Explore the vast range of titles available.

The current new type of inertial navigation system, including rotating inertial navigation systems and three-autonomy inertial navigation systems, has been increasingly widely applied. Benefited by the rotating mechanisms of these inertial navigation systems, alignment accuracy can be significantly enhanced by implementing IMU (Inertial Measurement Unit) rotation during the alignment process. The principle of suppressing initial alignment errors using rotational modulation technology was investigated, and the impact of various component error terms on alignment accuracy of IMU during rotation was analyzed. A corresponding error suppression scheme was designed to overcome the shortcoming of the significant scale factor error of fiber optic gyroscopes, and the research content of this paper is validated through corresponding simulations and experiments. The results indicate that the designed alignment scheme can effectively suppress the gyro scale factor error introduced by angular motion and improve alignment accuracy.

The technology of building a retaining roadway along goaf or a protecting roadway with a small coal pillar has been developed and applied for many years, and a satisfactory supporting effect has been obtained in medium–thick coal seam and thin coal seam mining. However, the gob-side roadway or small coal pillar mining in a thick coal seam is still subjected to technical problems occasioned by factors such as high roadway, high support pressure beside roadway, and waste of coal resources. To solve these problems, the author proposes an innovative technology of coal-free mining: the technology of driving roadway along goaf with a flexible formwork pre-cast wall. The article utilizes the 3503 and 3505 working faces of Wangzhuang Coal Industry Group as the research background, and comprehensively introduces the principle of the technology and the overburden rock movement law. Through theoretical calculations and numerical simulations, the support resistance and support parameters of flexible formwork pre-cast walls have been determined and successfully performed in industrial practice. The results indicate that the combination of the flexible mould pre-cast wall coal pillar-free mining technology and roof cutting process is more conducive to the maintenance of the roadway in the lower working face, and effectively reduces the stress and deformation of the surrounding rock. The roof and floor of the drivage roadway move, and the deformation of the two sides is small; furthermore, the overall roadway retention effect is satisfactory, which meets the requirements of mining in the lower working face. The coal pillar pertaining to the 20 m section of the 5 m high mining height face was recovered for Wangzhuang Coal Mine, and the recovery rate of the coal resources and the driving speed of the roadway were improved. The proposed method can be popularised and applied in this mine and even in the mining of 15# large-height coal seams in the two cities.

This article introduces a design scheme for a distributed load follow-up loading system for large passenger aircraft flaps. The follow-up loading system includes tape lever components, follow-up pulley and drive components, force control actuators, fixed pulley and cable components, and support structures. At the same time, a loading control system was also designed. The dynamic loading system can simulate the deformation of flaps under distributed aerodynamic loads during the entire retraction and extension process, greatly improving the fidelity of the test environment and comprehensively assessing the interference between flaps and surrounding structures under all operating conditions.

CuGaS 2 (CGS) nanoplates were successfully synthesized by one-pot thermolysis of a mixture solution of CuCl, GaCl 3 , and 1-dodecanethiol in noncoordinating solvent 1-octadecene. Their morphology, crystalline phase, and composition were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), powder X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS), respectively. Crystalline structure analysis showed that the as-prepared CGS nanoplates were polytypic, in which the wurtzite phase was interfaced with zincblende domains. The growth process of CGS nanoplates was investigated. It was found that copper sulfide nanoplates were firstly formed and then the as-formed copper sulfide nanoplates gradually transformed to CGS nanoplates with proceeding of the reaction. The optical absorption of the as-synthesized CGS nanoplates was also measured and the direct optical bandgap was determined to be 2.24 eV.

This paper delves into the critical issues of relay protection setting calculation in high-voltage power grids with large-scale integration of renewable energy sources, such as wind and solar power. By analyzing the topological structure of renewable energy systems, models of permanent magnet direct-drive wind turbines and photovoltaic power sources are established, with a particular focus on the short-circuit current characteristics of these renewable energy sources. Subsequently, a fault iterative method for short-circuit current calculation is proposed. This method effectively improves the accuracy of short-circuit current calculation by iteratively analyzing the fault region and considering the voltage-controlled current source characteristics of renewable energy sources. The paper also conducts in-depth research on various aspects of relay protection settings after the integration of renewable energy devices, including main transformer neutral grounding strategies, tie-line protection and reclosing principles, islanding prevention, and boundary backup protection management. By applying this method to a practical engineering case in G Province, China, the short-circuit current is calculated, and partial setting values are determined, demonstrating the ability of this method to enhance system safety and stability. This research provides valuable insights for operators of modern power systems.

In this study, Sylgard 184 silicone rubber (SylSR) matrix composites with shear thickening fluid (STF) microcapsules (SylSR/STF) were fabricated. Their mechanical behaviors were characterized by dynamic thermo-mechanical analysis (DMA) and quasi-static compression. Their damping properties increased with the addition ofSTF into the SR in DMA tests and the SylSR/STF composites presented decreased stiffness and an obvious positive strain rate effect in the quasi-static compression test. Moreover, the impact resistance behavior of the SylSR/STF composites was tested by the drop hammer impact test. The addition of STF enhanced the impact protective performance of silicone rubber, and the impact resistance increased with the increase of STF content, which should be ascribed to the shear thickening and energy absorption of STF microcapsules in the composites. Meanwhile, in another matrix, hot vulcanized silicone rubber (HTVSR) with a mechanical strength higher than Sylgard 184, the impact resistance capacity of its composite with STF (HTVSR/STF) was also examined by the drop hammer impact test. It is interesting to note that the strength of the SR matrix obviously influenced the enhancement effect of STF on the impact resistance of SR. The stronger the strength of SR, the better the effect of STF on improving the impact protective performance of SR. This study not only provides a new method for packaging STF and improving the impact resistance behavior of SR, but is also beneficial for the design of STF-related protective functional materials and structures.

With the rapid development of the economy, Non-transposition Lines on the Same Tower (NTLST) are widely used in power systems. The significant asymmetry in electrical parameters impacts the sensitivity and accuracy of zero sequence current differential protection (ZSCDT). An electromagnetic transient model of the NTLST is built to simulate the characteristics of zero sequence current in NTLST under different operation modes in this paper. The parameters of the NTLST, such as line length, power flow magnitude, and fault location, which affect the operation characteristic of ZSCDT are studied. The adaptability of ZSCDT under different operating conditions, such as normal operation and out-of-zone short circuits, inner cross-line faults within the same phase zone, cross-line faults within non-identical phase zones, and single-line faults, are simulated and analyzed. When faults out of NTLST occur, no matter what type it is, the ZSCDT will not maloperate. When cross-line faults of non-identical phase zones in NTLST occur, the ZSCDT will maloperate. The research results not only improve the performance of ZSCDT for non-transposition lines on the same tower, but also provide theoretical guidance for the design, construction, and operation of power grid engineering.

This study is intended to investigate dynamic characteristics of a heavy truck. An experimental setup is designed for full vehicle vibration test consisting of four electro-mechanical shakers with high force rating (35000kgf). Transfer matrix is taken into account for multiple-input multiple-output (MIMO) vibration control. Vibration inputs under the tires can simulate both vertical and rotational excitations of the road. Furthermore, transfer function estimate (TFE) can be obtained based on the known road inputs and measured dynamic responses. Operational modal analysis has been carried out to identify the rigid mode shapes pitch, bounce, roll in low frequency range (1-10Hz). Based on experimental results, vibration response is higher on seat, which results in an uncomfortable level.

It has been established that the innate and adaptive immune suppression was heterogeneous in septic and nonseptic critically ill patients, while the value of immune function in pediatric patients with nonseptic critical illness is limited. We conducted a single-center retrospective study to explore this issue. A total of 65 children with nonseptic illnesses were studied for lymphocyte subpopulations, immunoglobulin concentrations, complement concentrations, and cytokines in peripheral blood in the next 72 hours after admission to our Pediatric Intensive Care Unit (PICU). When compared to clinically recovered patients, patients with disease progression had a numerically lower but not significantly different median pediatric critical illness score and longer PICU median stays. The analysis of serum immunoglobulin (IgG, IgM, and IgA), serum complement (C3, C4) concentrations, and lymphocyte subpopulations showed no significantly difference between patients with and without relieved clinical symptoms by day 4. For the cytokine analysis, the level of IL-6 was significantly higher in patients with disease progression than that in patients who clinically recovered (p=0.046). In the univariate Cox regression analysis, plasma IL-6 levels were associated with outcome. Multivariate analysis evidenced that the level of plasma IL-6 was one of the factors determining the length of hospital stays. In conclusions, our results demonstrate that increased IL-6 levels in the initial 72 hours post admission are associated with prolonged stays and disease progression in nonseptic critically ill children in the PICU.

This study aimed to examine and quantify the effectiveness of an optional breastfeeding course for multidisciplinary undergraduate healthcare students and to provide advice for education improvement based on students’ characteristics and learning feedback. Breastfeeding has received global awareness and educating undergraduate healthcare students is a prospective way to promote breastfeeding. This is the first report from mainland China to verify the education effects and formulate a proposal for improvement. A quasi-experimental study with a one-group pretest-posttest design. An optional breastfeeding course covering eight topics based on the Health Belief Model was conducted for multidisciplinary students in a medical college. The Breastfeeding Knowledge Questionnaire, Iowa Infant Feeding Attitude Scale and Breastfeeding Promotion Intention Scale were completed for pre- and post-education comparison. The Wilcoxon signed-rank test, MannWhitney U test, KruskalWallis test and chi-square test were used for statistical analysis. The class average normalized gain and individual students’ normalized gain were calculated to quantify the effectiveness from the perspective of learning gain. From March to November 2021, 102 students specialized mainly in nursing, clinical medicine, medical imaging technology and midwifery took the course. Knowledge, attitudes and intention scores improved significantly (Z = 8.70, 8.72, 7.64, respectively, p < .001) and the class average normalized gains were 81.0%, 52.3% and 70.6%, respectively. Insignificant differences were found for students of different genders and categories of specialties (p > .05). Students of first year had significantly higher individual normalized gains (p < .05). In learning feedback, the top-ranked advice for course improvement was to increase practice and experience (75.5%). This optional breastfeeding course produced medium to high learning gains for multidisciplinary healthcare undergraduates. Independent breastfeeding education based on behavioral theory for multidisciplinary students is recommended to be conducted in medical colleges. The addition of practice and experience may add value to such education.