Parametrical analysis of the railways dynamic response at high speed moving loads

The paper introduces some findings about a sensitivity analysis conducted on every geometrical and mechanical parameters which characterize the use of a railway superstructure at the high velocity. This analysis was carried out by implementing a forecast model that is derived from the simplified Gazetas and Dobry one. This model turns out to be particularly appropriate in the explication of problems connected to high velocity, since it evaluates both inertial and viscous effects activated by the moving load speed. The model implementation requires the transfer function determination that represents the action occurred by the bed surfaces on the railway and it therefore contains information concerning the geometrical and the mechanical characteristics of the embankment, of the ballast and of the sub-ballast. The transfer function H has been evaluated with the finite elements method and particularly, by resorting the ANSYS code with a harmonic structural analysis in the frequencies field. The authors, from the critic examination of the system＇s dynamics response in its entirety, glean a series of observations both of a general and a specific character, finally attaining a propose of a design modification of the standard railway superstructure at the high velocity of train operation adopted today especially in Italy.

Physiological Response to High Temperature and Evaluation of Heat Tolerance of Different Grape Cultivars

[Objectives]This study was conducted to investigate the differences in the physiological responses of different grape cultivars to high temperature.[Methods]The 19 tested cultivars were selected from the grape germplasm resources pool of Turpan Research Institute of Xinjiang Academy of Agricultural Sciences.Twelve physiological indexes including gas exchange parameters,chlorophyll content,antioxidant enzyme activity and proline content were determined in grape leaves under field conditions during the middle period of local natural high temperature period(July,daily maximum air temperature>35℃).The heat tolerance of different cultivars was evaluated by fuzzy membership function analysis and optimum partitioning clustering of ordered samples.[Results](1)Under natural high temperature conditions in Turpan,the 19 tested grape cultivars responded differently to high temperature.‘Red Globe’,‘Fujiminori’,‘Beta’,‘Hetianhuang’had strong heat tolerance,while‘Thompson Seedless’,‘Hongqi Tezaomeigui’,‘Shuijing Wuhe’,‘Victoria’,‘Yatomi Rosa’and‘Crimson Seedless’had weak heat tolerance.(2)Among the 12 physiological indexes,malondialdehyde content and antioxidant enzyme activity were mostly different among various grape cultivars.The grape cultivars with strong heat tolerance,‘Red Globe’and‘Fujiminori’,had relatively lower malondialdehyde contents,while‘Beta’and‘Hetianhuang’had relatively higher malondialdehyde contents.But they had higher activity of antioxidant enzymes.(3)The results of fuzzy membership function analysis showed that the cumulative membership value(AR)of each physiological index was consistent with its apparent heat tolerance performance,suggesting that AR can be a potential index for the evaluation of heat tolerance of grape cultivars.Further cluster analysis classified the tested cultivars as strong,medium and weak.‘Red Globe’,‘Fujiminori’,‘Beta’and‘Hetianhuang’had strong heat tolerance.[Conclusions]This study provides a reference for grape cultivation under high temperature and stress and breeding of heat-tolerant varieties.

Study on a New High Frequency Moving Coil Permanent Magnet Linear Motor

In order to improve the characteristics of a conventional moving coil permanent magnet linear motor （MCPMLM）, such as weak points on export force, response time, response speed, we studied a permanent magnet （PM） structure that is a key component of MCPMLM. Different magnetization techniques of single PM and differ- ent array structures of multiple PMs are compared, and a new MCPMLM magnetized along the external field force lines wing eight pieces of a tegular Halbach magnet array with air gaps is proposed as well. The analysis on magnetic field and experimental results of MCPMLM demonstrates that the force between the coil and the PM increases by more than 40%. The simulation frequeney is close to 350 Hz at -3 dB , and the response time is O. 005 s. In addition, the experiment frequency reaches 300 Hz at -3 dB and the response time is 0. 004 s, which agrees well with the simulation results. It means that the developed MCPMLM enjoys advantages in high frequency and rapid response, and can satisfy the requirements of a high speed electro-hydraulic proportional valve.

Endometrial Mucin-1 and Pinopode in Peri-implantation Phase in Ovarian High Responders during Controlled Ovarian Hyperstimulation Cycles

Objective To investigate effects of ovarian high response on endometrial mucin-1 （MUC1） and pinopode in peri-implantation phase in controlled ovarian hyperstimulation （COH） cycles. Methods Ovarian high response was defined as serum E2 〉 15 000 pmol/L on the day of hCG administration in COH cycle using GnRH agonist and recombinant FSH （n=8）. Healthy and fertile women were used as the natural control （n=10）. Endometrial biopsies were performed on the day of LH＋ 7/hCG＋ 7. Pinopode formation was observed by scanning electron microscope. Expression of MUC1 was detected with quantitative Real-time PCR and immunohistochemistry. Results In high response group, the lumen surface was covered with variant pinopodes and microvillous. The expression of MUC1 mRNA in high response group was lower than that in the natural control （P〈0.05）. Immunostaining for MUC1 protein in glandular and luminal epithelium in high response group was lower than that in the natural control （P〈0. 05）. Conclusion Asynchronized pinopode appearance and lower expression of MUC1 during peri-implantation period were the characteristics of endometrium in high response group, Which may provide a clue of decreased endometrial receptivity in the supraphysiological hormone milieu.

High-responsivity solar-blind photodetector based on MOCVD-grown Si-dopedβ-Ga_(2)O_(3)thin film

Si-dopedβ-Ga_(2)O_(3)films are fabricated through metal-organic chemical vapor deposition(MOCVD).Solar-blind ultraviolet(UV)photodetector(PD)based on the films is fabricated by standard photolithography,and the photodetection properties are investigated.The results show that the photocurrent increases to 11.2 mA under 200μW·cm^(-2)254 nm illumination and±20 V bias,leading to photo-responsivity as high as 788 A·W^(-1).The Si-dopedβ-Ga2O3-based PD is promised to perform solar-blind photodetection with high performance.

Development of a Novel Parallel-spool Pilot Operated High-pressure Solenoid Valve with High Flow Rate and High Speed

High-pressure solenoid valve with high flow rate and high speed is a key component in an underwater driving system.However,traditional single spool pilot operated valve cannot meet the demands of both high flow rate and high speed simultaneously.A new structure for a high pressure solenoid valve is needed to meet the demand of the underwater driving system.A novel parallel-spool pilot operated high-pressure solenoid valve is proposed to overcome the drawback of the current single spool design.Mathematical models of the opening process and flow rate of the valve are established.Opening response time of the valve is subdivided into 4 parts to analyze the properties of the opening response.Corresponding formulas to solve 4 parts of the response time are derived.Key factors that influence the opening response time are analyzed.According to the mathematical model of the valve,a simulation of the opening process is carried out by MATLAB.Parameters are chosen based on theoretical analysis to design the test prototype of the new type of valve.Opening response time of the designed valve is tested by verifying response of the current in the coil and displacement of the main valve spool.The experimental results are in agreement with the simulated results,therefore the validity of the theoretical analysis is verified.Experimental opening response time of the valve is 48.3 ms at working pressure of 10 MPa.The flow capacity test shows that the largest effective area is 126 mm2 and the largest air flow rate is 2320 L/s.According to the result of the load driving test,the valve can meet the demands of the driving system.The proposed valve with parallel spools provides a new method for the design of a high-pressure valve with fast response and large flow rate.

Simulation and Design of a High Responsibility PIN Photodetector

A silicon-based PIN photodetector structure with the characteristics of high responsibility and high cut-off frequency fabricated with the PERL(the passivated emitter and the rear locally-diffused)technologies is introduced in this paper.After making some tiny adjustments of the structure,Silvaco software is used to simulate three similar structures of PIN photodetector by measuring the spectral response,dark current,cut-off frequency and dc characteristics.From the results,it is concluded that PIN photodetector with the middle shallow diffusion area is superior to the other two ones in dark current,at least 35% lower.The responsibility of these three kinds of detector reaches the degree of 0.3A/W,and the highest spectral response is around 600nm.Their cut-off frequencies are all over 108Hz.

Hemodynamic monitoring and management of patients undergoing high-risk surgery:a survey among Chinese anesthesiologists

Hemodynamic monitoring and optimization improve postoperative outcome during high-risk surgery.However,hemodynamic management practices among Chinese anesthesiologists are largely unknown.This study sought to evaluate the current intraoperative hemodynamic management practices for high-risk surgery patients in China.From September 2010 to November 2011,we surveyed anesthesiologists working in the operating rooms of 265 hospitals representing 28 Chinese provinces.All questionnaires were distributed to department chairs of anesthesiology or practicing anesthesiologists.Once completed,the 29-item questionnaires were collected and analyzed.Two hundred and 10 questionnaires from 265 hospitals in China were collected.We found that 91.4%of anesthesiologists monitored invasive arterial pressure,82.9%monitored central venous pressure（CVP）,13.3%monitored cardiac output（CO）,10.5%monitored mixed venous saturation,and less than 2%monitored pulse pressure variation（PPV） or systolic pressure variation（SPV） during high-risk surgery.The majority（88%） of anesthesiologists relied on clinical experience as an indicator for volume expansion and more than 80%relied on blood pressure,CVP and urine output.Anesthesiologists in China do not own enough attention on hemodynamic parameters such as PPV,SPV and CO during fluid management in high-risk surgical patients.The lack of CO monitoring may be attributed largely to the limited access to technologies,the cost of the devices and the lack of education on how to use them.There is a need for improving access to these technologies as well as an opportunity to create guidelines and education for hemodynamic optimization in China.

InP-based evanescently coupled high-responsivity photodiodes with extremely low dark current density integrated diluted waveguide at 1550 nm

In this paper, we have demonstrated a high performance waveguide photodiode integrated diluted waveguide serving as a fibre-to-waveguide coupler to achieve high coupling efficiency. High responsivity （〉 1 A/W）, high saturation power （〉 45 mA） in the static state and extremely low dark current density （0.04 pA/μm2） with 3 dB bandwidth at 13.4 GHz have been achieved.

Graphene/SrTiO3 interface-based UV photodetectors with high responsivity

Strontium titanate(SrTiO3),which is a crucial perovskite oxide with a direct energy band gap of 3.2 eV,holds great promise for ultraviolet(UV)photodetection.However,the response performance of the conventional SrTiO3-based photodetectors is limited by the large relative dielectric constant of the material,which reduces the internal electric field for electron-hole pair separation to form a current collected by electrodes.Recently,graphene/semiconductor hybrid photodetectors by van-der-Waals heteroepitaxy method demonstrate ultrahigh sensitivity,which is benefit from the interface junction architecture and then prolonged lifetime of photoexcited carriers.Here,a graphene/SrTiO3 interface-based photodetector is demonstrated with an ultrahigh responsivity of 1.2×106 A/W at the wavelength of 325 nm and∼2.4×104 A/W at 261 nm.The corresponding response time is in the order of∼ms.Compared with graphene/GaN interface junctionbased hybrid photodetectors,∼2 orders of magnitude improvement of the ultrahigh responsivity originates from a gain mechanism which correlates with the large work function difference induced long photo-carrier lifetime as well as the low background carrier density.The performance of high responsivity and fast response speed facilitates SrTiO3 material for further efforts seeking practical applications.

A 2DEG back-gated graphene/AlGaN deep-ultraviolet photodetector with ultrahigh responsivity

A graphene/AlGaN deep-ultraviolet(UV)photodetector is presented with ultrahigh responsivity of 3.4×105 A/W at 261 nm incident wavelength and 149 pW light power.A gain mechanism based on electron trapping at the potential well is proposed to be responsible for the high responsivity.To optimize the trade-off between responsivity and response speed,a back-gate electrode is designed at the AlGaN/GaN two-dimensional electron gas(2DEG)area which eliminates the persistent photocurrent effect and shortens the recovery time from several hours to milliseconds.The 2DEG gate is proposed as an alternative way to apply the back gate electrode on AlGaN based devices on insulating substrates.This work sheds light on a possible way for weak deep-UV light detection.

Reliability and sensitivity analyses of HPT blade-tip radial running clearance using multiply response surface model

To reasonably design the blade-tip radial running clearance(BTRRC) of high pressure turbine and improve the performance and reliability of gas turbine, the multi-object multi-discipline reliability sensitivity analysis of BTRRC was accomplished from a probabilistic prospective by considering nonlinear material attributes and dynamic loads. Firstly, multiply response surface model(MRSM) was proposed and the mathematical model of this method was established based on quadratic function. Secondly, the BTRRC was decomposed into three sub-components(turbine disk, blade and casing), and then the single response surface functions(SRSFs) of three structures were built in line with the basic idea of MRSM. Thirdly, the response surface function(MRSM) of BTRRC was reshaped by coordinating SRSFs. From the analysis, it is acquired to probabilistic distribution characteristics of input-output variables, failure probabilities of blade-tip clearance under different static blade-tip clearances δ and major factors impacting BTRRC. Considering the reliability and efficiency of gas turbine, δ=1.87 mm is an optimally acceptable option for rational BTRRC. Through the comparison of three analysis methods(Monte Carlo method, traditional response surface method and MRSM), the results show that MRSM has higher accuracy and higher efficiency in reliability sensitivity analysis of BTRRC. These strengths are likely to become more prominent with the increasing times of simulations. The present study offers an effective and promising approach for reliability sensitivity analysis and optimal design of complex dynamic assembly relationship.

High Responsivity Organic Ultraviolet Photodetector Based on NPB Donor and C60 Acceptor

We report fabrication and characterization of organic heterojunction UV detectors based on N,N＇-bis（naphthalen- 1-y1）-N,N＇-bis （phenyl） benzidine （NPB） and fullerene C60. The effects of different thicknesses of NPB and C60 layers are studied and compared. Notably, the optimal thicknesses of electron acceptor C60 and electron donor NPB are 40 nm and 80 nm, respectively. The J V characteristic curves of the device demonstrate a three-order- of-magnitude difference when illuminated under a 350nm UV light and in the dark at -0.5 V. The device exhibits high sensitivity in the region of 320-380nm with the peak located around 35Onm. Especially, it shows excellent photo-response characteristic with a responsivity as high as 315 mA/W under the illumination of 192μW.cm 2 350nm UV light at -5 V. These results indicate that the NPB/C60 heterojunction structure device might be used as low-cost low-voltage UV photodetectors.

Double-cliff-layer uni-traveling-carrier photodiode with high responsivity and ultra-broad bandwidth

A novel backside-illuminated double-cliff-layer uni-traveling-carrier(DCL-UTC)photodiode with both high responsivity and ultra-broad bandwidth is designed and demonstrated.A thick absorption layer is adopted for high responsivity,and a depletion region with double cliff layers is proposed to alleviate the space charge effect and maintain overshoot electron velocity under large photocurrents.In addition,inductive coplanar waveguide electrodes are employed to enhance the frequency response performance.The 6-μm-diameter photodiode exhibits a high responsivity of 0.51 A/W and a large 3-dB bandwidth of 102 GHz.A high RF output power of 2.7 dBm is recorded at 100 GHz.

Modes of Action of Phytochromes in Establishing Different Phototropic Responsiveness of Maize Coleoptiles

Previous studies have examined the effects of red light (R) on phototropism of maize ( Zea mays L. cv. Royaldent Hit 85) coleoptiles. The R effect on time-dependent phototropism (TDP) was further studied by characterizing its fluence-response relationship. The results showed the R effect was a low-fluence-response, unlike those on pulse-induced phototropisms that show a very-low-fluence-response mode. A subsequent pulse of far-red light (FR) could reverse the R effect. TDP responsiveness, however, recovered as the following FR was extended, The FR-dependent increase in TDP responsiveness was obtained even coleoptiles were pretreated only with FR. It suggested that TDP responsiveness could also be established in response to a FR signal. The fluence-response relationship for the effect of FR was then investigated. The effect of FR depended on the time of irradiation and required high photon fluences. Because reciprocity was invalid at the higher fluence range, the effect of FR would be a high-irradiance-response mode. Relation between phytochrome action modes and possible multiple pathways for phototropic signal transduction was analyzed based on the experiment results.

Molecular mechanisms governing plant responses to high temperatures

The increased prevalence of high temperatures （HTs） around the world is a major global concern, as they dramatically affect agronomic productivity. Upon HT exposure, plants sense the temperature change and initiate cellular and metabolic responses that enable them to adapt to their new environmental conditions.Decoding the mechanisms by which plants cope with HT will facilitate the development of molecular markers to enable the production of plants with improved thermotolerance. In recent decades, genetic, physiological, molecular, and biochemical studies have revealed a number of vital cellular components and processes involved in thermoresponsive growth and the acquisition of thermo- tolerance in plants. This review summarizes the major mechanisms involved in plant HT responses, with a special focus on recent discoveries related to plant thermosensing, heat stress signaling, and HT-regulated gene expression networks that promote plant adaptation to elevated environmental temperatures.

Homogenous Sn-doped K(Ta,Nb)O_(3) single crystals and its high piezoelectric response

Perovskite K(Ta,Nb)O_(3)(KTN)single crystal has drawn great interests for its outstanding electro-optic performance and excellent piezoelectric response.However,growth of compositionally uniform KTN single crystals has always been a great challenge for the great segregation difference between Nb and Ta.In this work,we propose a thermal field optimization strategy to resolve this challenge.Homogenous Sn doped KTN(Sn:KTN)single crystal with significantly reduced composition gradient(0.003 mol/mm,1/4 e1/8 of other KTN system),minimal TC variation(13℃)and excellent piezoelectric and dielectric response(d_(33)=373 pC/N andε^(T)_(33)=5206)has been successfully achieved.We found that the functional properties of Sn:KTN were greatly affected by the near-room temperature tetragonal-cubic phase transition.From the intrinsic aspect,longitudinal lattice deformation becomes much easier,resulting in maximum piezoelectric(d^(*)_(33)),dielectric(ε^(T*)_(33)),elastic(s^(E*)_(33))and electromechanical coupling(k^(*)_(33))coefficients along polar direction[001]_(C).From the extrinsic aspect,both domain wall density and domain wall mobility are greatly improved for the reduced lattice distortion,which also contribute a lot to the functional properties.This work provides a simple and practical route for designing and growing high quality crystals,and more importantly,reveals the fundamental mechanism of the phase transitions/boundaries on the functional properties.

Hydrogen sulfide protects against high glucose-induced H9c2 cardiomyocyte injury and inflammatory response by inhibiting ROS-TLR4 pathway

Objective To investigate whether exogenous hydrogen sulfide（H2S）protects high glucose（HG）-inducedH9c2 cardiomyocyte injury and inflammation response by inhibiting reactive oxygen species（ROS）-Toll-like receptor 4（TLR4）pathway.Methods Cell counter kit-8（CCK-8）assay was used to measure the cell viability,

Atomically thin heterostructure with gap-mode plasmon for overcoming trade-off between photoresponsivity and response time

Two-dimensional(2D)materials have recently provided a new perspective on optoelectronics because of their unique layered structure and excellent physical properties.However,their potential use as optoelectric devices has been limited by the trade-off between photoresponsivity and response time.Here,based on a vertically stacked atomically thin p-n junction,we propose a gap-mode plasmon structure that simultaneously enables enhanced responsivity and rapid photodetection.The atomically thin 2D materials act as a spacer for enhancing the gap-mode plasmons,and their short transit length in the vertical direction allows fast photocarrier transport.We demonstrate a high responsivity of up to 8.67 A/W with a high operation speed that exceeds 35 MHz under a 30 nW laser power.Spectral photocurrent,absorption,and a numerical simulation are used to verify the effectiveness of the gap-mode plasmons in the device.We believe that the design strategy proposed in this study can pave the way for a platform to overcome the trade-off between responsivity and response time.

Profiling kidney microRNAs from juvenile grass carp(Ctenopharyngodon idella) after 56 days of oral exposure to decabromodiphenyl ethane

Grass carp（Ctenopharyngodon idella） is one of the most important species in China.Decabromodiphenyl ethane（DBDPE） is a brominated flame retardant that has been used widely in industry, and has been observed to accumulate in the tissues of fish from South China. Evidence has shown that DBDPE is toxic to aquatic animals, but the molecular response has been unclear. MicroRNAs（miRNAs） are small noncoding and negative regulatory RNAs that are 20–24 nucleotides in length, which are involved in a wide range of biological processes. We took advantage of deep-sequencing techniques to accurately and comprehensively profile the kidney mi RNA expression of grass carp after 8 weeks of oral exposure to DBDPE. After mapping sequencing data to the genome and Expressed Sequence Tags（ESTs） of grass carp, we identified 493 miRNAs in the sequenced grass carp samples, which included 51 new miRNAs. The results indicated that 5 miRNAs were significantly down-regulated and 36 miRNAs were significantly up-regulated（FDR 〈 0.001,1.5-fold change） after DBDPE exposure. Real-time quantitative PCR（RT-qPCR） was performed on 4 miRNAs from the two samples, and the sequencing and RT-qPCR data were consistent. This study provides the first comprehensive identification of grass carp miRNAs, and the first expression analysis of grass carp miRNAs following DBDPE exposure.The results indicated that miRNAs have potential for use as biomarkers.