%, respectively), whereas the simplified contextual and HOTSAT algorithms are prone to missing hot-spot pixels (with a maximum miss rate of up to 71% and 54%, respectively). The FYVOLC algorithm has the best detection accuracy owing to the adopted NBTDI and image-based mid-infrared brightness temperature criterion. The maximum false alert rate of FYVOLC is 12%, and the maximum miss rate is 11%. By analysing the thermal anomaly time-series of the 147 images, it was found that the detection results of FYVOLC are basically consistent with the actual hot spots, except for some images that were strongly affected by cloud cover. This study is the first to realize the automated detection of volcanic hot spots and monitor temporally dynamic thermal phenomena based on FY-4A satellite data. The results have significance for the continuing development of global volcanic early-warning systems and for the dynamic monitoring of volcanoes after eruptions. [ABSTRACT FROM AUTHOR]

The laser spallation technique for measuring the interface strength between a coating and a substrate is similar to laser shock peening, in which the stress wave induced by laser shock cause debond on the interface between a hard coating with micron thickness and a metal substrate. According to the modified experiment setup of the laser spallation technique, finite element analysis simulated the process of the film spallation by taking the laser loading as a direct input. We presented a numerical model of finite element that the laser spallation process includes two related, but uncoupled procedures. One was transient heat transfer in a two-layer medium. The other was the related transient elastic wave propagation in the same two-layer media, which was the result of the thermal misfit by transient heating. Based on the threshold of film spallation, we analyzed the process of laser shocking to study the propagation of stress wave and evaluate the spall resistance of sputtered films. The analysis result showed the dynamic adhesive strength of the interface between the TiN coating and the 304 stainless steel substrate was 193.0 MPa. © 2003 American Institute of Physics. [ABSTRACT FROM AUTHOR]

The velocities of longitudinal and transverse waves for aluminum alloy 2024-T62 shocked by a high-power Nd: Glass laser are investigated by a laser ultrasonics method. The results show that the velocity of the longitudinal wave measured after the laser-shock processing increases at the center and decreases at the edge of the laser-shocked area (LSA). The maximum relative increase is 28% and the maximum decrease up to 10%, when compared with that measured before the alloy was shocked by laser processing. The velocity of the transverse wave decreases at any position within LSA, the maximum relative decrease being 13%. The decrease at the edge of LSA is larger than that at the center. © 2002 American Institute of Physics. [ABSTRACT FROM AUTHOR]

The miR399 is a conserved microRNA (miRNA) family, and it has been characterized as an essential regulator of phosphorus transport in plants. However, the biological function of miR399 in Cunninghamia lanceolata is still largely unclear. In this study, the comparison of mature miR399 sequence revealed a high similarity between Arabidopsis thaliana and C. lanceolate, and the pre-miR399 was capable of forming a typical stem-loop hairpin structure. A gene PHOSPHATE 2 (PHO2) was identified as a target of cln-miR399 using 5' rapid amplification of cDNA ends. Furthermore, the relationship between cln-miR399 and PHO2 was further confirmed through a transient co-expression of both genes in Nicotiana benthamiana. To examine the function of miR399 in Arabidopsis, miR399-overexpressing transgenic Arabidopsis thaliana was acquired using Agrobacterium-mediated approach. Real-time PCR showed that the amount of cln-MIR399 transcripts was higher in miR399-overexpressing plants than in wild-type plants, which was accompanied with down-regulation of expression of its target gene AtPHO2. The P content was 1.40 to 1.56-fold higher in the leaves of three transgenic lines than in wild type plants. However, the P content in the roots of the three transgenic lines was 24.5 - 37.2 % less than that in wild type plants. Moreover, the transcriptions of three phosphate transporter genes (PHT1, PHT2, and PHT3) were up-regulated in roots of miR399-overexpressing Arabidopsis plants. Interestingly, the transgenic lines exhibited retarded growth under normal P conditions compared with the wild type. Our findings demonstrate that cln-miR399 may play crucial roles in P transport and plant growth via regulation of its target gene PHO2. [ABSTRACT FROM AUTHOR]

OBJECTIVE: The aim is to determine the efficacy and specific mechanism of microRNA- 543-5p (miR-543-5p) on spinal cord injury (SCI). MATERIALS AND METHODS: The model of spinal cord injury was established in 6-week-old rats. Firstly, quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) was used to detect the changes of miR-543-5p in the spinal cord of rats in each group after spinal cord injury. Next, we observed the alterations in nuclear factor- kappa B (NF-κB) RNA level after injection of miR-543-5p. In addition, the enzyme-linked immunosorbent assay (ELISA) was used to detect the expression of the inflammatory cytokines, and we used Western blotting to detect the protein associated with nerve regeneration at the protein levels. Finally, the Basso-Beattie-Bresnahan (BBB) rating scale was utilized to measure the recovery of hindlimbs function in rats. RESULTS: After spinal cord injury, the RNA expression of miR-543-5p in the rat spinal cord was decreased, and the RNA level of NF-κB was found to be decreased after the artificial injection of miR-543-5p. In the inflammatory expression, we found that the expression of various inflammatory mediators was also downregulated. However, the expression of nerve regeneration related factors was significantly upregulated, and it was observed that the evaluated score of the miR-543-5p group was higher than that of the SCI group within 1 month. CONCLUSIONS: MiR-543-5p inhibited NF-κB pathway and reduced the inflammatory factors, and ameliorated nerve regeneration, which ultimately promoted hindlimbs locomotor function. [ABSTRACT FROM AUTHOR]

The estimation of unsaturated permeability coefficients (UPC) is of great importance on the properties of the matrix. Aim to study the relationship between the UPC and oxidation - reduction potential (ORP) in different matrix depths in the subsurface wastewater infiltration system (SWIS) and provide scientific basis for regulating SWIS and increasing pollutant removal, a test experiment of simulating the SWIS which included an inflow period (12 h) and a drying period (12 h) in one cycle was designed with a hydraulic load of 0.10 m3·(m2·d)-1. Results investigated that ORP could increase with UPC increasing in 70 and 115 cm and decrease with the UPC increasing in 100 and 130 cm matrix depths. Phenomena indicated that capillary action could affect UPC and ORP obviously. Moreover, the existence of oxygen and low volumetric water contents could impose UPC and ORP. UPC in the 100 cm matrix depth below proved that anaerobic area could be found in aerobic environment under alternation conditions. UPC in different matrix depths of a satisfactory SWIS could change from 2.49 × 10-7 to 1.16 × 10-3 cm·s-1. Treated water met reused requirements and no clogging was found. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To investigate the role of theacrine in the protection of ventricular remodeling and chronic heart failure after myocardial infarction in the estrogen-deficient mice. MATERIALS AND METHODS: Female C57BL/6 mice aged 8 weeks old were selected and then subjected to bilateral oophorectomy. At 7 days after surgery, the models of the myocardial infarction were established by ligating the anterior descending coronary artery. On the first day after myocardial infarction, Theacrine (20 mg/kg) was administered via gavage for continuous 28 days. Thereafter, the cardiac function in each group of mice was detected via cardiac ultrasonography for small animals at 7, 14, and 28 days after surgery. The mice were sacrificed after 28 days. The infarct size of mice was determined through 2,3,5-triphenyltetrazolium chloride (TTC) and Evan blue double staining assay, while the myocardial fibrosis was assessed via Masson staining assay. The expression levels of collagen-related proteins Collagen I, Collagen III, alpha-smooth muscle actin (α-SMA), and the transforming growth factor-β (TGF-β) were measured by Western blotting (WB). The terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) staining assay was applied to evaluate the myocardial apoptosis, and the WB was employed to detect apoptosis- associated proteins. The expression level of silent information regulator 2 homologue 3 (SIRT3) protein was detected by immunohistochemistry, and the expression levels of SIRT3, β-catenin and peroxisome proliferator-activated receptor gamma (PPARγ) protein were measured via WB. RESULTS: Compared with those in the Sham group, the ejection fraction (EF) and fractional shortening (FS) in estrogen-deficient mice were significantly lowered, the myocardial fibrosis and myocardial apoptosis were clearly aggravated, and the SIRT3 expression was decreased at 28 days after myocardial infarction. The theacrine could improve the cardiac function after the myocardial infarction in estrogen-deficient mice and relieve both myocardial fibrosis and myocardial apoptosis during chronic remodeling after myocardial infarction in estrogen-deficient mice. After the intervention with theacrine, the estrogen-deficient mice with myocardial infarction had up-regulated SIRT3 and PPARγ levels and a reduced β-catenin level in the heart. CONCLUSIONS: Theacrine is able to activate SIRT3 and repress myocardial fibrosis and apoptosis after myocardial infarction in ovariectomized mice, thereby improving the cardiac function of ovariectomized mice with myocardial infarction through the possible downstream signal pathway β-catenin/PPARγ. [ABSTRACT FROM AUTHOR]

OBJECTIVE: Ventilator-induced lung injury (VILI) remains a challenge. This study was designed to investigate the effects of ambroxol on VILI and the underlying mechanisms in a rodent model. MATERIALS AND METHODS: Male Wistar rats weighing 310-380 g were divided into four groups (n=8 per group): 1) saline only, 2) ventilation plus saline, 3) ventilation plus ambroxol (2 mg/kg), and 4) ventilation plus ambroxol (50 mg/kg). Rats in groups 1 and 2 were treated (i.p.) with 2.5 ml of saline once a day for six days and last injected 1 h prior to tracheotomy. Rats in groups 3 and 4 received ambroxol on the same schedule. Rats were ventilated for 90 minutes at a tidal volume (VT) of 30 ml/kg. The expression levels of c-Jun, a component of activator protein-1 (AP-1), and gamma-glutamylcysteine synthetase (γ-GCS), the rate-limiting enzyme in the synthesis of glutathione (gamma-glutamyl-cysteinyl-glycine, GSH), an endogenous antioxidant, were measured with immunohistochemical staining and in situ hybridization. Both AP-1 and GSH are involved in VILI. RESULTS: Ambroxol at 50 mg/kg inhibited ventilation-induced lung inflammation, significantly elevated the ventilation-induced down-regulation of γ-GCS mRNA and protein, and significantly decreased the ventilation-induced up-regulation of c-Jun mRNA and protein. It has been reported that reactive oxygen species (ROS) can activate AP-1, leading to the production of pro-inflammatory cytokines and lung inflammation. CONCLUSIONS: Ambroxol increases γ-GCS to promote GSH production, which in turn, inhibits ROS-dependent AP-1 activation and inflammation. [ABSTRACT FROM AUTHOR]

"Digital heritage", as defined in this paper, is the integration of cultural heritage with digitization technology ("cultural heritage + digitization") and of digital knowledge with research. It includes not only the three conventional aspects of cultural heritage digitization--digital collection and documentation, digital research and information management, digital presentation and interpretation--but also the creation and innovative use/application of the digital content (cultural heritage intellectual property/IP, experiential education, cultural tourism, film and media). Through analysis of two case studies, the Palazzo Valentini in Rome, Italy, and the Old Summer Palace (Yuanmingyuan) in Beijing, China, the paper assesses the concept of "digital heritage" and proposes a conceptual framework to capture recent developments and future prospects with regard to the industry. [ABSTRACT FROM AUTHOR]

In China, the invasive American serpentive leafminer, Liriomyza trifolii (Burgess), was first detected in Guangdong province in 2005. Within only a few years of its discovery, its range had expanded rapidly to another 11 provinces and caused economic damage to a wide range of agricultural crops. L. trifolii has displaced the previously established exotic species L. sativae Blanchard to become the dominant species on some major horticultural crops across Hainan Island. Differential insecticide susceptibilities and local specific cropping systems might be major factors driving the ongoing displacement of L. sativae by L. trifolii. Further research should focus on monitoring established species to collect detailed data to enhance overall understanding of biology and ecology of invasion by L. trifolii. Urgent action is needed to improve management programs for this widespread invasive insect pest. [ABSTRACT FROM AUTHOR]

A novel biosensor was developed based on the cation-exchange of CuS nanoparticles (NPs) and Cu(i)-based click chemistry of functionalized gold nanoparticles (AuNPs). As a proof-of-principle, novel applications of this method as a versatile biosensor for single-nucleotide polymorphisms (SNPs) and DNA methyltransferase (MTase) were presented. [ABSTRACT FROM AUTHOR]

An efficient method for processing superhydrophobic surface is presented in this paper, which can realise the microstructure machining on a large area. First, the microgroove arrays were processed by high speed precision micromilling machine on the surface of the aluminium alloy. Then, the surface of the microgroove was ground by 1000 # electrostatic sand alumina water resistant abrasive belt. The machined surface topography was observed by SEM, which showed that the microgroove arrays were uniform. The contact angles of the water on the microgroove arrays were measured in different directions. In the parallel direction, the contact angle of microgroove arrays is 142±0·5°, whereas in the vertical direction, it arrives 160±0·6°. The above values of contact angle mean that a stable superhydrophobic metallic surface was prepared by the micromilling and grinding. [ABSTRACT FROM AUTHOR]

Hydroxyl terminated polybutadiene bound 2,2-methylenebis (4-methyl-6-tert-butylphenol) (HTPB-IPDI-MPH) was prepared by binding 2,2-methylenebis (4-methyl-6-tert-butylphenol) (MPH) onto hydroxyl terminated polybutadiene (HTPB) using isophorone diisocyanate (IPDI) as bridging agent. The structure of HTPB-IPDI-MPH was characterised by Fourier transform infrared spectroscopy, 1H nuclear magnetic resonance (NMR) spectroscopy, 13C NMR spectroscopy and gel permeation chromatography. The thermal stability of HTPB-IPDI-MPH was studied by thermal gravity analysis (TGA). The thermo-oxidative aging resistance of HTPB-IPDI-MPH for natural rubber (NR) vulcanizates was investigated by mechanical properties, cross-link density assessment and TGA, and then, possible mechanism of thermo-oxidative aging resistance of HTPB-IPDI-MPH for NR was proposed. The results showed that HTPB-IPDI-MPH had better thermal stability than the corresponding low molecular antioxidant MPH. The thermo-oxidative aging resistance and thermo-oxidative degradation of NR vulcanizates containing HTPB-IPDI-MPH were better than that of NR vulcanizates containing MPH obviously, indicating that the synergetic effect of phenolic -OH and -NHCOO- groups existed in HTPB-IPDI-MPH, which could enhance ability to scavenge free radical. [ABSTRACT FROM AUTHOR]

Structures and stabilities of clusters have been systematically studied via using density functional theory (DFT) with generalized gradient approximation (GGA). The calculations show that the stable configurations of are such structures with one N atom bonded to the external of the basic constructions consisting of Os atoms. Meanwhile, clusters represent 'magic number' effect, and 8 is the magic number. Additionally, the ground-state structures of clusters have the best stability, while that of cluster possesses the worst stability. The result of the study on the ionization potential (IP) and the electron affinity (EA) shows that there are not topological differences among the configurations of clusters. [ABSTRACT FROM AUTHOR]

OBJECTIVE: The aim of this study was to investigate clinical application of remifentanil in local anesthesia for resection of tumors in functional brain area. PATIENTS AND METHODS: Twenty-four patients were randomly divided into two groups: control group and remifentanil group. In remifentanil group remifentanil was infused intravenously with micro pump in 0.05-0.1 µg⋅kg-1⋅min-1. The hemodynamic changes and complications during operation were monitored. RESULTS: The satisfactory degree for surgical procedure was evaluated. The surgery of two groups could be completed in a conscious state. Mean artery pressure (MAP), heart rate (HR) in remifentanil group during opening or closing skull or intra- cranial period were significantly lower than control group (p < 0.05). There were no conspicuous complications in two groups such as respiratory depression, nausea, vomitting and dysphoria. Satisfaction rate of remifentanyl group was significantly higher than control group (p < 0.05). CONCLUSIONS: Awake brain tumor surgery could be completed in rational use of remifentanil on the base of good local anesthesia, and hemodynamics were stable and the patients were well tolerated. [ABSTRACT FROM AUTHOR]

In this paper, we introduce the principle of high speed train eddy current braking, and establish a complete mathematical model for solving eddy current force definite solution problem. The eddy current braking process is a dynamic process. The air gap distance between the magnetic pole and guide rail induction plate is constantly changing, and the change of air gap and the eddy current brake force are mutually coupled. Obviously, the dynamic coupling process of eddy current braking force with air gap cannot be characterized by static analytical expressions. We propose a method to calculate the dynamic simulation of eddy current braking force considering the change of air gap. First, the finite element method is used to establish the 2-dimensional (2D) model, and then the ANSYS software is applied to simulate the calculation. Finally, the results of eddy current brake force (i.e., horizontal braking force) and the normal force change with speed are obtained. We did the analysis on the simulation results, which were further compared with the experimental data. The reasons of the error were analyzed too. This paper provides a reference for the design of high speed train eddy current device. [ABSTRACT FROM AUTHOR]

SUMMARY In this paper, an experimental work is carried out to investigate the characteristics of solar thermal collection using supercritical CO2. This solar thermal conversion is based on supercritical CO2 natural convection, which is much easily induced because a small change in temperature can result in large change in density close to the critical point. In addition, its critical temperature is 31.1°C and low enough to be easily reached in the low-temperature solar thermal conversion system. The obtained results show that the supercritical CO2 flow rate is smooth curve and not affected by the sudden variation of the solar radiation. The solar thermal conversion operation process can be divided into three periods: starting-up, transition, and stable period. When the system reaches the stable period, the CO2 flow rate will keep at a high value even if the solar radiation stays at a low level. It is also found that the smaller local solar radiation variation is, the better ability of keeping the flow rate near the peak level the supercritical CO2 fluid owns. It is also found that a small pressure difference can drive a supercritical CO2 flow with high flow rate. Furthermore, high solar thermal conversion efficiency is found at a high mass flow rate and under operation pressure near the critical point. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

A compact ultra-wideband (UWB) bandpass filter (BPF) with a narrow notched band based on ridged waveguide is presented. Capacitive loading stub structure is introduced to reject the undesired wireless local-area network (WLAN) radio signals. By simply adjusting the height of the capacitive loading post, the centre frequencies of the notched band can be changed from 5.16 to 6.2GHz, while the bandpass is nearly not affected. The UWB BPF has been simulated, fabricated and measured, with good agreement between the simulated and measured results. The measured insertion loss of the UWB BPF is less than 0.7 dB throughout the pass band of 3.05 to 10.9GHz, the variation of group delay less than 0.20 ns in this band except for the notched band. The notched band of the BPF centred at 5.2GHz has 10dB fractional bandwidth of about 3.7%. [ABSTRACT FROM PUBLISHER]

There is a rapid transition in the semiconductor packaging industry of devices moving toward 40/45-nm extreme low k (ELK) from the development phase into mainstream semiconductor assembly manufacturing. The drive to achieve adoption without major changes to process and equipment infrastructure while meeting the superior yield necessary is high. The main goal of this paper is to share learning's and provide solutions for integration and qualifications of 40/45-nm ELK devices into flip-chip (FC) and wire-bond (WB) package technology. The scope of this paper covers the fine-pitch ball grid array for the WB packages and FC chip-scale package for the FC Devices. The main challenge and focus point for WB 45/40-nm interconnects is on the first bond process. This paper will share some detailed analysis on the following. 1) Characterization for 45 nm ELK ultrafine-pitch. 2) Key factors for good Au ball bond integrity. 3) Recommendations for achieving the required levels of reliability for 45-nm Cu ELK. The challenge of FC Technology today has been changing at a faster rate and more and more adoption has been made from the conventional eutectic solder bumps or high lead solder bumps toward the lead free solder bump mainly due to the Green initiatives. This paper will share analysis on the following areas. 1) Thermo-mechanical simulation on key input factors and its correlation to actual evaluations. 2) Integration of Pb Free ELK bumps with 40-nm ELK technology are various critical processes. 3) Moldable underfill technology for Pb Free + ELK devices. In addition, critical process control is also required at the wafer level process of wafer thinning and dicing, including the need of Laser Grooving will also be covered. [ABSTRACT FROM PUBLISHER]

We introduce and investigate e-small and s-essential submodules, and prove that Rade(M)= ∩{ N ⊴ M / N is maximal in M }=∑ { N ⊆ M / N ≪e M} and Socs(M)=∑{ N ≪ M / N is minimal in M }=∩{ L ≤ M / L⊴sM}. As an application, we introduce the e-gH and s-wcH pairs of modules, and show that they are dual to each other under Morita duality. [ABSTRACT FROM AUTHOR]

In this article, a supercritical CO2-based solar Rankine cycle system (SRCS) with a novel-concept thermally driven pump is studied. The thermally driven pump is a refrigerant-circulating pump composed of two expansion tanks and having merits of low power consumption and high reliability in comparison with conventional mechanical pump. The application of the present thermally driven pump in the supercritical CO2-based SRCS shows that an oscillatory flow is realized in the system and the system thermal efficiency is enhanced compared to the SRCS using the mechanical feed pump. [ABSTRACT FROM AUTHOR]

Contents The maturation and developmental potential on cumulus-cell-free oocytes is of great importance theoretically and practically. The present study was to investigate the effects ofl-ascorbic acid, α-tocopherol and co-culture on in vitro developmental potential of porcine denuded oocytes (DOs). Porcine DOs were cultured in maturation medium supplemented with vitamin C (0, 50, 100, 250, 500, 750 μM) and vitamin E (0, 10, 20, 50, 100, 250 μm), respectively. And they were also co-cultured with dispersed cumulus cells (group CCscoculture), intact cumulus cells oocyte complexes (COCs) (group COCscoculture), and COCs whose oocytes were removed (group OOXcoculture), respectively. After 44 h incubation, the maturation rates, cleavage rates and blastocyst rates after parthenogenetic activation in three experiments mentioned above were collected and analysed, respectively.L-Ascorbic acid promoted porcine DOs in vitro maturation and blastocyt development after parthenogenetic activation while α-tocopherol did not increase the in vitro maturation rates, but improved the blastocyst rate. None of the three co-culture manner promoted the in vitro maturation and the cleavage of porcine DOs after parthenogenetic activation, but all the co-culture manners improved the blastocyst rates. Both Vitamin C and E enhance the in vitro developmental potential of porcine DOs. Co-culture increases the developmental potential of porcine DOs. [ABSTRACT FROM AUTHOR]

Soil degradation and subsequent yield decline are the main factors limiting further development of agriculture on the farming–pastoral transition zone of China. A 10-year field experiment was conducted in Inner Mongolia to compare the long-term effects of no-tillage with straw cover (NT), subsoiling with straw cover (ST), rototilling with straw cover (RT) and traditional tillage (TT) using ploughs on soil properties and productivity in a spring wheat–oat cropping system. Long-term conservation tillage increased soil organic matter in the top 20 cm by 21.4%, total N by 31.8% and Olsen’s P by 34.5% in the 0–5 cm layer compared to traditional tillage. Mean percentage of macro-aggregates (>0.25 mm, +20%) and macroporosity (>60 μm, +52.1%) also improved significantly in the 0–30 cm soil layer ( P < 0.05). The largest yield improvements coupled with greatest water use efficiency (WUE) were achieved by no-tillage with straw cover. Ten-year mean crop yields increased by 14.0% and WUE improved by 13.5% compared to traditional tillage due to greater soil moisture and improved soil physical and chemical status. These improvements in soil properties and productivity are of considerable importance for the seriously degraded soils in semiarid Inner Mongolia, as well as for food security, sustainable agriculture and carbon storage in the farming–pasture transition regions of China. [ABSTRACT FROM AUTHOR]