Hsiung Shih-I’s Lady Precious Stream has won the favor of the British theatre market since its release.Since hitting the stage of the West End theaters of London,it has not only achieved great success at the box offi...Hsiung Shih-I’s Lady Precious Stream has won the favor of the British theatre market since its release.Since hitting the stage of the West End theaters of London,it has not only achieved great success at the box office,but also attracted the attention of the British theatre elite.From the journal’s comments,reports,and archives in the 1930s,with the“Chinese theatre convention”and“British theatre performance”dual cultural context identity,since Lady Precious Stream performed in public,it got the British theater’s attention and absorption quickly,and gradually became part of the self-innovation in the British theatre movement.The reasons are not only the obsession and enthusiasm of the British society and the theatre audience with the concept of“China”,but also the recognition and admiration of the traditional Chinese theatrical techniques by the British theatre elite,and the profound influence of the international situation on the theatre culture of the two countries.This research from the perspective of archives,by the bear in the creation of Lady Precious Stream background analysis,and the review in the British theatrical performance and evaluation,explain in early 20th century,how the concept of British“Chinese Theatre”is known by the British theatre,use and spread to the people,and the resulting of transformation image in Chinese theatre.展开更多
Based on the in-situ self-reduction and chemical stability,graphdiyne(GDY)and graphdiyne oxide(GDYO)are used as trapping agents to investigate the ability for recovering Au^(3+),Ag^+,and Pd^(2+)under different pH valu...Based on the in-situ self-reduction and chemical stability,graphdiyne(GDY)and graphdiyne oxide(GDYO)are used as trapping agents to investigate the ability for recovering Au^(3+),Ag^+,and Pd^(2+)under different pH values and interfering ions.Under strong acidity at pH=1,these two agents demonstrate high select recovery towards the three precious metal ions,which could be insitu reduced to nanoparticles(NPs).In addition,superparamagnetic Fe_(3)O_(4)NPs are deposited on the surfaces of GDY and GDYO.The magnetic responses enable GDYFe_(3)O_(4)to recover precious metals conveniently and efficiently by the aid of an external magnetic field.This study also confirms the antibacterial activity of the as-recovered NPs deposited on GDY and GDYO against Escherichia coli and Staphylococcus aureus(1×10^(5)colony-forming unit(CFU)·mL^(-1)),and the antibacterial rates are 100%.This strategy of recovering precious metals and subsequently reusing to combat pathogens will be of great significance for environmental remediation and biomedical applications.展开更多
The 8th China-Africa Youth Festival was a precious opportunity to not only learn about Chinese culture but also to explore the rich tapestry of cultures of different African countries.Participants had the chance to ta...The 8th China-Africa Youth Festival was a precious opportunity to not only learn about Chinese culture but also to explore the rich tapestry of cultures of different African countries.Participants had the chance to talk to young leaders from across the continent,fostering new bonds and connections that can potentially benefit everyone involved in the future.This cultural exchange not only broadened our understanding but also paved the way for collaboration and enduring friendships that could be good for personal development.展开更多
Commodity markets,such as crude oil and precious metals,play a strategic role in the economic development of nations,with crude oil prices influencing geopolitical relations and the global economy.Moreover,gold and si...Commodity markets,such as crude oil and precious metals,play a strategic role in the economic development of nations,with crude oil prices influencing geopolitical relations and the global economy.Moreover,gold and silver are argued to hedge the stock and cryptocurrency markets during market downsides.Therefore,accurate forecasting of crude oil and precious metals prices is critical.Nevertheless,due to the nonlinear nature,substantial fluctuations,and irregular cycles of crude oil and precious metals,predicting their prices is a challenging task.Our study contributes to the commodity market price forecasting literature by implementing and comparing advanced deep-learning models.We address this gap by including silver alongside gold in our analysis,offering a more comprehensive understanding of the precious metal markets.This research expands existing knowledge and provides valuable insights into predicting commodity prices.In this study,we implemented 16 deep-and machine-learning models to forecast the daily price of the West Texas Intermediate(WTI),Brent,gold,and silver markets.The employed deep-learning models are long short-term memory(LSTM),BiLSTM,gated recurrent unit(GRU),bidirectional gated recurrent units(BiGRU),T2V-BiLSTM,T2V-BiGRU,convolutional neural networks(CNN),CNN-BiLSTM,CNN-BiGRU,temporal convolutional network(TCN),TCN-BiLSTM,and TCN-BiGRU.We compared the forecasting performance of deep-learning models with the baseline random forest,LightGBM,support vector regression,and k-nearest neighborhood models using mean absolute error(MAE),mean absolute percentage error,and root mean squared error as evaluation criteria.By considering different sliding window lengths,we examine the forecasting performance of our models.Our results reveal that the TCN model outperforms the others for WTI,Brent,and silver,achieving the lowest MAE values of 1.444,1.295,and 0.346,respectively.The BiGRU model performs best for gold,with an MAE of 15.188 using a 30-day input sequence.Furthermore,LightGBM exhibits comparable performance to TCN and is the best-performing machine-learning model overall.These findings are critical for investors,policymakers,mining companies,and governmental agencies to effectively anticipate market trends,mitigate risk,manage uncertainty,and make timely decisions and strategies regarding crude oil,gold,and silver markets.展开更多
From the perspective of long-term and short-term, the methods of TY causality test, generalized impulse response function, variance decomposition were used to investigate the impacts of international oil prices and ma...From the perspective of long-term and short-term, the methods of TY causality test, generalized impulse response function, variance decomposition were used to investigate the impacts of international oil prices and macroeconomic variables on Chinese gold, silver and platinum prices, but also the feedback effects of Chinese precious metal prices under this impact. The results show that international oil prices play an important role in precious metal price variation both in long-term and short-term, and exchange rate only has an effect in short-term, while interest rate is ineffective in predicting precious metal prices. In addition, precious metal prices have some feedback effects on international oil prices and interest rate in short-term.展开更多
The proceeds of the illicit trade in precious metals are used as currency to pay for,for example,other illicit goods and support terrorism.Precious metals are often mined in less developed countries and exported to an...The proceeds of the illicit trade in precious metals are used as currency to pay for,for example,other illicit goods and support terrorism.Precious metals are often mined in less developed countries and exported to and refined in more industrialised regions.International cooperation,sophisticated analytical techniques,combined with representative databases make it possible to trace the source of these stolen precious metals with the aim of obtaining successful prosecution of the culprits.In this paper the problem of illicit trade in precious metal-bearing materials and the effects it has on the countries in which the material originates is discussed.Combined with geological knowledge of the origin of the material and knowledge of the beneficiation processes utilized,enables determination of the provenance of unknown materials and whether the suspect material is illicit or not.Recent legislation with regard to international trade and the need to ensure the legality of the material traded is discussed,and some examples of the effectiveness of the forensic investigation of gold and platinum-group metal criminal cases are provided.展开更多
Based on the subdivision into three members of the Lower Cretaceous Jiufotang Formation in western Liaoning, this paper deals mainly with the division and correlation of precious fossil birdand reptile-bearing beds of...Based on the subdivision into three members of the Lower Cretaceous Jiufotang Formation in western Liaoning, this paper deals mainly with the division and correlation of precious fossil birdand reptile-bearing beds of the formation in the Dachengzi, Chaoyang, Dapingfang.Meileyingzi and Fuxin-Yixian basins. Among them, the precious fossil-bearing beds in the Dachengzi Basin may be recognized as the Xidagou Bed of the second member and the Yangcaogoudonggou Bed of the third member; those in the Chaoyang Basin may be confirmed as the Shangheshou Bed of the second member and the Dongpochi Bed of the third member; those in the Dapingfang-Meileyingzi Basin are as the Lamagou Bed of the second member, the Huanghuagou Bed of the lower third member and the Yuanjiawa Bed of the upper third member; and those in the Fuxin-Yixian Basin are listed as the Tuanshanzi Bed of the second member and the Pijiagou Bed of the third member. Since these basins are distinctly separated and the bird and reptile fossils are mostly new genera and species, we have to use the associated fossil ostracod assemblages as index to correlate the Xidagou Bed with the Shangheshou Bed and the Lamagou Bed, and to correlate the Yuanjiawa Bed with the Yangcaogoudonggou Bed and the Pijiagou Bed. Primarily, we established the sequence of the precious fossil-bearing beds of the Jiufotang Formation in western Liaoning. They are represented by, in ascending order, the Xidagou Bed of the second member, the Huanghuagou Bed of the lower third member, and the Yuanjiawa Bed of the upper third member. Obviously, this work has significance for the study on the time-space distribution and radiation of birds and dinosaurs during the period of the middle Early Cretaceous.展开更多
A series of precious metals catalysts （M/TiO/, M = Ru, Rh, Pd, Ag, Ir, Pt or Au） were prepared by a light deposition method and the synergistic photocatalytic degradations of pyridine （20 mg/L） under UV irradiati...A series of precious metals catalysts （M/TiO/, M = Ru, Rh, Pd, Ag, Ir, Pt or Au） were prepared by a light deposition method and the synergistic photocatalytic degradations of pyridine （20 mg/L） under UV irradiation （365 nm） using M/TiO2 with electron capture agent KBrO3 have been investigated. The results show that KBrO3 has a greatly synergistic role on M/TiO2 and the photocatalytic activity of M/TiO2 is closely related to its work function. Ag could greatly enhance the activity of TiO2 due to the binding characteristics of pyridine on Ag. Under the conditions of 0.5 wt.% Ag loading, Ag/TiO2 concentration of 0.1 g/L, KlrO3 concentration of 10 mmol/L and reaction liquid pH value at 9, the pyridine can be degraded by 64% within 3 hr, doubled than TiO2 photocatalytic system. The degradation kinetics of pyridine follows first-order kinetics and k = 5.53 × 10-3 min^-1.展开更多
Precious metal-support interaction plays an important role in thermal stability and catalytic performance of the automotive exhaust catalysts. The support is not only a cartier for active compotmds in catalysts but al...Precious metal-support interaction plays an important role in thermal stability and catalytic performance of the automotive exhaust catalysts. The support is not only a cartier for active compotmds in catalysts but also can improve the dispersion of precious metals and suppress the sintering of precious metals at high temperature; meanwhile, noble metals can also enhance the redox performance and oxygen storage capacity of support. The mechanism of metal-support interactions mainly includes electronic interaction, formation of alloy and inward diffusion of metal into the support or covered by support. The form and degree of precious metal-sup- port interaction depend on many factors, including the content of precious metal, the species of support and metal, and preparation methods. The research results about strong metal-support interaction （SMSI） gave a theory support for developing a kind of new cata- lyst with excellent performance. This paper reviewed the interaction phenomenon and mechanism of precious metals （Pt, Pd, Rh） and support such as A1203, CeO2, and CeO2-based oxides in automotive exhaust catalysts. The factors that affect SMSI and the catalysts developed by SMSI were also discussed.展开更多
As a carbon-free energy carrier,hydrogen has become the pivot for future clean energy,while efficient hydrogen production and combustion still require precious metal-based catalysts.Single-atom catalysts(SACs)with hig...As a carbon-free energy carrier,hydrogen has become the pivot for future clean energy,while efficient hydrogen production and combustion still require precious metal-based catalysts.Single-atom catalysts(SACs)with high atomic utilization open up a desirable perspective for the scale applications of precious metals,but the general and facile preparation of various precious metal-based SACs remains challenging.Herein,a general movable printing method has been developed to synthesize various precious metal-based SACs,such as Pd,Pt,Rh,Ir,and Ru,and the features of highly dispersed single atoms with nitrogen coordination have been identified by comprehensive characterizations.More importantly,the synthesized Pt-and Ru-based SACs exhibit much higher activities than their corresponding nanoparticle counterparts for hydrogen oxidation reaction and hydrogen evolution reaction(HER).In addition,the Pd-based SAC delivers an excellent activity for photocatalytic hydrogen evolution.Especially for the superior mass activity of Ru-based SACs toward HER,density functional theory calculations confirmed that the adsorption of the hydrogen atom has a significant effect on the spin state and electronic structure of the catalysts.展开更多
The recovery of precious metals from the secondary resources by microwave technology has emerged in recent years. Microwave technology as a new method for the recovery of precious metals has shown significant advantag...The recovery of precious metals from the secondary resources by microwave technology has emerged in recent years. Microwave technology as a new method for the recovery of precious metals has shown significant advantages against the conventional recovery procedures. This paper presents a review of the advances in microwave technology applied to the recovery of precious metals from the secondary resources. Many different applications are considered, including microwave-assisted leaching, microwave augmented ashing and microwave pyrolysis. In general, microwave enhanced recovery of precious metals from secondary resources.展开更多
Photocatalytic recovery,a novel precious metal recycling technology,dedicates to solving the environmental and energy consumption problems caused by traditional technologies.The activation of molecular oxygen (O_(2)) ...Photocatalytic recovery,a novel precious metal recycling technology,dedicates to solving the environmental and energy consumption problems caused by traditional technologies.The activation of molecular oxygen (O_(2)) is one of the most critical steps in the whole process.Herein,we regulated the different adsorption intensity of oxygen on the surface by designing phosphate (PO_(4)^(3-)) modified titanium oxide(TiO_(2)).The results show that the adsorption of oxygen on the photocatalyst surface is gradually enhanced,which effectively improves the dissolution rate of precious metals.PO_(4)^(3-)modification increased the photocatalytic dissolution rate of gold (Au) by 2.8 times.The photocatalytic activity of other precious metals dissolution (such as palladium (Pd),platinum (Pt),rhodium (Rh),ruthenium (Ru) and iridium (Ir)) was also significantly improved.It is applied to the recovery of precious metals from spent catalysts and electronic devices to significantly promote the recovery efficiency.This indicates the direction for designing more efficient photocatalysts for precious metal recovery.展开更多
A new technique of swelling oxidizing roasting and alkaline leaching was proposed for deselenization and detellurization of pre- cious-metal ore concentrates. Alkali-metal and alkaline-earth-metal chlorides and carbon...A new technique of swelling oxidizing roasting and alkaline leaching was proposed for deselenization and detellurization of pre- cious-metal ore concentrates. Alkali-metal and alkaline-earth-metal chlorides and carbonates were preliminarily selected as swelling agents. The roasting removal rate and alkaline leaching rate of selenium and tellurium were investigated, and NaCl was selected as an appropriate swelling agent. Furthermore, the effects of various factors on the selenium gasification rate and leaching rate of selenium and tellurium were investigated. The results show that the selenium gasification rate reaches 88.41% after swelling oxidizing roasting for 2 h at 510~C using an NaC1 dosage coefficient of 100 and a sulfuric acid dosage coefficient of 1.3; the amorphous elemental tellurium is completely transformed into TeO2. The roasted product is subjected to alkaline leaching using a 100 g/L NaOH solution, which results in a selenium leaching rate of 10.51%, a total selenium removal rate of 98.92%, and a tellurium leaching rate of 97.64%. In the alkaline leaching residue, the contents of selenium, tellurium, gold, platinum, and palladium are 0.7825%, 5.492%, 8.333%, 0.2587%, and 1.113%, respectively; the precious metals are enriched approximately sixfold.展开更多
Hydrothermal plume is an important constituent of seabed hydrothermal circulation and is also one of the characteristics of active hydrothermal vents. Portable Miniature Autonomous Plume Recorders （MAPR） attached to...Hydrothermal plume is an important constituent of seabed hydrothermal circulation and is also one of the characteristics of active hydrothermal vents. Portable Miniature Autonomous Plume Recorders （MAPR） attached to a towed deep-sea instrument was used to search for hydrothermal plumes and hydrothermal vents. We introduced the basic principle of MAPR based on deep towing technology to detect plumes, then analyzed the factors affecting the quality of the MAPR data and presented a data correction method for MAPR, including instrument location correction, noise reduction processing, system error elimination and seawater background reduction. Finally we applied the method to analyze MAPR data obtained during the Chinese DY115-21 cruise on R/VDayang Iin the “Precious Stone Mountain” hydrothermal field on the Gala-pagos Microplate. The results provided a better understanding of the distribution of the hydrothermal activ-ity in this field, indicating the presence of a new hydrothermal vent.展开更多
To achieve a sustainable development in the electronic and electrical equipment(EEE) industry, it is necessary to protect the available natural resources.In addition, to satisfy the increasing demand on EEE, it is nec...To achieve a sustainable development in the electronic and electrical equipment(EEE) industry, it is necessary to protect the available natural resources.In addition, to satisfy the increasing demand on EEE, it is necessary to provide alternative sources of raw materials.In this paper, laptops were imported to Jordan in 2011 as an example to show the potential recovery of metals and precious metals from high grade waste electronic and electrical equipment by conducting a mass flow rate analysis using the STAN program.The results show that considerable amounts of gold, silver, cobalt, palladium,and copper could be recovered.This will reduce the amounts needed from primary natural resources and offset the CO2 emissions produced from mining the primary raw material resources.展开更多
The Jianchang Basin is one of the main localities of the precious fossils of Jehol Biota in western Liaoning.The fossil-bearing horizons are mainly in the Yixian-and Jiufotang formations.In the Weijialing--Yaolugou of...The Jianchang Basin is one of the main localities of the precious fossils of Jehol Biota in western Liaoning.The fossil-bearing horizons are mainly in the Yixian-and Jiufotang formations.In the Weijialing--Yaolugou of southwest Jianchang Basin,many precious fossils have been found at Luojiagou Bed of the 2nd Member of the Yixian Formation and at Xidian Bed of the 1st member of the Jiufotang Formation.The geologic setting,sedimentary environment and paleogeography of the precious fossil-bearing beds were also studied.展开更多
With the increasing awareness of environmental protection, people’s concern of pollution issues arising. Vehicles, as the most important means of transportation, its exhaust emission has received considerable attenti...With the increasing awareness of environmental protection, people’s concern of pollution issues arising. Vehicles, as the most important means of transportation, its exhaust emission has received considerable attention. The catalytic converter is able to purify harmful substances in exhaust gas. The absolute content of precious metals in the catalytic converter dominates the exhaust gas purification effect. Accurate detection of precious metal content is of great significance for controlling the cost of catalysts, ensuring catalytic performance and recovering precious metals from spent catalysts. We herein summarized several instruments for precious metals content exploration, such as X-ray fluorescence spectrometer (XRF), atomic absorption spectrometer (AAS), inductively coupled plasma emission spectrometer (ICP) and spectrophotometer. In this thesis, the feasibility of using various devices for characterizing precious metal content in catalytic converters is analyzed and their strengths or weaknesses are elaborated.展开更多
The CD retrieval svstem of Journal of Traditional Chinese Medicine(JTCM)contains all of the periodicals of JTCM published from 1981 to 2008.You can read any articles on computer bv searching any words or combination o...The CD retrieval svstem of Journal of Traditional Chinese Medicine(JTCM)contains all of the periodicals of JTCM published from 1981 to 2008.You can read any articles on computer bv searching any words or combination of the words.The retrieval results can be printed or downloaded.You may retrieve the relevant articles about a certain disease,therapy or drug in a few seconds,user-friendly with convenient handling.展开更多
Aimed at high content of valuable metals, complicated composition, difficult to separation of precious metals six component alloy wastes, the present paper proposed a new technology of high efficient separation and pu...Aimed at high content of valuable metals, complicated composition, difficult to separation of precious metals six component alloy wastes, the present paper proposed a new technology of high efficient separation and purification. Using fragmentation technology realizes fast dissolution of palladium, silver, copper and zinc in the wastes, and high efficient and complete separation of them from gold and platinum; using evaporation thermal decomposition technology of mixed solution produced by nitric acid dissolving palladium, silver, copper and zinc, complete and high efficient separation of silver from palladium was realized; by control of solution acidity, using hydrazine reduction method, high efficient and complete separation of gold from platinum was realized. Using this new technology, the recovery rates of palladium and silver are above 99%, and gold and platinum above 98%, the grade of pure metals are above 99.95%.展开更多
Situated in Kunming,Yunnan Province,the institute is a scientific research organiza-tion with a history of fifty years.It is nowaffiliated with the China National NonferrousMetals Industry Corporation.At the beginning...Situated in Kunming,Yunnan Province,the institute is a scientific research organiza-tion with a history of fifty years.It is nowaffiliated with the China National NonferrousMetals Industry Corporation.At the beginning of the nineteen sixties,the institute commenced research workin the field of precious metals.It has sincethen developed and extended greatly,andits activities now cover various fields ofprecious metals science and technology,including the comprehensive utilization展开更多
文摘Hsiung Shih-I’s Lady Precious Stream has won the favor of the British theatre market since its release.Since hitting the stage of the West End theaters of London,it has not only achieved great success at the box office,but also attracted the attention of the British theatre elite.From the journal’s comments,reports,and archives in the 1930s,with the“Chinese theatre convention”and“British theatre performance”dual cultural context identity,since Lady Precious Stream performed in public,it got the British theater’s attention and absorption quickly,and gradually became part of the self-innovation in the British theatre movement.The reasons are not only the obsession and enthusiasm of the British society and the theatre audience with the concept of“China”,but also the recognition and admiration of the traditional Chinese theatrical techniques by the British theatre elite,and the profound influence of the international situation on the theatre culture of the two countries.This research from the perspective of archives,by the bear in the creation of Lady Precious Stream background analysis,and the review in the British theatrical performance and evaluation,explain in early 20th century,how the concept of British“Chinese Theatre”is known by the British theatre,use and spread to the people,and the resulting of transformation image in Chinese theatre.
基金financially supported by the National Natural Science Foundation of China(Nos.22062017 and 22164015)Inner Mongolia Autonomous Region Program for Key Science and Technology(No.2020GG0161)+3 种基金Ordos City Program for Key Science and Technology(No.2022YY003)the Program of Higher-Level Talents of Inner Mongolia University(No.10000-22311201/035)the Research Program of science and technology at Universities of Inner Mongolia Autonomous Region(No.NJZZ23091)the Program for Innovative Research Team in Universities of Inner Mongolia Autonomous Region(No.NMGIRT2210)。
文摘Based on the in-situ self-reduction and chemical stability,graphdiyne(GDY)and graphdiyne oxide(GDYO)are used as trapping agents to investigate the ability for recovering Au^(3+),Ag^+,and Pd^(2+)under different pH values and interfering ions.Under strong acidity at pH=1,these two agents demonstrate high select recovery towards the three precious metal ions,which could be insitu reduced to nanoparticles(NPs).In addition,superparamagnetic Fe_(3)O_(4)NPs are deposited on the surfaces of GDY and GDYO.The magnetic responses enable GDYFe_(3)O_(4)to recover precious metals conveniently and efficiently by the aid of an external magnetic field.This study also confirms the antibacterial activity of the as-recovered NPs deposited on GDY and GDYO against Escherichia coli and Staphylococcus aureus(1×10^(5)colony-forming unit(CFU)·mL^(-1)),and the antibacterial rates are 100%.This strategy of recovering precious metals and subsequently reusing to combat pathogens will be of great significance for environmental remediation and biomedical applications.
文摘The 8th China-Africa Youth Festival was a precious opportunity to not only learn about Chinese culture but also to explore the rich tapestry of cultures of different African countries.Participants had the chance to talk to young leaders from across the continent,fostering new bonds and connections that can potentially benefit everyone involved in the future.This cultural exchange not only broadened our understanding but also paved the way for collaboration and enduring friendships that could be good for personal development.
文摘Commodity markets,such as crude oil and precious metals,play a strategic role in the economic development of nations,with crude oil prices influencing geopolitical relations and the global economy.Moreover,gold and silver are argued to hedge the stock and cryptocurrency markets during market downsides.Therefore,accurate forecasting of crude oil and precious metals prices is critical.Nevertheless,due to the nonlinear nature,substantial fluctuations,and irregular cycles of crude oil and precious metals,predicting their prices is a challenging task.Our study contributes to the commodity market price forecasting literature by implementing and comparing advanced deep-learning models.We address this gap by including silver alongside gold in our analysis,offering a more comprehensive understanding of the precious metal markets.This research expands existing knowledge and provides valuable insights into predicting commodity prices.In this study,we implemented 16 deep-and machine-learning models to forecast the daily price of the West Texas Intermediate(WTI),Brent,gold,and silver markets.The employed deep-learning models are long short-term memory(LSTM),BiLSTM,gated recurrent unit(GRU),bidirectional gated recurrent units(BiGRU),T2V-BiLSTM,T2V-BiGRU,convolutional neural networks(CNN),CNN-BiLSTM,CNN-BiGRU,temporal convolutional network(TCN),TCN-BiLSTM,and TCN-BiGRU.We compared the forecasting performance of deep-learning models with the baseline random forest,LightGBM,support vector regression,and k-nearest neighborhood models using mean absolute error(MAE),mean absolute percentage error,and root mean squared error as evaluation criteria.By considering different sliding window lengths,we examine the forecasting performance of our models.Our results reveal that the TCN model outperforms the others for WTI,Brent,and silver,achieving the lowest MAE values of 1.444,1.295,and 0.346,respectively.The BiGRU model performs best for gold,with an MAE of 15.188 using a 30-day input sequence.Furthermore,LightGBM exhibits comparable performance to TCN and is the best-performing machine-learning model overall.These findings are critical for investors,policymakers,mining companies,and governmental agencies to effectively anticipate market trends,mitigate risk,manage uncertainty,and make timely decisions and strategies regarding crude oil,gold,and silver markets.
基金Project(13&ZD169)supported by the Major Program of the National Social Science Foundation,ChinaProject(13YJAZH149)supported by Research Project in Humanities and Social Sciences Conducted by the Ministry of Education,China+2 种基金Project(2011ZK2043)supported by the Key Program of the Soft Science Research Project of Hunan Province,ChinaProject(2015JJ2182)supported by Natural Science Foundation of Hunan Province of ChinaProject(2009JYJR035)supported by Emergency Project "The Study of International Financial Crisis" of Ministry of Education of China
文摘From the perspective of long-term and short-term, the methods of TY causality test, generalized impulse response function, variance decomposition were used to investigate the impacts of international oil prices and macroeconomic variables on Chinese gold, silver and platinum prices, but also the feedback effects of Chinese precious metal prices under this impact. The results show that international oil prices play an important role in precious metal price variation both in long-term and short-term, and exchange rate only has an effect in short-term, while interest rate is ineffective in predicting precious metal prices. In addition, precious metal prices have some feedback effects on international oil prices and interest rate in short-term.
文摘The proceeds of the illicit trade in precious metals are used as currency to pay for,for example,other illicit goods and support terrorism.Precious metals are often mined in less developed countries and exported to and refined in more industrialised regions.International cooperation,sophisticated analytical techniques,combined with representative databases make it possible to trace the source of these stolen precious metals with the aim of obtaining successful prosecution of the culprits.In this paper the problem of illicit trade in precious metal-bearing materials and the effects it has on the countries in which the material originates is discussed.Combined with geological knowledge of the origin of the material and knowledge of the beneficiation processes utilized,enables determination of the provenance of unknown materials and whether the suspect material is illicit or not.Recent legislation with regard to international trade and the need to ensure the legality of the material traded is discussed,and some examples of the effectiveness of the forensic investigation of gold and platinum-group metal criminal cases are provided.
文摘Based on the subdivision into three members of the Lower Cretaceous Jiufotang Formation in western Liaoning, this paper deals mainly with the division and correlation of precious fossil birdand reptile-bearing beds of the formation in the Dachengzi, Chaoyang, Dapingfang.Meileyingzi and Fuxin-Yixian basins. Among them, the precious fossil-bearing beds in the Dachengzi Basin may be recognized as the Xidagou Bed of the second member and the Yangcaogoudonggou Bed of the third member; those in the Chaoyang Basin may be confirmed as the Shangheshou Bed of the second member and the Dongpochi Bed of the third member; those in the Dapingfang-Meileyingzi Basin are as the Lamagou Bed of the second member, the Huanghuagou Bed of the lower third member and the Yuanjiawa Bed of the upper third member; and those in the Fuxin-Yixian Basin are listed as the Tuanshanzi Bed of the second member and the Pijiagou Bed of the third member. Since these basins are distinctly separated and the bird and reptile fossils are mostly new genera and species, we have to use the associated fossil ostracod assemblages as index to correlate the Xidagou Bed with the Shangheshou Bed and the Lamagou Bed, and to correlate the Yuanjiawa Bed with the Yangcaogoudonggou Bed and the Pijiagou Bed. Primarily, we established the sequence of the precious fossil-bearing beds of the Jiufotang Formation in western Liaoning. They are represented by, in ascending order, the Xidagou Bed of the second member, the Huanghuagou Bed of the lower third member, and the Yuanjiawa Bed of the upper third member. Obviously, this work has significance for the study on the time-space distribution and radiation of birds and dinosaurs during the period of the middle Early Cretaceous.
基金supported by the National Natural Science Foundation of China(No.20907012)the National High Technology Research and Development Program of China(No.2012ZX07206-002)the Special Fund for the Development of Strategic and New Industry in Shenzhen(No.JCYJ20120613114951217)
文摘A series of precious metals catalysts （M/TiO/, M = Ru, Rh, Pd, Ag, Ir, Pt or Au） were prepared by a light deposition method and the synergistic photocatalytic degradations of pyridine （20 mg/L） under UV irradiation （365 nm） using M/TiO2 with electron capture agent KBrO3 have been investigated. The results show that KBrO3 has a greatly synergistic role on M/TiO2 and the photocatalytic activity of M/TiO2 is closely related to its work function. Ag could greatly enhance the activity of TiO2 due to the binding characteristics of pyridine on Ag. Under the conditions of 0.5 wt.% Ag loading, Ag/TiO2 concentration of 0.1 g/L, KlrO3 concentration of 10 mmol/L and reaction liquid pH value at 9, the pyridine can be degraded by 64% within 3 hr, doubled than TiO2 photocatalytic system. The degradation kinetics of pyridine follows first-order kinetics and k = 5.53 × 10-3 min^-1.
基金supported by National Science & Technology Pillar Program(2012BAE06B00)
文摘Precious metal-support interaction plays an important role in thermal stability and catalytic performance of the automotive exhaust catalysts. The support is not only a cartier for active compotmds in catalysts but also can improve the dispersion of precious metals and suppress the sintering of precious metals at high temperature; meanwhile, noble metals can also enhance the redox performance and oxygen storage capacity of support. The mechanism of metal-support interactions mainly includes electronic interaction, formation of alloy and inward diffusion of metal into the support or covered by support. The form and degree of precious metal-sup- port interaction depend on many factors, including the content of precious metal, the species of support and metal, and preparation methods. The research results about strong metal-support interaction （SMSI） gave a theory support for developing a kind of new cata- lyst with excellent performance. This paper reviewed the interaction phenomenon and mechanism of precious metals （Pt, Pd, Rh） and support such as A1203, CeO2, and CeO2-based oxides in automotive exhaust catalysts. The factors that affect SMSI and the catalysts developed by SMSI were also discussed.
基金National Natural Science Foundation of China,Grant/Award Numbers:62105083,22109034,22109035,52164028Start-up Research Foundation of Hainan University,Grant/Award Numbers:KYQD(ZR)-20008,KYQD(ZR)-20082,KYQD(ZR)-20083,KYQD(ZR)-20084,KYQD(ZR)-21065,KYQD(ZR)-21124,KYQD(ZR)-21125+4 种基金Basic and Applied Basic Research Foundation of Guangdong Province,Grant/Award Number:2019A1515110558Hainan Provincial Postdoctoral Science Foundation,Grant/Award Number:RZ2100007123Hainan Province Science and Technology Special Fund,Grant/Award Numbers:ZDYF2020037,ZDYF2020207Hainan Provincial Natural Science Foundation,Grant/Award Numbers:222MS009,222RC548The specific research fund of The Innovation Platform for Academicians of Hainan Province。
文摘As a carbon-free energy carrier,hydrogen has become the pivot for future clean energy,while efficient hydrogen production and combustion still require precious metal-based catalysts.Single-atom catalysts(SACs)with high atomic utilization open up a desirable perspective for the scale applications of precious metals,but the general and facile preparation of various precious metal-based SACs remains challenging.Herein,a general movable printing method has been developed to synthesize various precious metal-based SACs,such as Pd,Pt,Rh,Ir,and Ru,and the features of highly dispersed single atoms with nitrogen coordination have been identified by comprehensive characterizations.More importantly,the synthesized Pt-and Ru-based SACs exhibit much higher activities than their corresponding nanoparticle counterparts for hydrogen oxidation reaction and hydrogen evolution reaction(HER).In addition,the Pd-based SAC delivers an excellent activity for photocatalytic hydrogen evolution.Especially for the superior mass activity of Ru-based SACs toward HER,density functional theory calculations confirmed that the adsorption of the hydrogen atom has a significant effect on the spin state and electronic structure of the catalysts.
文摘The recovery of precious metals from the secondary resources by microwave technology has emerged in recent years. Microwave technology as a new method for the recovery of precious metals has shown significant advantages against the conventional recovery procedures. This paper presents a review of the advances in microwave technology applied to the recovery of precious metals from the secondary resources. Many different applications are considered, including microwave-assisted leaching, microwave augmented ashing and microwave pyrolysis. In general, microwave enhanced recovery of precious metals from secondary resources.
基金supported by the National Key Research and Development Program of China (No. 2020YFA0211004)the National Natural Science Foundation of China (Nos. 22176128, 21876114)+4 种基金Sponsored by Program of Shanghai Government (Nos. 21XD1422800, 19DZ1205102, 19160712900)Chinese Education Ministry Key Laboratory and International Joint Laboratory on Resource Chemistry, and Shanghai Eastern Scholar Program“111 Innovation and Talent Recruitment Base on Photochemical and Energy Materials” (No. D18020)Shanghai Engineering Research Center of Green Energy Chemical Engineering (No. 18DZ2254200)Shanghai Frontiers Science Center of Biomimetic Catalysis。
文摘Photocatalytic recovery,a novel precious metal recycling technology,dedicates to solving the environmental and energy consumption problems caused by traditional technologies.The activation of molecular oxygen (O_(2)) is one of the most critical steps in the whole process.Herein,we regulated the different adsorption intensity of oxygen on the surface by designing phosphate (PO_(4)^(3-)) modified titanium oxide(TiO_(2)).The results show that the adsorption of oxygen on the photocatalyst surface is gradually enhanced,which effectively improves the dissolution rate of precious metals.PO_(4)^(3-)modification increased the photocatalytic dissolution rate of gold (Au) by 2.8 times.The photocatalytic activity of other precious metals dissolution (such as palladium (Pd),platinum (Pt),rhodium (Rh),ruthenium (Ru) and iridium (Ir)) was also significantly improved.It is applied to the recovery of precious metals from spent catalysts and electronic devices to significantly promote the recovery efficiency.This indicates the direction for designing more efficient photocatalysts for precious metal recovery.
文摘A new technique of swelling oxidizing roasting and alkaline leaching was proposed for deselenization and detellurization of pre- cious-metal ore concentrates. Alkali-metal and alkaline-earth-metal chlorides and carbonates were preliminarily selected as swelling agents. The roasting removal rate and alkaline leaching rate of selenium and tellurium were investigated, and NaCl was selected as an appropriate swelling agent. Furthermore, the effects of various factors on the selenium gasification rate and leaching rate of selenium and tellurium were investigated. The results show that the selenium gasification rate reaches 88.41% after swelling oxidizing roasting for 2 h at 510~C using an NaC1 dosage coefficient of 100 and a sulfuric acid dosage coefficient of 1.3; the amorphous elemental tellurium is completely transformed into TeO2. The roasted product is subjected to alkaline leaching using a 100 g/L NaOH solution, which results in a selenium leaching rate of 10.51%, a total selenium removal rate of 98.92%, and a tellurium leaching rate of 97.64%. In the alkaline leaching residue, the contents of selenium, tellurium, gold, platinum, and palladium are 0.7825%, 5.492%, 8.333%, 0.2587%, and 1.113%, respectively; the precious metals are enriched approximately sixfold.
基金The National Basic Research Program of China(973 Program)under contract No.2012CB417305China Ocean Mineral Resources R&D Association"Twelfth Five-Year"Major Program under contract Nos DY125-11-R-01 and DY125-11-R-05+1 种基金the Natural Science Foundation of Zhejiang Province under contract No.LY12D06006the scientific research fund of the Second Institute of Oceanography under contract No.JG1203
文摘Hydrothermal plume is an important constituent of seabed hydrothermal circulation and is also one of the characteristics of active hydrothermal vents. Portable Miniature Autonomous Plume Recorders （MAPR） attached to a towed deep-sea instrument was used to search for hydrothermal plumes and hydrothermal vents. We introduced the basic principle of MAPR based on deep towing technology to detect plumes, then analyzed the factors affecting the quality of the MAPR data and presented a data correction method for MAPR, including instrument location correction, noise reduction processing, system error elimination and seawater background reduction. Finally we applied the method to analyze MAPR data obtained during the Chinese DY115-21 cruise on R/VDayang Iin the “Precious Stone Mountain” hydrothermal field on the Gala-pagos Microplate. The results provided a better understanding of the distribution of the hydrothermal activ-ity in this field, indicating the presence of a new hydrothermal vent.
文摘To achieve a sustainable development in the electronic and electrical equipment(EEE) industry, it is necessary to protect the available natural resources.In addition, to satisfy the increasing demand on EEE, it is necessary to provide alternative sources of raw materials.In this paper, laptops were imported to Jordan in 2011 as an example to show the potential recovery of metals and precious metals from high grade waste electronic and electrical equipment by conducting a mass flow rate analysis using the STAN program.The results show that considerable amounts of gold, silver, cobalt, palladium,and copper could be recovered.This will reduce the amounts needed from primary natural resources and offset the CO2 emissions produced from mining the primary raw material resources.
基金Supported by Projects of the State Key Laboratory of Geological Processes and Mineral Resources,China University of Geosciences(No.GPMR200603)Project of Education Bureau of Liaoning Province(No.20060805)
文摘The Jianchang Basin is one of the main localities of the precious fossils of Jehol Biota in western Liaoning.The fossil-bearing horizons are mainly in the Yixian-and Jiufotang formations.In the Weijialing--Yaolugou of southwest Jianchang Basin,many precious fossils have been found at Luojiagou Bed of the 2nd Member of the Yixian Formation and at Xidian Bed of the 1st member of the Jiufotang Formation.The geologic setting,sedimentary environment and paleogeography of the precious fossil-bearing beds were also studied.
文摘With the increasing awareness of environmental protection, people’s concern of pollution issues arising. Vehicles, as the most important means of transportation, its exhaust emission has received considerable attention. The catalytic converter is able to purify harmful substances in exhaust gas. The absolute content of precious metals in the catalytic converter dominates the exhaust gas purification effect. Accurate detection of precious metal content is of great significance for controlling the cost of catalysts, ensuring catalytic performance and recovering precious metals from spent catalysts. We herein summarized several instruments for precious metals content exploration, such as X-ray fluorescence spectrometer (XRF), atomic absorption spectrometer (AAS), inductively coupled plasma emission spectrometer (ICP) and spectrophotometer. In this thesis, the feasibility of using various devices for characterizing precious metal content in catalytic converters is analyzed and their strengths or weaknesses are elaborated.
文摘The CD retrieval svstem of Journal of Traditional Chinese Medicine(JTCM)contains all of the periodicals of JTCM published from 1981 to 2008.You can read any articles on computer bv searching any words or combination of the words.The retrieval results can be printed or downloaded.You may retrieve the relevant articles about a certain disease,therapy or drug in a few seconds,user-friendly with convenient handling.
文摘Aimed at high content of valuable metals, complicated composition, difficult to separation of precious metals six component alloy wastes, the present paper proposed a new technology of high efficient separation and purification. Using fragmentation technology realizes fast dissolution of palladium, silver, copper and zinc in the wastes, and high efficient and complete separation of them from gold and platinum; using evaporation thermal decomposition technology of mixed solution produced by nitric acid dissolving palladium, silver, copper and zinc, complete and high efficient separation of silver from palladium was realized; by control of solution acidity, using hydrazine reduction method, high efficient and complete separation of gold from platinum was realized. Using this new technology, the recovery rates of palladium and silver are above 99%, and gold and platinum above 98%, the grade of pure metals are above 99.95%.
文摘Situated in Kunming,Yunnan Province,the institute is a scientific research organiza-tion with a history of fifty years.It is nowaffiliated with the China National NonferrousMetals Industry Corporation.At the beginning of the nineteen sixties,the institute commenced research workin the field of precious metals.It has sincethen developed and extended greatly,andits activities now cover various fields ofprecious metals science and technology,including the comprehensive utilization
