Search

Based on the thin plate stability theory determined by energy criterion, the finite element model of unstable deformation of ultra-thin plate laser welded joint was established. The temperature field and stress field of 316L steel foil plate surfacing welding with 0.07 mm thickness were simulated by ABAQUS, and the distribution of inherent strain was obtained. The eigenvalue buckling analysis of the post-welding instability deformation behavior in thin plate was carried out by using inherent strain obtained by integral calculation as equivalent load. Compared with the measured deformation results of laser welding, it was found that the ultra-thin metal plate presents concave-convex deformation mode after lower heat input, while convex-concave deformation occurs after higher heat input in the thin plate. The parameters of the numerical model were optimized, and the reasons for the change of the deformation mode of the thin plate were discussed. The nonlinear buckling analysis was carried out by introducing the low-order eigenvalue buckling mode as the initial deformation trend, and the unstable deformation was simulated, which is basically consistent with the actual deformation measurement results. Keeping the ratio of length to width of the thin plate at 1:1 and changing the size of the thin plate, the numerical relationship between the critical instability load and the size of the thin plate was fitted. The results show that the smaller the area of the thin plate is, the greater the critical buckling load of the thin plate is. With the increase of the thickness of the thin plate, the critical buckling load is increased significantly.

Recently, the advancement in communications, intelligent transportation systems, and computational systems has opened up new opportunities for intelligent traffic safety, comfort, and efficiency solutions. Artificial intelligence (AI) has been widely used to optimize traditional data-driven approaches in different areas of the scientific research. Vehicle-to-everything (V2X) system together with AI can acquire the information from diverse sources, can expand the driver's perception, and can predict to avoid potential accidents, thus enhancing the comfort, safety, and efficiency of the driving. This paper presents a comprehensive survey of the research works that have utilized AI to address various research challenges in V2X systems. We have summarized the contribution of these research works and categorized them according to the application domains. Finally, we present open problems and research challenges that need to be addressed for realizing the full potential of AI to advance V2X systems.

Accurate determination of boron in coal is significant to the understanding of the original peat-forming environment. Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) is a reliable technique to determine most trace elements in coal samples. However, the procedure for the determination of boron is complex and the results are inaccurate, due to the special chemical and physical properties of boron, such as high volatility. In this study attempts to determine boron in coal samples using an improved procedure of ICP-MS technique with microwave digestion are made. Samples were digested in a microwave oven with H3PO4, HNO3 and HF, and then were heated to remove acid on the heating plate. Due to the high volatility of halogenides of boron, phosphoric acid was added to chelate the boron which minimizes boron volatilization during heating. Beryllium was added online as the internal standard, which compensated for matrix effects. Diluted ammonium hydroxide solution was used as the wash solution, which significantly reduced the memory effect of boron. Measurement was taken under high resolution mode, in order to minimize spectral interference from 12C and 40Ar4+. The instrument detection limit was 0.22 ng/mL, and the method detection limit was 0.34 ng/mL with high sensitivity and accuracy, verified by standard materials. The results show that this method is a simple and rapid procedure, and can be used for routine determination of boron for batch coal samples.

In deep buried rock engineering, in situ stress is a significant factor affecting the mechanical response of rocks to dynamic loads. This work focuses on the effect of confining pressure on dynamic deformation of rocks. Considering the limitation of observation in laboratory experiments, numerical simulation method is adopted. The numerical model of split Hopkinson pressure bar test system with confining pressure is established in a two-dimensional particle flow code. Dynamic compression tests of sandstone under different confining pressure conditions are then simulated. The axial dynamic compressive deformation, crack evolution, failure modes and dynamic dilation of specimen are obtained. The results indicate that confining pressure has a constraint influence on both axial and transverse deformation of rock. Under the compression of confining pressure, the axial dynamic deformation, and damage degree are weakened while the elasticity of rock may be enhanced. Compared with that without confining pressure, the failure modes of rock specimens are different under the confining pressure. Dynamic dilation of rock specimen is triggered synchronously with the crack initiation. Confining pressure can weaken the dilation, and contraction of rocks may even happen after the dynamic unloading under a high confining pressure, resulting in a secondary damage to rocks. The results can benefit to comprehend the dynamic deformation and failure of deep buried rocks. [ABSTRACT FROM AUTHOR]

The experiment was to study the effect of calcium zinc mixture feed additives on production performance and milk quality of dairy cows. A total of 180 lactating period Holstein dairy cows with similar pens, parity and days of lactation were randomly divided into two groups, with 90 replicates in each group. The dairy cows in control group were fed with a full-mixed diet, and the dairy cows in test group were fed with a full-mixed diet + 500 mL/(head ·d) calcium and zinc mixture, for 3 d consecutive, then stopped for 4 d, lasted for 35 d. The results showed that compared with control group, the feed conversion rate of dairy cows in test group was increased by 2.18%. Milk yield of dairy cows in test group was increased by 0.35%, 11.31%, 2.89%, 3.10%, 1.83% and 3.84% on the 7th, 14th, 21th, 28th and 35th day and the whole process, respectively. Milk yield of dairy cows on the 14th day increased significantly. Milk fat percentage and milk protein of dairy cows in test group were slightly lower. Somatic cell number and persistence of dairy cows in test group were increased slightly. Urea nitrogen of dairy cows in test group was decreased slightly. The average economic benefit in each cow per day of dairy cows in test group was increased by 8.24%. The experiment indicates that adding calcium zinc mixture in total mixed diet has no significant effect on feed conversion rate, tends to improve milk yield in a certain stage, which has no significant effect on milk quality, can improve economic benefit. [ABSTRACT FROM AUTHOR]

The experiment studied the effect of feed the stem and leaf of Glycyrrhiza uralensis on ruminal fermentation and microbial populations in dairy cow. 20 healthy (258±12) d Holstein dairy cows were used in a paired design with milk yield, lactation time and parity, which divided into control group (alfalfa group) and test group (stem and leaf of Glycyrrhiza uralensis group) with ten replicates in each group. The experimental period was 28 d. The results showed that the stem and leaf of Glycyrrhiza uralensis extremely increased the concentration of acetic acid, propionic acid and valeric acid (P<0.01), significantly increased the concentration of butyric acid (P<0.05), and significantly decreased the acetic/propionic (P<0.05). The stem and leaf of Glycyrrhiza uralensissignificantly decreased the number of Ruminococcus albus, Genus Ruminococcus and Butyrivibrio fibrisolvens (P<0.05), and extremely decreased the number of Ruminococcus flavefaciens (P<0.01). The study indicates that the stem and leaf of Glycyrrhiza uralensis instead of alfalfa to feed dairy cows has an inhibitory effect on the Ruminococcus albus, Ruminococcus flavefaciens, Butyrivibrio fibrisolvens and Genus Ruminococcus in the rumen fluid, and improves the rumen parameters of dairy cows, which is beneficial to improve the utilization efficiency of feed. [ABSTRACT FROM AUTHOR]

The study on rare metals in coal and coal-bearing strata is a hot point issue in the field of coal geology. Rare metals that could be highly-enriched in coal and coal-bearing strata and thus can be industrially utilized include Li, Sc, Ti, V, Ga, Ge, Se, Zr, Nb, Hf, Ta, U, rare earth elements (lanthanides and Y), and noble metals. In this paper, the geological origin, modes of occurrence, and evaluation methods for coal-hosted rare metal deposits including Ge, Ga, U, Nb, rare earth element ore deposits are reviewed. The study on coal-hosted rare metal ore deposits can not only provide important evidence of coal geochemistry and coal mineralogy for coal formation origin, coal-seam correlation, coal basin formation and epigenetic deformation, regional geology-evolution, and sudden geological event, but also are practically significant for the development of coal circular economy, environmental protection during coal utilization, and for the security of national rare metal resources. [ABSTRACT FROM AUTHOR]

Objective: To observe the clinical effect of Sizhi-Xifang in the improvement of postoperative ankle function., Methods: From Jan. 2006 to Mar. 2008,49 patients were divided randomly into treatment group and control group. The treatment group included 16 males and 8 females with an average age of (41.3 +/- 13.2) years, involving 13 cases of tye A, 9 of type B and 2 of type C based on AO classification. The control group included 15 males and 10 females with an average age of (38.2 +/- 10.9) years, involving 12 cases of type A, 10 of type B, 3 of type C. Minimal invasive percutaneous plate were used in each group. In treatment group 24 cases were treated with Sizhi-Xifang after the incisions were healed., Results: There were no incision infections, flaps necrosis, bone and plate exposure after treatment in two groups. All patients were followed-up for 4 to 16 months with an average of 8.6 months. According to Johner-Wruhs evaluation standard, there were 7 cases in excellent, 12 good, 5 in fair in treatment group and in control group there were 5 cases in excellent, 7 in good, 10 in fair and 3 in poor. The comparison of effect between two groups had significant difference (P < 0.05)., Conclusion: Sizhi-Xifang is helpful to improve the ankle postoperative function.