This article investigated molybdenum recovery from oxygen pressure water leaching residue of Ni-Mo ore using alkaline leaching, followed by chemical treatment of leach liquor. Parameters affecting Mo leaching rate, su...This article investigated molybdenum recovery from oxygen pressure water leaching residue of Ni-Mo ore using alkaline leaching, followed by chemical treatment of leach liquor. Parameters affecting Mo leaching rate, such as sodium hydroxide concentration, reaction time, a liquid- to-solid ratio, and temperature for the preliminary alkaline leaching were experimentally determined. The results showed that more than 88 % of molybdenum was leached under the optimum conditions （2.5 ml.g-1 NaOH, 80 ℃, a liquid to solid ratio 3 ml.g-1, and reaction time 3 h）. After the purification of leach liquor, a CaMoO4 product of 99.2 % purity could be obtained by CaCla precipitation method. The whole Mo recovery reached about 82.7 %.展开更多
We present a faithful and efficient hyperentanglement purification protocol(hyper-EPP)for nonlocal two-photon systems in spatial-polarization-time-bin hyperentangled Bell states.As the single-photon detectors can dete...We present a faithful and efficient hyperentanglement purification protocol(hyper-EPP)for nonlocal two-photon systems in spatial-polarization-time-bin hyperentangled Bell states.As the single-photon detectors can detect and herald the undesirable properties caused by side leakage and finite coupling strength,the parity-check gates and swap gates of our hyper-EPP in the spatial,polarization and time-bin mode degrees of freedom(DoFs)work faithfully.The qubit-flip errors in photon systems in three DoFs can be corrected effectively with the faithful parity-check gates and the photon pairs can be reused to distill high-fidelity ones by introducing the faithful swap gates,which greatly increases the efficiency of our hyper-EPP.Further,the maximal hyperentanglement can be obtained in principle by operating multiple rounds of the hyper-EPP.展开更多
We present an error-detected hyperparallel Toffoli(hyper-Toffoli)gate for a three-photon system based on the interface between polarized photon and cavity-nitrogen-vacancy(NV)center system.This hyper-Toffoli gate can ...We present an error-detected hyperparallel Toffoli(hyper-Toffoli)gate for a three-photon system based on the interface between polarized photon and cavity-nitrogen-vacancy(NV)center system.This hyper-Toffoli gate can be used to perform double Toffoli gate operations simultaneously on both the polarization and spatial-mode degrees of freedom(DoFs)of a three-photon system with a low decoherence,shorten operation time,and less quantum resources required,in compared with those on two independent three-photon systems in one DoF only.As the imperfect cavity-NVcenter interactions are transformed into the detectable failures rather than infidelity based on the heralding mechanism of detectors,a near-unit fidelity of the quantum hyper-Toffoli gate can be implemented.By recycling the procedures,the efficiency of our protocol for the hyper-Toffoli gate is improved further.Meanwhile,the evaluation of gate performance with achieved experiment parameters shows that it is feasible with current experimental technology and provides a promising building block for quantum compute.展开更多
In recent years,RS and GIS technologies have played an increasingly important role in various aspects of rainfall induced landslide research.In order to systematically understand their application situation,this paper...In recent years,RS and GIS technologies have played an increasingly important role in various aspects of rainfall induced landslide research.In order to systematically understand their application situation,this paper extensively used various visualization analysis technologies for in-depth analysis of 1,161 documents collected by the WOS data platform in the past 27 years by combining quantitative and qualitative methods.Then,this article focuses on sub domain analysis from four aspects:landslide detection and monitoring,prediction models,sensitivity mapping,and risk assessment.The study found that the number of literature in thisfield has steadily increased and is expected to continue to rise.This literature review has attracted widespread attention from the academic community,but it challenging to meet research needs.Frequent and effective cooperationis between countries,institutions,and authors is very beneficial for promoting progress in thisfield.The future development direction is a new intelligent hybrid model that integrates multiple research methods.This study can provide researchers in thisfield with the core research force,hot topic evolution,and future development trends of future rainfall-induced landslides and contribute to landslide prevention and control decision-making and achieving the United Nations’sustainable development goals.展开更多
All-inorganic CsPbBr_(3)perovskite solar cells(PSCs)have attracted more attentions due to the excellent environmental stability,however,the wide bandgap and relatively poor crystallinity of CsPbBr_(3)have been the mai...All-inorganic CsPbBr_(3)perovskite solar cells(PSCs)have attracted more attentions due to the excellent environmental stability,however,the wide bandgap and relatively poor crystallinity of CsPbBr_(3)have been the main obstacle to improve their power conversion efficiency(PCE).Herein,we proposed an efficient and simple strategy of precursor additive in the two-step aqueous-solution method,the resulted CsPbBr_(3)film has achieved more uniform grain size,almost pure perovskite phase,smoother surface,less defects,enhanced light absorption and longer carrier lifetime.This is due to the rapid evaporation of additive(IPA and CH_(3)OH)in the CsBr/H_(2)O precursor leads to a relatively higher local CsBr concentration on the surface of PbBr_(2),which can provide more nucleation sites and accelerate the crystallization of perovskite.Further,when utilizing the optimal additive of 5%(in volume)IPA,the HTM-free carbonbased CsPbBr_(3)PSCs obtained a PCE improvement from 9.09%to 10.29%,and an ultrahigh fill factor(FF)of 85.21%.What is more,by adding 0.1 mol/L PbCl_(2)into the PbBr_(2)solution in the first step,the open circuit voltage of device has increased from 1.36 V to 1.48 V,the champion PCE reached 10.37%(steady output PCE of 10.17%),and the non-encapsulated device could maintain 85%of its initial efficiency after 50 d in the air.This work provides a cost-effective approach to grow CsPbBr_(3)film and boosts the efficiency benchmark of the CsPbBr_(3)PSCs to more than 10%,it is desirable that the highly efficient and stable CsPbBr_(3)PSCs can be developed in future.展开更多
Economists have put forward various proposals to deal with the growing risks of the global reserve currency system. In this paper we recommend that Asian economies hold each other＇s currencies as part of their foreig...Economists have put forward various proposals to deal with the growing risks of the global reserve currency system. In this paper we recommend that Asian economies hold each other＇s currencies as part of their foreign reserves. Different from crisis-fighting currency swap arrangements or crisis-rescuing fund mechanisms, this mechanism means that reserves wouM be held, with a regular arrangement in place and on an ongoing basis. We propose that the global reserve system shouM be pushed in the direction of diversification, which could be a transitional step toward a new single reserve system. This mechanism would not necessitate any currency being a globally accepted reserve currency but would mean that every currency carried some weight in the reserve system. Establishment of such a system would require significant development of regional bond markets and facilitation of macroeconomic surveillance among the economies.展开更多
In responding to a view that attributes sharp downturns in the Chinese economy in late 2008 and early 2009 to the ＂collapse of external demand,＂ the present paper scrutinizes three relevant issues： How have large C...In responding to a view that attributes sharp downturns in the Chinese economy in late 2008 and early 2009 to the ＂collapse of external demand,＂ the present paper scrutinizes three relevant issues： How have large Chinese importers behaved in a demand-price setting？ How have Chinese commodity imports and exports interacted in recent years？ Did the downturns in China＇s export growth come earlier and were they deeper than those in Chinese import growth？ All answers appear to suggest a conclusion contrary to the abovementioned view： sharp downturns in China＇s trade and economy during the reeent global financial crisis were, to a large extent, caused by certain domestic factors, or by factors that should not be regarded as entirely ＂external. ＂ Insomuch as globalization has advanced, a large economy like China＇s today faces new potential sources of macroeeonomic disturbances, from inside and outside.展开更多
基金supported by the National High Technology Research and Development Program of China(No.2009AA06Z106)Yunnan Provincial Science and Technology Department of China(No.2011GA004)
文摘This article investigated molybdenum recovery from oxygen pressure water leaching residue of Ni-Mo ore using alkaline leaching, followed by chemical treatment of leach liquor. Parameters affecting Mo leaching rate, such as sodium hydroxide concentration, reaction time, a liquid- to-solid ratio, and temperature for the preliminary alkaline leaching were experimentally determined. The results showed that more than 88 % of molybdenum was leached under the optimum conditions （2.5 ml.g-1 NaOH, 80 ℃, a liquid to solid ratio 3 ml.g-1, and reaction time 3 h）. After the purification of leach liquor, a CaMoO4 product of 99.2 % purity could be obtained by CaCla precipitation method. The whole Mo recovery reached about 82.7 %.
基金Project supported by the National Natural Science Foundation of China(Grant No.61901420 and 11604226)the Shanxi Province Science Foundation for Youths(Grant No.201901D211235)+1 种基金the Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi(Grant No.2019L0507)the Program of Beijing Municipal Commission of Education of China(Grant Nos.CIT&TCD201904080 and KM201810028005)。
文摘We present a faithful and efficient hyperentanglement purification protocol(hyper-EPP)for nonlocal two-photon systems in spatial-polarization-time-bin hyperentangled Bell states.As the single-photon detectors can detect and herald the undesirable properties caused by side leakage and finite coupling strength,the parity-check gates and swap gates of our hyper-EPP in the spatial,polarization and time-bin mode degrees of freedom(DoFs)work faithfully.The qubit-flip errors in photon systems in three DoFs can be corrected effectively with the faithful parity-check gates and the photon pairs can be reused to distill high-fidelity ones by introducing the faithful swap gates,which greatly increases the efficiency of our hyper-EPP.Further,the maximal hyperentanglement can be obtained in principle by operating multiple rounds of the hyper-EPP.
基金This work was supported in part by the National Natural Science Foundation of China under Contract 61901420the Shanxi Province Science Foundation for Youths under Contract 201901D211235+1 种基金the Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi under Contract 2019L0507the Shanxi“1331 Project”Key Subjects Construction。
文摘We present an error-detected hyperparallel Toffoli(hyper-Toffoli)gate for a three-photon system based on the interface between polarized photon and cavity-nitrogen-vacancy(NV)center system.This hyper-Toffoli gate can be used to perform double Toffoli gate operations simultaneously on both the polarization and spatial-mode degrees of freedom(DoFs)of a three-photon system with a low decoherence,shorten operation time,and less quantum resources required,in compared with those on two independent three-photon systems in one DoF only.As the imperfect cavity-NVcenter interactions are transformed into the detectable failures rather than infidelity based on the heralding mechanism of detectors,a near-unit fidelity of the quantum hyper-Toffoli gate can be implemented.By recycling the procedures,the efficiency of our protocol for the hyper-Toffoli gate is improved further.Meanwhile,the evaluation of gate performance with achieved experiment parameters shows that it is feasible with current experimental technology and provides a promising building block for quantum compute.
基金supported by the National Key R&D Program of China(2019YFC1510700)the Sichuan Science and Technology Program(2023Y FS0380,2023YFS0377,2023NSFSC1989,2022YFS0539).
文摘In recent years,RS and GIS technologies have played an increasingly important role in various aspects of rainfall induced landslide research.In order to systematically understand their application situation,this paper extensively used various visualization analysis technologies for in-depth analysis of 1,161 documents collected by the WOS data platform in the past 27 years by combining quantitative and qualitative methods.Then,this article focuses on sub domain analysis from four aspects:landslide detection and monitoring,prediction models,sensitivity mapping,and risk assessment.The study found that the number of literature in thisfield has steadily increased and is expected to continue to rise.This literature review has attracted widespread attention from the academic community,but it challenging to meet research needs.Frequent and effective cooperationis between countries,institutions,and authors is very beneficial for promoting progress in thisfield.The future development direction is a new intelligent hybrid model that integrates multiple research methods.This study can provide researchers in thisfield with the core research force,hot topic evolution,and future development trends of future rainfall-induced landslides and contribute to landslide prevention and control decision-making and achieving the United Nations’sustainable development goals.
基金the National Natural Science Foundation of China under Grants 62004151,62274126 and 62204189the Special Financial Grant from the China Postdoctoral Science Foundation under Grant 2020T130490+1 种基金Young Talent Fund of Association for Science and Technology in Shaanxi under Grant 20220115Fundamental Research Funds for the National 111 Center.
文摘All-inorganic CsPbBr_(3)perovskite solar cells(PSCs)have attracted more attentions due to the excellent environmental stability,however,the wide bandgap and relatively poor crystallinity of CsPbBr_(3)have been the main obstacle to improve their power conversion efficiency(PCE).Herein,we proposed an efficient and simple strategy of precursor additive in the two-step aqueous-solution method,the resulted CsPbBr_(3)film has achieved more uniform grain size,almost pure perovskite phase,smoother surface,less defects,enhanced light absorption and longer carrier lifetime.This is due to the rapid evaporation of additive(IPA and CH_(3)OH)in the CsBr/H_(2)O precursor leads to a relatively higher local CsBr concentration on the surface of PbBr_(2),which can provide more nucleation sites and accelerate the crystallization of perovskite.Further,when utilizing the optimal additive of 5%(in volume)IPA,the HTM-free carbonbased CsPbBr_(3)PSCs obtained a PCE improvement from 9.09%to 10.29%,and an ultrahigh fill factor(FF)of 85.21%.What is more,by adding 0.1 mol/L PbCl_(2)into the PbBr_(2)solution in the first step,the open circuit voltage of device has increased from 1.36 V to 1.48 V,the champion PCE reached 10.37%(steady output PCE of 10.17%),and the non-encapsulated device could maintain 85%of its initial efficiency after 50 d in the air.This work provides a cost-effective approach to grow CsPbBr_(3)film and boosts the efficiency benchmark of the CsPbBr_(3)PSCs to more than 10%,it is desirable that the highly efficient and stable CsPbBr_(3)PSCs can be developed in future.
文摘Economists have put forward various proposals to deal with the growing risks of the global reserve currency system. In this paper we recommend that Asian economies hold each other＇s currencies as part of their foreign reserves. Different from crisis-fighting currency swap arrangements or crisis-rescuing fund mechanisms, this mechanism means that reserves wouM be held, with a regular arrangement in place and on an ongoing basis. We propose that the global reserve system shouM be pushed in the direction of diversification, which could be a transitional step toward a new single reserve system. This mechanism would not necessitate any currency being a globally accepted reserve currency but would mean that every currency carried some weight in the reserve system. Establishment of such a system would require significant development of regional bond markets and facilitation of macroeconomic surveillance among the economies.
文摘In responding to a view that attributes sharp downturns in the Chinese economy in late 2008 and early 2009 to the ＂collapse of external demand,＂ the present paper scrutinizes three relevant issues： How have large Chinese importers behaved in a demand-price setting？ How have Chinese commodity imports and exports interacted in recent years？ Did the downturns in China＇s export growth come earlier and were they deeper than those in Chinese import growth？ All answers appear to suggest a conclusion contrary to the abovementioned view： sharp downturns in China＇s trade and economy during the reeent global financial crisis were, to a large extent, caused by certain domestic factors, or by factors that should not be regarded as entirely ＂external. ＂ Insomuch as globalization has advanced, a large economy like China＇s today faces new potential sources of macroeeonomic disturbances, from inside and outside.
