A porous metal-organic framework with ultrahigh acetylene uptake capacity under ambient conditions

Acetylene, an important petrochemical raw material, is very difficult to store safely under compression because of its highly explosive nature. Here we present a porous metal-organic framework named FJI-H8, with both suitable pore space and rich open metal sites, for efficient storage of acetylene under ambient conditions. Compared with existing reports, FJI-H8 shows a record-high gravimetric acetylene uptake of 224 cm(3) (STP) g(−1) and the second-highest volumetric uptake of 196 cm(3) (STP) cm(−3) at 295 K and 1 atm. Increasing the storage temperature to 308 K has only a small effect on its acetylene storage capacity (∼200 cm(3) (STP) g(−1)). Furthermore, FJI-H8 exhibits an excellent repeatability with only 3.8% loss of its acetylene storage capacity after five cycles of adsorption–desorption tests. Grand canonical Monte Carlo simulation reveals that not only open metal sites but also the suitable pore space and geometry play key roles in its remarkable acetylene uptake

Estimation of state of charge of lithium-ion batteries usedin HEV using robust extended kalman filtering

A robust extended Kalman filter (EKF) is proposed as a method for estimation of the state of charge (SOC) of lithium-ion batteries used in hybrid electric vehicles (HEVs). An equivalent circuit model of the battery, including its electromotive force (EMF) hysteresis characteristics and polarization characteristics is used. The effect of the robust EKF gain coefficient on SOC estimation is analyzed, and an optimized gain coefficient is determined to restrain battery terminal voltage from fluctuating. Experimental and simulation results are presented. SOC estimates using the standard EKF are compared with the proposed robust EKF algorithm to demonstrate the accuracy and precision of the latterfor SOC estimation

Identifying the optimal cutoff point of Ki-67 in breast cancer: a single-center experience

Objective Ki-67 is associated with breast cancer subtypes, but the optimal cutoff point of Ki-67 has not been established in our center. We evaluated the cutoff point of Ki-67 in breast cancer and analyzed the associations among Ki-67, clinicopathological features, and prognosis. Methods The clinicopathological data and prognostic information of patients with breast cancer treated in our center were retrospectively collected, and the optimal cutoff point of Ki-67 was determined by univariate and multivariate survival risk analyses. The cutoff point was used to group the patients, and the differences in the clinicopathological features and prognosis were analyzed between the two groups. Results In total, 609 patients with estrogen receptor-positive and human epidermal growth factor receptor 2-negative primary breast cancer were enrolled. The mean Ki-67 value was 22.3% ± 15.4%, the median was 20%, and a cutoff point of 30% was an independent factor influencing recurrence-free survival. When 30% was used as the cutoff point, patients with a Ki-67 value of ≤30% had a better prognosis and lower tumor malignancy. Conclusion The optimal cutoff point of Ki-67 in breast cancer in our center is 30%

Numerical and Field Investigations of Tremors Induced by Thick-Hard Strata Fracture

Large energy mining-induced tremors are generally caused by the rupture of thick-hard overlying strata, and the roadway is prone to rockburst danger under its dynamic load. Through numerical simulations, the laws and influencing factors of stress, deformation, fracture and energy caused by mining-induced tremors (red bed breaking) were revealed, and the results were verified by field observations. The main conclusions were obtained: (1) the tensile stress and the compressive stress were concentrated in the middle of the thick-hard rock and both sides of the goaf, which were prone to tensile and shear failure type caused by mining-induced tremors, respectively; (2) after the goaf was formed, the compressive stress around the roadway was transformed into tensile stress. When a strong mining-induced tremor occurred, the tensile stress increased further. Meanwhile, when it was close to the tensile strength of the coal around the roadway, a rockburst occurred; (3) the energy of the mining-induced tremor released by shear failure was larger than that of the tensile failure. With the increase in shear strength of the roof, the released energy also increased; (4) according to the frequency-spectrum of the mining-induced tremors located in the extremely thick-hard overlying strata above the working face in the Baodian coal mine, the dynamic load generated by the tremors was superimposed on the high static load around the roadway, which was very likely to induce the instability of the roadway. The research conclusions have certain guiding significance for rockburst prevention in coal mines with thick-hard strata roofs

Ultrastructure of Antennal Sensilla in Adults of Dioryctria rubella Hampson (Lepidoptera: Pyralidae)

Antennal sensilla play an essential role in insect life because they receive environmental cues. Dioryctria rubella is an important pine pest in China, but information on the morphology and distribution of its sensilla is limited. To elucidate the mechanism of insect-plant chemical communication, we examined the insect antennae and sensilla by scanning electron microscopy. The results showed that the antennae of D. rubella were filiform and consisted of a basal scape, a pedicel, and a flagellum with tapered flagellomeres. We identified seven types of sensilla, including trichodea, coeloconica, auricillica, basiconica, styloconica (two subtypes), Böhm’s bristles, and squamiformia, all of which were distributed on the antennae of both sexes. Nevertheless, some sensilla exhibited various degrees of sexual dimorphism; for instance, sensilla trichodea, squamiformia, and basiconica were more abundant in males than in females. Many pores were observed on the surface of the cuticular wall in sensilla trichodea and auricillica, and their biological function may be related to olfaction. This study presented a thorough inventory of sensilla on the antennae of D. rubella and laid a solid foundation for future functional studies

Numerical and Field Investigations of Tremors Induced by Thick-Hard Strata Fracture

Large energy mining-induced tremors are generally caused by the rupture of thick-hard overlying strata, and the roadway is prone to rockburst danger under its dynamic load. Through numerical simulations, the laws and influencing factors of stress, deformation, fracture and energy caused by mining-induced tremors (red bed breaking) were revealed, and the results were verified by field observations. The main conclusions were obtained: (1) the tensile stress and the compressive stress were concentrated in the middle of the thick-hard rock and both sides of the goaf, which were prone to tensile and shear failure type caused by mining-induced tremors, respectively; (2) after the goaf was formed, the compressive stress around the roadway was transformed into tensile stress. When a strong mining-induced tremor occurred, the tensile stress increased further. Meanwhile, when it was close to the tensile strength of the coal around the roadway, a rockburst occurred; (3) the energy of the mining-induced tremor released by shear failure was larger than that of the tensile failure. With the increase in shear strength of the roof, the released energy also increased; (4) according to the frequency-spectrum of the mining-induced tremors located in the extremely thick-hard overlying strata above the working face in the Baodian coal mine, the dynamic load generated by the tremors was superimposed on the high static load around the roadway, which was very likely to induce the instability of the roadway. The research conclusions have certain guiding significance for rockburst prevention in coal mines with thick-hard strata roofs