Texture-Differentiated Grain Growth in Silicon Steel: Experiments and Modeling.

Grain growth for various texture components in silicon steel was investigated via experiments and modeling. It was found that the clustered spatial arrangement of grains with specific orientations significantly altered the local environment for grain growth and consequently resulted in texture-differentiated grain size distribution (GSD) evolution. A novel local-field model was proposed to describe grain growth driven by continuous changing orientation and size distribution of adjacent grains. The modelling results show that the texture-differentiated grain growth in microstructure with grain clusters can produce a GSD with increased proportion in small-sized range and large-sized range by more than two-times, accompanied with an evident change in area fractions of various texture components. The effect of clustered spatial arrangement on grain growth can be precisely predicted, which is valuable to design and control the texture-differentiated GSD as well as the global GSD.

A 4.8 ps root-mean-square resolution time-to-digital converter implemented in a 20 nm Cyclone-10 GX field-programmable gate array.

It is difficult to improve the resolution and precision of a field-programmable gate array (FPGA)-based time-to-digital converter (TDC) in time interval measurement. In this study, we design a carry-look-ahead delay chain structure and integrate an interleaved sampling method with an online calibration and bin readjustment approach to implement a TDC. We take advantage of the adaptive logic module units applied in a Cyclone-10 GX (10CX220YF780E5G), which is a 20 nm low-power consumption and low-cost FPGA. In this new generation FPGA, we implemented a high-precision time interval measurement, which exceeded all our previous works with a 4.8 ps root-mean-square resolution and a 5.68 ps least-significant-bit resolution.

Characterization and Calculation of the Dynamic Recrystallization Texture in Fe-3.0 Wt.% Si Alloy.

High-temperature plane-strain compression tests were performed on Fe-3.0 wt.% Si alloy from 900 °C to 1150 °C at strain rates of 5 s-1 to 1 s-1, and the texture development from different initial textures was investigated by means of electron backscattered diffraction. Dynamic recrystallization occurs by strain-induced boundary migration, and the evolutions of the microstructure and different texture components vary with the initial texture. The critical orientation boundary separating the weakened and enhanced texture components moves with the initial texture, and a quantitative relationship is established to represent the dependence of the critical Taylor factor on the instantaneous texture. A model is proposed to describe the dynamic recrystallization texture by incorporating the oriented nucleation probability with a variable critical Taylor factor. The present work could improve the accuracy of hot deformation texture prediction based on strain-induced boundary migration.

[Soil stoichiometry of Pinus massoniana forest in red soil erosion area under different management patterns]. / 红壤侵蚀退化马尾松林下不同治理模式土壤化学计量特征.

We investigated the concentrations of carbon (C), nitrogen (N), and phosphorus (P) and C:N:P stoichiometry in soil and litter of Pinus massoniana forest under four different management patterns: inefficient forest transformation, mixture of arbor with shrub and herb, shallow ditch grass planting, and being banned in serious erosion and degradation of red soil in southern China. Our findings could provide scientific basis for soil erosion control and vegetation restoration in this area. The results showed that there were significant differences in soil organic carbon (SOC), TN, TP and litter nutrient content among different management patterns. The nutrient contents in soil and litter under all the four management patterns were significantly higher than that of control, with mixture of arbor with shrub and herb having the highest concentrations. The concentrations of SOC, TN and TP decreased with the increases of soil layer. However, the shallow ditch grass planting mana-gement pattern presented as follows: the concentrations of SOC, TN and TP decreased first and then increased with the increases of soil layer, with the lowest value in 5-20 cm soil layer. There were significant differences in soil C:N, C:P, N:P and litter C:P among different management patterns, and the soil spatial variation was C:N>C:P>N:P. Excepted for mixture of arbor with shrub and herb, C:N was still at a lower level in the other management patterns, and soil C:P and N:P showed higher values overall. Litter C:N, C:P and N:P had opposite change pattern, with inefficient forest transformation and mixture of arbor with shrub and herb being much smaller than the control. Soil C:N and C:P were mainly controlled by SOC content and litter C content, and soil N:P was mainly controlled by soil TP content and litter P content. Soil stoichiometry was affected by soil water content, soil bulk density, pH, and other factors. The relationship between litter and soil nutrients was closely related and showed similar changes.

Calibration algorithm for cooled mid-infrared systems considering the influences of ambient temperature and integration time.

Midwave infrared systems with cooled detectors are generally used for high-precision or quantitative measurement, such as radiometry and thermometry. As a basis of these applications, radiometric calibration aims to obtain the relationship between the infrared images and the incident radiant flux generated by the scene or targets. Conventional radiometric calibration algorithms do not take the influences of integration and ambient temperature into consideration. As a consequence, the accuracy of calibration deteriorates whenever the temperature or the integration time varies. To solve this problem, we analyzed the effects of integration time and ambient temperature on coefficients of the radiometric calibration formula by theoretical and experimental analysis. Then, a radiometric calibration method is deduced to remove the variation of integration time and ambient temperature on the accuracy of calibration and radiometry. Several radiometric calibration experiments were conducted using a midwave infrared camera inside a chamber with controllable temperature. The results indicate that the proposed calibration algorithm is more effective and accurate, compared with conventional calibration methods, in complicated working conditions with variable integration times and ambient temperatures.

Application of neutral-density filters to nonuniformity correction.

Two-point nonuniformity correction (NUC) is the most effective and commonly used algorithm for scientific and commercial infrared imagers. However, conventional two-point NUC requires two references at different levels of flux, which are sometimes difficult to obtain. To overcome this drawback, a neutral-density filter based solution for two-point NUC of cooled infrared focal plane arrays is proposed in this paper. Benefiting from the specially designed filters and an additional concave mirror, NUC can be conducted by using a single reference at ambient temperature. Several experiments were conducted to validate the performance of the proposed NUC method. The results indicate that it yields excellent performance compared with conventional NUC methods; moreover it is more economical and convenient in various applications.

ERRFI1 Inhibits Proliferation and Inflammation of Nucleus Pulposus and Is Negatively Regulated by miR-2355-5p in Intervertebral Disc Degeneration.

STUDY DESIGN: In vivo and in vitro studies of the role of miR-2355-5p and its possible targets in intervertebral disc degeneration (IVDD). OBJECTIVE: To elucidate the regulatory role of miR-2355-5p in IVDD and the underlying mechanisms. SUMMARY OF BACKGROUND DATA: IVDD, which is caused by multiple factors, is the main cause of lower back pain with or without extremity pain. However, the underlying cellular mechanisms of IVDD pathogenesis are not well elucidated. Cell hyper-proliferation, inflammation, and epidermal growth factor receptor activation have been implicated in IVDD. Up-regulated miR-2355-5p level was identified to associate with IVDD. ERRFI1 (the product of mitogen-inducible gene 6 [MIG6]) was known to inhibit epidermal growth factor receptor activation. METHODS: We monitored the expression of miR-2355-5p and ERRFI1 in IVDD tissues and lipopolysaccharides (LPS)-treated nucleus pulposus (NP) cells. We explored the effects of ERFFI1 on NP cells proliferation and LPS-induced pro-inflammatory cytokines production. We searched the targets of miR-2355-5p and explored the effects of miR-2355-5p on NP cells proliferation and cytokines production. RESULTS: We identified the up-regulation of miR-2355-5p and down-regulation of ERFFI1 in IVDD samples and LPS-treated NP cells. ERFFI1 inhibited NP cells proliferation and LPS-induced pro-inflammatory cytokine production. MiR-2355-5p targeted ERFFI1 and negatively regulated ERFFI1 expression. MiR-2355-5p regulated IVDD by targeting ERFFI1. CONCLUSION: MiR-2355-5p negatively regulated ERFFI1 and prevented the effects of ERRFI1 on inhibiting NP cells proliferation and inflammation. LEVEL OF EVIDENCE: N/A.

Internal stray radiation measurement for cryogenic infrared imaging systems using a spherical mirror.

Internal stray radiation is a key factor that influences infrared imaging systems, and its suppression level is an important criterion to evaluate system performance, especially for cryogenic infrared imaging systems, which are highly sensitive to thermal sources. In order to achieve accurate measurement for internal stray radiation, an approach is proposed, which is based on radiometric calibration using a spherical mirror. First of all, the theory of spherical mirror design is introduced. Then, the calibration formula considering the integration time is presented. Following this, the details regarding the measurement method are presented. By placing a spherical mirror in front of the infrared detector, the influence of internal factors of the detector on system output can be obtained. According to the calibration results of the infrared imaging system, the output caused by internal stray radiation can be acquired. Finally, several experiments are performed in a chamber with controllable inside temperatures to validate the theory proposed in this paper. Experimental results show that the measurement results are in good accordance with the theoretical analysis, and demonstrate that the proposed theories are valid and can be employed in practical applications. The proposed method can achieve accurate measurement for internal stray radiation at arbitrary integration time and ambient temperatures. The measurement result can be used to evaluate whether the suppression level meets the system requirement.

Ambient temperature-independent dual-band mid-infrared radiation thermometry.

For temperature measurements of targets at low temperatures, dual-band radiation thermometry using mid-infrared detectors has been investigated extensively. However, the accuracy is greatly affected by the reflected ambient radiation and stray radiation, which depend on the ambient temperature. To ensure measurement accuracy, an improved dual-band measurement model is established by considering the reflected ambient radiation and the stray radiation. The effect of ambient temperature fluctuation on temperature measurement is then further analyzed in detail. Experimental results of measuring a gray-body confirm that the proposed method yields high accuracy at varying ambient temperatures. This method provides a practical approach to remove the effect of ambient temperature fluctuations on temperature measurements.

Radiometric calibration method for large aperture infrared system with broad dynamic range.

Infrared radiometric measurements can acquire important data for missile defense systems. When observation is carried out by ground-based infrared systems, a missile is characterized by long distance, small size, and large variation of radiance. Therefore, the infrared systems should be manufactured with a larger aperture to enhance detection ability and calibrated at a broader dynamic range to extend measurable radiance. Nevertheless, the frequently used calibration methods demand an extended-area blackbody with broad dynamic range or a huge collimator for filling the system's field stop, which would greatly increase manufacturing costs and difficulties. To overcome this restriction, a calibration method based on amendment of inner and outer calibration is proposed. First, the principles and procedures of this method are introduced. Then, a shifting strategy of infrared systems for measuring targets with large fluctuations of infrared radiance is put forward. Finally, several experiments are performed on a shortwave infrared system with Φ400 mm aperture. The results indicate that the proposed method cannot only ensure accuracy of calibration but have the advantage of low cost, low power, and high motility. Hence, it is an effective radiometric calibration method in the outfield.