Experiments carried out in the system granites-H2O-HF at 0. 1 GPa show that the crystal-liquid equllibrium temperature of quartz rises and that of alkali-feldspar goes down with increasing F content. The calculated re...Experiments carried out in the system granites-H2O-HF at 0. 1 GPa show that the crystal-liquid equllibrium temperature of quartz rises and that of alkali-feldspar goes down with increasing F content. The calculated results of quartz and alkali feldspar crystal-liquid equilibri-um show that the activity of SiO2 in melt increases and the activities of NaAlSi3O8 (Ab) and KAlSi3O8(Or) decrease, with a greater decreasing extent for than . These systematic changes are believed to be caused by F complexing with Al, Na, K, but not Si in the melt,and are consistent with F decomposing AlO2 tetrahedra and more preferentially forming com-plexes with Na than K. The comarison between effects of F and H2O on phase equilibrium suggests that the maximum difference affecting melt structure between F and OH is F complex-ing without Si and OH complexing with Si in granitic melt.展开更多
Achieving room-temperature superconductivity has been an enduring scientific quest,while hydrogen-rich compounds have emerged as highly promising candidates.Here,we systematically investigated the thermodynamic stabil...Achieving room-temperature superconductivity has been an enduring scientific quest,while hydrogen-rich compounds have emerged as highly promising candidates.Here,we systematically investigated the thermodynamic stability,crystal structure,electronic properties,and superconductivity within the ternary Y-Hf-H system under high pressure.Several distinct hydrides have been revealed,in which the hydrogen atoms are present in various hydrogenic motifs.A15-type hydride P_(m)3-YHfH_(6)with isolated H−is predicted to be dynamically stabilized down to 10GPa.The H atoms form pentagonal graphene-like layered-H10 anions in the Hf plane of P6-YHfH_(19),with aT_(c)of 95K at 100GPa.There are H cages in C_(mmm)-Y_(3)HfH_(24),and attributed to the robust electron–phonon coupling and high electronic density of states of hydrogen at the Fermi level,it demonstrates near-room temperature superconductivity with a T_(c)of 275K at 250GPa.Our work makes contributions to the understanding of the fundamental properties of ternary hydrides under high pressure and provides essential references for further research in this field.展开更多
The influence of Hf on the precipitation behavior of γ'phase and the subsequent tensile properties of a Ni-Cr-Mo alloy after long-term thermal exposure was investigated.The results reveal that the addition of Hf ...The influence of Hf on the precipitation behavior of γ'phase and the subsequent tensile properties of a Ni-Cr-Mo alloy after long-term thermal exposure was investigated.The results reveal that the addition of Hf increases the average diameter ofγ'phases after thermal exposure at 700℃ for 5000 h,which enhances the critical resolved shear stress required for dislocations to shear the γ'phases in the Ni-Cr-Mo alloy.Simultaneously,element Hf incorporated into the γ'phases increases the lattice mismatch between the γ'and γ phase,thereby strengthening the coherency strengthening effect.These two factors collectively contribute to the enhanced strength of the alloy.Thus,Hf alloying effectively improves the yield strength of the Ni-Cr-Mo alloy after thermal exposure at 700℃.展开更多
This paper investigates the channel diversity problem in high frequency(HF) communication systems. Due to the limited HF spectrum resources, a HF communication system with shared channels is considered, where each use...This paper investigates the channel diversity problem in high frequency(HF) communication systems. Due to the limited HF spectrum resources, a HF communication system with shared channels is considered, where each user equipment(UE) has individual communication demand. In order to maximize the communication probability of the whole system, a matching-potential game framework is designed. In detail, the channel diversity problem is decomposed into two sub-problems. One is channel-transmitter matching problem, which can be formulated as a many-to-one matching game. The other is the transmitter allocation problem which decides the transmission object that each transmitter communicates with under channel-transmitter matching result, and this sub-problem can be modeled as a potential game. A multiple round stable matching algorithm(MRSMA) is proposed, which obtains a stable matching result for the first sub-problem, and a distributed BR-based transmitter allocation algorithm(DBRTAA) is designed to reach Nash Equilibrium(NE) of the second sub-problem. Simulation results verify the effectiveness and superiority of the proposed method.展开更多
The Wurinitu Mo deposit is one of the newly found molybdenum deposits in the southwestern part of the late Paleozoic–Mesozoic Erenhot–Dong-Ujimqin metallogenic belt(S-EDMB),Inner Mongolia,China.In the present study,...The Wurinitu Mo deposit is one of the newly found molybdenum deposits in the southwestern part of the late Paleozoic–Mesozoic Erenhot–Dong-Ujimqin metallogenic belt(S-EDMB),Inner Mongolia,China.In the present study,the mineralization age of the Wurinitu deposit is constrained to 137.3±1.3 to 131.9±1.5 Ma based on a combination of the laser ablation–inductively coupled plasma–mass spectrometry(LA–ICP–MS)zircon U–Pb dating of the mineralization related fine-grained monzonitic granite and the post-mineralization granite porphyry.The results of zircon Lu–Hf isotopes,combined with the geochemical characteristics of the granites in the S-EDMB,suggest that the Wurinitu Mo deposit was formed in an extensional environment in relation to the subduction of the Paleo-Pacific plate in late Mesozoic.The Wurinitu deposit shares similarities with the classical Climax-type porphyry molybdenum deposits in tectonic setting,mineral assemblages,and metal zonation.展开更多
GdF3 was synthesized with Gd2O3 and NH4HF2 under atmospheric pressure and vacuum. The effects of pressure,temperature,and reactant ratio on the reaction process were investigated. A new mechanism for the synthesis of ...GdF3 was synthesized with Gd2O3 and NH4HF2 under atmospheric pressure and vacuum. The effects of pressure,temperature,and reactant ratio on the reaction process were investigated. A new mechanism for the synthesis of GdF3 was proposed. Powdered Gd2O3 started to react with NH4HF2 at low temperature,and the products were GdNH4F4,NH4F,NH3,and H2O. GdNH4F4 decomposed to GdF3 and NH4F after further high-temperature treatment,accompanying the volatilization and decomposition of NH4F. The whole process could be divided into three steps： synthesis,decomposition,and deamination. The initial and final reaction temperatures decreased under vacuum condition. An optimized process for the preparation of GdF3 was obtained： synthesis under atmospheric pressure at low temperature and decomposition and deamination under vacuum at high temperature.展开更多
The Sanchahe quartz monzonite intrusion is situated in the middle segment of the North Qinling tectonic belt, Central China mainland, and consists chiefly of sanukitoid–like and granodioritic-monzogranitic rocks. The...The Sanchahe quartz monzonite intrusion is situated in the middle segment of the North Qinling tectonic belt, Central China mainland, and consists chiefly of sanukitoid–like and granodioritic-monzogranitic rocks. The sanukitoid–like rocks are characterized by quartz monzonites, which display higher Mg#（55.0–59.0）, and enrichments in Na2 O＋K2 O（7.28–8.94 %）, Ni（21-2312 ppm）, Cr（56-4167 ppm）, Sr（553-923 ppm）, Ba（912-1355 ppm） and LREE（（La/Yb）N =9.47–15.3）, from negative to slightly positive Eu anomalies（δEu=＋0.61 to ＋1.10）, but also depletion in Nb, Ta and Ti. The granodioritic-monzogranitic rocks diaplay various Mg#of 6.00-53.0, high Na2 O＋K2 O（7.20– 8.30%）, Sr（455–1081 ppm） and（La/Yb）N（27.6–47.8）, with positive Eu anomalies（δEu=1.03–1.57） and depleted Nb, Ta and Ti. Laser ablation inductively coupled plasma mass spectrometry（LA-ICPMS） zircon U-Pb isotopic dating reveals that the sanukitoid-like rocks were emplaced at two episodes of magmatism at 457±3 Ma and 431±2 Ma, respectively. The monzogranites were emplaced at 445±7Ma. Sanukitoid–like rocks have their εHf（t） values ranging from ＋0.3 to ＋15.1 with Hf–depleted mantle model ages of 445 to 1056 Ma, and the monzogranite shows its εHf（t） values ranging from 21.6 to ＋10.8 with Hf–depleted mantle model ages of 635 to 3183 Ma. Petrological, geochemical and zircon Lu –Hf isotopic features indicate that the magmatic precursor of sanukitoid–like rocks was derived from partial melting of the depleted mantle wedge materials that were metasomatized by fluids and melts related to subduction of oceanic slab, subsequently the sanukitoid magma ascended to crust level. This emplaced mantle magma caused partial melting of crustally metamorphosed sedimentary rocks, and mixing with the crustal magma, and suffered fractional crystallization, which lead to formations of quartz monzonites. However, the magmatic precursor of the granodioritic-monzogranitic rocks were derived from partial melting of subducted oceanic slab basalts. Integrated previous investigation for the adackitic rocks in the south of the intrusion, the Sanchahe intrusion signed that the North Qinling tectonic zone was developed in an early Paleozoic transitionally tectonic background from an island arc to back–arc.展开更多
文摘Experiments carried out in the system granites-H2O-HF at 0. 1 GPa show that the crystal-liquid equllibrium temperature of quartz rises and that of alkali-feldspar goes down with increasing F content. The calculated results of quartz and alkali feldspar crystal-liquid equilibri-um show that the activity of SiO2 in melt increases and the activities of NaAlSi3O8 (Ab) and KAlSi3O8(Or) decrease, with a greater decreasing extent for than . These systematic changes are believed to be caused by F complexing with Al, Na, K, but not Si in the melt,and are consistent with F decomposing AlO2 tetrahedra and more preferentially forming com-plexes with Na than K. The comarison between effects of F and H2O on phase equilibrium suggests that the maximum difference affecting melt structure between F and OH is F complex-ing without Si and OH complexing with Si in granitic melt.
基金supported by the National Natural Science Foundation of China(Grant Nos.52072188,12122405,and 12274169)Program for Science and Technology Innovation Team in Zhejiang Province,China(Grant No.2021R01004)+2 种基金Natural Science Foundation of Zhejiang Province,China(Grant No.LQ24A040001)the Natural Science Foundation of Ningbo City,China(Grant No.2024J200)the Fundamental Research Funds for the Provincial Universities of Zhejiang(Grant No.SJLY2023003)。
文摘Achieving room-temperature superconductivity has been an enduring scientific quest,while hydrogen-rich compounds have emerged as highly promising candidates.Here,we systematically investigated the thermodynamic stability,crystal structure,electronic properties,and superconductivity within the ternary Y-Hf-H system under high pressure.Several distinct hydrides have been revealed,in which the hydrogen atoms are present in various hydrogenic motifs.A15-type hydride P_(m)3-YHfH_(6)with isolated H−is predicted to be dynamically stabilized down to 10GPa.The H atoms form pentagonal graphene-like layered-H10 anions in the Hf plane of P6-YHfH_(19),with aT_(c)of 95K at 100GPa.There are H cages in C_(mmm)-Y_(3)HfH_(24),and attributed to the robust electron–phonon coupling and high electronic density of states of hydrogen at the Fermi level,it demonstrates near-room temperature superconductivity with a T_(c)of 275K at 250GPa.Our work makes contributions to the understanding of the fundamental properties of ternary hydrides under high pressure and provides essential references for further research in this field.
基金National Key Research and Development Program of China(2021YFB3704103)National Natural Science Foundation of China(51571191)。
文摘The influence of Hf on the precipitation behavior of γ'phase and the subsequent tensile properties of a Ni-Cr-Mo alloy after long-term thermal exposure was investigated.The results reveal that the addition of Hf increases the average diameter ofγ'phases after thermal exposure at 700℃ for 5000 h,which enhances the critical resolved shear stress required for dislocations to shear the γ'phases in the Ni-Cr-Mo alloy.Simultaneously,element Hf incorporated into the γ'phases increases the lattice mismatch between the γ'and γ phase,thereby strengthening the coherency strengthening effect.These two factors collectively contribute to the enhanced strength of the alloy.Thus,Hf alloying effectively improves the yield strength of the Ni-Cr-Mo alloy after thermal exposure at 700℃.
基金supported by the Natural Science Foundation for Distinguished Young Scholars of Jiangsu Province under Grant No. BK20160034in part by the National Natural Science Foundation of China under Grant No. 61671473 and No. 61631020in part by the Open Research Foundation of Science and Technology on Communication Networks Laboratory
文摘This paper investigates the channel diversity problem in high frequency(HF) communication systems. Due to the limited HF spectrum resources, a HF communication system with shared channels is considered, where each user equipment(UE) has individual communication demand. In order to maximize the communication probability of the whole system, a matching-potential game framework is designed. In detail, the channel diversity problem is decomposed into two sub-problems. One is channel-transmitter matching problem, which can be formulated as a many-to-one matching game. The other is the transmitter allocation problem which decides the transmission object that each transmitter communicates with under channel-transmitter matching result, and this sub-problem can be modeled as a potential game. A multiple round stable matching algorithm(MRSMA) is proposed, which obtains a stable matching result for the first sub-problem, and a distributed BR-based transmitter allocation algorithm(DBRTAA) is designed to reach Nash Equilibrium(NE) of the second sub-problem. Simulation results verify the effectiveness and superiority of the proposed method.
基金the joint financial support from the National Natural Science Foundation of China(No 41302263)a research project on“Quantitative models for prediction of strategic mineral resources in China”(201211022)by China Geological Survey
文摘The Wurinitu Mo deposit is one of the newly found molybdenum deposits in the southwestern part of the late Paleozoic–Mesozoic Erenhot–Dong-Ujimqin metallogenic belt(S-EDMB),Inner Mongolia,China.In the present study,the mineralization age of the Wurinitu deposit is constrained to 137.3±1.3 to 131.9±1.5 Ma based on a combination of the laser ablation–inductively coupled plasma–mass spectrometry(LA–ICP–MS)zircon U–Pb dating of the mineralization related fine-grained monzonitic granite and the post-mineralization granite porphyry.The results of zircon Lu–Hf isotopes,combined with the geochemical characteristics of the granites in the S-EDMB,suggest that the Wurinitu Mo deposit was formed in an extensional environment in relation to the subduction of the Paleo-Pacific plate in late Mesozoic.The Wurinitu deposit shares similarities with the classical Climax-type porphyry molybdenum deposits in tectonic setting,mineral assemblages,and metal zonation.
文摘GdF3 was synthesized with Gd2O3 and NH4HF2 under atmospheric pressure and vacuum. The effects of pressure,temperature,and reactant ratio on the reaction process were investigated. A new mechanism for the synthesis of GdF3 was proposed. Powdered Gd2O3 started to react with NH4HF2 at low temperature,and the products were GdNH4F4,NH4F,NH3,and H2O. GdNH4F4 decomposed to GdF3 and NH4F after further high-temperature treatment,accompanying the volatilization and decomposition of NH4F. The whole process could be divided into three steps： synthesis,decomposition,and deamination. The initial and final reaction temperatures decreased under vacuum condition. An optimized process for the preparation of GdF3 was obtained： synthesis under atmospheric pressure at low temperature and decomposition and deamination under vacuum at high temperature.
基金financially supported by the National Geological Survey Project and National Scientific and Technological Support Project (Grant Nos. 1212011085534 and 2011BAB04B05)
文摘The Sanchahe quartz monzonite intrusion is situated in the middle segment of the North Qinling tectonic belt, Central China mainland, and consists chiefly of sanukitoid–like and granodioritic-monzogranitic rocks. The sanukitoid–like rocks are characterized by quartz monzonites, which display higher Mg#（55.0–59.0）, and enrichments in Na2 O＋K2 O（7.28–8.94 %）, Ni（21-2312 ppm）, Cr（56-4167 ppm）, Sr（553-923 ppm）, Ba（912-1355 ppm） and LREE（（La/Yb）N =9.47–15.3）, from negative to slightly positive Eu anomalies（δEu=＋0.61 to ＋1.10）, but also depletion in Nb, Ta and Ti. The granodioritic-monzogranitic rocks diaplay various Mg#of 6.00-53.0, high Na2 O＋K2 O（7.20– 8.30%）, Sr（455–1081 ppm） and（La/Yb）N（27.6–47.8）, with positive Eu anomalies（δEu=1.03–1.57） and depleted Nb, Ta and Ti. Laser ablation inductively coupled plasma mass spectrometry（LA-ICPMS） zircon U-Pb isotopic dating reveals that the sanukitoid-like rocks were emplaced at two episodes of magmatism at 457±3 Ma and 431±2 Ma, respectively. The monzogranites were emplaced at 445±7Ma. Sanukitoid–like rocks have their εHf（t） values ranging from ＋0.3 to ＋15.1 with Hf–depleted mantle model ages of 445 to 1056 Ma, and the monzogranite shows its εHf（t） values ranging from 21.6 to ＋10.8 with Hf–depleted mantle model ages of 635 to 3183 Ma. Petrological, geochemical and zircon Lu –Hf isotopic features indicate that the magmatic precursor of sanukitoid–like rocks was derived from partial melting of the depleted mantle wedge materials that were metasomatized by fluids and melts related to subduction of oceanic slab, subsequently the sanukitoid magma ascended to crust level. This emplaced mantle magma caused partial melting of crustally metamorphosed sedimentary rocks, and mixing with the crustal magma, and suffered fractional crystallization, which lead to formations of quartz monzonites. However, the magmatic precursor of the granodioritic-monzogranitic rocks were derived from partial melting of subducted oceanic slab basalts. Integrated previous investigation for the adackitic rocks in the south of the intrusion, the Sanchahe intrusion signed that the North Qinling tectonic zone was developed in an early Paleozoic transitionally tectonic background from an island arc to back–arc.
