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The ash content of rubber was determined by thermogravimetric analysis (TGA) and the effects of sample amount, sample representativeness, heating rate, combustion temperature and combustion atmosphere on the test results were studied and the repeatability and reproducibility of the method were determined. The results showed that the optimal conditions of TGA were sample mass between 10 mg and 20 mg, heating rate of 20 ℃/min or 30 ℃/min, combustion temperature for raw rubber and compounded rubber (or vulcanized rubber) of 550 ℃ and 650 ℃, respectively. The repeatability and reproducibility of TGA were all good. When ash mass fraction of 4 types of different rubbers were from 0.29% to 5.12%, the repeatability within laboratory was from 0.110% to 0.303%, and the reproducibility between laboratories was from 0.283% to 0.676%.

Four kinds of methods were selected to evaluate the chromatography detection results of gas chromatograph from each company, then the application results of each evaluation methods in the evaluation of transformer oil chromatographic detection capability were researched・ The result showed that the iterative robust statistical method combined with the repeatability requirements in GB/T 17623--2017 has higher reliability・ The Z-score classical statistical method is stricter than the Z-score robust statistical method, but both of them have the risk of over deleted・ It is suggested to set the "dissatisfied, evaluation criteria for both of them as IZI m3 and apply them in combination w让h the repeatability requirement in GB/T 17623--2017. The iterative robust statistical method has a high agreement with the boxplot outlier removal results in the Z-score classical statistical method・ Besides, only one gas detection parameter of one instrument is removed by the boxplot outlier but not by the 让erative robust statistical method, and other removal results are all included in the removal results of the iterative robust statistical method・ The result showed that the iterative robust statistical method has high credibility in removing outliers, and the boxplot can be used directly to remove outliers for evaluation when the Z-score classical statistical method is applied. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Beijing University of Technology is the property of Journal of Beijing University of Technology, Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In response to the problems of slow detection speed, cumbersome operation, and solvent pollution in the detection of petroleum ether extract in tobacco leaves using the current traditional Soxhlet extraction method, low field nuclear magnetic resonance technology was used to detect the petroleum ether extract content in tobacco leaves. The detection parameters such as drying time, sample quality, echo time, and number of repeated scans were optimized to verify the repeatability and accuracy of the method, and the detection results were compared with the traditional Soxhlet extraction method. The results showed that 3. 0 g of tobacco leaf powder passing through a 40 mesh sieve was dried at 80 °C for 4 hours. Under the conditions of echo time of 0. 25 ms and 8 repeated scans, the petroleum ether extract detection results were good. The standard curve R2 reached 0. 999 81, and the relative standard deviation of repeatability was 1. 45% to 2. 99%. The intra day and inter day precision were 2. 61% and 1. 10%, respectively. The correlation coefficient between the detection results of this method and the Soxhlet extraction method reaches 0. 998 55, with an absolute error within 0. 02% ~ 0. 35% and a relative error within 0. 26%~3. 69%. Compared with the traditional Soxhlet extraction method, this method is simple, fast, accurate, and solvent free, making it suitable for the accurate quantification of petroleum ether extracts from large quantities of flue-cered tobacco leaves. [ABSTRACT FROM AUTHOR]

Aiming at the problems of sudden damping change and low load of aerostatic guide platform in precision machine tools, a large-load magneto fluid two-dimensional guideway platform was proposed based on magnetic fluid bearings. Firstly, the key problems of guideway platform based on magnetic fluid were studied, including air loss and magnetic fluid wake. Secondly, a double U-shaped guideway platform structure was designed by using magnetic fluid pressure bearings, and a liquid storage layer was formed on the rotor by placing the top, bottom and side bearing pads closely together. The guideway platform with upper and lower magnetization configuration had six bearing pads, and each bearing pad was composed of a plurality of small magnets. Then, the load capacity, stiffness and eddy current damping were numerically simulated. Finally, kerosene-based magnetic fluid, aluminum material and ferritic stainless steel were selected to prepare the platform prototype, and the performance was tested, and the validity of the guideway platform was verified. The results show that the flatness of the platform is ± 7 μm, which has high repeatability and is obviously superior to the existing precision motion system based on magnetic fluid bearings. Under the same stroke and size, compared with the pneumatic platform, the maximum effective load is 140 N, which is increased by 40%. The damping is relatively constant and predictable between 2 N·s/ m and 4 N·s/ m, which avoids the sudden change of damping of the pneumatic platform and is beneficial to realize high-precision positioning. [ABSTRACT FROM AUTHOR]

Magnetic resonance fingerprinting (MRF) is a revolutionary new technique for rapid quantitative magnetic resonance imaging. We reviewed the imaging technology and clinical application of MRF in an all-round way. We focus on three technical aspects: data collection, dictionary generation, and pattern recognition from traditional quantitative framework to deep learning quantitative framework. We also analyzed the technical challenges and limitations of MRF. The clinical applications of MRF in various human body regions were summarized, and the current status of MRF technology verification in terms of repeatability and reproducibility was introduced. Finally, we discussed the potential barriers and opportunities for MRF to enter clinical application and envision the future development direction of MRF technology.

Copyright of Journal of Isotopes is the property of Journal of Isotopes Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

By using image analysis technology and automatic control technology, the artificial intelligence technology was applied to the detection of unsound wheat kernels. The automatic, rapid and nondestructive detection instrument for unsound wheat kernels was developed. Through the verification of accuracy, repeatability, stability, difference between two instruments and other related performance parameters, the results showed that the instrument had stable performance. The accuracy, repeatability, stability and difference between two instruments met the requirements of industry standards. The operation was simple, and the detection speed was fast. It can overcome the problems of strong subjectivity, poor repeatability and poor inspection consistency among different personnel with manual checking, achieving the automatic and rapid nondestructive testing of unsound wheat kernels, and meeting the testing demand of grain collection and storage enterprises, processing enterprises and inspection agencies.

Six kinds of flexible strain sensors were prepared by carbonizing cotton and viscose knitted fabrics into conductive materials and then compounding them with thermoplastic urethane film, to systematically investigate the sensing properties of flexible strain sensors for carbonized knitted fabrics. The influences of tensile direction, fiber material, carbonized fabric structure and density on the sensitivity coefficient and repeatability of the sensors were investigated by tensile test. The results indicate that the sensing properties of the sensors in the course direction is better than that in the wale direction. The sensing properties of the strain sensor made of cotton is superior to that made of viscose. The comprehensive sensing properties of cotton plain knitted fabric strain sensor are the best, followed by 1x1 rib fabric, and interlock fabric is the worst. The smaller the fabric density, the better the sensing properties of the sensor. The research has guiding significance for the design of strain sensor. [ABSTRACT FROM AUTHOR]

Copyright of China Tropical Medicine is the property of China Tropical Medicine Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective: To improve the accuracy and validity of the measurement data of solvent residues in food packaging paper. Methods: Taking the HS GC-MS measurement system as the research object, variation sources in the measurement process was separated by using the measurement system analysis, and the traditional control chart and EWMA control chart of repeatability and reproducibility were established respectively to effectively monitor the detection error of the measurement system. Results: ① HS GC/MS had high measurement accuracy, with GRR of about 9.76%, and the gauging ability of the measurement system was relatively good. ② Through the combination of periodic measurement system analysis and control chart method, the effective separation and monitoring of repeatability and reproducibility variance components can be realized. ③ The repeatability can be monitored in real time through the daily gauging data, which was helpful to find the fault of measurement equipment in time and ensure the reliability of gauging results. ④ EWMA chart of repeatability can give early warning of measuring equipment fault faster than traditional control chart. Conclusion: Separating and monitoring variation sources of the measurement system by using variance analysis method can effectively ensure the stability of HS GC-MS equipment and improve the effectiveness of solvent residue detection.

为了定量分析亚麻籽油中α-亚麻酸（ALA）顺反异构体，采用SLB-IL111色谱柱，对气相色谱法测定反式亚麻酸（TALA）的分析条件（载气流速和升温程序）进行优化，并对所建立的方法进行评价。结果表明：载气流速选择0.3 mL/min；升温程序为60 ℃保持5 min，以20 ℃/min升温至175 ℃保持15 min，以1 ℃/min升温至180 ℃保持28 min，以0.2 ℃/min升温至185 ℃保持40 min；该方法可实现9c,12t,15t-C18∶ 3和9t,12c,15t-C18∶ 3的较好分离，分离度为0.9，其余各TALA的分离度在1.6~8.7之间；所建立的方法重复性好，测定加热亚麻籽油样时各异构体日间相对标准偏差（RSD）为3.16%~5.65%，日内RSD为2.00%~4.13%，检出限为0.678 2~0.879 0 mg/L，定量限为2.260 6~2.930 1 mg/L；各ALA异构体含量与峰面积之间线性关系良好，相关系数均为0.999 8。综上，所建立的方法可用于亚麻籽油中8种不同构型ALA顺反异构体的定量分析。 In order to quantitatively analyze the cis- and trans- isomers of α-linolenic acid (ALA) in linseed oil, the analytical conditions (carrier gas flow rate and temperature program) for the determination of trans-linolenic acid (TALA) by gas chromatography were optimized on the SLB-IL111 column,and the established method was evaluated. The results showed that the optimal carrier gas flow rate was 0.3 mL/min, and the chromatographic column was initially heated at 60 ℃ for 5 min, then ramped at 20 ℃/min to 175 ℃ and held for 15 min, ramped at 1 ℃/min to 180 ℃ and held for 28 min, finally ramped at 0.2 ℃/min to 185 ℃ and held for 40 min. The method established had effective separation of 9c,12t,15t-C18∶ 3 and 9t,12c,15t-C18∶ 3 with a separation degree of 0.9. The separation degree of the other TALA ranged from 1.6 to 8.7. The method was reproducible and the relative standard deviation (RSD) of inter-day repetition of each isomer in heated lineseed oil was 316%-565%, and the RSD of intra-day was 200%-413%.The detection limit was 0.678 2-0.879 0 mg/L, and the limit of quantification was 2.260 6-2.930 1 mg/L. The linear relationship between the content of each ALA isomer and the peak area was good, and all the correlation coefficient was 0.999 8. In conclusion, the established method can be used for the quantitative analysis of 8 different isomer of ALA in linseed oil.

Proxy re-encryption allows a proxy to convert a ciphertext related to a certain access policy into another one with a different access policy without uncovering the underlying plaintext, which makes the proxy re-encryption technology to be an important technology for data sharing between users.However, the proxy re-encryption schemes are mostly based on single authority, which have some problems such as single power and performance bottleneck of the authority organization and high computing burden on user’s client.At the same time, most schemes do not have the five basic characteristics of proxy re-encryption: one-way encryption, non-interaction, repeatability, controllability and verifiability.In order to solve these problems, a CP-ABE proxy re-encryption scheme for cloud computing based on multi-authority with repeatability and controllability was proposed.Based on the ciphertext policy attribute encryption scheme, proxy servers of encryption and decryption were introduced to reduce the computing burden on the user’s client, and multi-attribute authorization were set to disperse the authority of the central authority.The proxy re-encryption was improved from multiple aspects.Random factors and ciphertext sub-item set in the re-encryption key can realize one-way encryption and controllability.The re-encryption key was independently generated by the client without the participation of servers, which can support users to share data when the data owner is not online.Encrypting the ciphertext sub-item set in the initial ciphertext many times can achieve repeatability.The verification sub-item set in the initial ciphertext allowed the user to verify whether the outsourcing and re-encryption results were correct.Compared with other schemes, the user’s client computing overhead of the proposed scheme was small, and the user can decrypt the original ciphertext only by performing constant times of exponential operation.Based on q-parallel BDHE assumption, the security analysis showed that the proposed scheme is secure against chosen-ciphertext attack (CCA) under the standard model.

Revise ISO 22768∶2017 based on China′s industrial standards, and expand the scope of application to latex. The effects of sample preparation method, gas flow rate, heating rate and sample amount on the determination results of glass transition temperature were investigated, and the precision of the method was established. The results showed that, when the drying method was selected, the gas flow rate was 20 mL/min, the sample amount was 5-20 mg, and the heating rate was 20 ℃/min, the method had good precision, the standard deviation of repeatability was less than 0.30 ℃ and the standard deviation of reproducibility was less than 1.01 ℃.

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Copyright of Petroleum Refinery Engineering is the property of Petroleum Refinery Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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【Objective】The study aimed to establish droplet digital detection system and verify the effectiveness of it, in order to provide a more accurate and sensitive method for the detection of Bursaphelenchus xylophilus. 【Method】Genus-specific primers and probe were designed based on 16 S rDNA gene sequence in using online tools for primers and probe design. Optimize the PCR reaction conditions and determine the best reaction conditions of droplet digital detection system. The specificity of this system was detected by using the genomic DNA solutions of 6 strains of B. xylophilus and 12 strains of B. mucronatus, B. thailandae, B. sexdentati, B. dalianensis, Aphelenchoides parasaprophilus, A.resinosi and Cylindrotylenchus pini. The sensitivity of this system was verified by setting different concentration gradients with 10 times diluted standard DNA as a template. The repeatability of droplet digital PCR was detected by three different concentrations of DNA standard dilution templates. Finally, the practicability of this system was verified by using the DNA extract of nematode samples and susceptible pine samples as templates. 【Result】（i）A set of pine wood nematode specific primers and probe were designed which named primers: P1904-F, P2057-R; Probe: Probe-1938.（ii）The optimize annealing temperature of PCR reaction system was determined to be 55 ℃.（iii）The Specificity verification showed that the designed primers and probe could distinguish the B. xylophilus from other similar nematodes.（iv）The results of sensitivity detection showed that the detection concentration of this detection system was between 0.51-20 000 copies/μL.（v）The repeatability test of three groups of standard samples with different concentrations found that the coefficient of variation of this detection system was between 0.31%-9.12%, and the sample concentration was negatively correlated with the coefficient of variation.（vi）Dd-PCR were used to test the wood sample which collected from affected trees and simulation add B. xylophilus, the results has shown that this method can detect B. xylophilus in the samples, moreover, the copy number was positively correlated with the amount of nematodes in the sample. 【Conclusion】In this study, the dd-PCR detection system of pine wood nematode was established. This method exhibit high specificity, high sensitivity, low coefficient of variation, and it can detect B. xylophilus in wood samples with high efficiency. The establishment of this system could provide reliable data for the study of pathology and ecology of B. xylophilus. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Network & Information Security is the property of Beijing Xintong Media Co., Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Rice processing precision is an important index to evaluate rice quality. In this paper, a new technology for the detection of rice processing precision was studied. The rice samples were dyed by eosin y-methylene blue method, and then placed in the rice processing accuracy tester to determine the degree of leather retention, and then determine the rice processing accuracy level. Through the statistical analysis of the validation results among different laboratories, it was showed that the method has good repeatability, reproducibility, stability in line with the requirements of national standards, and meets the needs of quantitative detection of rice processing accuracy. The repeatability limit R and reproducibility limit r were calculated according to the inter laboratory validation data, and the method was standardized to guide the practical application.

Copyright of Bulletin of Botanical Research is the property of Bulletin of Botanical Research Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to promote the calibration accuracy of pressure drop standards, a calibration method via adjusting volume flow was proposed. The proposed calibration method was compared with the existing CFO(Critical Flow Orifice) method in terms of repeatability and stability. The proposed calibration method was used in the collaborative studies of pressure drop standards organized by CORESTA. The results showed that: 1) Comparing with CFO method, the volume flow-based method decreased the standard deviation, the variance coefficient of calibration results and the extreme error of calibration results in a period of five months by more than 50%. 2) The relative extreme error between the mean values of calibration results of the laboratory in ZTRI (Zhengzhou Tobacco Research Institute, Zhengzhou, China) and three foreign laboratories was less than 0.40%; the coefficient of variation of calibration results in the four laboratories was less than 0.10%. This method can be used to improve the accuracy of measurement results of cigarette draw resistance and filter pressure drop. [ABSTRACT FROM AUTHOR]

BACKGROUND: The domestic and overseas scholars have conducted a large number of studies on the measurement of spinal canal area in patients with lumbar spinal stenosis by CT and MRI. However, due to differences of individuals, spinal canal morphologys, measurement methods and measurement planes, there is no recognized measurement standard and value for the measurement of lumbar spinal canal area at present. There are few reports to evaluate the consistency and repeatability of CT and MRI in measuring lumbar spinal canal area. OBJECTIVE: To analyze the consistency and repeatability of three-dimensional reconstruction CT and MRI in measuring the cross-sectional area of lumbar spinal stenosis, and to explore the best imaging measurement method for the cross-sectional area of lumbar spinal stenosis. METHODS: The preoperative imaging data of 102 patients with lumbar spinal stenosis who underwent surgical treatment in Department of Spinal surgery, the Affiliated Hospital of Southwest Medical University from January 2013 to January 2018 with three-dimensional reconstruction CT and lumbar MRI were collected. The corresponding spinal canal area of each narrow intervertebral disc on three-dimensional reconstruction CT and lumbar MRI images was measured by two spinal surgeons at three different time points. The spinal canal area corresponding to the midline plane of the narrow intervertebral disc parallel to the lower endplate of the upper vertebral body was selected for measurement. Paired t-test was used to analyze the difference in spinal canal area between the results of the two methods. Pearson correlation analysis was used to evaluate the correlation between the results of spinal canal area between the two methods. Intraclass correlation coefficient and Bland-Altman plot were used to analyze the consistency and repeatability of the two methods in measuring the area of narrow lumbar spinal canal. Z-test was used to compare the ICC values of interobserver and intraobserver in measurement of narrow lumbar spinal canal area by the two methods. The protocols were approved by the Affiliated Hospital of Southwest Medical University Ethics Committee (approval No. KY2020176). RESULTS AND CONCLUSION: (1) The values of narrow lumbar spinal canal measured by three-dimensional reconstruction CT and MRI were (136.28±2.38) mm2 and (139.98±2.30) mm²; there were significant differences between them (t=-3.96, P < 0.001). Pearson correlation analysis showed that there was a positive correlation between three-dimensional reconstruction CT and MRI measurement of narrow lumbar spinal canal area (r=0.950, P < 0.001). (2) The values of interobserver ICC and intraobserver ICC were 0.908-0.937 and 0.942-0.971. The values of interobserver ICC and intraobserver ICC measured by lumbar MRI were higher than those measured by three-dimensional reconstruction CT (P < 0.05). (3) Bland-Altman plot showed that the 95% distribution range of the difference of spinal canal area between the two methods was -8.0-5.5 mm². Six points were outside the range, accounting for 3.66%. (4) The results showed that there was a significant difference in spinal canal area between three-dimensional reconstruction CT and MRI, but there was a strong positive correlation. The consistency and reproducibility of measurement of narrow lumber spinal canal area by two imaging examinations were good, but the consistency and repeatability of lumbar MRI in measuring narrow lumber spinal canal area were better than that of three-dimensional reconstruction CT. [ABSTRACT FROM AUTHOR]

Objective To assess the repeatability and reproducibility of OCULUS Binoptometer's subjective visual quality in healthy eyes. early age-related cataracts, and cataract surgery with implantation of single-focus intraocular lens, Methods 35 health y eyes (group A).35 age-related early cataract eyes (group B) and 35 (group C) were selected from our hospital from November 2019 to January 2020. The two examiners used the OCULUS Binoptometer's to measure the subjects' full range of vision. contrast sensitivity glare sensitivity and intermediate and stereoscopic vision. The first checker made 3 measurements in a row in one hour interval, and the another checker made 1 measurement in the next day. Repentability and reproducibility were evaluated by intra class correlation coefficient (ICC). coefficient of variation (CV), paired t-test, Results The ICC about full range of vision (5 m.3 m and 1 m.80 cm.67 cm.50 cm.40 cm.33 cm), stereoscopic vision (5 m. 40 cm).contrast sensitivity (0. 40.0. 25 and 0, 16 logo).glare sensitivity and intermediate (no glare-glare) were greater than 0. 8 in group A group B and group C, The CV value is less than 15%. There was no statistically significant difference in the measurement results among the three groups with different inspector. Conclusion OCULUS Binoptometer can reflect the subjective visual quality of human eyes and has good repeatability and repro ducibility. [ABSTRACT FROM AUTHOR]

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This paper discusses the calculaion approach of the coordinates of the BeiDou monitoring stations by proposing two schemes, one is precise point positioning (PPP) and the other is net‐solution with MGEX. Only BDS observation data is used to verify two schemes. Especially, the improvement for the BeiDou satellites orbit determination accuracy with regional tracking network after coordinates refinement is analyzed. Initial results indicate that the PPP repeatability of station coordinates bias for days is better than 2.3 cm in the horizontal component and 3.4 cm in the vertical component, the net‐solution repeatability for days is better than 0.8 cm in the horizontal component and 2.2 cm in the vertical component. BDS orbit determination accuracy with regional tracking network has a great enhancement after coordinates update using net‐solution. The accuracy of IGSOs 3D overlap improves by 15.4%, while MEOs improves by 25.8%. The SLR validation reveals that laser residuals of BD‐2 satellites reduce from 0.39 m to 0.24 m, the accuracy improves by 38%, the residuals of BD‐3 satellites reduce from 0.25 m to 0.18 m, the accuracy improves by 28%. [ABSTRACT FROM AUTHOR]

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Copyright of Journal of Tiangong University is the property of Journal of Tianjin Polytechnic University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Zinc oxide (ZnO) was added to carboxyl nitrile rubber (XNBR) by in-situ blending in situ reaction to form unsaturated zinc carboxylate, and ionic XNBR was prepared by constructing ion network. When no filler was added, ionic XNBR had high strength and high elasticity, and the reversibility of ion network made the product repeatable. Fourier transform infrared spectroscopy showed that carboxyl group reacted with ZnO to form zinc carboxylate. When the amount of ZnO increased to 10 phr. The mechanical properties of the obtained materials were optimal. After the molded specimen was cut into pieces and remolded, the strength retention rate was as high as 99.5%. The dielectric test results showed that the existence of ion network accelerates the ion conduction rate and significantly improved the antistatic properties of the material.

Aiming at the influence of various static performance parameters of line structured light sensors on its measurement accuracy, a plan of line structured light sensors static performance test scheme was designed. A second level gauge block, nano-positioning table and laser interferometer were used on high-precision mobile platform. The important static performance parameters ,such as stability, repeatability and linearity, were analyzed to quantify the influence of various static performance parameters on the measurement accuracy of the sensor. The working surface of the second level gauge block was used as the measurement surface during the test. The high-precision mobile platform was used to test the whole measurement area of the sensor. The laser interferometer was used to compensate the positioning error of the mobile platform, which improved the reliability of the measurement result. The research results indicate that the sensor needs 1 hour to ensure the measurement accuracy, and the repeatability of the middle measurement area is the best with an average value of 0.418 μm. The linearity of the sensor has the greatest influence on the measurement accuracy. The error caused by the sensor nonlinearity is at most 11.2 μm. [ABSTRACT FROM AUTHOR]

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Background and objective Subsolid pulmonary nodules tend to exhibit considerably slower growth rates than solid lesions, nevertheless, higher malignancy probability. The diagnosis of indeterminate nodules largely depends on the growth evaluation during follow-up. The growth can manifested as an increase in size or the appearance and/or subsequent increase of solid components. The mass reflect the product of volume and density and can be more sensitive in growth evaluation. However, the repeatability needs a further validation. The purpose of this study is to assess the intra and inter-observer variability of mass measurement for subsolid nodules. Methods 80 subsolid nodules in 44 patients were retrospectively enrolled. Both the volume and mass were measured by two radiologists using blind method independently. Intra-observer and inter-observer variability were analyzed and compared by Bland-Altman method intra-class correlation test and Wilcoxon test. Results Software achieved satisfied segmentation for 92.5% nodules. Of them, 35% underwent manual modification. The 95% limits of agreement for intra-observer variability were -11.5%-10.4% for mass and -8.4%-8.8% for volume. The 95% limits of agreement for inter-observer variability were -17.4%-19.3% for mass and -17.9%-19.4% for volume.The intra-class correlation foefficients between volume and mass measument was 0.95 and 0.93 (both P

Copyright of Forest Research is the property of Forest Research Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Benzene series (BTEX) usually include aromatic compounds such as benzene, toluene, ethylbenzene and xylene. In general, natural gas contains trace benzene series. In natural gas production and processing, it is important to detect the content of benzene series components and predict natural gas dew point/hydrocarbon content. Through the experiment, the method of analyzing the content of benzene series by gas chromatography is established, the qualitative repeatability (RSD7) of each benzene series is not more than 0.01%, the quantitative repeatability of benzene and toluene (RSD7) is not more than 2.5%, the quantitative repeatability of ethylbenzene and xylene (RSD7) is between 7% and 11%, and the minimum detection limit of each component can reach about 2×10-10 g/s, and the separation degree of para-xylene and m-xylene is 2.2. The feasibility and applicability of the method are verified by analyzing the actual natural gas sample, and the obtained conclusion can provide technical reference for accurately detecting the benzene content in natural gas, which can provide basic data for accurately predicting hydrocarbon dew point by using natural gas composition data, and has practical significance for the process design of the dealkylation unit of the natural gas treatment plant and the safe operation of the gas pipeline. [ABSTRACT FROM AUTHOR]

Background and objective Software oriented three-dimensional (3D) volumetric measurement of pulmonary nodules has been feasible in the follow-up of indeterminate pulmonary nodules, however, its value need a further validation. The purpose of this study is to retrospectively analyze the chest CT data of patients with pulmonary nodules to compare the intra-observer variability of 3D and two-dimensional (2D) volumetric measurement. Methods Eighty-six pulmonary nodules in chest CT scans of 79 subjects were retrospectively analyzed. One radiologist measured the nodules twice with a 7 days interval using 2D and 3D methods respectively. The maximal diameter (X), the perpendicular diameter (Y) on maximal cross sectional area of the nodule and the caudo-cranial diameter (Z) were measured and the volume was calculated by two models: spherical and elliptical model. The 3D measurements were acquired with semi-automated software with manual adjustment on unsatisfied nodule segmentation. Logistic regression analysis was performed to evaluate the effect of nodule location and morphology on 3D nodule segmentation. ANOVA and correlation test were used to evaluate the difference among three methods. Bland-Altman method was applied to quantify the intra-observer variability. Results Software achieved satisfied segmentation for 86.4% nodules. The irregular and juxtavacular nodules have significantly high odds rations (OR) of unsatisfied segmentation as 4.0, 4.5, respectively. The volume measured by three method was significantly different (F=6.5, P=0.012), while the repeated measurements did not led to significant difference (F=1.813, P=0.182). The Spearman correlation efficient between 3D volume and 2D volume with sphere and ellipsoid model was 0.97, 0.88. The 95% limits of agreement of RD between two repeated measurements were -14%-11.6%, -37.7%-39.9% and -39.8%-45.8% for 3D, 2D with elliptical model and spherical model, respectively. Conclusion The 3D volume measurement of pulmonary nodules is more repeatable than 2D volume measurement. Unsatisfied segmentation can occurred on a small number of nodules, especially for irregular and juxtavascular nodules. For these nodules, the measurement of 3D diameters is recommended.

Copyright of Journal of Harbin Institute of Technology. Social Sciences Edition / Haerbin Gongye Daxue Xuebao. Shehui Kexue Ban is the property of Harbin Institute of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Natural gas composition analysis is the most basic analysis item in the natural industry. The two indexes of carbon dioxide content and superior calorific value provided in GB 17820 —2012 Natural Gas relate to natural gas composition analysis. The precision requirement of analysis results is an important technical parameter for natural gas composition analysis method. This paper compared the precision of natural gas conventional composition analysis methods at home and abroad, and verified the precision through experiment by using the different analysis methods. The precision reasonability and consistency of the different analysis methods were discussed. The conclusion could provide a reference for the users to choose different methods to analyze natural gas composition. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Harbin Institute of Technology. Social Sciences Edition / Haerbin Gongye Daxue Xuebao. Shehui Kexue Ban is the property of Harbin Institute of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective: To explore the accuracy of a dietary recording tool based on the mobile phone WeChat applet-"Zhishi AI Dietitian" applied to dietary records., Methods: The research subjects were 109 full-time undergraduates from Zhejiang University. Respondents completed one round of dietary records of "Zhishi AI Dietitian" for three non-consecutive days and one round of non-consecutive three-day 24-hour dietary review method records. The two method must overlap for one day. The energy, nutrients and various food intake data obtained from the Zhishi AI nutritionist survey were sorted and compared with the corresponding survey result of the 24-hour dietary review method. Pearson correlation coefficient or Spearman correlation coefficient was used for correlation analysis, intra-group correlation coefficient was used for reliability analysis, and Bland-Atlman scatter plot was used for consistency analysis., Results: In terms of reliability, the two method had certain reliability in assessing intake of various foods, energy and nutrients. After energy correction, the reliability of nutrient intake was enhanced. In terms of correlation, the correlation coefficients of food groups ranged from 0.34 to 0.79(mean 0.60), and the energy and nutrient correlation coefficients ranged from 0.34 to 0.72(mean 0.55). In terms of consistency, the proportion of research subjects outside the 95% consistency interval is less than 10%, indicating that the two have good consistency., Conclusion: Zhishi AI Dietitian applied to college students&apos; dietary records has good accuracy.

Copyright of Journal of the Tianjin Polytechnic University / Tianjin Gongye Daxue Xuebao is the property of Journal of Tianjin Polytechnic University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper introduces a set of gas flow standard facilities based on combined turbine flow meters, which is newly built by Chengdu Verification Branch of National Oil and Gas Large Flow Rate Measurement Station, including the process of the standard facilities, testing requirements and results of the metering performance. The standard facilities are used for actual flow verification of the natural gas flow meter and guaranteeing the accuracy and reliability of onsite trade measurement of natural gas. By analyzing the testing data, it has confirmed that the uncertainty of standard test results is better than 0.33%. Both the repeatability and stability of test results meet the verification requirements for gas flow measuring instruments. [ABSTRACT FROM AUTHOR]

The Reynolds-Averaged Navier-Stokes (RANS) method is conducted to simulate flow around airfoil at high AOA. The separation is well captured using two-equation shear stress transport (SST/k-ω) turbulence model accounting for turbulence motions. Calculation shows that the wing separation vortices are stable in several equilibrium stats, with the wing thickness up to a certain criteria, and AOA in a certain range. Meanwhile the separation transfers from one stable state to anther when certain disturbance is intruded. Comparing different disturbances, the translation is inclined to happen under heaving-pitching motions rather than forward-afterward vibrations. That is the exact one of most important reasons for aerodynamic loads data variation of airfoil at high AOA in wind tunnel test. [ABSTRACT FROM AUTHOR]

JJG 695 -- 2003 Verification Regulation of Sulfur Hydrogen Gas Detectors is established for hydrogen sulfide alert. However, there is no related regulation about calibration and verification of on--line hydrogen sulfide analyzer. This paper has referenced JJG 695 -- 2003 to make a calibration method of hydrogen sulfide analyzer according to he application of it. The calibration method is focus on the errors of the measurement values, repeatability and the consistency on the analysis results of the reference gases. This method was also applied in some natural gas metering stations, which obtained satisfactory results. [ABSTRACT FROM AUTHOR]

Salmonella enterica serovar Enteritidis (SE) is one of the most important zoonotic pathogens that cause enteritis and systemic infection in animals and human. Understanding invasive capacities of SE isolates is of vital importance to elucidate pathogenesis of Salmonella infection. To improve the throughput capacity and repeatability of classical gentamicin protection assay (GPA), a modified PGA was developed by taking high-throughput advantage of 96-well cell plates and multichannel pipettes. In addition, drop plate technique rather than spread plate method was applied in the modified GPA protocol for bacterial enumeration. The modified GPA protocol was evaluated by phenotyping intracellular replication of a high virulent and a low virulent SE isolates, JL228 and LN248, in a phagocytic cell line RAW264.7. The protocol was then applied in invasive phenotype determination of 16 SE strains to non-phagocytes (HT-29) and the intracellular replication of 43 SE strains to phagocytes (RAW264.7). Significant lower intra-group and inter-group coefficient of variations of the modified GPA was observed, implying good repeatability and reproducibility over traditional protocol. Further, replication phenotypes were also correlated with those from direct observation by confocal microscopy. Collectively, the improved GPA protocol had advantages of high throughput capacity, good repeatability and reliability, it was also noticed that the protocol also represented a fast and labor-saving alternative scheme for the invasive phenotype determination of Salmonella Enteritidis, and providing reliable phenotype profiles for Salmonella-host interplay interpretation.

Objective: To compare the results obtained from the computer-aided sperm analysis (CASA) systems of the two fully-automated commercial sperm quality analyzers, Hamilton-Thorn IVOS Ⅱ (IVOS Ⅱ) and Spanish Sperm Class Analyzer (SCA)., Methods: A total of 99 semen samples were collected in the Center of Reproduction of Shenzhen Zhongshan Urology Hospital from September 2018 to October 2018 and, according to the sperm concentration, divided into groups A (<15 ×10⁶/ml), B (15－50 ×10⁶/ml) and C (>50 ×10⁶/ml). IVOS Ⅱ, SCA and manual microscopy were used for the examination of each sample, followed by comparison of the sperm concentration, sperm motility and percentage of progressively motile sperm (PMS) obtained from IVOS Ⅱ and SCA., Results: The sperm concentrations derived from IVOS Ⅱ and SCA were significantly higher than that from manual microscopy in group A (［10.24 ± 4.60］ and ［10.20 ± 5.11］ vs ［8.45 ± 4.15］ ×10⁶/ml, P < 0.05), but showed no statistically significant difference in group B (［30.95 ± 11.84］ and ［31.81 ± 12.90］ vs ［29.14 ± 10.65］ ×10⁶/ml, P > 0.05) or C (［102.14 ± 45.97］ and ［109.48 ± 46.32］ vs ［104.74 ± 41.87］ ×10⁶/ml, P > 0.05). Significant differences were not observed between IVOS Ⅱ and SCA in the percentage of PMS (［24.21 ± 14.62］% vs ［23.92 ± 15.42］%, P > 0.05) or sperm motility (［37.48 ± 19.34］% vs ［37.69 ± 16.61］%, P > 0.05) in group B, nor in group C (PMS: ［30.80 ± 12.06］% vs ［32.98 ± 16.10］%, P > 0.05; sperm motility: ［44.50 ± 15.62］% vs ［47.26 ± 17.46］%, P > 0.05). Both the percentage of PMS and sperm motility obtained from IVOS Ⅱ were remarkably lower than those derived from SCA in group A (PMS: ［18.54 ± 12.96］% vs ［22.90 ± 12.88］%, P < 0.05; sperm motility: ［26.97 ± 14.05］% vs ［34.90 ± 15.18］%, P < 0.05). IVOS Ⅱ and SCA both showed a high repeatability (CV <15%), and the former exhibited an even higher one than the latter, in detection of sperm concentration, sperm motility and the percentage of PMS., Conclusions: IVOS Ⅱ and SCA both had a good consistency in the results of sperm concentration, motility and progressive motility, but showed a poor comparability with low-concentration semen samples.

Objective: To compare the reliability and repeatability of simplified skeletal maturity scoring (SSMS) and thumb ossification composite index (TOCI) in the assessment of skeletal maturity in adolescent idiopathic scoliosis(AIS) and their clinical utilization. Methods: A review was conducted on 500 AIS patients treated between October 2006 and August 2013 in Nanjing Drum Tower Hospital and one follow-up of each patient was randomly selected for this study.Based on SSMS and TOCI, the radiographs of the left palm were assessed by three observers independently with an interval of 2 weeks.The inter-observer reliability and intra-observer repeatability of two methods were analyzed by using Kappa value. Results: A total of 3 000 measurements were performed by the 3 surgeons for each method.For SSMS, 50 cases were described as stage 1 258 cases as stage 2 962 cases as stage 3 340 cases as stage 4 315 cases as stage 5 304 cases as stage 6 589 cases as stage 7 and 182 cases as stage 8.The inter-observer and intra-observer agreements was 76.8%-82.0% ( Kappa value 0.716-0.778) and 75.8%-82.4% ( Kappa value 0.705-0.782), respectively.For TOCI, 27 cases were described as stage 1 183 cases as stage 2 167 cases as stage 3 171 cases as stage 4 745 cases as stage 5 536 cases as stage 6 410 cases as stage 7 and 761 cases as stage 8.The inter-observer and intra-observer agreements was 91.6%-92.4% ( Kappa value 0.897-0.907) and 90.4%-92.0%( Kappa value 0.882-0.902), respectively. Conclusions: The two methods of SSMS and TOCI have substantial inter-observer reliability and intra-observer reproducibility for the assessment of skeletal maturity in AIS.TOCI has relatively higher reliability and repeatability when compared with SSMS.