The strong metal-support interaction inducing combined effect plays a crucial role in the catalysis reaction. Herein, we revealed that the combined advantages of MoSe_(2), Ru, and hollow carbon spheres in the form of ...The strong metal-support interaction inducing combined effect plays a crucial role in the catalysis reaction. Herein, we revealed that the combined advantages of MoSe_(2), Ru, and hollow carbon spheres in the form of Ru nanoparticles(NPs) anchored on a two-dimensionally ordered MoSe_(2) nanosheet-embedded mesoporous hollow carbon spheres surface(Ru/MoSe_(2)@MHCS) for the largely boosted hydrogen evolution reaction(HER) performance. The combined advantages from the conductive support, oxyphilic MoSe_(2), and Ru active sites imparted a strong synergistic effect and charge redistribution in the Ru periphery which induced high catalytic activity, stability, and kinetics for HER. Specifically, the obtained Ru/MoSe_(2)@MHCS required a small overpotential of 25.5 and 38.4 mV to drive the kinetic current density of 10 mA cm^(-2)both in acid and alkaline media, respectively, which was comparable to that of the Pt/C catalyst. Experimental and theoretical results demonstrated that the charge transfer from MoSe_(2) to Ru NPs enriched the electronic density of Ru sites and thus facilitated hydrogen adsorption and water dissociation. The current work showed the significant interfacial engineering in Ru-based catalysts development and catalysis promotion effect understanding via the metal-support interaction.展开更多
化石燃料的大量消耗所带来的全球性挑战推动人们大力发展清洁和可持续的能源.氢能作为一种绿色、无污染的能源载体,是能源向绿色经济转换的关键,而利用可再生能源进行的电解水制氢被认为是实现绿色制氢的最佳选择.然而由于析氧反应(OER...化石燃料的大量消耗所带来的全球性挑战推动人们大力发展清洁和可持续的能源.氢能作为一种绿色、无污染的能源载体,是能源向绿色经济转换的关键,而利用可再生能源进行的电解水制氢被认为是实现绿色制氢的最佳选择.然而由于析氧反应(OER)的氧化电位(1.23 V)较高,动力学缓慢,实际水电解需要更多的能量输入.具有低氧化电位的甲醇辅助水电解(0.016 V)可以匹配可再生能源实现低能耗电解制氢,受到了广泛关注.开发高效的用于催化甲醇氧化(MOR)和析氢反应(HER)的双功能催化剂是实现这一愿景的前提.传统的Pt基催化剂容易受到阳极侧MOR过程中产生的CO中间体毒化,严重影响甲醇辅助水电解制氢的效率.为了提升Pt基催化剂的催化活性和稳定性,一种有效的策略是引入合适的功能组分来促进催化反应.例如,贵金属颗粒和亲氧化成分(如过渡金属氧化物和磷化物)之间的金属-载体相互作用可以有效提高Pt基催化剂的抗CO中毒能力.过渡金属硒化物由于其优良的金属性和亲氧性作为催化促进剂受到越来越多的关注.硒化钼(MoSe_(2))具有良好的稳定性和导电性并且其2H相中的不饱和边缘具有水活化和解离活性,同时其吸附H原子的吉布斯自由能(ΔGH^(*))接近于零.考虑到MoSe_(2)的高水活化/解离能力,本文成功制备了二维MoSe_(2)纳米片负载的Pt纳米粒子复合催化剂(Pt/MoSe_(2))用于高效甲醇电解制氢.密度泛函理论计算表明,亲氧组分MoSe_(2)显著优化了CO^(*)和H^(*)在Pt表面的吸附能,从而大大提高了甲醇辅助水电解的活性和稳定性.其中,Pt/MoSe_(2)的甲醇氧化峰值电流密度为67.8 m Acm^(-2),是商业Pt/C催化剂的2.5倍;在10 m A·cm^(-2)的电流密度下,HER的过电位低至32 m V.由Pt/MoSe_(2)|Pt/MoSe_(2)组装的两电极电解槽驱动10 m A·cm^(-2)的电流密度仅需要0.67 V的电压,与相同条件下的水电解相比节省了约1.09 V的电池电压,大大降低了能量输入.催化性能的提升可以归因于改善的电荷转移以及Pt与亲氧MoSe_(2)之间的金属-载体相互作用,该相互作用使得Pt从MoSe_(2)载体上得到了部分电子,增加了Pt周围的电子密度,使得邻近Pt的d带中心下移,从而通过削弱CO-Pt键进而增强了Pt位点的抗CO中毒能力.综上,本文对开发用于甲醇辅助水电解制氢的新型双功能催化剂具有借鉴意义.展开更多
In the process of using the original key stratum theory to predict the height of a water-flowing fractured zone(WFZ),the influence of rock strata outside the calculation range on the rock strata within the calculation...In the process of using the original key stratum theory to predict the height of a water-flowing fractured zone(WFZ),the influence of rock strata outside the calculation range on the rock strata within the calculation range as well as the fact that the shape of the overburden deformation area will change with the excavation length are ignored.In this paper,an improved key stratum theory(IKS theory)was proposed by fixing these two shortcomings.Then,a WFZ height prediction method based on IKS theory was established and applied.First,the range of overburden involved in the analysis was determined according to the tensile stress distribution range above the goaf.Second,the key stratum in the overburden involved in the analysis was identified through IKS theory.Finally,the tendency of the WFZ to develop upward was determined by judging whether or not the identified key stratum will break.The proposed method was applied and verified in a mining case study,and the reasons for the differences in the development patterns between the WFZs in coalfields in Northwest and East China were also fully explained by this method.展开更多
Age-related osteoporosis is a metabolic skeletal disorder caused by estrogen deficiency in postmenopausal women.Prolonged use of anti-osteoporotic drugs such as bisphosphonates and FDA-approved anti-resorptive selecti...Age-related osteoporosis is a metabolic skeletal disorder caused by estrogen deficiency in postmenopausal women.Prolonged use of anti-osteoporotic drugs such as bisphosphonates and FDA-approved anti-resorptive selective estrogen receptor modulators(SERMs)has been associated with various clinical drawbacks.We recently discovered a low-molecular-weight biocompatible and osteoanabolic phytoprotein,called HKUOT-S2 protein(32 kDa),from Dioscorea opposita Thunb that can accelerate bone defect healing.Here,we demonstrated that the HKUOT-S2 protein treatment can enhance osteoblasts-induced ossification and suppress osteoporosis development by upregulating skeletal estrogen receptors(ERs)ERα,ERβ,and GPR30 expressions in vivo.Also,HKUOT-S2 protein estrogenic activities promoted hMSCs-osteoblasts differentiation and functions by increasing osteogenic markers,ALP,and RUNX2 expressions,ALP activity,and osteoblast biomineralization in vitro.Fulvestrant treatment impaired the HKUOT-S2 protein-induced ERs expressions,osteoblasts differentiation,and functions.Finally,we demonstrated that the HKUOT-S2 protein could bind to ERs to exert osteogenic and osteoanabolic properties.Our results showed that the biocompatible HKUOT-S2 protein can exert estrogenic and osteoanabolic properties by positively modulating skeletal estrogen receptor signaling to promote ossification and suppress osteoporosis.Currently,there is no or limited data if any,on osteoanabolic SERMs.The HKUOT-S2 protein can be applied as a new osteoanabolic SERM for osteoporosis treatment.展开更多
基金supported by the National Natural Science Foundation of China (21972124, 22272148)the Priority Academic Program Development of Jiangsu Higher Education Institution。
文摘The strong metal-support interaction inducing combined effect plays a crucial role in the catalysis reaction. Herein, we revealed that the combined advantages of MoSe_(2), Ru, and hollow carbon spheres in the form of Ru nanoparticles(NPs) anchored on a two-dimensionally ordered MoSe_(2) nanosheet-embedded mesoporous hollow carbon spheres surface(Ru/MoSe_(2)@MHCS) for the largely boosted hydrogen evolution reaction(HER) performance. The combined advantages from the conductive support, oxyphilic MoSe_(2), and Ru active sites imparted a strong synergistic effect and charge redistribution in the Ru periphery which induced high catalytic activity, stability, and kinetics for HER. Specifically, the obtained Ru/MoSe_(2)@MHCS required a small overpotential of 25.5 and 38.4 mV to drive the kinetic current density of 10 mA cm^(-2)both in acid and alkaline media, respectively, which was comparable to that of the Pt/C catalyst. Experimental and theoretical results demonstrated that the charge transfer from MoSe_(2) to Ru NPs enriched the electronic density of Ru sites and thus facilitated hydrogen adsorption and water dissociation. The current work showed the significant interfacial engineering in Ru-based catalysts development and catalysis promotion effect understanding via the metal-support interaction.
文摘化石燃料的大量消耗所带来的全球性挑战推动人们大力发展清洁和可持续的能源.氢能作为一种绿色、无污染的能源载体,是能源向绿色经济转换的关键,而利用可再生能源进行的电解水制氢被认为是实现绿色制氢的最佳选择.然而由于析氧反应(OER)的氧化电位(1.23 V)较高,动力学缓慢,实际水电解需要更多的能量输入.具有低氧化电位的甲醇辅助水电解(0.016 V)可以匹配可再生能源实现低能耗电解制氢,受到了广泛关注.开发高效的用于催化甲醇氧化(MOR)和析氢反应(HER)的双功能催化剂是实现这一愿景的前提.传统的Pt基催化剂容易受到阳极侧MOR过程中产生的CO中间体毒化,严重影响甲醇辅助水电解制氢的效率.为了提升Pt基催化剂的催化活性和稳定性,一种有效的策略是引入合适的功能组分来促进催化反应.例如,贵金属颗粒和亲氧化成分(如过渡金属氧化物和磷化物)之间的金属-载体相互作用可以有效提高Pt基催化剂的抗CO中毒能力.过渡金属硒化物由于其优良的金属性和亲氧性作为催化促进剂受到越来越多的关注.硒化钼(MoSe_(2))具有良好的稳定性和导电性并且其2H相中的不饱和边缘具有水活化和解离活性,同时其吸附H原子的吉布斯自由能(ΔGH^(*))接近于零.考虑到MoSe_(2)的高水活化/解离能力,本文成功制备了二维MoSe_(2)纳米片负载的Pt纳米粒子复合催化剂(Pt/MoSe_(2))用于高效甲醇电解制氢.密度泛函理论计算表明,亲氧组分MoSe_(2)显著优化了CO^(*)和H^(*)在Pt表面的吸附能,从而大大提高了甲醇辅助水电解的活性和稳定性.其中,Pt/MoSe_(2)的甲醇氧化峰值电流密度为67.8 m Acm^(-2),是商业Pt/C催化剂的2.5倍;在10 m A·cm^(-2)的电流密度下,HER的过电位低至32 m V.由Pt/MoSe_(2)|Pt/MoSe_(2)组装的两电极电解槽驱动10 m A·cm^(-2)的电流密度仅需要0.67 V的电压,与相同条件下的水电解相比节省了约1.09 V的电池电压,大大降低了能量输入.催化性能的提升可以归因于改善的电荷转移以及Pt与亲氧MoSe_(2)之间的金属-载体相互作用,该相互作用使得Pt从MoSe_(2)载体上得到了部分电子,增加了Pt周围的电子密度,使得邻近Pt的d带中心下移,从而通过削弱CO-Pt键进而增强了Pt位点的抗CO中毒能力.综上,本文对开发用于甲醇辅助水电解制氢的新型双功能催化剂具有借鉴意义.
基金supported by the Key Projects of Natural Science Foundation of China(No.41931284)the Scientific Research Start-Up Fund for High-Level Introduced Talents of Anhui University of Science and Technology(No.2022yjrc21).
文摘In the process of using the original key stratum theory to predict the height of a water-flowing fractured zone(WFZ),the influence of rock strata outside the calculation range on the rock strata within the calculation range as well as the fact that the shape of the overburden deformation area will change with the excavation length are ignored.In this paper,an improved key stratum theory(IKS theory)was proposed by fixing these two shortcomings.Then,a WFZ height prediction method based on IKS theory was established and applied.First,the range of overburden involved in the analysis was determined according to the tensile stress distribution range above the goaf.Second,the key stratum in the overburden involved in the analysis was identified through IKS theory.Finally,the tendency of the WFZ to develop upward was determined by judging whether or not the identified key stratum will break.The proposed method was applied and verified in a mining case study,and the reasons for the differences in the development patterns between the WFZs in coalfields in Northwest and East China were also fully explained by this method.
基金supported by the Seed Fund for Translational and Applied Research from the University Research Committee(URC),The University of Hong Kong(HKU),Hong Kong China(Project Codes:201910160024 and 202010160009).
文摘Age-related osteoporosis is a metabolic skeletal disorder caused by estrogen deficiency in postmenopausal women.Prolonged use of anti-osteoporotic drugs such as bisphosphonates and FDA-approved anti-resorptive selective estrogen receptor modulators(SERMs)has been associated with various clinical drawbacks.We recently discovered a low-molecular-weight biocompatible and osteoanabolic phytoprotein,called HKUOT-S2 protein(32 kDa),from Dioscorea opposita Thunb that can accelerate bone defect healing.Here,we demonstrated that the HKUOT-S2 protein treatment can enhance osteoblasts-induced ossification and suppress osteoporosis development by upregulating skeletal estrogen receptors(ERs)ERα,ERβ,and GPR30 expressions in vivo.Also,HKUOT-S2 protein estrogenic activities promoted hMSCs-osteoblasts differentiation and functions by increasing osteogenic markers,ALP,and RUNX2 expressions,ALP activity,and osteoblast biomineralization in vitro.Fulvestrant treatment impaired the HKUOT-S2 protein-induced ERs expressions,osteoblasts differentiation,and functions.Finally,we demonstrated that the HKUOT-S2 protein could bind to ERs to exert osteogenic and osteoanabolic properties.Our results showed that the biocompatible HKUOT-S2 protein can exert estrogenic and osteoanabolic properties by positively modulating skeletal estrogen receptor signaling to promote ossification and suppress osteoporosis.Currently,there is no or limited data if any,on osteoanabolic SERMs.The HKUOT-S2 protein can be applied as a new osteoanabolic SERM for osteoporosis treatment.
