The Yueguang gold deposit is located in Fengjia,Xinhua County,Hunan Province,South China.It represents a recently discovered small-scale gold deposit situated in the southwestern region of the Jiangnan Orogenic Belt,w...The Yueguang gold deposit is located in Fengjia,Xinhua County,Hunan Province,South China.It represents a recently discovered small-scale gold deposit situated in the southwestern region of the Jiangnan Orogenic Belt,west of the Baimashan granitic batholith.In order to discern the characteristics of the ore-formingfluids,the underlying mineralization processes,and establish a foundation for the origin of the Yueguang gold depositfluid inclusion micro-thermometry,as well as quartz hydrogen and oxygen isotope analysis,have been carried out on samples obtained from various stages of mineralization.The hydrothermal miner-alization stages within the Yueguang gold deposit can be categorized into three stages:(i)the barren,pre-ore quartz-pyrite stage(Stage Ⅰ),the quartz-pyrite-gold stage(Stage Ⅱ),and the post-ore quartz-carbonate stage(Stage Ⅲ),with the second stage being the main mineralization stage.Thefluid inclusions identified in samples from the main min-eralization stage can predominantly be described with the NaCl–H_(2)O and CO_(2)–NaCl–H_(2)O systems.These inclusions display homogenization temperatures ranging from 158.8 to 334.9℃,and thefluid salinity ranges from 0.3%to 4.0%(wt.%NaCl equiv.).Laser Raman spectroscopy analysis of individual inclusions further reveals the presence of gas-phases such as CO_(2),CH_(4),and N_(2).Isotopic analysis indicatesδ^(18)Ofluid values ranging from 3.95 to 6.7‰ and δDH_(2)O values ranging from-71.9 to-55.7‰.These results indi-cate that the ore-formingfluid of the Yueguang gold deposit belongs to metamorphic hydrothermalfluids of middle-low temperature and low salinity.In the process of ore formation,gold is transported in the form of Au(HS)2-complexes,with gold deposition being driven byfluid immiscibility.Therefore,the Yueguang gold deposit is categorized as an orogenic gold deposit dominated by metamorphic hydrother-malfluid.It may become a new target for gold exploration in the Baimashan region,central Hunan Province.展开更多
The 0.98(K_(0.5)Na_(0.5))NbO_(3)-0.02Ba(Nb_(0.5)Co_(0.5))O_(3-δ) ceramics with doped Ba^(2+) and Co^(2+) ions are fabricated,and the impacts of the thermal process are studied.Compared with the rapidly cooled (RC) sa...The 0.98(K_(0.5)Na_(0.5))NbO_(3)-0.02Ba(Nb_(0.5)Co_(0.5))O_(3-δ) ceramics with doped Ba^(2+) and Co^(2+) ions are fabricated,and the impacts of the thermal process are studied.Compared with the rapidly cooled (RC) sample,the slowly cooled (SC) sample possesses superior dielectric and ferroelectric properties,and an 11 K higher ferroelectricparaelectric phase transition temperature,which can be attributed to the structural characteristics such as the grain size and the degree of anisotropy.Heat treatment can reversibly modulate the content of the oxygen vacancies,and in turn the ferroelectric hysteresis loops of the samples.Finally,robust and tunable ferroelectric property is achieved in SC samples with good structural integrity.展开更多
Fines migration induced by injection of low-salinity water(LSW) into porous media can lead to severe pore plugging and consequent permeability reduction. The deepbed filtration(DBF) theory is used to model the aforeme...Fines migration induced by injection of low-salinity water(LSW) into porous media can lead to severe pore plugging and consequent permeability reduction. The deepbed filtration(DBF) theory is used to model the aforementioned phenomenon, which allows us to predict the effluent concentration history and the distribution profile of entrapped particles. However, the previous models fail to consider the movement of the waterflood front. In this study, we derive a stochastic model for fines migration during LSW flooding, in which the Rankine-Hugoniot condition is used to calculate the concentration of detached particles behind and ahead of the moving water front. A downscaling procedure is developed to determine the evolution of pore-size distribution from the exact solution of a large-scale equation system. To validate the proposed model,the obtained exact solutions are used to treat the laboratory data of LSW flooding in artificial soil-packed columns. The tuning results show that the proposed model yields a considerably higher value of the coefficient of determination, compared with the previous models, indicating that the new model can successfully capture the effect of the moving water front on fines migration and precisely match the effluent history of the detached particles.展开更多
The Mengya’a Lead–zinc deposit is a large skarn deposit in the north of the eastern segment of Gangdese metallogenic belt.The garnet is the main altered mineral in the Mengya’a area.The color of the garnet varies f...The Mengya’a Lead–zinc deposit is a large skarn deposit in the north of the eastern segment of Gangdese metallogenic belt.The garnet is the main altered mineral in the Mengya’a area.The color of the garnet varies from chartreuse to dark yellow brown and to russet.The brown garnet(Grt1)is related to pyrrhotite and chalcopyrite,and the green garnet(Grt2)is associated with lead–zinc mineralization.LA-ICP-MS is the induced coupled plasma mass spectrometry.This paper has used this technique to investigate Grt1 and Grt2.Grt1 develops core–rim textures with strong oscillation zone occurring in rim,whereas Grt2lacks core–rim textures and featured by oscillation zone.LA–ICP–MS analysis shows that garnets of Mengya’a are rich in CaO(29.90–37.52%)and FeO(21.17–33.35%),but low in Al_(2)O_(3)(0.05–4.85%).The calculated end members belong to grandite(grossular–andradite)garnets andradite.The negative Al(IV)versus Fe^(3+),positive Al(IV)versus total Al stoichiometric number,the positive Al(IV)versus Fe^(3+),and the negative Al(IV)versus total REE,all indicate that the substitution of REEs in garnets is controlled by YAG.All Garnets are depleted in large lithophile elements(e.g.,Rb=0.00–4.01 ppm,Sr=0.03–8.56 ppm).The total REE in Grt1 core is high(ΣREE=233–625 ppm),with HREE enriched pattern(LREE/HREE=0.33–1.69)and weak negative Eu anomalies(δEu=0.21–0.47).In contrast,the total REEs in the Grt1 rim and Grt2 are low(ΣREE=12.4–354 ppm;ΣREE=21.0–65.3 ppm),with LREE enriched pattern(LREE/HREE=0.54–34.4;LREE/HREE=11.4–682)and positive Eu anomalies(δEu=0.35–27.2;δEu=1.02–30.7).After data compilation of garnet chemicals,we found that the early fluid responsible for the core of Grt1 was a relatively closed and chloride-depleted fluid system.It was close-to-neutral,with a low water–rock ratio.The core of garnet was formed by fluid diffusion in metasomatic processes.The fluid was changed into a relatively open system with reduced,chloride-rich,and weakacid fluid.It was fluid infiltration and metasomatism that resulted in the formation of Grt1 rim and Grt2.展开更多
Ferroelectric Sr_(0.6)Ba_(0.4)Nb_(2)O_(6)(SBN)shows typical unfilled tetragonal tungsten bronze structure where 1/6 A sites and all C sites are unoccupied.The presence of such structural vacancy provides the possibili...Ferroelectric Sr_(0.6)Ba_(0.4)Nb_(2)O_(6)(SBN)shows typical unfilled tetragonal tungsten bronze structure where 1/6 A sites and all C sites are unoccupied.The presence of such structural vacancy provides the possibility to further modulate the crystal structure and electrical properties.In this work,alkali ions(Li^(+),Na^(+),K^(+))doped SBN ceramics have been fabricated via solid-solution reaction method.In general,each doping promotes the crystal structure evolves from unfilled toward filled tungsten bronze.However,the different doping ion radius causes the differences in occupying initial structural vacancies,resulting in significantly different electrical properties,Li^(+)doping enhances relaxor characteristic whereas Na+and K^(+)doping lead to normal ferroelectric behavior,accompanying an increase in Curie temperature(TC)from 36℃ of SBN to 40,212,148℃ of Li^(+),Na^(+)and K^(+)doping,respectively.Benefiting from improved relaxor degree and high density,the Li^(+)doped SBN displays a good energy storage performance.Since the ratio of Sr/Ba and(Sr+Ba)/Nb has not been changed,this work presents direct evidence for the effect of structural vacancy on crystal structure and properties,as well as inspiration for further work on unfilled tungsten bronze.展开更多
OBJECTIVE: To evaluate the therapeutic effect of scalp electroacupuncture for mild cognitive impairment (MCI) in the early stage. METHODS: Two hundred and thirty three MCI patients were randomly divided into three gro...OBJECTIVE: To evaluate the therapeutic effect of scalp electroacupuncture for mild cognitive impairment (MCI) in the early stage. METHODS: Two hundred and thirty three MCI patients were randomly divided into three groups: the drug group, the scalp electroacupuncture group, and the syndrome differentiation group. For the scalp electroacupuncture group, the points of Baihui (DU 20), Sishecong (EX-HN1), Fengchi (GB 20), and Shenting (DU 24) were selected. For the syndrome differentiation group, specific acupoints were added on the basis of syndrome differentiation and according to the scale for the differentiation of syndromes in vascular dementia (SDSVD) beside the acupoints used in the scalp electroacupuncture group. For the drug group, nimodipine was orally administered. Each patient was treated for two courses, eight weeks. The score differences in minimental state examination (MMSE), picture recognition, and clock drawing test were observed before and after the treatment. RESULTS: After treatment, the score differences in MMSE and clock drawing test were of obvious statistical significance among three groups (P<0.01, P<0.05). The score differences in picture recognition were of extremely statistical significance between the scalp electroacupuncture group and the syndrome differentiation group (P<0.01), while the difference was not found in the drug group (P>0.05). There were statistical significant differences in therapeutic effects between the scalp electroacupuncture group and the drug group, and between the syndrome differentiation group and the drug group (P<0.05), while no statistical difference was found between scalp electroacupuncture group and the syndrome differentiation group (P>0.05). CONCLUSION: All the three therapies may improve the cognitive function of MCI patients. The therapeutic effects in the scalp electroacupuncture and syndrome differentiation groups were basically the same, but superior to nimodipine.展开更多
Unlike prior studies that investigate research and development(R&D)accounting as a dichotomous choice between capitalizing vs.expensing, this study identifies low-reliability R&D capitalization by the occurren...Unlike prior studies that investigate research and development(R&D)accounting as a dichotomous choice between capitalizing vs.expensing, this study identifies low-reliability R&D capitalization by the occurrence of ex post impairment of capitalized R&D costs.I find that low-reliability capitalization is associated with higher discretionary accruals but fails to signal future innovation, whereas normal capitalization without subsequent impairment lacks earnings aggressiveness and predicts future innovation positively, compared to expensing firms.Next, this study shows that Big 4 and industry specialist auditors improve reliability by notably decreasing the likelihood of lowreliability R&D capitalization.The results remain robust after controlling for R&D investment intensity and potential endogeneity in the capitalization decision.Additional tests show that managers strategically time the recognition of impairment for big-bath and earnings-smoothing purposes, and that analyst coverage does not help differentiate between low-reliability and normal R&D capitalization.Collectively, this paper increases our understanding of R&D accounting and auditing and contributes to the debate on the reliability of R&D capitalization.展开更多
The large-scale Qixiashan Pb-Zn Deposit in the eastern Middle-Lower Yangtze metallogenic belt is hosted in carbonate rocks.Based on a detailed mineral paragenesis study,in-situ LA-ICP-MS(laser ablation inductively cou...The large-scale Qixiashan Pb-Zn Deposit in the eastern Middle-Lower Yangtze metallogenic belt is hosted in carbonate rocks.Based on a detailed mineral paragenesis study,in-situ LA-ICP-MS(laser ablation inductively coupled plasma mass spectrometer)trace element geochemistry data for pyrite and sphalerite from different stages in the Qixiashan Deposit are reported,the Pb-Zn mineralization processes are reconstructed,and a genetic model is constructed.Four paragenetic stages of Pb-Zn ore deposition are identified:the biogenic pyrite mineralization stage(Stage 1),the early stage of hydrothermal Pb-Zn mineralization(Stage 2),the late stage of hydrothermal Pb-Zn mineralization(Stage 3),and the carbonate stage(Stage 4).Stages 2 and 3 are the main ore stages.The trace element characteristics of the sulfide in stages 2 and 3,such as the higher Co/Ni and lower trace element contents of the pyrite and the Fe,Mn,and Ge contents of the sphalerite,indicate that they were generated by magmatic-hydrothermal processes.Furthermore,the lower Cu,Ag,Sb,and Pb contents of the pyrite and sphalerite of Stage 3 compared to Stage 2 suggest an increase in magmatic-hydrothermal activity from Stage 2 to Stage 3.The hydrothermal fluids leached trace elements(e.g.,Cu,Ag,Sb,and Pb)from the previously deposited primary pyrite and sphalerite,which were precipitated in the later hydrothermal stage Cu,Au,Ag,Sb,and Pb bearing minerals and secondary pyrite and sphalerite with lower trace element contents(e.g.,Cu,Au,Ag,Sb,and Pb).Compared with the pyrite from stages 2 and 3,the Stage 1 pyrite has relatively higher trace elements contents(Sb,Cu,Zn,Au,Ag,Pb,As,and Ni).However,their lower Co/Ni ratio suggests a syngenetic sedimentary origin.Based on the petrographic features and trace element data,a multi-stage mineralization model is proposed.The Stage 1 biogenic pyrite formed stratiform pyrite layers,which provided reducing conditions and a base for the subsequent Pb-Zn mineralization.During Stage 2,subsequent hydrothermal fluid interacted with the stratiform pyrite layers,which resulted in sulfide precipitation and the formation of stratiform Pb-Zn orebodies.In Stage 3,the hydrothermal fluid replaced the limestone along the fractures,which triggered the formation of Pb-Zn vein orebodies.展开更多
The theory of audit pricing suggests that audit fees are positively associated with areas of higher inherent risk. Inventory is commonly cited as one such area, and many Western studies have reported a positive associ...The theory of audit pricing suggests that audit fees are positively associated with areas of higher inherent risk. Inventory is commonly cited as one such area, and many Western studies have reported a positive association between inventory and audit fees. However, most Chinese studies have reported a significant negative association. This study finds that this puzzling association is attributable to Chinese auditors charging a significant discount on the opening balance of inventory, whereas their U.S. counterparts charge a significant premium. Meanwhile, we show that opening-balance inventory is associated with higher inherent risk both in China and the U.S. On the other hand, both Chinese and U.S. auditors charge a significant discount on the net increase in inventory as of the current year end, and we show that this is associated with lower inherent risk. Therefore, Chinese auditors appear to underreact to the inherent risk associated with opening-balance inventory, which helps explain the puzzling negative association between inventory and audit fees in China.展开更多
基金support from several sources,including the Backbone Teacher Training Program(10912-SJGG2021-04233)the Teaching Reform Project of Chengdu University of Technology(JG2130131)+1 种基金the University-Industry Collaborative Education Project,Ministry of Education,China(22097130210756)National Natural Science Foundation of China(42272129).
文摘The Yueguang gold deposit is located in Fengjia,Xinhua County,Hunan Province,South China.It represents a recently discovered small-scale gold deposit situated in the southwestern region of the Jiangnan Orogenic Belt,west of the Baimashan granitic batholith.In order to discern the characteristics of the ore-formingfluids,the underlying mineralization processes,and establish a foundation for the origin of the Yueguang gold depositfluid inclusion micro-thermometry,as well as quartz hydrogen and oxygen isotope analysis,have been carried out on samples obtained from various stages of mineralization.The hydrothermal miner-alization stages within the Yueguang gold deposit can be categorized into three stages:(i)the barren,pre-ore quartz-pyrite stage(Stage Ⅰ),the quartz-pyrite-gold stage(Stage Ⅱ),and the post-ore quartz-carbonate stage(Stage Ⅲ),with the second stage being the main mineralization stage.Thefluid inclusions identified in samples from the main min-eralization stage can predominantly be described with the NaCl–H_(2)O and CO_(2)–NaCl–H_(2)O systems.These inclusions display homogenization temperatures ranging from 158.8 to 334.9℃,and thefluid salinity ranges from 0.3%to 4.0%(wt.%NaCl equiv.).Laser Raman spectroscopy analysis of individual inclusions further reveals the presence of gas-phases such as CO_(2),CH_(4),and N_(2).Isotopic analysis indicatesδ^(18)Ofluid values ranging from 3.95 to 6.7‰ and δDH_(2)O values ranging from-71.9 to-55.7‰.These results indi-cate that the ore-formingfluid of the Yueguang gold deposit belongs to metamorphic hydrothermalfluids of middle-low temperature and low salinity.In the process of ore formation,gold is transported in the form of Au(HS)2-complexes,with gold deposition being driven byfluid immiscibility.Therefore,the Yueguang gold deposit is categorized as an orogenic gold deposit dominated by metamorphic hydrother-malfluid.It may become a new target for gold exploration in the Baimashan region,central Hunan Province.
基金supported by the National Key R&D Program of China (Grant No.2022YFA1402903)the National Natural Science Foundation of China (Grant Nos.52172116 and 62171214)the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)。
文摘The 0.98(K_(0.5)Na_(0.5))NbO_(3)-0.02Ba(Nb_(0.5)Co_(0.5))O_(3-δ) ceramics with doped Ba^(2+) and Co^(2+) ions are fabricated,and the impacts of the thermal process are studied.Compared with the rapidly cooled (RC) sample,the slowly cooled (SC) sample possesses superior dielectric and ferroelectric properties,and an 11 K higher ferroelectricparaelectric phase transition temperature,which can be attributed to the structural characteristics such as the grain size and the degree of anisotropy.Heat treatment can reversibly modulate the content of the oxygen vacancies,and in turn the ferroelectric hysteresis loops of the samples.Finally,robust and tunable ferroelectric property is achieved in SC samples with good structural integrity.
基金the National Natural Science Foundation of China(Nos.51804316,51734010,and U1762211)the National Science and Technology Major Project of China(No.2017ZX05009)the Science Foundation of China University of Petroleum,Beijing(No.2462017YJRC037)。
文摘Fines migration induced by injection of low-salinity water(LSW) into porous media can lead to severe pore plugging and consequent permeability reduction. The deepbed filtration(DBF) theory is used to model the aforementioned phenomenon, which allows us to predict the effluent concentration history and the distribution profile of entrapped particles. However, the previous models fail to consider the movement of the waterflood front. In this study, we derive a stochastic model for fines migration during LSW flooding, in which the Rankine-Hugoniot condition is used to calculate the concentration of detached particles behind and ahead of the moving water front. A downscaling procedure is developed to determine the evolution of pore-size distribution from the exact solution of a large-scale equation system. To validate the proposed model,the obtained exact solutions are used to treat the laboratory data of LSW flooding in artificial soil-packed columns. The tuning results show that the proposed model yields a considerably higher value of the coefficient of determination, compared with the previous models, indicating that the new model can successfully capture the effect of the moving water front on fines migration and precisely match the effluent history of the detached particles.
基金funded by the Surface Project of National Natural Science Foundation of China (41372093)。
文摘The Mengya’a Lead–zinc deposit is a large skarn deposit in the north of the eastern segment of Gangdese metallogenic belt.The garnet is the main altered mineral in the Mengya’a area.The color of the garnet varies from chartreuse to dark yellow brown and to russet.The brown garnet(Grt1)is related to pyrrhotite and chalcopyrite,and the green garnet(Grt2)is associated with lead–zinc mineralization.LA-ICP-MS is the induced coupled plasma mass spectrometry.This paper has used this technique to investigate Grt1 and Grt2.Grt1 develops core–rim textures with strong oscillation zone occurring in rim,whereas Grt2lacks core–rim textures and featured by oscillation zone.LA–ICP–MS analysis shows that garnets of Mengya’a are rich in CaO(29.90–37.52%)and FeO(21.17–33.35%),but low in Al_(2)O_(3)(0.05–4.85%).The calculated end members belong to grandite(grossular–andradite)garnets andradite.The negative Al(IV)versus Fe^(3+),positive Al(IV)versus total Al stoichiometric number,the positive Al(IV)versus Fe^(3+),and the negative Al(IV)versus total REE,all indicate that the substitution of REEs in garnets is controlled by YAG.All Garnets are depleted in large lithophile elements(e.g.,Rb=0.00–4.01 ppm,Sr=0.03–8.56 ppm).The total REE in Grt1 core is high(ΣREE=233–625 ppm),with HREE enriched pattern(LREE/HREE=0.33–1.69)and weak negative Eu anomalies(δEu=0.21–0.47).In contrast,the total REEs in the Grt1 rim and Grt2 are low(ΣREE=12.4–354 ppm;ΣREE=21.0–65.3 ppm),with LREE enriched pattern(LREE/HREE=0.54–34.4;LREE/HREE=11.4–682)and positive Eu anomalies(δEu=0.35–27.2;δEu=1.02–30.7).After data compilation of garnet chemicals,we found that the early fluid responsible for the core of Grt1 was a relatively closed and chloride-depleted fluid system.It was close-to-neutral,with a low water–rock ratio.The core of garnet was formed by fluid diffusion in metasomatic processes.The fluid was changed into a relatively open system with reduced,chloride-rich,and weakacid fluid.It was fluid infiltration and metasomatism that resulted in the formation of Grt1 rim and Grt2.
基金This work was supported by the National Natural Science Foundation of China(No.12174179)the Natural Science Foundation of Jiangsu Province(No.BK20221251)the Dengfeng B project of Nanjing University and the Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.KYCX23_0149).
文摘Ferroelectric Sr_(0.6)Ba_(0.4)Nb_(2)O_(6)(SBN)shows typical unfilled tetragonal tungsten bronze structure where 1/6 A sites and all C sites are unoccupied.The presence of such structural vacancy provides the possibility to further modulate the crystal structure and electrical properties.In this work,alkali ions(Li^(+),Na^(+),K^(+))doped SBN ceramics have been fabricated via solid-solution reaction method.In general,each doping promotes the crystal structure evolves from unfilled toward filled tungsten bronze.However,the different doping ion radius causes the differences in occupying initial structural vacancies,resulting in significantly different electrical properties,Li^(+)doping enhances relaxor characteristic whereas Na+and K^(+)doping lead to normal ferroelectric behavior,accompanying an increase in Curie temperature(TC)from 36℃ of SBN to 40,212,148℃ of Li^(+),Na^(+)and K^(+)doping,respectively.Benefiting from improved relaxor degree and high density,the Li^(+)doped SBN displays a good energy storage performance.Since the ratio of Sr/Ba and(Sr+Ba)/Nb has not been changed,this work presents direct evidence for the effect of structural vacancy on crystal structure and properties,as well as inspiration for further work on unfilled tungsten bronze.
基金Supported by the National Nature Science Foundation ofChina (No. 81173321)
文摘OBJECTIVE: To evaluate the therapeutic effect of scalp electroacupuncture for mild cognitive impairment (MCI) in the early stage. METHODS: Two hundred and thirty three MCI patients were randomly divided into three groups: the drug group, the scalp electroacupuncture group, and the syndrome differentiation group. For the scalp electroacupuncture group, the points of Baihui (DU 20), Sishecong (EX-HN1), Fengchi (GB 20), and Shenting (DU 24) were selected. For the syndrome differentiation group, specific acupoints were added on the basis of syndrome differentiation and according to the scale for the differentiation of syndromes in vascular dementia (SDSVD) beside the acupoints used in the scalp electroacupuncture group. For the drug group, nimodipine was orally administered. Each patient was treated for two courses, eight weeks. The score differences in minimental state examination (MMSE), picture recognition, and clock drawing test were observed before and after the treatment. RESULTS: After treatment, the score differences in MMSE and clock drawing test were of obvious statistical significance among three groups (P<0.01, P<0.05). The score differences in picture recognition were of extremely statistical significance between the scalp electroacupuncture group and the syndrome differentiation group (P<0.01), while the difference was not found in the drug group (P>0.05). There were statistical significant differences in therapeutic effects between the scalp electroacupuncture group and the drug group, and between the syndrome differentiation group and the drug group (P<0.05), while no statistical difference was found between scalp electroacupuncture group and the syndrome differentiation group (P>0.05). CONCLUSION: All the three therapies may improve the cognitive function of MCI patients. The therapeutic effects in the scalp electroacupuncture and syndrome differentiation groups were basically the same, but superior to nimodipine.
基金the financial support from the National Natural Science Foundation of China (approval number: NSFC-71902137)
文摘Unlike prior studies that investigate research and development(R&D)accounting as a dichotomous choice between capitalizing vs.expensing, this study identifies low-reliability R&D capitalization by the occurrence of ex post impairment of capitalized R&D costs.I find that low-reliability capitalization is associated with higher discretionary accruals but fails to signal future innovation, whereas normal capitalization without subsequent impairment lacks earnings aggressiveness and predicts future innovation positively, compared to expensing firms.Next, this study shows that Big 4 and industry specialist auditors improve reliability by notably decreasing the likelihood of lowreliability R&D capitalization.The results remain robust after controlling for R&D investment intensity and potential endogeneity in the capitalization decision.Additional tests show that managers strategically time the recognition of impairment for big-bath and earnings-smoothing purposes, and that analyst coverage does not help differentiate between low-reliability and normal R&D capitalization.Collectively, this paper increases our understanding of R&D accounting and auditing and contributes to the debate on the reliability of R&D capitalization.
基金This study was supported by the National Natural Science Foundation of China(No.1212011220678)We are very grateful to Jiangsu East China Basic Geological Exploration Co.,Ltd.for providing basic geological data and assistance in the field.
文摘The large-scale Qixiashan Pb-Zn Deposit in the eastern Middle-Lower Yangtze metallogenic belt is hosted in carbonate rocks.Based on a detailed mineral paragenesis study,in-situ LA-ICP-MS(laser ablation inductively coupled plasma mass spectrometer)trace element geochemistry data for pyrite and sphalerite from different stages in the Qixiashan Deposit are reported,the Pb-Zn mineralization processes are reconstructed,and a genetic model is constructed.Four paragenetic stages of Pb-Zn ore deposition are identified:the biogenic pyrite mineralization stage(Stage 1),the early stage of hydrothermal Pb-Zn mineralization(Stage 2),the late stage of hydrothermal Pb-Zn mineralization(Stage 3),and the carbonate stage(Stage 4).Stages 2 and 3 are the main ore stages.The trace element characteristics of the sulfide in stages 2 and 3,such as the higher Co/Ni and lower trace element contents of the pyrite and the Fe,Mn,and Ge contents of the sphalerite,indicate that they were generated by magmatic-hydrothermal processes.Furthermore,the lower Cu,Ag,Sb,and Pb contents of the pyrite and sphalerite of Stage 3 compared to Stage 2 suggest an increase in magmatic-hydrothermal activity from Stage 2 to Stage 3.The hydrothermal fluids leached trace elements(e.g.,Cu,Ag,Sb,and Pb)from the previously deposited primary pyrite and sphalerite,which were precipitated in the later hydrothermal stage Cu,Au,Ag,Sb,and Pb bearing minerals and secondary pyrite and sphalerite with lower trace element contents(e.g.,Cu,Au,Ag,Sb,and Pb).Compared with the pyrite from stages 2 and 3,the Stage 1 pyrite has relatively higher trace elements contents(Sb,Cu,Zn,Au,Ag,Pb,As,and Ni).However,their lower Co/Ni ratio suggests a syngenetic sedimentary origin.Based on the petrographic features and trace element data,a multi-stage mineralization model is proposed.The Stage 1 biogenic pyrite formed stratiform pyrite layers,which provided reducing conditions and a base for the subsequent Pb-Zn mineralization.During Stage 2,subsequent hydrothermal fluid interacted with the stratiform pyrite layers,which resulted in sulfide precipitation and the formation of stratiform Pb-Zn orebodies.In Stage 3,the hydrothermal fluid replaced the limestone along the fractures,which triggered the formation of Pb-Zn vein orebodies.
文摘The theory of audit pricing suggests that audit fees are positively associated with areas of higher inherent risk. Inventory is commonly cited as one such area, and many Western studies have reported a positive association between inventory and audit fees. However, most Chinese studies have reported a significant negative association. This study finds that this puzzling association is attributable to Chinese auditors charging a significant discount on the opening balance of inventory, whereas their U.S. counterparts charge a significant premium. Meanwhile, we show that opening-balance inventory is associated with higher inherent risk both in China and the U.S. On the other hand, both Chinese and U.S. auditors charge a significant discount on the net increase in inventory as of the current year end, and we show that this is associated with lower inherent risk. Therefore, Chinese auditors appear to underreact to the inherent risk associated with opening-balance inventory, which helps explain the puzzling negative association between inventory and audit fees in China.