Accuracy of axial length measurements from immersion B-scan ultrasonography in highly myopic eyes

AIM:To evaluate the accuracy of axial length(AL)measurements obtained from immersion B-scan ultrasonography(immersion B-scan)for intraocular lens(IOL)power calculation in patients with high myopia and cataracts.METHODS:Immersion B-scan,contact A-scan ultrasonography(contact A-scan),and the IOLMaster were used to preoperatively measure the AL in 102 eyes from 102 patients who underwent phacoemulsification and IOL implantation.Patients were divided into two groups according to the AL:one containing patients with22 mm≤AL【26 mm(group A)and the other containing patients with AL≥26 mm(group B).The mean error(ME)was calculated from the difference between the AL measurement methods predicted refractive error and the actual postoperative refractive error.RESULTS:Ingroup A,ALs measured byimmersion Bscan(23.48±1.15)didn’t differ significantly from those measured by the IOLMaster(23.52±1.17)or from those by contact A-scan(23.38±1.20).In the same group,the standard deviation(SD)of the mean error(ME)of immersion B-scan(-0.090±0.397 D)didn’t differ significantly from those of IOLMaster(-0.095±0.411 D)and contact A-scan(-0.099±0.425 D).In group B,ALs measured by immersion B-scan(27.97±2.21 mm)didn’t differ significantly from those of the IOLMaster(27.86±2.18 mm),but longer than those measured by Contact A-scan(27.75±2.23 mm,P=0.009).In the same group,the standard deviation(SD)of the mean error(ME)of immersion B-scan(-0.635±0.157 D)didn’t differ significantly from those of the IOLMaster(-0.679±0.359 D),but differed significantly from those of contact A-scan(-0.953±1.713 D,P=0.028).CONCLUSION:ImmersionB-scanexhibitsmeasurement accuracy comparable to that of the IOLMaster,and is thus a good alternative in measuring AL in eyes with high myopia when the IOLMaster can’t be used,and it is more accurate than the contact A-scan.

Comparison of ocular parameters of two biometric measurement devices in highly myopic eyes

AIM: To compare the differences and agreement of ocular biometric parameters in highly myopic eyes obtained by optical biometric measurement instruments, the OA-2000 and IOLMaster 500. METHODS: Totally, 90 patients(90 eyes) were included. They were divided into high myopia group and control group. Ocular parameters, including axial length(AL), mean keratometry(Km), anterior chamber depth(ACD), and white to white(WTW), were obtained from the OA-2000 and IOLMaster 500. RESULTS: For the control group, we applied BlandAltman graphs to assess the 95% limits of agreement(LoA) for most parameters including AL, ACD, Km, and WTW(-0.24 to 0.29 mm,-0.22 to 0.45 mm,-0.39 to 0.31 D, and-0.90 to 0.86 mm, respectively). In high myopia patients, AL, ACD, Km values had wider 95% LoA(-0.34 to 0.32 mm,-0.36 to 0.34 mm,-0.57 to 0.47 D, respectively), except WTW(-0.80 to 0.68 mm). Differences were not statistically significant between these two instruments(P>0.05). CONCLUSION: Most parameters obtained by the OA-2000 and IOLMaster 500 are comparable, including the AL, ACD, and K values. Among them, the agreement of the high myopia patients is poor compared to the patients without high myopia.

A TWO-DIMENSIONAL LAGRANGIAN TECHNIQUE FOR FLOW FIELD MEASUREMENT UNDER HIGH DYNAMIC PRESSURE

In this paper,a two-dimensional(2-D)Lagrangian technique for flow field measurement under high dynamic pressure is presented,which includes a set of experimental device and 2-D Lagrange composite manganin-constantan ring gages.With this kind of gage,the histories of pressure and radial displacement can be measured simultaneously at different Lagrange positions in an axisymmetric shock loading flow field. The technique has some advantages over the 1-D one,such as,simplified loading device,continuously adjust- able output pressure,no restriction on sample length and the availability for the study of lateral rarefaction in shock propogation.As a preliminary application,the processes of 2-D shock initiation and attenuation in compacted TNT are measured.

Highly sensitive digital optical sensor with large measurement range based on the dual-microring resonator with waveguide-coupled feedback

We propose a novel high-performance digital optical sensor based on the Mach-Zehnder interferential effect and the dual-microring resonators with the waveguide-coupled feedback. The simulation results show that the sensitivity of the sensor can be orders of magnitude higher than that of aconventional sensor, and high quality factor is not critical in it. Moreover, by optimizing the length of the feedback waveguide to be equal to the perimeter of the ring, the measurement range of the proposed sensor is twice as much as that of the conventional sensor in the weak coupling case.

Similarity measure design for high dimensional data

Information analysis of high dimensional data was carried out through similarity measure application. High dimensional data were considered as the a typical structure. Additionally, overlapped and non-overlapped data were introduced, and similarity measure analysis was also illustrated and compared with conventional similarity measure. As a result, overlapped data comparison was possible to present similarity with conventional similarity measure. Non-overlapped data similarity analysis provided the clue to solve the similarity of high dimensional data. Considering high dimensional data analysis was designed with consideration of neighborhoods information. Conservative and strict solutions were proposed. Proposed similarity measure was applied to express financial fraud among multi dimensional datasets. In illustrative example, financial fraud similarity with respect to age, gender, qualification and job was presented. And with the proposed similarity measure, high dimensional personal data were calculated to evaluate how similar to the financial fraud. Calculation results show that the actual fraud has rather high similarity measure compared to the average, from minimal 0.0609 to maximal 0.1667.

Design and application of thickness measurement calibration system based on laser displacement sensor

This study aims to improve the accuracy and safety of steel plate thickness calibration.A differential noncontact thickness measurement calibration system based on laser displacement sensors was designed to address the problems of low precision of traditional contact thickness gauges and radiation risks of radiation-based thickness gauges.First,the measurement method and measurement structure of the thickness calibration system were introduced.Then,the hardware circuit of the thickness system was established based on the STM32 core chip.Finally,the system software was designed to implement system control to filter algorithms and human-computer interaction.Experiments have proven the excellent performance of the differential noncontact thickness measurement calibration system based on laser displacement sensors,which not only considerably improves measurement accuracy but also effectively reduces safety risks during the measurement process.The system offers guiding significance and application value in the field of steel plate production and processing.

High Impedance Fault Detection of Distribution Network by Phasor Measurement Units

This paper proposes a new algorithm for High Impedance Fault (HIF) detection using Phasor Measurement Unit (PMU). This type of faults is difficult to detect by over current protection relays because of low fault current. In this paper, an index based on phasors change is proposed for HIF detection. The phasors are measured by PMU to obtain the square summation of errors. Two types of data are used for error calculation. The first one is sampled data and the second one is estimated data. But this index is not enough to declare presence of a HIF. Therefore another index introduces in order to distinguish the load switching from HIF. Second index utilizes 3rd harmonic current angle because this number of harmonic has a special behaviour during HIF. The verification of the proposed method is done by different simulation cases in EMTP/MATLAB.

High-pressure synergetic measurement station(HP-SymS)

In the High-Pressure Synergetic Measurements Station （HP-SymS） of the Synergic Extreme Condition User Facility （SECUF）, we will develop ultrahigh-pressure devices based on diamond-anvil cell （DAC） techniques, with a target pressure up to 300 GPa. With the use of cryostat and magnet, we will reach 300 GPa4.2 K-9 T and conduct simultaneous measurements of the electrical-transport property and Raman/Brillouin spectrascopy. With resistance heating and laser heating, we will reach temperatures of at least 1000 and 3000 K, respectively, coupled with Raman/Brillouin spectroscopy measurements. Some designs of supporting devices, such as a femtosecond laser gasket-drilling device, electrode-deposition device, and the gas-loading device, are also introduced in this article. Finally, we conclude by providing some perspectives on the applications of the DAC in related research fields.

Instantaneous Creep in Face-centered Cubic Metals at Ultra- low Strain Rates by a High-resolution Strain Measurement

Instantaneous creep in face-centered cubic metals, 5N Al（99.999%）, 2N Al （99%） and 4N Cu （99.99%） with different grain sizes, was firstly investigated by sudden stress-change experiments at ultra- low strain rates ε ≤10-10 s-1 and temperature T 〈 0.32 Tn. The experimental results indicate that the observed instantaneous creep is strongly dependent on grain size, the concentration of impurity, and stacking fault energy. Creep in high-purity aluminum, 5N Al, with a very large grain size, d 〉 1600μm, shows non-viscous behavior, and is controlled by the recovery of dislocations in the boundary of dislocation cells. On the other hand, for 5N A1 with a small grain size, d=30μm, and low-purity aluminum, 2N A1, with d8= 25μm, creep shows viscous behavior and may be related to ＇low temperature grain boundary sliding＇. For high-purity copper, 4N Cu, with d= 40 grn and lower stacking fault energy, creep shows a non-viscous behavior, and is controlled by the recovery process of dislocations. For all of the samples, creep shows anelastic behavior.

Analysis on High-yield Experience and Protective Measures of Wheat and Corn: A Case Study of Jieshou City in Anhui Province

This paper summarized the experience in high yield of wheat and corn in Jieshou City and made a further study on the supporting measures for the high yield of wheat and corn on this basis.

Quantitative Measurement of the Proportions of High-Order Harmonics for the 4B7B Soft-X-Ray Source at Beijing Synchrotron Radiation Facility

A transmission grating coupled with an X-ray charge coupled device （CCD） is used to quantitatively measure the proportion of high-order harmonics of the soft-X-ray source of beam line 4B7B. The results show that the monochromatic X-ray has third-order and second-order harmonics. The proportion of second-order harmonic of 4B7B is less than 9.0% and the third- order harmonic is below 0.7% when no suppressing method is applied. When suppression methods are used, the proportion of second-order harmonic is less than 1.7% and the third-order harmonic is ignorable.

The Measurements of Highly Stripped Bromine Atom Spectra

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Preliminary Application of Combinatorial Measurement and Regression Analysis Method to High Precision Instrumental Analysis

With determination micro-Fe by 1, 10-phenanthroline spectrophotometry for example, they are systematically introduced the combinatorial measurement and regression analysis method application about metheodic principle, operation step and data processing in the instrumental analysis, including: calibration curve best linear equation is set up, measurand best linear equation is set up, and calculation of best value of a concentration. The results showed that mean of thrice determination , s = 0 μg/mL, RSD = 0. Results of preliminary application are simply introduced in the basic instrumental analysis for atomic absorption spectrophotometry, ion-selective electrodes, coulometry and polarographic analysis and are contrasted to results of normal measurements.

Wide-Temperature-Range Dielectric Permittivity Measurement under High Pressure

Two measurement systems are developed for in-situ dielectric property measurement under high pressure in a wide-temperature range from 77K to 1273 K. The high-temperature system ranging from room temperature up to 1273K is equipped with a hexahedron anvils press, while the low-temperature system ranging from liquid nitrogen temperature to normal condition is equipped using the piston cylinder setup with a specially designed sample chamber. Using these configurations, the dielectric property measurement of ferroelectrie BaTiO3 and multiferroie Tm0.5Gd0.5MnO3 compounds are demonstrated, which proves the validity of the systems through the tuning of the polarization and phase transition boundary by high pressure. These two systems will be equally applicable to a wide variety of electronic and transport property measurements of insulators, semiconductors, as well as battery materials.

High Precision Tungsten Isotope Measurements by MC-ICPMS

1 Introduction The short-lived 182Hf-182W system is generally acknowledged as the best chronometer of metal-silicate segregation that occurred during the early evolution of asteroids and terrestrial planets due to its following properties:(1)Hf-W fractionation commonly occurs during metal-silicate differentiation;(2)Both Hf and W are highly refractory elements,therefore most bulk

Breeding of National Authorized New Wheat Variety Shannong 116 and Supporting Cultivation Technical Measures for High Yield, High Quality and High Efficiency

Shannong 116 is a strong gluten,high yield and multi-resistance wheat variety bred by Shandong Agricultural University,which was approved by the State in 2021 and by Shandong Province in 2022.Shannong 116 combines the excellent characteristics of the female parent(strong gluten,disease resistance and early maturity)and the male parent(high yield,water saving and lodging resistance),with a plant height of 76.9 cm,compact plant type,orderly spike layer and good maturity performance,which is suitable for large-scale promotion and market order planting in Huanghuai wheat area.In this paper,the characteristics of Shannong 116 are analyzed,and cultivation technical measures for high yield,high quality and high efficiency are put forward,in order to provide a technical support for the popularization and application of the variety.

High-speed railway channel measurements and characterizations: a review

Wireless communication for high-speed railways （HSRs） that provides reliable and high data rate communi- cation between the train and trackside networks is a challenging task. It is estimated that the wireless communication traffic could be as high as 65 Mbps per high-speed train. The development of such HSR communications systems and standards requires, in turn, accurate models for the HSR propagation channel. This article provides an overview of ex- isting HSR channel measurement campaigns in recent years. Particularly, some important measurement and modeling results in various HSR scenarios, such as viaduct and U-shaped groove （USG）, are briefly described and analyzed. In addition, we review a novel channel sounding method, which can highly improve the measurement efficiency in HSR environment.

Cold Atom Cloud with High Optical Depth Measured with Large Duty Cycle

We present a cold atom system with a dark-line two-dimensional magneto-optical trap, to increase the atomic density by suppressing the atomic radiation pressure. Optical depth （OD） and duty cycle are used to evaluate the system performance. We demonstrate a 100% increase in OD with the dark line, and obtain an ultrahigh OD of 264 with 10% for the duty cycle. Also, with an efficient dark line region, the OD could maintain above i00 with duty cycle as high as 30%. The cold atomic ensemble with an ultrahigh OD with a 10%-30% duty cycle is particularly advantageous in quantum i^formation processing and communication.

A fast emittance measurement unit for high intensity DC beam

A combined unit, which has the ability to measure the current and emittance of the high intensity direct current（DC）ion beam, is developed at Peking University（PKU）. It is a multi-slit single-wire（MSSW）-type beam emittance meter combined with a water-cooled Faraday Cup, named high intensity beam emittance measurement unit-6（HIBEMU-6）. It takes about 15 seconds to complete one measurement of the beam current and its emittance. The emittance of a 50-mA@50-kV DC proton beam is measured.

Technical Measures for High Quality and High Yield of Free-range Sows in Rural Areas

Today,with the rapid development of modern and large-scale pig industry,free-range pig farming is still an important part of the breeding industry.Different from large-scale pig farms,there are many shortcomings in feeding management,pig disease prevention and control and so on for small-scale farmers.In the long-term clinical diagnosis and production practice,it is found that sows raised by small-scale farmers often have some problems,such as non-estrus,repeated infertility and"false pregnancy",weak farrowing,stillbirth,and postpartum piglet death.This paper makes a comprehensive analysis on the performance and etiology of the above-mentioned free-range sows,and puts forward the corresponding prevention and control measures,in order to provide a theoretical basis for the feeding and management of rural free-range sows.