Selective hydrogenolysis of glycerol to 1,3‐propanediol（1,3‐PD） is an important yet challenging method for the transformation of biomass into value‐added chemicals due to steric hindrance and unfavorable thermody...Selective hydrogenolysis of glycerol to 1,3‐propanediol（1,3‐PD） is an important yet challenging method for the transformation of biomass into value‐added chemicals due to steric hindrance and unfavorable thermodynamics. In previous studies, chemoselective performances were found de‐manding and sensitive to H2 pressure. In this regard, we manipulate the chemical/physical charac‐teristics of the catalyst supports via doping Nb into WOx and prepared 1D needle‐, 2D flake‐, and 3D sphere‐stack mesoporous structured Nb‐WOx with increased surface acid sites. Moreover, Nb dop‐ing can successfully inhibit the over‐reduction of active W species during glycerol hydrogenolysis and substantially broaden the optimal H2 pressure from 1 to 5 MPa. When Nb doping is 2%, sup‐ported Pt catalysts showed promising performance for the selective hydrogenolysis of glycerol to 1,3‐PD over an unprecedentedly wide H2 pressure range, which will guarantee better catalyst sta‐bility in the long run, as well as expand their applications to other hydrogen‐related reactions.展开更多
Diverse promoters,including noble metals（such as Ru,Ir and Rh） and transition metal oxides（such as Re,La,Fe,Zr,Sn and Ce oxides） were introduced into Pt/WOx and Pt/WOx/Al2O3 catalysts to investigate the ability of...Diverse promoters,including noble metals（such as Ru,Ir and Rh） and transition metal oxides（such as Re,La,Fe,Zr,Sn and Ce oxides） were introduced into Pt/WOx and Pt/WOx/Al2O3 catalysts to investigate the ability of these promoters to modify activity and selectivity during glycerol hydrogenolysis to 1,3-propanediol.Among these,La exhibited the greatest promotional effect;the introduction of 0.1% La to the Pt/WOx improved activity,selectivity and stability,although the significant increase in selectivity came at the cost of a slight activity loss in the case of the Pt/WOx/Al2O3 catalyst.Transmission electron microscopy,high angle annular dark field scanning tunneling electron microscopy and NH3-temperature programmed desorption all demonstrated that the introduction of La generates a greater quantity of acidic sites on the catalyst surface,and that the majority of the La species are associated with Pt particles.Most of the other additives resulted in only minimal improvements or even detrimental effects with regard to both activity and selectivity,although some appear to improve the stability of the catalyst.展开更多
The tectonic setting of the northern Alxa region during the Late Paleozoic is highly controversial.The key to resolve this controversy is to recognize the Late Paleozoic magmatic processes in the northern Alxa.In this...The tectonic setting of the northern Alxa region during the Late Paleozoic is highly controversial.The key to resolve this controversy is to recognize the Late Paleozoic magmatic processes in the northern Alxa.In this paper,we present new zircon U-Pb ages,Hf-isotopic compositions and whole-rock geochemical data of four granitoids along the Zhusileng-Hangwula Tectonic Belt in the northern Alxa region that could provide critical information about the tectonic evolution of this region.The zircon U-Pb data could be grouped as two phases:Late Devonian granite and diorite(ca.373-360 Ma),and Late Carboniferous granodiorite(ca.318 Ma).The Late Devonian granites and diorites are metaluminous to slightly peraluminous,with A/CNK and A/NK ratios of 0.90-1.11 and0.95-2.19,respectively.The Late Devonian diorites are characterized by high MgO,Cr and Ni contents and MgO#values,together with variableεHf(t)values from-1.0 to+1.3 and old TDM2 ages varied from 1283 Ma to 1426 Ma,indicating the primary magma was potentially derived from magma mixing of depleted mantle with Mesoproterozoic continental crust.Even though the Late Devonian granites yielded most positive and minor negative eHf(t)values between-1.1 to+5.7(three grains are negative)with two-stage model ages(TDM2)of 1003-1438 Ma,they display low MgO,Cr and Ni contents and MgO#values,suggesting that they were mainly derived from juvenile crustal materials,mixed with a small amount of ancient crust.The Late Carboniferous granitoids are metaluminous and medium-K calc-alkaline series,with A/CNK and A/NK ratios ranging from 0.88 to 0.95 and1.75 to 1.90,respectively.These rocks were potentially derived from juvenile crustal materials mixed with depleted mantle,as evidenced by their highεHf(t)values(+11.6 to+14.1)and young TDM2 ages(427 Ma to 586 Ma),as well as high Mg#values,and MgO,Ni and Cr contents.Our data,along with available sedimentary evidence and previous researches,indicate that the Late Devonian and Late Carboniferous rocks are arc-related granitoids under the subduction setting.The identification of arc-related granitoids in the northern Alxa region not only reveals the Late Paleozoic magmatic process in response to the subduction of Paleo Asian Ocean,but also provide significant constrains to the tectonic evolution of the Central Asian Orogenic Belt.展开更多
The Liupanshan Basin constitutes a major portion of the northern North-South tectonic belt. The Lower Cretaceous strata in the Liupanshan Basin recorded the tectono-sedimentary evolution processes of this area and are...The Liupanshan Basin constitutes a major portion of the northern North-South tectonic belt. The Lower Cretaceous strata in the Liupanshan Basin recorded the tectono-sedimentary evolution processes of this area and are pivotal for understanding the original sedimentary appearance of the Liupanshan Basin. In this work, we present a study of provenance and tectono-sedimentary evolution of the Liupanshan Basin during the Early Cretaceous. Integrated-paleocurrent directions, gravel clast compositions, and detrital zircon U-Pb isotopic analysis of the Lower Cretaceous Sanqiao and Heshangpu formations were applied to determine the provenance. The gravel clast compositions of Sanqiao Formation conglomerates(mainly including magmatic rocks, metamorphic rocks and limestones) display various features in different places, revealing different rock components of source areas. The paleocurrent directions of the Sanqiao and Heshangpu formations suggest that the sediments were transported from the basin margin to the center. Detrital zircons of two samples from the Huoshizhai Section(northwestern Liupanshan Basin) yield a dominant unimodal distribution from 420 to 500 Ma, suggesting a single-sourced provenance. Based on the above analyses, comparing to the magmatic records in the Qilian-Qinling orogenic belt, the detritus of the Sanqiao and Heshangpu formations were mainly from the proximal metamorphic and magmatic rocks of the Qilian-Qinling orogenic belt and the limestones of the archaic uplift. Combined with sedimentary characteristics, we concluded that the Liupanshan Basin experienced multi-stage evolution history:(1) the early rifting extension stage(Sanqiao Period),(2) the middle spanning and depression stage(Heshangpu–Early Naijiahe Period), and(3) the late extinction stage(Late Naijiahe Period). The evolution of Liupanshan Basin is closely related to that of Ordos Basin and it is further associated with tectonic transition of the northern North-South tectonic belt.展开更多
Owing to the atomic dispersion of active sites via electronic interaction with supports,single-atom catalysts(SACs)grant maximum utilization of metals with unique activity and/or selectivity in various catalytic proce...Owing to the atomic dispersion of active sites via electronic interaction with supports,single-atom catalysts(SACs)grant maximum utilization of metals with unique activity and/or selectivity in various catalytic processes.However,the stability of single atoms under oxygen-poor conditions,and the mechanism of hydrogen activation on SACs remain elusive.Here,through a combination of theoretical calculation and experiments,the stabilization of metal single atoms on tungsten oxide and its catalytic properties in H2 activation are investigated.Our calculation results indicate that the oxygen defects on the WO3(001)surface play a vital role in the stabilization of single metal atoms through electron transfer from the oxygen vacancies to the metal atoms.In comparison with Pd and Au,Pt single atoms possess greatly enhanced stability on the WOx(001)surface and carry negative charge,facilitating the dissociation of H-2 to metal-H species(Hδ-)via homolytic cleavage of H2 similar to that occurring in metal ensembles.More importantly,the facile diffusion of Pt-H to the WOx support results in the formation of Bronsted acid sites(Hδ+),imparting bifunctionality to Pt1/WOx.The dynamic formation of Br?nsted acid sites in hydrogen atmosphere proved to be the key to chemoselective hydrogenolysis of glycerol into 1,3-propanediol,which was experimentally demonstrated on the Pt1/WOx catalyst.展开更多
Objective:The choice of chemotherapeutic regimen for triple-negative breast cancer(TNBC)remains controversial.Homologous recombination deficiency(HRD)has attracted increasing attention in informing chemotherapy treatm...Objective:The choice of chemotherapeutic regimen for triple-negative breast cancer(TNBC)remains controversial.Homologous recombination deficiency(HRD)has attracted increasing attention in informing chemotherapy treatment.This study was aimed at investigating the feasibility of HRD as a clinically actionable biomarker for platinum-containing and platinum-free therapy.Methods:Chinese patients with TNBC who received chemotherapy between May 1,2008 and March 31,2020 were retrospectively analyzed with a customized 3D-HRD panel.HRD positivity was defined by an HRD score≥30 or deleterious BRCA1/2 mutation.A total of 386 chemotherapy-treated patients with TNBC were screened from a surgical cohort(NCT01150513)and a metastatic cohort,and 189 patients with available clinical and tumor sequencing data were included.Results:In the entire cohort,49.2%(93/189)of patients were identified as HRD positive(40 with deleterious BRCA1/2 mutations and 53 with BRCA1/2 intact with an HRD score of≥30).In the first-line metastatic setting,platinum therapy was associated with longer median progression-free survival(mPFS)than platinum-free therapy[9.1 vs.3.0 months;hazard ratio(HR),0.43;95%confidence interval 0.22–0.84;P=0.01].Among HRD-positive patients,the mPFS was significantly longer in those treated with platinum rather than platinum-free therapy(13.6 vs.2.0 months;HR,0.11;P=0.001).Among patients administered a platinum-free regimen,HRD-negative patients showed a PFS significantly superior to that of HRD-positive patients(P=0.02;treatment-biomarker P-interaction=0.001).Similar results were observed in the BRCA1/2-intact subset.In the adjuvant setting,HRD-positive patients tended to benefit more from platinum chemotherapy than from platinum-free chemotherapy(P=0.05,P-interaction=0.02).Conclusions:HRD characterization may guide decision-making regarding the use of platinum treatment in patients with TNBC in both adjuvant and metastatic settings.展开更多
Pt/Au/WO_3 bimetallic catalysts were prepared by impregnation of Pt onto preformed Au/WO_3,obtained by a hexadecyl trmethyl ammonium bromide（CTAB）-assisted one-pot synthesis method.The resulting Pt/Au/WO_3 catalysts...Pt/Au/WO_3 bimetallic catalysts were prepared by impregnation of Pt onto preformed Au/WO_3,obtained by a hexadecyl trmethyl ammonium bromide（CTAB）-assisted one-pot synthesis method.The resulting Pt/Au/WO_3 catalysts exhibited remarkable synergistic effects for selective hydrogenolysis of glycerol to 1,3-propanediol. The characterization results showed that doping of Au promoted the reduction of both Pt and W at low temperatures and uniform dispersion of Pt on the WO_3 support. Furthermore, more low-valence Pt species were produced on the WO_3 surface after introduction of Au. These changes in electronic properties resulted in enhancement of both glycerol conversion and selectivity for 1,3-propanediol.展开更多
This investigation reports the first discovery of more than 70 tuff intervals in the Upper Triassic,South Qilian Basin.Petrographic and geochemical analyses were carried out on ten tuff samples and zircon U-Pb dating ...This investigation reports the first discovery of more than 70 tuff intervals in the Upper Triassic,South Qilian Basin.Petrographic and geochemical analyses were carried out on ten tuff samples and zircon U-Pb dating were on three.Thin section and X-ray diffraction(XRD)results indicate that the tuffs were composed of crystal shards and altered glass shards;crystal shards include plagio-clase and quartz.Most of the tuffs had been transformed into illite/smectite mixed-layers(I/S).In addition,calcite,pyrite,dolomite and siderite were also identified in some of the tuff samples.Analysis of major elements suggests that the tuffs are peraluminous high-K calcalkaline series.Trace elements indicate that the tuffs are enriched in high field strength elements(HFSE),including Th,U,Ta,Zr and Hf.Geochemical characteristics suggest that the tuffs originated from comendite pantellerite and rhyolite from within plate setting.Zircon U-Pb dating(236.0±1.7,231.4±1.6,and 223.1±3.9 Ma)indicate that the tuffs were erupted in the Late Triassic.Comparative chronology and geochemical analyses suggest that the West Qinling belt and the East Kunlun belt are the potential source regions of these tuffs,and they originated from the within plate magma during a post-collisional period.展开更多
A binder-free Ir-dispersed ordered mesoporous carbon（Ir-OMC） catalytic electrode has been prepared through a designed in-situ carbonization method, which involves coating resorcinol and formaldehyde mixtures with ir...A binder-free Ir-dispersed ordered mesoporous carbon（Ir-OMC） catalytic electrode has been prepared through a designed in-situ carbonization method, which involves coating resorcinol and formaldehyde mixtures with iridium precursors onto the three-dimensional nickel foam framework, followed by insitu calcination in Natmosphere at 800 ℃ for 3 h. This electrode shows a large surface area, ordered mesoporous structure and homogeneous distribution of metal nanoparticles. It presents good activity and stability towards hydrogen evolution reaction, which is attributed to the efficient mass and electron transport from the intimate contact among Ir nanoparticles, ordered mesoporous carbon matrix and 3 D conductive substrate. We hope that this in-situ carbonization synthetic route can also be applied to design more high-performance catalysts for water splitting, fuel cells and other clean energy devices.展开更多
Lithium-ion batteries(LIBs)are widely used in portable consumer electronics,clean energy storage,and electric vehicle applications.However,challenges exist for LIBs,including high costs,safety issues,limited Li resour...Lithium-ion batteries(LIBs)are widely used in portable consumer electronics,clean energy storage,and electric vehicle applications.However,challenges exist for LIBs,including high costs,safety issues,limited Li resources,and manufacturingrelated pollution.In this paper,a novel manganese-based lithium-ion battery with a LiNi_(0.5)Mn_(1.5)O_(4) ‖ Mn_(3)O_(4) structure is reported that is mainly composed of environmental friendly manganese compounds,where Mn_(3)O_(4) and LiNi_(0.5)Mn_(1.5)O_(4) (LNMO)are adopted as the anode and cathode materials,respectively.The proposed structure improves battery safety and reduce costs compared with current battery technology,provides comparable energy density with that of traditional graphite-based batteries.First,the characteristics and the electrochemical performances of the Mn_(3)O_(4) anode and the LNMO cathode are investigated separately against Li metal in half cell configurations,with promising performances being demonstrated by both electrodes.Then,a full cell structure with Mn_(3)O_(4) against LNMO is constructed that provides an average discharge voltage of 3.5 V and an initial specific capacity of 86.2 mA;h;g−1.More importantly,the electrochemical performance of the LNMO‖ Mn_(3)O_(4) full cell and its possible decay mechanisms are discussed systemically;and efficient strategies are proposed to further improve both the electrochemical performance of Mn_(3)O_(4) and the stability of LNMO.展开更多
As a hydrocarbon-rich sedimentary basin in China,the Ordos Basin has enormous potential for shale gas resources.The shale of the Upper Carboniferous Benxi Formation is rich in organic matter,however,its palaeoenvironm...As a hydrocarbon-rich sedimentary basin in China,the Ordos Basin has enormous potential for shale gas resources.The shale of the Upper Carboniferous Benxi Formation is rich in organic matter,however,its palaeoenvironment and organic matter enrichment mode are yet to be revealed.In this study,the geochemical characteristics of the shale of the Benxi Formation in the east-central part of the Ordos Basin were analyzed to investigate its palaeoenvironment.At the same time,the organic matter enrichment modes in different sedimentary facies were compared and analyzed.The results indicate that:1)the shale of the Benxi Formation was mainly deposited on the continental margin and strong terrestrial clastic input;2)the deposition period of the Benxi Formation shale had a hot and humid climate with high palaeoproductivity and local volcanic hydrothermal fluid,and a high sedimentation rate with the strong stagnant environment.The bottom water was in dysoxic conditions and a semi-saline deposition environment;3)multiple factors,such as palaeoproductivity,volcanic hydrothermal,redox conditions,and palaeosalinity interact to influence the enrichment of shale organic matter in Benxi Formation;4)the organic matter enrichment modes of continental,marine-continental transitional,and marine shales can be classified into three types:“production mode”,“hybrid mode of preservation and production”,and“preservation mode”,respectively.This study provides a reference for the organic matter enrichment mode,shale gas formation conditions,and core area evaluation in these marine-continental transitional shales,and also offers new guidance for exploration ideas for shale gas in different sedimentary facies.展开更多
基金supported by the National Natural Science Foundation of China (2169008, 21690084, 21673228, 21303187, 21403218)the Strategic Priority Research Program of the Chinese Academy of Sciences (XDB17020100)+1 种基金DICP ZZBS 201612Key Projects for Fundamental Research and Development of China (2016YFA0202801)~~
文摘Selective hydrogenolysis of glycerol to 1,3‐propanediol（1,3‐PD） is an important yet challenging method for the transformation of biomass into value‐added chemicals due to steric hindrance and unfavorable thermodynamics. In previous studies, chemoselective performances were found de‐manding and sensitive to H2 pressure. In this regard, we manipulate the chemical/physical charac‐teristics of the catalyst supports via doping Nb into WOx and prepared 1D needle‐, 2D flake‐, and 3D sphere‐stack mesoporous structured Nb‐WOx with increased surface acid sites. Moreover, Nb dop‐ing can successfully inhibit the over‐reduction of active W species during glycerol hydrogenolysis and substantially broaden the optimal H2 pressure from 1 to 5 MPa. When Nb doping is 2%, sup‐ported Pt catalysts showed promising performance for the selective hydrogenolysis of glycerol to 1,3‐PD over an unprecedentedly wide H2 pressure range, which will guarantee better catalyst sta‐bility in the long run, as well as expand their applications to other hydrogen‐related reactions.
基金supported by the National Natural Science Foundation of China(21176235,21373206,21303187)~~
文摘Diverse promoters,including noble metals（such as Ru,Ir and Rh） and transition metal oxides（such as Re,La,Fe,Zr,Sn and Ce oxides） were introduced into Pt/WOx and Pt/WOx/Al2O3 catalysts to investigate the ability of these promoters to modify activity and selectivity during glycerol hydrogenolysis to 1,3-propanediol.Among these,La exhibited the greatest promotional effect;the introduction of 0.1% La to the Pt/WOx improved activity,selectivity and stability,although the significant increase in selectivity came at the cost of a slight activity loss in the case of the Pt/WOx/Al2O3 catalyst.Transmission electron microscopy,high angle annular dark field scanning tunneling electron microscopy and NH3-temperature programmed desorption all demonstrated that the introduction of La generates a greater quantity of acidic sites on the catalyst surface,and that the majority of the La species are associated with Pt particles.Most of the other additives resulted in only minimal improvements or even detrimental effects with regard to both activity and selectivity,although some appear to improve the stability of the catalyst.
基金granted by the National Natural Science Foundation of China(Grant Nos.41802119 and 41330315)the Special Projects of China Geological Survey(Grant No.121201011000161111)Doctor’s Fund of Xi’an University of Science and Technology(Grant No.6310117052)。
文摘The tectonic setting of the northern Alxa region during the Late Paleozoic is highly controversial.The key to resolve this controversy is to recognize the Late Paleozoic magmatic processes in the northern Alxa.In this paper,we present new zircon U-Pb ages,Hf-isotopic compositions and whole-rock geochemical data of four granitoids along the Zhusileng-Hangwula Tectonic Belt in the northern Alxa region that could provide critical information about the tectonic evolution of this region.The zircon U-Pb data could be grouped as two phases:Late Devonian granite and diorite(ca.373-360 Ma),and Late Carboniferous granodiorite(ca.318 Ma).The Late Devonian granites and diorites are metaluminous to slightly peraluminous,with A/CNK and A/NK ratios of 0.90-1.11 and0.95-2.19,respectively.The Late Devonian diorites are characterized by high MgO,Cr and Ni contents and MgO#values,together with variableεHf(t)values from-1.0 to+1.3 and old TDM2 ages varied from 1283 Ma to 1426 Ma,indicating the primary magma was potentially derived from magma mixing of depleted mantle with Mesoproterozoic continental crust.Even though the Late Devonian granites yielded most positive and minor negative eHf(t)values between-1.1 to+5.7(three grains are negative)with two-stage model ages(TDM2)of 1003-1438 Ma,they display low MgO,Cr and Ni contents and MgO#values,suggesting that they were mainly derived from juvenile crustal materials,mixed with a small amount of ancient crust.The Late Carboniferous granitoids are metaluminous and medium-K calc-alkaline series,with A/CNK and A/NK ratios ranging from 0.88 to 0.95 and1.75 to 1.90,respectively.These rocks were potentially derived from juvenile crustal materials mixed with depleted mantle,as evidenced by their highεHf(t)values(+11.6 to+14.1)and young TDM2 ages(427 Ma to 586 Ma),as well as high Mg#values,and MgO,Ni and Cr contents.Our data,along with available sedimentary evidence and previous researches,indicate that the Late Devonian and Late Carboniferous rocks are arc-related granitoids under the subduction setting.The identification of arc-related granitoids in the northern Alxa region not only reveals the Late Paleozoic magmatic process in response to the subduction of Paleo Asian Ocean,but also provide significant constrains to the tectonic evolution of the Central Asian Orogenic Belt.
基金supported financially by the National Natural Science Foundation of China (Nos. 41802119 and 41330315)Natural Science Foundation of Shaanxi (No. 2019JQ-088)+1 种基金China Postdoctoral Science Foundation (No. 2019M663779)Doctor’s Foundation of Xi’an University of Science and Technology (No. 6310117052)。
文摘The Liupanshan Basin constitutes a major portion of the northern North-South tectonic belt. The Lower Cretaceous strata in the Liupanshan Basin recorded the tectono-sedimentary evolution processes of this area and are pivotal for understanding the original sedimentary appearance of the Liupanshan Basin. In this work, we present a study of provenance and tectono-sedimentary evolution of the Liupanshan Basin during the Early Cretaceous. Integrated-paleocurrent directions, gravel clast compositions, and detrital zircon U-Pb isotopic analysis of the Lower Cretaceous Sanqiao and Heshangpu formations were applied to determine the provenance. The gravel clast compositions of Sanqiao Formation conglomerates(mainly including magmatic rocks, metamorphic rocks and limestones) display various features in different places, revealing different rock components of source areas. The paleocurrent directions of the Sanqiao and Heshangpu formations suggest that the sediments were transported from the basin margin to the center. Detrital zircons of two samples from the Huoshizhai Section(northwestern Liupanshan Basin) yield a dominant unimodal distribution from 420 to 500 Ma, suggesting a single-sourced provenance. Based on the above analyses, comparing to the magmatic records in the Qilian-Qinling orogenic belt, the detritus of the Sanqiao and Heshangpu formations were mainly from the proximal metamorphic and magmatic rocks of the Qilian-Qinling orogenic belt and the limestones of the archaic uplift. Combined with sedimentary characteristics, we concluded that the Liupanshan Basin experienced multi-stage evolution history:(1) the early rifting extension stage(Sanqiao Period),(2) the middle spanning and depression stage(Heshangpu–Early Naijiahe Period), and(3) the late extinction stage(Late Naijiahe Period). The evolution of Liupanshan Basin is closely related to that of Ordos Basin and it is further associated with tectonic transition of the northern North-South tectonic belt.
基金supported by the National Key R&D Program of China(2018YFB1501602 and 2016YFA0202801)the National Natural Science Foundation of China(21690080,21690084,21673228,21721004,21776269,and 21606227)+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB17020100)Dalian National Laboratory for Clean Energy(DNL180303)~~
文摘Owing to the atomic dispersion of active sites via electronic interaction with supports,single-atom catalysts(SACs)grant maximum utilization of metals with unique activity and/or selectivity in various catalytic processes.However,the stability of single atoms under oxygen-poor conditions,and the mechanism of hydrogen activation on SACs remain elusive.Here,through a combination of theoretical calculation and experiments,the stabilization of metal single atoms on tungsten oxide and its catalytic properties in H2 activation are investigated.Our calculation results indicate that the oxygen defects on the WO3(001)surface play a vital role in the stabilization of single metal atoms through electron transfer from the oxygen vacancies to the metal atoms.In comparison with Pd and Au,Pt single atoms possess greatly enhanced stability on the WOx(001)surface and carry negative charge,facilitating the dissociation of H-2 to metal-H species(Hδ-)via homolytic cleavage of H2 similar to that occurring in metal ensembles.More importantly,the facile diffusion of Pt-H to the WOx support results in the formation of Bronsted acid sites(Hδ+),imparting bifunctionality to Pt1/WOx.The dynamic formation of Br?nsted acid sites in hydrogen atmosphere proved to be the key to chemoselective hydrogenolysis of glycerol into 1,3-propanediol,which was experimentally demonstrated on the Pt1/WOx catalyst.
基金granted by Capital’s Funds for Health Improvement and Research(Grant No.2018-2-4023)the National Natural Science Foundation of China(Grant No.82001559)。
文摘Objective:The choice of chemotherapeutic regimen for triple-negative breast cancer(TNBC)remains controversial.Homologous recombination deficiency(HRD)has attracted increasing attention in informing chemotherapy treatment.This study was aimed at investigating the feasibility of HRD as a clinically actionable biomarker for platinum-containing and platinum-free therapy.Methods:Chinese patients with TNBC who received chemotherapy between May 1,2008 and March 31,2020 were retrospectively analyzed with a customized 3D-HRD panel.HRD positivity was defined by an HRD score≥30 or deleterious BRCA1/2 mutation.A total of 386 chemotherapy-treated patients with TNBC were screened from a surgical cohort(NCT01150513)and a metastatic cohort,and 189 patients with available clinical and tumor sequencing data were included.Results:In the entire cohort,49.2%(93/189)of patients were identified as HRD positive(40 with deleterious BRCA1/2 mutations and 53 with BRCA1/2 intact with an HRD score of≥30).In the first-line metastatic setting,platinum therapy was associated with longer median progression-free survival(mPFS)than platinum-free therapy[9.1 vs.3.0 months;hazard ratio(HR),0.43;95%confidence interval 0.22–0.84;P=0.01].Among HRD-positive patients,the mPFS was significantly longer in those treated with platinum rather than platinum-free therapy(13.6 vs.2.0 months;HR,0.11;P=0.001).Among patients administered a platinum-free regimen,HRD-negative patients showed a PFS significantly superior to that of HRD-positive patients(P=0.02;treatment-biomarker P-interaction=0.001).Similar results were observed in the BRCA1/2-intact subset.In the adjuvant setting,HRD-positive patients tended to benefit more from platinum chemotherapy than from platinum-free chemotherapy(P=0.05,P-interaction=0.02).Conclusions:HRD characterization may guide decision-making regarding the use of platinum treatment in patients with TNBC in both adjuvant and metastatic settings.
基金supported by the National Natural Science Foundation of China(21690080,21690084,21721004,21673228)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB17020100)the National Key Projects for Fundamental Research and Development of China(2016YFA0202801)~~
文摘Pt/Au/WO_3 bimetallic catalysts were prepared by impregnation of Pt onto preformed Au/WO_3,obtained by a hexadecyl trmethyl ammonium bromide（CTAB）-assisted one-pot synthesis method.The resulting Pt/Au/WO_3 catalysts exhibited remarkable synergistic effects for selective hydrogenolysis of glycerol to 1,3-propanediol. The characterization results showed that doping of Au promoted the reduction of both Pt and W at low temperatures and uniform dispersion of Pt on the WO_3 support. Furthermore, more low-valence Pt species were produced on the WO_3 surface after introduction of Au. These changes in electronic properties resulted in enhancement of both glycerol conversion and selectivity for 1,3-propanediol.
基金supported by the National Natural Science Foundation of China(Nos.41702144,42002194)the Natural Science Basic Research Plan of Shaanxi Province,China(Nos.2019JQ-991,2020JQ-746).
文摘This investigation reports the first discovery of more than 70 tuff intervals in the Upper Triassic,South Qilian Basin.Petrographic and geochemical analyses were carried out on ten tuff samples and zircon U-Pb dating were on three.Thin section and X-ray diffraction(XRD)results indicate that the tuffs were composed of crystal shards and altered glass shards;crystal shards include plagio-clase and quartz.Most of the tuffs had been transformed into illite/smectite mixed-layers(I/S).In addition,calcite,pyrite,dolomite and siderite were also identified in some of the tuff samples.Analysis of major elements suggests that the tuffs are peraluminous high-K calcalkaline series.Trace elements indicate that the tuffs are enriched in high field strength elements(HFSE),including Th,U,Ta,Zr and Hf.Geochemical characteristics suggest that the tuffs originated from comendite pantellerite and rhyolite from within plate setting.Zircon U-Pb dating(236.0±1.7,231.4±1.6,and 223.1±3.9 Ma)indicate that the tuffs were erupted in the Late Triassic.Comparative chronology and geochemical analyses suggest that the West Qinling belt and the East Kunlun belt are the potential source regions of these tuffs,and they originated from the within plate magma during a post-collisional period.
基金support of the National Natural Science Foundation of China (21403218, 21476226, 21403029)Ministry of Science and Technology of the People’s Republic of China under contact of 2016YFA0202800+2 种基金the Youth Innovation Promotion Association of the CASthe Scientific Research Project of the Education Department of Liaoning Province (L2014022)the Fundamental Research Funds for the Central Universities (DUT15ZD225)
文摘A binder-free Ir-dispersed ordered mesoporous carbon（Ir-OMC） catalytic electrode has been prepared through a designed in-situ carbonization method, which involves coating resorcinol and formaldehyde mixtures with iridium precursors onto the three-dimensional nickel foam framework, followed by insitu calcination in Natmosphere at 800 ℃ for 3 h. This electrode shows a large surface area, ordered mesoporous structure and homogeneous distribution of metal nanoparticles. It presents good activity and stability towards hydrogen evolution reaction, which is attributed to the efficient mass and electron transport from the intimate contact among Ir nanoparticles, ordered mesoporous carbon matrix and 3 D conductive substrate. We hope that this in-situ carbonization synthetic route can also be applied to design more high-performance catalysts for water splitting, fuel cells and other clean energy devices.
基金support provided by the National Natural Science Foundation of China(NSFC)(Nos.51602058,51702103)the Special Support Plan for High-Level Talents of Guangdong Province(No.2017TQ04N840)the Science and Technology Planning Project of Guangdong Province(Nos.2017A010103011,2017A030313081).
文摘Lithium-ion batteries(LIBs)are widely used in portable consumer electronics,clean energy storage,and electric vehicle applications.However,challenges exist for LIBs,including high costs,safety issues,limited Li resources,and manufacturingrelated pollution.In this paper,a novel manganese-based lithium-ion battery with a LiNi_(0.5)Mn_(1.5)O_(4) ‖ Mn_(3)O_(4) structure is reported that is mainly composed of environmental friendly manganese compounds,where Mn_(3)O_(4) and LiNi_(0.5)Mn_(1.5)O_(4) (LNMO)are adopted as the anode and cathode materials,respectively.The proposed structure improves battery safety and reduce costs compared with current battery technology,provides comparable energy density with that of traditional graphite-based batteries.First,the characteristics and the electrochemical performances of the Mn_(3)O_(4) anode and the LNMO cathode are investigated separately against Li metal in half cell configurations,with promising performances being demonstrated by both electrodes.Then,a full cell structure with Mn_(3)O_(4) against LNMO is constructed that provides an average discharge voltage of 3.5 V and an initial specific capacity of 86.2 mA;h;g−1.More importantly,the electrochemical performance of the LNMO‖ Mn_(3)O_(4) full cell and its possible decay mechanisms are discussed systemically;and efficient strategies are proposed to further improve both the electrochemical performance of Mn_(3)O_(4) and the stability of LNMO.
基金supported from the Natural Science Basic Research Program of Shaanxi Province(No.2020JQ-744)China Postdoctoral Science Foundation(No.2020M673443)+2 种基金Shaanxi Provincial Education Department general special project(No.21JK0775)Opening Project of Key Laboratory of Coal Resources Exploration and Comprehensive Utilization,Ministry of Natural Resources(No.KF2021-7)National Natural Science Foundation of China(Grant No.4210021463).
文摘As a hydrocarbon-rich sedimentary basin in China,the Ordos Basin has enormous potential for shale gas resources.The shale of the Upper Carboniferous Benxi Formation is rich in organic matter,however,its palaeoenvironment and organic matter enrichment mode are yet to be revealed.In this study,the geochemical characteristics of the shale of the Benxi Formation in the east-central part of the Ordos Basin were analyzed to investigate its palaeoenvironment.At the same time,the organic matter enrichment modes in different sedimentary facies were compared and analyzed.The results indicate that:1)the shale of the Benxi Formation was mainly deposited on the continental margin and strong terrestrial clastic input;2)the deposition period of the Benxi Formation shale had a hot and humid climate with high palaeoproductivity and local volcanic hydrothermal fluid,and a high sedimentation rate with the strong stagnant environment.The bottom water was in dysoxic conditions and a semi-saline deposition environment;3)multiple factors,such as palaeoproductivity,volcanic hydrothermal,redox conditions,and palaeosalinity interact to influence the enrichment of shale organic matter in Benxi Formation;4)the organic matter enrichment modes of continental,marine-continental transitional,and marine shales can be classified into three types:“production mode”,“hybrid mode of preservation and production”,and“preservation mode”,respectively.This study provides a reference for the organic matter enrichment mode,shale gas formation conditions,and core area evaluation in these marine-continental transitional shales,and also offers new guidance for exploration ideas for shale gas in different sedimentary facies.
