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Humite-group minerals play a crucial role in transporting water and fluorine to the Earth’s deep mantle through slab sinking. In this study, we have used Brillouin scattering to determine the single-crystal elastic constants of four natural humite-group minerals with varying H2O and fluorite contents under ambient conditions, including one chondrodite [Mg4.88Si1.94O8(OH0.78F1.22)] (F61-Chn), one humite [Mg7.03Si3.07O12(OH1.26F0.74)] (F37-Hu), and two clinohumite [Mg8.85Ti0.19Si3.93O16(OH1.11F0.89) and Mg8.63Fe0.10Ti0.24Si3.97O16(OH1.84F0.16)] (F45-Chu and F8-Chu) samples. The adiabatic bulk (KS0) and shear (G0) moduli calculated from the elastic constants using Voigt-Reuss-Hill averages are: KS0= 120.4(3) GPa and G0= 74.1(5) GPa for F61-Chn, KS0= 122.4(3) GPa and G0= 78.4(2) GPa for F37-Hu, KS0= 126.2(3) GPa and G0= 79.7(2) GPa for F45-Chu, and KS0= 120.5(3) GPa and G0= 76.8(2) GPa for F8-Chu. Our results indicate that the addition of F leads to a noticeable increase in the elasticity of clinohumite and chondrodite, which is in contrast to the effect of H2O. Although Fe has a negligible effect on the bulk modulus of clinohumite, it can produce a substantial decrease in the shear modulus. These results provide important insights into the influence of humite-group minerals on the mantle velocity structure. Furthermore, we have investigated the effects of composition on the elasticity and sound velocities of minerals along the forsterite-brucite join in the MgO-SiO2-H2O system, confirming previous observations. Increasing H2O content along the forsterite-brucite join leads to apparent reductions in the elasticity and sound velocities. The influence of Fe on the elasticity and sound velocities of these minerals has also been evaluated.

Orthopyroxene is one of the dominant minerals in the Earth’s upper mantle. In this study, we used Raman spectroscopy to investigate the lattice vibration and phase transition of orthopyroxene with four different compositions using diamond-anvil cells up to 34 GPa at 300 K. Our orthopyroxene samples contain 0 (En100), 9% (En91Fs9), 11% (En86Fs11), and 21% (En74Fs21) Fe. At ambient conditions, the Raman modes exhibit a negative dependence on the Fe content, with the exception of the modes at ~850 and 930 cm–1. In contrast, these two Raman modes increase with increasing the Fe content. The phase transition from metastable α- to β-phase was observed at 12.9–15 GPa for samples with <21 mol% Fe and varying Fe content has a minor effect on the phase transition pressure. Besides Fe, incorporation of 2–24 mol% Al can cause an increase in the phase transition pressure from 10–13 to 14–16 GPa. At 29–30.1 GPa, we observed the second apparent change in the Raman spectra for all four investigated samples. For Fe-bearing orthopyroxene, this change in the Raman spectra and frequency shift is associated with the phase transition from β- to γ-phase, whereas for En100, it should be caused by the change of coordination number of Si from 4 to 6 or the presence of α-popx phase. Using the obtained Raman frequency shifts, we calculated the Grüneisen parameters at high pressures. These parameters are useful for understanding the thermoelastic properties of orthopyroxene at high pressures.

China is home to the second largest population of children and adolescents in the world. Yet demographic shifts mean that the government must manage the challenge of fewer children with the needs of an ageing population, while considering the delicate tension between economic growth and environmental sustainability. We mapped the health problems and risks of contemporary school-aged children and adolescents in China against current national health policies. We involved multidisciplinary experts, including young people, with the aim of identifying actionable strategies and specific recommendations to promote child and adolescent health and wellbeing. Notwithstanding major improvements in their health over the past few decades, contemporary Chinese children and adolescents face distinct social challenges, including high academic pressures and youth unemployment, and new health concerns including obesity, mental health issues, and sexually transmitted infections. Inequality by gender, geography, and ethnicity remains a feature of health risks and outcomes. We identified a mismatch between current health determinants, risks and outcomes, and government policies. To promote the health of children and adolescents in China, we recommend a set of strategies that target government-led initiatives across the health, education, and community sectors, which aim to build supportive and responsive families, safe communities, and engaging and respectful learning environments.

Asymmetric synthesis based on a metallate shift of tetracoordinate borons is an intriguing and challenging topic. Despite the construction of central chirality from tetracoordinate boron species via a 1,2-metallate shift, catalytic asymmetric synthesis of axially chiral compounds from such boron ‘ate’ complexes is an ongoing challenge. Axially chiral alkenes have received great attention due to their unique characteristics and intriguing molecular scaffolds. Here we report an enantioselective nickel-catalysed strategy for the construction of axially chiral alkenes via a 1,3-metallate shift of alkynyl tetracoordinate boron species. The chemoselectivity, regioselectivity and atroposelectivity can be regulated and well-controlled from readily accessible starting materials with a cheap transition-metal catalyst. Downstream transformations indicate the powerful conversion ability of such compounds in this protocol, and late-stage elaborations of bioactive compounds can also be achieved. Mechanistic experiments reveal that regioselective syn-addition of an aryl–Ni complex with a carbon–carbon triple bond and subsequent 1,3-phenyl migration are the two key steps for the synthesis of axially chiral alkenes.

The reinsured (original insurer) would face liability by section 13A of the Insurance Act 2015 in the UK and incur the costs or expenses of investigating and defending against the insured’s valid claims, where the reinsured withholds or delays paying insurance proceeds to the insured. The reinsurer generally would not be held liable for the unreinsured contractual liability and costs unless special requirements are met. The critical points for the reinsured to recover the reimbursement of damages and expenses from the reinsurer are to confirm the reinsurer’s actual participation or intention in refusing to indemnify the original assured timeously or in defending against the insured’s valid claims by way of proving the reinsurer’s compulsion or identifying them as a joint enterprise. The follow-the-settlements clause cannot render the reinsurer liable for the unreinsured liability. It is more reasonable that the policy limits only restrict the sums reinsured but do not cap the unreinsured damages and costs.

The reinsured (original insurer) would face liability by section 13A of the Insurance Act 2015 in the UK and incur the costs or expenses of investigating and defending against the insured’s valid claims, where the reinsured withholds or delays paying insurance proceeds to the insured. The reinsurer generally would not be held liable for the unreinsured contractual liability and costs unless special requirements are met. The critical points for the reinsured to recover the reimbursement of damages and expenses from the reinsurer are to confirm the reinsurer’s actual participation or intention in refusing to indemnify the original assured timeously or in defending against the insured’s valid claims by way of proving the reinsurer’s compulsion or identifying them as a joint enterprise. The follow-the-settlements clause cannot render the reinsurer liable for the unreinsured liability. It is more reasonable that the policy limits only restrict the sums reinsured but do not cap the unreinsured damages and costs.

In this study, we concentrate on the seismic signature of subducted sediments and suggest the formation of the L‐discontinuity beneath the ancient craton related to migrated sediment dehydration. We first determined the single‐crystal elasticity of topaz, the product of sediment dehydration, at high pressures and temperatures by Brillouin scattering. Using the derived elastic parameters, we establish the velocity and density profiles of subducted sediments in the upper mantle. According to our modeling results, 8.5–17.5 vol.% sediments intruding into the upper mantle will induce a 2%–4% low‐VSanomaly at 210–260 km. Meanwhile, continuous heating will lead to the dehydration of phengite in sediments. The dehydration of this amount sediments can generate a 3%–6% ISSwith negative Clapeyron slopes, satisfying the observed L‐discontinuity in northern Finland and northern America without the anisotropy changes but accompanied by low‐velocity anomalies. Our study thus provides new insights into the origin of the L‐discontinuity. The origin of the global seismic discontinuities in the Earth's mantle has been well understood, but the formation mechanism of some local seismic discontinuities is still vague. Lehmann discontinuity (L‐discontinuity) is one of the regional discontinuities in the upper mantle with a 2%–6% impendence contrast (ISS) and negative Clapeyron slope. However, the deformation mechanism changes of olivine cannot explain the formation of the L‐discontinuity without the anisotropy changes. Here, we emphasize the significance of the migration and dehydration of the subducted sediments in the origin of the L‐discontinuity beneath the ancient craton. We determined the single‐crystal elasticity of topaz, the product of the sediment dehydration, and then investigated the seismic signature of subducted sediments. Our modeling results indicated that ∼17.5 vol.% sediments intruding into the upper mantle would lead to ∼4% low‐VSanomalies at 210–260 km. After the continuous heating, these intruding sediments would dehydrate by the reaction with the negative Clapeyron slopes, thus producing significant ISS. Therefore, the migration and dehydration of the subducted sediments can reasonably interpret the seismic characteristics of the L‐discontinuity beneath the cratonic regions such as northern Finland and northern America. Our results deepen the understanding of the origin of the L‐discontinuity. Single‐crystal elasticity of topaz under high pressure and temperature has been investigated by Brillouin scatteringThe obtained elasticity parameters are used to model the density and velocity profiles of the subducted sedimentsWe suggest the formation of the L‐discontinuity beneath the ancient craton related to migrated sediment dehydration Single‐crystal elasticity of topaz under high pressure and temperature has been investigated by Brillouin scattering The obtained elasticity parameters are used to model the density and velocity profiles of the subducted sediments We suggest the formation of the L‐discontinuity beneath the ancient craton related to migrated sediment dehydration

To observe the clinical efficacy of acupuncture on dystonia in brain-type Wilson's disease (WD) with internal retention of damp heat pattern.

In this study, we have determined the single‐crystal elasticity of clinohumite [Mg8.85Ti0.19Si3.93O16(OH1.11F0.89)] using Brillouin measurement up to 21 GPa at 300 K and 1 bar at 750 K, respectively. The elasticity of clinohumite was determined to be KS0= 126.2(3) GPa, G0= 79.7(2) GPa with pressure derivatives KS′ = 4.2(1), G′ = 1.3(1), pressure derivatives ∂KS/∂T= −0.024(1) GPa/K, and ∂G/∂T= −0.011(1) GPa/K). We comprehensively examined the effects of varying H2O, fluorine content and thermal states, on the velocity and density structures of the subducted harzburgite layer. Assuming a typical H2O content of 2 wt.% within harzburgite, our modeling has shown that hydrous harzburgite with clinohumite as the decomposition product of serpentine along a hot slab geotherm even has the VPand VS0.4–0.8(6)% greater than it dry counterpart at 250–380 km depth. Yet in the top transition zone, the addition of H2O and F can effectively lower the sound velocities and density. The F‐bearing hydrous harzburgite has the VPand VS1.1(5)–1.3(3)% lower than its dry counterpart, and only 0.6(5)% and 2.3(5)% greater than the pyrolitic mantle. Along cold slab geotherm, phase A will replace clinohumite as the dominant hydrous phase in the harzburgite, the VPand VSare 4.8(5)–5.3(3)% and 5.9(5)–6.0(3)% greater than the pyrolitic mantle in the upper mantle. In the top transition zone, the difference is approximately 3% in VPand 5% in VS. Our results provide crucial experimental evidence for future assessments of the seismic signals of subducted slabs with different hydrous minerals and thermal states. Subducted slab plays a crucial role in connecting the Earth's surface to the interior. Transportation of H2O and other important volatiles to the Earth's mantle via subducted slab can greatly influence a series of physical properties of mantle minerals. Clinohumite is one of the most important H2O and fluorine (F) carriers in the subducted slab. Here, we determined the single‐crystal elasticity of F‐bearing clinohumite at high pressures and temperatures. The obtained elasticity data were applied to model the velocity profiles of the hydrous harzburgite. Our results show that the addition of H2O and F can enhance the velocity difference between harzburgite and pyrolitic mantle at 250–380 km depth along the hot slab geotherm, and VPand VSof harzburgite with 2 wt.% H2O and clinohumite as the H2O‐bearing phase are 0.4–0.8(6)% greater than those of dry harzburgite. In the transition zone depth, addition of H2O and Fe lowers the sound velocities of harzburgite. Hydrous harzburgite has a lower VPand VSthan its corresponding dry phase. These new velocity constraints can help us better understand the circulation of H2O and F within Earth's interior and identify the detected seismic observations of subducted slabs with different compositions and thermal states. Single‐crystal elasticity of F‐bearing clinohumite was determined to 21 GPa and 750 K and shows strong dependence with F contentThe obtained results were used to model the velocity profiles of the hydrous harzburgite layer considering the thermal state and compositionH2O and F in clinohumite have significant influence on the velocity profile of subduction slab Single‐crystal elasticity of F‐bearing clinohumite was determined to 21 GPa and 750 K and shows strong dependence with F content The obtained results were used to model the velocity profiles of the hydrous harzburgite layer considering the thermal state and composition H2O and F in clinohumite have significant influence on the velocity profile of subduction slab

Magnesite (MgCO3) entering the lower mantle together with the subducted oceanic crust is an important carbon carrier. The reaction between magnesite and mantle minerals has been documented, but its influence on the density and velocity profiles of lower mantle remains unexplored. To decipher the deep carbon transportation and its associated effect, here we determined the thermal equations of state of magnesite up to 120 GPa and 2600 K using X‐ray diffraction in laser‐heated diamond anvil cells. The obtained thermal elastic parameters of magnesite facilitated a comprehensive understanding on the influence of magnesite‐SiO2reaction, variation of carbon and SiO2content, and temperature on the origin of lower‐mantle scatterers at 1,000–1,800 km depth. Our modeling revealed that the depth of the lower‐mantle VSscatterers is mainly controlled by the Al2O3content in SiO2, while its magnitude depends on the SiO2content. Along normal geotherm, the magnesite‐SiO2reaction would occur before the post‐stishovite transition, consuming substantial SiO2in the subducted oceanic crust. Depending on the amount of residual SiO2, the post‐stishovite transition can produce a 2.5–5.2 (2)% VSreduction, compatible with the observed seismic scatterers in Izu‐Bonin and Mariana subduction zones. Along slab geotherm, this reaction occurs after the post‐stishovite transition, generating a greater VSreduction of 4.4–6.4 (4)%. We thus propose that the reaction between sinking MgCO3and SiO2in the slab is one of the potential factors influencing the magnitude of the lower‐Vs scatterers at 1,000–1,900 km depth. Our results provide new insights into the deep‐mantle carbonate transportation influencing regional geophysics. Carbonates could enter the deep Earth with the subducted oceanic crust. Magnesite is the most likely carbonate to exist stably in the lower mantle. During the subduction process, magnesite would interact with subducted oceanic crust and influence the density and velocity structure of the lower mantle. Here we determined the thermal equations of state (EoS) of magnesite up to 120 GPa and 2600 K. With the obtained EoS parameters, we discussed the influence of magnesite‐SiO2reaction, variation of carbon, SiO2content, and temperature on the velocity and density profiles across the post‐stishovite phase transition of SiO2and explain the origin of lower‐mantle VS scatterers at 1,000–1,900 km depth. Our findings reveal that the depth and magnitude of lower‐mantle VS scatterers depend on Al2O3content in SiO2and SiO2content, respectively. With the variation of temperature and residual SiO2content of the reaction, the post‐stishovite phase transition of SiO2can generate a VS reduction in the range of 2.5%–6.4%. Our findings are important in understanding deep‐mantle carbonate transportation and its implications for regional Geophysics. The velocity change across the MgCO3‐SiO2reaction were modeled, with the determined thermal EoS of magnesite up to 120 GPa and 2600 KThe VSreduction during the post‐stv transition could be influence by temperature, CO2and SiO2content, and Al content in SiO2The post‐stv transition and the reaction between SiO2and MgCO3could explain the lower‐VSscatterers at 1,000–1,900 km depth The velocity change across the MgCO3‐SiO2reaction were modeled, with the determined thermal EoS of magnesite up to 120 GPa and 2600 K The VSreduction during the post‐stv transition could be influence by temperature, CO2and SiO2content, and Al content in SiO2 The post‐stv transition and the reaction between SiO2and MgCO3could explain the lower‐VSscatterers at 1,000–1,900 km depth

Abundant and diverse small shelly fossils have been reported from Cambrian Series 2 in North China, but the co-occurring brachiopods are still poorly known. Herein, we describe seven genera, five species and two undetermined species of organophosphatic brachiopods including one new genus and new species from the lower Cambrian Xinji Formation at Shuiyu section, located on the southern margin of North China Platform. The brachiopod assemblage comprises one mickwitziid (stem group brachiopoda), Paramickwitzia boreussinaensisn. gen. n. sp., a paterinide, Askepasma toddenseLaurie, 1986, an acrotretoid, Eohadrotretacf. zhenbaensisLi and Holmer, 2004, a botsfordiid, Schizopholis yorkensis(Holmer and Ushatinskaya in Gravestock et al., 2001) and three linguloids, Spinobolussp., Eodicellomuscf. elkaniiformisHolmer and Ushatinskaya in Gravestock et al., 2001and Eoobolussp. This brachiopod assemblage suggests a late Age 3 to early Age 4 for the Xinji Formation and reveals a remarkably strong connection with coeval faunas from East Gondwana, particularly the Hawker Group in South Australia. The high degree of similarity (even at species level) further supports a close palaeogeographic position between the North China Platform and Australian East Gondwana during the early Cambrian as indicated by small shelly fossil data.

The interfacial heat transfer coefficient between hot profile surface and cooling water was determined by using inverse heat conduction model combined with end quenching experiment. Then, a Deform-3D thermo-mechanical coupling model for simulating the on-line water quenching of extruded profile with unequal and large thicknesses was developed. The temperature field, residual stress field and distortion of profile during quenching were investigated systematically. The results show that heat transfer coefficient increases as water flow rate increases. The peak heat transfer coefficient with higher water flow rates appears at lower interface temperatures. The temperature distribution across the cross-section of profile during quenching is severe nonuniform and the maximum temperature difference is 300 °C at quenching time of 3.49 s. The temperature difference through the thickness of different parts of profile first increases sharply to a maximum value, and then gradually decreases. The temperature gradient increases obviously with the increase of thickness of parts. After quenching, there exist large residual stresses on the inner side of joints of profile and the two ends of part with thickness of 10 mm. The profile presents a twisting-type distortion across the cross-section under non-uniform cooling and the maximum twisting angle during quenching is 2.78°.

A visible-light catalyzed [3 + 1 + 2] annulation for the synthesis of unsymmetrical trisubstituted amino-1,3,5-triazines from amidines, isothiocyanates, and 1,1,3,3-tetramethylguanidines has been developed. This method exhibits the advantages of easily available starting materials, insensitive to air and moisture, wide substrate scopes, high step economy, mild, metal- and ligand-free conditions, which has potential applications in the organic, medicinal, and material chemistry.

This study examines the effects of water and carbon on the velocity profiles of subducted oceanic crust in the upper mantle. High pressure and temperature Brillouin measurements were conducted to determine the single‐crystal elasticity of aragonite (CaCO3) up to 20 GPa and 600 K, respectively. Using the finite‐strain method, we determined the elastic parameters: KS0= 70.7 GPa, G0= 36.1(3) GPa with KS′ = 5.0(1), G′ = 1.3(1), ∂KS/∂T= −0.020(2) GPa/K, and ∂G/∂T= −0.015(1) GPa/K. When combined with literature results, our findings reveal that neither hydrous minerals nor carbonate alone can explain the observed 3%–4% and 3%–7% low velocity anomalies in the compressional (VP) and shear‐wave (VS) velocities of subducted oceanic crust in the circum‐Pacific region at 150–250 km depth. Considering the combined effect of water and carbonate, the addition of 5.9–6.9 vol.% aragonite together with 10 vol.% lawsonite in the oceanic crust can produce a 3%–4% and 6.1%–8.1% low velocity anomalies in the VPand VSat 150–250 km depth, respectively, consistent with the seismic observations in the region. Complete dehydration of lawsonite accompanied by the gradual decarbonization of the subducted oceanic crust explains the absence of low‐velocity anomalies below 300‐km depth. Our findings help for a better understanding of the possible influence of carbon and water on seismic velocities of the mantle. As a result, the circulation of carbon and water may be better understood while taking the complex velocity structure of subduction zones and mineral physics findings into account. The subducting slab generally exhibits higher wave velocities than the normal mantle due to its lower temperatures. However, seismological studies have detected the existence of 3%–4% and 3%–7% low compressional (VP) and shear‐wave (VS) velocity anomalies in the subducted oceanic crust at 150–250 km depth in the circum‐Pacific region, respectively, which cannot be explained by water (lawsonite) alone. Our new experimental constraints on the single‐crystal elasticity of aragonite up to 20 GPa and 600 K indicate that aragonite, along with water, can significantly reduce the velocity of mid‐ocean ridge basalts which constitute a major component of the subducted oceanic crust. The presence of 5.9–6.9 vol.% aragonite together with 10 vol.% lawsonite can make the VPand VSof subducted oceanic crust 3%–4% and 6.1%–8.1% lower than surrounding mantle, respectively. Below 300‐km depth, subducted oceanic crust will be seismically detected as a high‐velocity structure due to complete dehydration of lawsonite and gradual decarbonization with aragonite content less than 8 vol.%. These findings contribute to our understanding of the complex relationship between carbon, water, and depth‐dependent velocity anomalies in the subduction process. Single‐crystal elasticity of aragonite was determined to 20 GPa and 600 K, showing the lowest VPand VScompared to magnesite and dolomiteThe obtained results were used to model the velocity profiles of the subducted oceanic crust in the upper mantleThe low‐velocity anomalies within the subducted oceanic crust at 150–250 km depth should be a net effect of water and carbon Single‐crystal elasticity of aragonite was determined to 20 GPa and 600 K, showing the lowest VPand VScompared to magnesite and dolomite The obtained results were used to model the velocity profiles of the subducted oceanic crust in the upper mantle The low‐velocity anomalies within the subducted oceanic crust at 150–250 km depth should be a net effect of water and carbon

The effect of dynamic recrystallization (DRX) on the microstructure and mechanical properties of 6063 aluminum alloy profile during porthole die extrusion was studied through experiment and simulation. The grain morphology was observed by means of electron backscatter diffraction (EBSD) technology. The results show that, at low ram speeds, increasing the ram speed caused an increase in DRX fraction due to the increase of temperature and strain rate. In contrast, at high ram speeds, further increasing ram speed had much less effect on the temperature, and the DRX faction decreased due to high stain rates. The microhardness and fraction of low angle boundaries in the welding zones were lower than those in the matrix zones. The grain size in the welding zone was smaller than that in the matrix zone due to lower DRX fraction. The decrease of grain size and increase of extrudate temperature were beneficial to the improvement of microhardness.