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In order to find the optimal combination method of secondary utilization of fly ash and graphite-phase carbon nitride (g-C3N4) modification, an efficient composite photocatalyst of γ-Al2O3/g-C3N4was obtained by calcining the composite precursors of Al(OH)3/ dicyandiamide (DCDA). The introduction of Al(OH)3prepared by combining fly ash into the precursors causes hydrogen-bonding interactions between Al(OH)3and DCDA, which facilitate the removal of N atoms from the edges of the CN framework of g-C3N4during condensation, and the composites prepared possess more cyano defects. In addition, γ-Al2O3and g-C3N4form a chemical bond at the interface, and this chemical bonding causes the density of the electron cloud in the vicinity of the N atoms to increase. Among them, the strongest chemical bonding between Al2O3and g-C3N4was observed in ACN-1, whereas the most cyanine defects were formed in ACN-1, which made ACN-1 exhibit the best photocatalytic degradation of methylene blue, which is 2.48 times higher than that of the pristine g-C3N4.

As an effective therapy for treating unilateral neglect, Mirror Therapy (MT) is employed in the upper limb motor function rehabilitation of hemiplegic patients. However, traditional MT has a serious limitation—the Impaired Limb (IL) doesn’t actually move. In this study, a novel performance-based assistance strategy suitable for Robotic Mirror Therapy (RMT) based on MT is proposed. A guiding assistance based on the progress difference HL and IL is constructed in trajectory guidance, and a multi-stiffness region correction force field based on trajectory tracking error is designed to constrain IL’s deviation from the intended path in trajectory correction assistance. To validate the presented strategy, a series of experiments on a RMT system based on the end-effector upper limb rehabilitation robot are conducted. The results verify the performance and feasibility of this strategy.

This study focuses on using the chemical compositions of plagioclase to further investigate the petrogenesis of Chang’E-5 young mare basalts and constrain its parental melt composition. Together with previously published data, our results show that the plagioclase in mare basalts overall displays large variations in major and trace element concentrations. Inversion of the plagioclase data indicates that the melt compositions parental to Chang’E-5 basalts have high rare earth elements (REE) concentrations similar to the high-K KREEP rocks (potassium, rare earth elements, and phosphorus). Such a signature is unlikely to result from the assimilation of KREEP components, because the estimated melt Sr shows positive correlations with other trace elements (e.g., Ba, La), which are far from the KREEP end-member. Instead, the nearly parallel REE distributions and a high degree of trace element enrichment in plagioclase indicate an extensive fractional crystallization process. Furthermore, the estimated melt REE concentrations from plagioclase are slightly higher than those from clinopyroxene, consistent with its relatively later crystallization. Using the Ti partition coefficient between plagioclase and melt, we estimated the parental melt TiO2content from the earliest crystallized plagioclase to be ~3.3 ± 0.4 wt%, thus providing robust evidence for a low-Ti and non-KREEP origin for the Chang’E-5 young basalts in the Procellarum KREEP terrane.

The past two decades of lunar exploration have seen the detection of substantial quantities of water on the Moon’s surface. It has been proposed that a hydrated layer exists at depth in lunar soils, buffering a water cycle on the Moon globally. However, a reservoir has yet to be identified for this hydrated layer. Here we report the abundance, hydrogen isotope composition and core-to-rim variations of water measured in impact glass beads extracted from lunar soils returned by the Chang’e-5 mission. The impact glass beads preserve hydration signatures and display water abundance profiles consistent with the inward diffusion of solar wind-derived water. Diffusion modelling estimates diffusion timescales of less than 15 years at a temperature of 360 K. Such short diffusion timescales suggest an efficient water recharge mechanism that could sustain the lunar surface water cycle. We estimate that the amount of water hosted by impact glass beads in lunar soils may reach up to 2.7 × 1014kg. Our direct measurements of this surface reservoir of lunar water show that impact glass beads can store substantial quantities of solar wind-derived water on the Moon and suggest that impact glass may be water reservoirs on other airless bodies.

Research on returned samples can provide ground truth for the study of the geological evolution history of the Moon. However, previous missions all collected samples from the near side of the Moon, which is significantly different from the far side of the Moon in terms of the thickness of the lunar crust, magma activity, and composition. Therefore, the samples from the far side of the Moon are of great significance for a comprehensive understanding of the history of the Moon. China’s Chang’e-6 (CE-6) probe has successfully landed on the lunar far side and will return samples in the coming days. With the precise location of the CE-6 landing site, a detailed analysis of the geological background is conducted in this research. The landing site of CE-6 is within the Apollo crater, which is inside the largest impact basin on the Moon, i.e., the South Pole-Aitken (SPA) basin. According to the numerical simulation of the formation process of the SPA basin, CE-6 landed at the edge of the SPA impact melting zone, which is presumably composed of impact melt of the lunar mantle. The Apollo crater subsequently excavated deep material again, which constitutes the basement of the CE-6 landing area. Later, erupted basalt covered these basement rocks, and they also constitute the main source of the CE-6 samples. Based on the dating method of crater size-frequency distribution, we find that the basalt is ∼2.50 Ga. The CE-6 samples also possibly contain basement rocks as excavated and ejected by craters, and they can provide crucial information for our understanding of lunar geological history along with the basalt samples.

In order to study the complex dynamic characteristics of hydro-mechanical CVT (hydro-mechanical continuously variable transmission), the gearbox machine dynamics simulation model based on AMESim was established for the most important of confluent planetary gear mechanism in the gearbox. Creo2.0 was used to draw 3D virtual prototype, and according to the actual movement of the link, added the corresponding constraints to get the planetary dynamics simulation model based on the multi-body dynamics simulation software ADAMS. Based on the classical formula of gear meshing force, the theoretical values of meshing force of planetary gear were calculated, and the dynamics analysis of planetary gear was carried out by using ADAMS. The simulation results were basically consistent with the theoretical values. It researched the influence of the speed regulation process on planetary gear engagement impact under the three case: speed regulation rate and speed direction, speed regulation under different load levels and different engine speed. The speed regulation under speed regulation rate and different load levels had obvious impact on planetary gear meshing force, the impact degree increased with the increasing of speed regulation rate and load; this work has good engineering and application value, and provides the reference for the structure optimization and adjustment.

Knowledge regarding the abundance and distribution of solar wind (SW)‐sourced water (OH/H2O) on the Moon in the shallow subsurface remains limited. Here, we report the NanoSIMS measurements of H abundances and D/H ratios on soil grains from three deepest sections of the Chang'E‐5 drill core sampled at depths of 0.45–0.8 m. High water contents of 0.13–1.3 wt.% are present on approximately half of the grain surfaces (topmost ∼100 nm), comparable to the values of Chang'E‐5 scooped soils. The extremely low δD values (as low as −995‰) and negative correlations between δD and water contents indicate that SW implantation is an important source of water beneath the lunar surface. The results are indicative of homogeneous distribution of SW‐derived water in the vertical direction, providing compelling evidence for the well‐mixed nature of the lunar regolith. Moreover, the findings demonstrate that the shallow subsurface regolith of the Moon contains a considerable amount of water. Recently, China's Chang'E‐5 mission targeted a higher latitude on the Moon than previous Apollo and Luna missions, and brought back scooped and drilled samples to the Earth. These new soil samples provide an opportunity to investigate the distribution, abundance, and origin(s) of water in Moon's middle latitude. Here, we focus on using the NanoSIMS technique to analyze water content on soil near‐surface regions to understand whether the solar wind (SW)‐derived water could be preserved after burial at depth. Our results show that more than half of the core soils have high water contents on the rims of grains, similar to those of the Chang'E‐5 scooped soils. This finding suggests that the SW remains an important source of water in the Moon's subsurface. Our work provides direct evidence that the lunar regolith below the surface contains considerable water from SW implantation. This type of water could be a promising water resource in future exploration. More than half of the soils from the single drill core have high water contents and low D/H ratios below the surfaceThe solar wind (SW)‐derived water could be preserved for hundreds of millions of years if buried at depthLunar regolith from the drill core contains considerable water from SW implantation, which is much more accessible More than half of the soils from the single drill core have high water contents and low D/H ratios below the surface The solar wind (SW)‐derived water could be preserved for hundreds of millions of years if buried at depth Lunar regolith from the drill core contains considerable water from SW implantation, which is much more accessible

In this paper, we research on two kinds of cover-avoiding subgroups of a finite group and get some results on p-supersolvable and p-nilpotent properties of a group G.

Aromatic carbon (C) doped graphitic carbon nitride (g-C3N4) is one of the effective strategies to improve the photocatalytic performance of g-C3N4. The present work developed a feasible method to construct C/g-C3N4 through carbonising the mixture of g-C3N4 and phenol-formaldehyde (PF) obtained in situ polymerisation. This synthesis method not only improves the interaction between PF and g-C3N4, but also promotes the preparation of aromatic carbon-doped g-C3N4in the subsequent calcinations process. The resulted C/g-C3N4-600 catalysts show developed optoelectronic properties, superior photocatalytic activity and higher surface area (1336 cm2g-1) due to the extended π-conjugation system and distinctive morphology.

The passive compliance plays a crucial role in steady and secure locomotion of the legged mammal. This paper aims to introduce the elastic element into the traditional high rigid leg structure to mimic the passive compliance capacity of the animal’s leg joint. For this purpose, based on the analysis of physiological structure of dog leg, the principle of passive compliance leg is proposed firstly. Further more, the single-edge dual-piston pneumatic prop characterizing by small size, large stiffness and high integration is designed and used to connect the thigh component in series with the calf by means of the added anti-torque arm. Finally, the effectiveness of the new structure is validated through the experiments on the single leg physical platform as well as the results from simulations. All results show that with the help of this passive compliance the impact force between the ground and robot feet can be effectively buffered no matter the actuator with poor responsiveness. In the meantime the motion stability and foot trajectory tracking accuracy are also effectively improved in both position control and force control.

In this paper, we investigate the influence of weakly s-semipermutable subgroups of prime power order on the structure of finite groups. We obtain a new criteria for supersolvability of finite group and improve some known results.

Let Gbe a finite group and $$H\le G$$ H≤G . In this paper, we investigate the influence of the index of Hin $$\langle H, H^{g}\rangle $$ ⟨H,Hg⟩ on the structure of G.

In-situseasonal δ18O measurements of section 236.3–235.6 cm of speleothem HS4, from Qingjiang Valley of the Middle reaches of Yangtze River, China, were performed by an Secondary Ionization Mass Spectrometry (SIMS) with Oka (Chinese primary calcite standard GBW04481) and UWC-3 (international calcite standard from University of Wisconsin). The potential of using SIMS δ18O measurements to establish speleothem time series has been explored and the differences between conventional and SIMS δ18O values have been discussed. During a 3-day period, UWC-3 δ18O has been measured on Cameca IMS 1280 Ion Microprobe Mass Spectrometer against “Oka” external standard. The measured mean value of UWC-3 (δ18OVPDB= −17.85‰±0.22‰, 1SD) matches well with its recommended value (δ18OVPDB=−17.83‰±0.08‰), suggesting that the instrument was stable. The same method applied on HS4 produced δ18O measurements at seasonal resolution with distinct annual cycles and the total cycle number in agreement with that from Mg/Ca cycles and lamination layer counting of the same section, so it offers an alternative for accessing speleothem time series. However, compared with conventional δ18O values of HS4, SIMS δ18O values are more negative by 0.90‰ with larger seasonal variation. The main reasons might come from the micro-cracks, micro-pores or liquid inclusions existing in HS4, and organic materials in the speleothem might be another factor affecting the SIMS δ18O values, indicating that to obtain reliable speleothem SIMS δ18O values, both compaction and purity of samples are crucial.

LA-ICPMS zircon U-Pb dating has been greatly advanced and widely applied in the past decade because it is a cheap and fast technique. The internal error of LA-ICPMS zircon U-Pb dating can be better than 1%, but reproducibility (accuracy) is relatively poor. In in order to quantitatively assess the accuracy of this technique, zircons from two dioritic rocks, a Mesozoic dioritic microgranular enclave (FS06) and a Neoproterozoic diorite (WC09-32), were dated independently in eight laboratories using SIMS and LA-ICPMS. Results of three SIMS analyses on FS06 and WC09-2 are indistinguishable within error and give a best estimate of the crystallization age of 132.2 and 760.5 Ma (reproducibility is ∼1%, 2RSD), respectively. Zircon U-Pb ages determined by LA-ICPMS in six laboratories vary from 128.3±1.0 to 135.0±0.9 Ma (2SE) for FS06 and from 742.9±3.1 to 777.8±4.7 Ma (2SE) for WC09-32, suggesting a reproducibility of ∼4% (2RSD). Uncertainty produced during LA-ICPMS zircon U-Pb analyses comes from multiple sources, including uncertainty in the isotopic ratio measurements, uncertainty in the fractionation factor calculation using an external standard, uncertainty in the age determination as a result of common lead correction, age uncertainty of the external standards and uncertainty in the data reduction. Result of our study suggests that the uncertainty of LA-ICPMS zircon U-Pb dating is approximately 4% (2RSD). The uncertainty in age determination must be considered in order to interpret LA-ICPMS zircon U-Pb data rationally.

Early Yanshanian (Jurassic) granitoids are widespread in the Nanling Range, South China. Whereas large granitic batholiths commonly crop out in the center of the Nanling Range (corresponding geographically to the central and northern parts of Guangdong Province), many small stocks occur in the southern part of Jiangxi Province. Most of the small stocks are associated closely with economically significant rare-metal deposits (W, Sn, Nb, Ta). Here we report the results for biotite granites and two-mica granites from three Yanshanian stocks of the Longyuanba complex. LA-ICPMS U-Pb dating of zircon yields an age of 156.1±2.1 Ma for Xiaomubei biotite granite, and U-Pb zircon dating using SIMS yields an age of 156.7±1.2 Ma for Longyuanba-Chengjiang biotite granite and 156.4±1.3 Ma for Jiangtoudong two-mica granite. Biotite granites are silica-rich (SiO2=70%–79%), potassic (K2O/Na2O>1.9), and peraluminous (ASI=1.05–1.33). Associated samples are invariably enriched in Rb, Th, Pb and LREE, yet depleted in Ba, Nb, Sr, P and Ti, and their REE pattern shows a large fractionation between LREE and HREE ((La/Yb)N=10.7–13.5) and a pronounced Eu negative anomaly (δEu=0.28–0.41). Two-mica granite samples are also silica-rich (SiO2=75%–79%), potassic (K2O/Na2O>1.2), and peraluminous (ASI=1.09–1.17). However, in contrast to the biotite granites, they are more enriched in Rb, Th, Pb and extremely depleted in Ba, Nb, Sr, P and Ti, and exhibit nearly flat ((La/Yb)N=0.75–1.08) chondrite-normalized REE patterns characterized by strong Eu depletion (δEu=0.02–0.04) and clear tetrad effect (TE1.3=1.10–1.14). Biotite granites and two-mica granties have comparable Nd isotopic signatures, and their ɛNd(t) are concentrated in the −13.0 to −9.6 and −11.5 to −7.7 respectively. Their zircon Hf-O isotopes of both also show similarity (biotite granites: ɛHf(t)=−10.8–−7.9, δ18O=7.98‰–8.89‰ and ɛHf(t)= −13.8 to −9.1, δ18O=8.31‰–10.08‰; two-mica granites: ɛHf(t)=−11.3 to −8.0, δ18O=7.91‰–9.77‰). The results show that both biotite and two-mica granites were derived mainly from sedimentary source rocks with a minor contribution from mantle-derived materials. In spite of some S-type characteristics, the biotite granites were formed by fractional crystallization of I-type magma and assimilation of peraluminous sedimentary rocks during their ascent to the surface. Therefore, they belong to highly fractionated I-type granites. Two-mica granites exhibit a tetrad effect in their REE patterns, but share the same isotopic features with the biotite granites, suggesting that they are highly fractionated I-type granites as well. Their Lanthanide tetrad effects may be attributed to the hydrothermal alteration by magmatic fluids that have suffered degassing at late stages. Granitic magmas undergoing fractional crystallization and wall-rock assilimation can generate highly evolved granites with no REE tetrad effect in the uni-phase system. However, in the late-stage of magmatic evolution in the multi-phase system (i.e., magmatic-hydrothermal system), these magmas also can lead to the highly evolved granites exhibiting mew-shaped REE pattern characterized by tetrad effect as the consequence of melt-fluid and fluid-vapor fractionation, and the resultant autometasomatism. We thus suggest that the REE pattern exhibiting tetrad effect feature is an important indicator of rare metal mineralization in the early Yanshanian time in southern China, implying the metamorphism of the ore fluid.

Abstract: We introduce and study the minimal inner-Σ-Ω-groups and the minimal outer-Σ-℧-groups. Then we give some applications and obtain some interesting results, including characterizations of nilpotent, supersolvable, solvable, and p-closed groups in terms of the join of two conjugate cyclic subgroups having the same property.

Zircon inclusions, extracted from garnet from an ultrahigh-pressure eclogite in the eastern part of the Dabie orogen, were investigated with high spatial resolution U-Pb geochronology. The unzoned zircon rims have garnet and omphacite inclusions and show weak cathodoluminescence, low-Th/U ratios (0.02-0.18), flat high rare-earth elements patterns, and an absence of Eu anomalies, which suggest metamorphic growth in the presence of garnet and in the absence of feldspar. Dispersed concordia U-Pb ages, ranging from 205.1 ± 3.3 to 255.3 ± 6.1 Ma, defined a weighted mean 206Pb/238U age of 223 ± 8 Ma (mean square of weighted deviation, MSWD = 38), which is significantly younger than the Lu-Hf garnet-whole rock age of 242.2 ± 2.6 Ma. The U-Pb age probability distribution indicates two age populations at ca. 241 and ca. 216 Ma. The zircon rims, with younger ages, are distinguished from those with older ages by the occurrence of garnet and omphacite inclusions. Well-preserved prograde major- and trace-element zoning in garnet and the significant contribution of older garnet cores in bulk isotopic digestion suggest that the Lu-Hf age mostly reflects an early phase of garnet growth likely at amphibolite facies conditions. The new Lu-Hf age combined with the U-Pb ages of the zircon inclusions in garnet suggest that garnet growth was sustained over a time interval of ~25 m.y.

Abstract: Let G be a finite p-group. If the order of the derived subgroup of each proper subgroup of G divides p i , G is called a D i -group. In this paper, we give a characterization of all D 1-groups. This is an answer to a question introduced by Berkovich.

Based on the numerical calculation method and statistical energy method, the acoustic model of composite sandwich panel is established to study the influence of different core materials, types of sound insulation pads and sandwich panel structure on its sound insulation. At the same time, the composite sandwich panel is prepared by prepreg molding and secondary bonding process, and its sound insulation performance is verified. The results show that ethylene propylene diene monomer with higher density has better sound insulation performance than ethylene vinyl acetate copolymer rubber with lower density. The light core steel has the highest sound insulation, and the measured sound insulation efficiency reaches 1.022. The results show that it is an effective way to improve the sound insulation by changing the thickness and the core material to improve the overall structural stiffness of the sandwich panel. The numerical results are consistent with the experimental results in the low frequency and the trend in the high frequency, which further verifies the rationality of the numerical analysis.

Abstract—The Dong Ujimqin Qi mesosiderite is the first recorded fall of a stony‐iron meteorite in China. According to silicate textures and metal composition, this meteorite is classified as a member of subgroup IB. Instrumental neutron activation analyses (INAA) of metals show that the matrix metal has lower concentrations of Os, Ir, Re, and Pt, but higher concentrations of Ni and Au than the 7.5 cm metal nodule present in the meteorite. We attribute these compositional differences to fractional crystallization of molten metal. Studies of olivine clasts show that FeO contents are uniform in individual olivine crystals but are variable for different olivine clasts. Although concentrations of rare earth elements (REEs) change within olivine clasts, they all exhibit a vee‐shaped pattern relative to CI chondrites. The relatively high concentrations of REEs in olivine and the shape of REE patterns require a liquid high in REEs and especially in light REEs. As such a liquid was absent from the region where basaltic and gabbroic clasts formed, mesosiderite olivine must have formed in a part of the differentiated asteroid that is different from the location where other mesosiderite silicate clasts formed.

The state of the atmospheric environment is related to the values of atmospheric path radiation in remote sensing data. As an important information resource, an atmospheric path radiation image derived from remotely sensed data can be used in many research fields. These include the research in the transmission properties of the atmosphere, the atmospheric modification of remote sensing image, the study of both regional and urban atmospheric environment, and the monitoring of the atmospheric environmental qualities. The principle and methodology for generating the heterogeneous atmospheric path radiation image are described in detail. It is based on known surface reflectance. Using remote sensing images from Shanghai City as a demonstration example, we briefly analyzed the properties of the resulting image of atmospheric path radiation.

According to the energy consumption characteristics of hydraulic actuator, the valuable foot trajectory characterized by using segmented cubic spline interpolation curve in the swing phase is proposed firstly to reduce the energy consumption of quadruped robots, which is implemented by using controlling parameters tfto change the duration of leg raising and falling in one gait cycle, and then realized the directly control to the time ratio between the piston extension and retraction. Then, the total energy consumption of the hydraulic actuated quadruped robot SCalf-II is modeled. Meanwhile, the parameters of the foot trajectory that have a large impact on the energy consumption are determined. Finally, simulation analysis and verification experiments of the robot moving with constant speeds at the key parameters are performed. The results show that for the given foot trajectory, the optimization ranges of the gait cycle and duration of leg lifting from the lowest to highest are determined in which the energy required for the robot locomotion is at a relatively low level.

Abstract: Nd model ages (T DM) of the Pre-Mesozoic crustal rock samples from Southeast China range from 1.2 to 3.2 Ga. Two age peaks of 1.4 Ga and 1.8 Ga are observed in the histogram ofT DM model ages. Available U-Pb zircon inheritance ages are concentrated around 1.2–1.4 Ga, 1.8 Ga and 2.5 Ga, respectively. The combined use of Sm-Nd and U-Pb zircon inheritance ages suggests that the formation of the Precambrian crust is of episodic character. The oldest crustal nucleus may have been formed during the Late Archean (2.5 Ga or older?). A rapid production of the crust took place 1.8 Ga ago, consistent with the global crust formation event at 1.7–1.9 Ga. Another important episode of the addition of juvenile crustal material from the mantle in Southeast China took place 1.2–1.4 Ga ago, during which the pre-existing crust was strongly reworked and/or remelted.