Jade ware Jue is one of the most fashionable ornament in ancient China from the Neolithic Age to the Han Dynasty.In this study,the remnants of jade ware Jue,from Lijiashan ancient tomb group have been tested and analy...Jade ware Jue is one of the most fashionable ornament in ancient China from the Neolithic Age to the Han Dynasty.In this study,the remnants of jade ware Jue,from Lijiashan ancient tomb group have been tested and analyzed respectively.The samples through a light etch surface showing glass luster and those with a severe etch surface showing earthen luster.With the aid of X-ray fluorescence Spectrometer(X-ray Fluorescence)test and X-ray diffraction(XRD)detection,the results show that tremolite is not the main mineral of the sample.The main components of the tested samples with light erosion are antigorite and talc,although the main components of the samples with severe erosion are calcite containing calcium carbonate barium.Furthermore,the research on jade ware Jue in Yunnan culture has not only contributed to our further understanding of the jade objects from Yunnan culture and the variety of jade material located in the Yunnan Province.It also provides a basis for the trace of the history and culture through the distribution and evolution of burial hierarchy laws.At the same time,the microscopic observation of the tested samples manifested a residual trace of“string”at the perforation,which has played a critical role in restoring the wearing of jade ware Jue from the tombs of the ancient Yunnan State and the handicraft skills at that time.展开更多
Taking the wireless enamel(wireless enamel refers to make enamel works without filigree)production technique in jewelry practice course as the research object,combined with years of enamel teaching experience in the G...Taking the wireless enamel(wireless enamel refers to make enamel works without filigree)production technique in jewelry practice course as the research object,combined with years of enamel teaching experience in the Gemmological Institute of China University of Geosciences(Wuhan),this study expounds the theoretical class,design preparation,creative idea and technique practice application from the course teaching objectives and the implementation,which also emphasizes the practical improvability of students’design practice ability and innovative thinking ability.During the period,it focuses on the core processes,such as wireless enamel glaze method,object correction,firing time,composite application and system integration,to help students solve the key and difficult problems in the wireless enamel firing process.展开更多
In gemmology,the term“Alexandrite effect”is used to describe colour change phenomenon when a gemstone is observed under different light sources,usually between daylight and incandescent light.The definition of the A...In gemmology,the term“Alexandrite effect”is used to describe colour change phenomenon when a gemstone is observed under different light sources,usually between daylight and incandescent light.The definition of the Alexandrite effect is constantly being broadened with new discovery of gem resource.The traditional definition of the Alexandrite effect attributing the colour change phenomenon to the presence of two maximum transmission regions and a maximum absorption region in the absorption spectra.In this study,7 blue spinels and 5 blue gemstones(including tanzanite,kyanite,fluorite,and 2 sapphires)showing the Alexandrite effect were investigated.The goal is to explain the cause of blue-to-violet Alexandrite effect and the spectral features causing such colour change.In the UV-Vis spectra,all samples showed a maximum absorption peak in the range of 534-610 nm,within the green region to orange region.The traditional explanation of green to red Alexandrite effect required a transmission window in the red region;however,some of our samples did not show this transmission window and the blue-to-violet Alexandrite effect was still visible.Therefore,it is incomplete to explain the mechanism of the Alexandrite effect according to their characteristic absorption spectra,a systematic study based on modern colour science and colour perception in human vision is required to elucidate the blue-to-violet Alexandrite effect.展开更多
Amber can emit room temperature phosphorescence(RTP)under the well-known 365 nm fluorescence ultraviolet light.This paper is devoted to the phosphorescence study of 20 pieces of amber materials from the Dominican Repu...Amber can emit room temperature phosphorescence(RTP)under the well-known 365 nm fluorescence ultraviolet light.This paper is devoted to the phosphorescence study of 20 pieces of amber materials from the Dominican Republic,Mexico,Baltic sea,Myanmar,and Fushun,China.The results show that amber from the same geographic origin has similar shape in phosphorescence spectra.However,the shape of the amber phosphorescence spectra varies depending on their different localities.Burmite(amber from Myanmar)and Fushun amber have a bright yellow phosphorescence with a long lifetime,while the Dominican and Mexican ones are weaker and last shorter.The irradiation of Baltic amber becomes faint or even inert.Phosphorescence spectral Gaussian fitting results suggest an emission maximum near 550 nm in most amber samples.Their phosphorescence lifetime,analyzed through the exponential function fitting,is up to 1 second in Burmite and Fushun samples,shorter in the Dominican and Mexican ones,about 0.230 s,and the shortest in Baltic amber,close to 0.151 s.These variations of phosphorescence lifetime and intensity are related to the relative geological ages of these amber.It indicated that the phosphorescence agent was probably formed during the long geological time.While the anomaly occurred in Baltic amber,the only one found in a sea secondary deposit form,it demonstrated that the terrestrial geological environment these amber preserved has prevented the phosphorescence agent to be deactivated.展开更多
Tengchong,an ancient border town located in southwest China,has more than 500years of history in the trading and processing of jadeite.It is an important distribution center for jadeite and the birthplace of China’s ...Tengchong,an ancient border town located in southwest China,has more than 500years of history in the trading and processing of jadeite.It is an important distribution center for jadeite and the birthplace of China’s jadeite culture.Tengchong has three key advantages:location,culture and history,and is able to integrate local culture to form the unique style of“Yunnan Jade Carving”.This article combines physical objects with related results of previous studies,based on the different usage and functions of jadeite jewelry and products in Tengchong,in order to analyze and summarize their classification and application.The four aspects of pattern,material,colour and technique are also been analyzed,as well as the linguistic features of jadeite jewelry and products in Tengchong,with the hope of providing ideas and references for the creation of modern jadeite jewelry.展开更多
Under the special background of China, the cooperative innovation between different government-industry-university-research institutes plays an increasingly important role in the agricultural field. However, the exist...Under the special background of China, the cooperative innovation between different government-industry-university-research institutes plays an increasingly important role in the agricultural field. However, the existing literature has paid little attention to it. Considering the cooperation patents, published in the agriculture field stemming from the Full-text Database of China Patents as the study object, the spatial and institutional attribute of the authors as the data source, and by combining the social network and spatial econometrics analysis, this paper analyzes the structure evolution characteristics of cooperative innovation networks of agricultural government-industry-university-research institute in the city level of China in 1985–2014, based on the triple helix theory, with the influence factors discussed. This shows that, 1) since 1985, China's agricultural innovation level has been substantially increased, but the development degree of the cooperative innovation network is low, and the patent cooperation mainly relies on authors in the same unit; 2) enterprises play a leading role in the agricultural cooperative innovation. The effect of the government and hybrid organizations driven by the government is not obvious; 3) the cooperative innovation in the province and city dominates, and a multi-pole pattern has been formed. The cooperative innovation network structure evolves from a single helix empty core and double helix multi core to a double helix hierarchical network; 4) the city's science, education funding and personnel investment are key factors determining the agricultural cooperative innovation, while the agricultural development of the city presents slight negative impacts on it. The spatial mismatch of supply and demand is present in the technical cooperative innovation of China's agriculture. Therefore, the science enhancement and education investment to big agricultural provinces should be promptly implemented.展开更多
With a thick sequence of early Eocene to Pleistocene terrestrial records, the Qaidam Basin on the northern Tibetan Plateau provides an important sedimentary archive for understanding the paleoenvironmental evolution o...With a thick sequence of early Eocene to Pleistocene terrestrial records, the Qaidam Basin on the northern Tibetan Plateau provides an important sedimentary archive for understanding the paleoenvironmental evolution of the northeast Tibetan Plateau. In this study, specimens of fossil fish remains are collected from the late Middle Miocene（Serravallian, -12 Ma） of the middle member of the Shang Youshashan Formation, Dahonggou（DHG） section, in the northern Qaidam Basin. Based on a systematic study of these materials, the remains have assigned to Cyprinidae, with typical pharyngeal teeth and dorsal fin spines with serrations on the posterior edge. Our discovery improves understanding of the cyprinid fish distribution characteristics in the Qaidam Basin during the Cenozoic. Cooccurrences of terrestrial brackish ostracod species Cyprideis and long chain alkenonesin the layer indicate that the studied cyprinid fish lived in a generally large brackish to saline water body during the late middle Miocene（Serravallian）, when the climate of Qaidam Basin was still not sufficiently dry to form an extreme saline water lake.展开更多
Due to various courses of formation of zircons from kimbedites, different kinds of zircons can provide useful information about the mantle and the crystallization of kimberlites. We chose 9 typical ones out of 33 zirc...Due to various courses of formation of zircons from kimbedites, different kinds of zircons can provide useful information about the mantle and the crystallization of kimberlites. We chose 9 typical ones out of 33 zircons from the Shengli- 1 kimberlite pipe in Mengyin County, Shandong Province to study their ages and formation by means of SHRIMP, CL, Raman spectroscopy, etc. The result shows that the ^207Pb/^206Pb ages of many zircons vary from 2567±13 Ma to 2636±42 Ma, which are close to the age of Archaean granitoid （2457.3±47 Ma） in the study area. The contents of U and Th in the samples are higher than those of zircons crystallized in kimbedite and vary from 89 to 398 ppm as well as from 10 to 283 ppm. Color zones are obvious in these samples under the CL. The inclusions are composed of feldspar, quartz, apatite, etc. The above results show that the zircon samples came from the crust of the earth, which means that the kimberlite magmas are contaminated by crustal substances. The position where a great deal of volatile escapes and even explodes during rapid rise of magmas is located at the boundary of the ancient basement and the Precambrian stratum.展开更多
In this study, Raman scattering measurements were obtained for momo corals covering their typical range of colors. Three different excitation wavelengths （785, 633, 514 nm） are used for the same samples at the same ...In this study, Raman scattering measurements were obtained for momo corals covering their typical range of colors. Three different excitation wavelengths （785, 633, 514 nm） are used for the same samples at the same points. All the samples show the two major Raman features of polyenic compounds assigned to double carbon-carbon （C=C） stretching vibration at approximately 1 500 cm^-1 and single carbon-carbon （C-C） stretching vibration at approximately 1 130 cm^-1 bond stretching mode. These peaks are not detected in the corresponding white parts of momo corals. However, some changes in intensities, shape, and position of C=C stretching vibrations of the same point are observed by using different excitation wavelengths. The exact position of C-C stretching vibration of polyenic molecules depends strongly on the number of double bonds contained in their polyenic chain. In addition, the number of double bonds contained in the polyenic chains shows that different colors of the red momo coral are caused by different mixtures of polyenic compounds.展开更多
Infrared （IR） absorption spectra and X-ray powder diffraction （XRD） patterrns of sexpenfine cat＇s eye from Sichuan Province have been investigated, and infrared absorption bands of the serpentine have been assign...Infrared （IR） absorption spectra and X-ray powder diffraction （XRD） patterrns of sexpenfine cat＇s eye from Sichuan Province have been investigated, and infrared absorption bands of the serpentine have been assigned in this paper. The results indicate that the bands near 3 600 - 3 700 cm^-1 belong to the stretching absorption band VOH, the bands in 948 - 1 100 cm^-1 axe assigned to the stretching vibraling band Usvo, and the bands at 600 570 and 440 cm^-1 respectively belong to the bending vibration band VOH, δMg-O and δSi-O. The serpentine cat＇ s eye includes two types： chrysotile and antigorite. Chrysotile has a sharp and intensive band at 3 688 cm^-1 and a weak band at 3 643 cm^-1 , while antigorite has only one intensive band in the region. At vibration band VSi-O, chrysotile and antigorite have a similar feature at 1 071 cm^-1, but the band at 980 cm^-1 in anfigorite has been split into two bands in chrysotile - a strong one at 1 027 cm^-1 and a weak one at 949 cm^-1. In addition, antigorite has a characteristic bending vibrating band δMg-O at 570 cm^-1. Based on the analysis of the feature of crystal structure, their IR differences axe well explained.展开更多
Negative temperature coefficient(NTC)thermistor plays a crucial role in science research and engineering applications for precise temperature monitoring.Although great progress has been achieved in NTC materials,enhan...Negative temperature coefficient(NTC)thermistor plays a crucial role in science research and engineering applications for precise temperature monitoring.Although great progress has been achieved in NTC materials,enhancing sensitivity and maintaining this high sensitivity along with linearity across extensive temperature ranges remain a significant challenge.In this study,we introduce a diamondbased thermistor(DT)characterized by its outstanding sensitivity,swift response time,and broad temperature monitoring capabilities.The temperature constant B for this DT,measured from 30 to 300°C(B30/300),achieves an exceptional value of 8012 K,which notably exceeds the temperature sensing capabilities of previously reported NTC thermistors within this extensive range.Moreover,diamond’s unique thermal conductivity and stability significantly boost the response speed and durability of the DT,offering substantial advantages over traditional ceramic thermistors.The enhanced temperature-sensitive properties of the DT are attributed to the presence of impurity elements in polycrystalline diamond.Impedance analysis indicates a hopping conduction mechanism,likely involving C-H or C-N dipoles at the diamond grain boundaries.This study marks a significant leap forward in diamond thermistor technology and sheds light on the mechanisms of thermal active conduction in diamond materials.展开更多
Kaolin/metakaolin-insulating ceramic components fabricated using direct ink writing(DIW)have important ap-plication prospects in architecture and aerospace.The accuracy of the entire process including the forming and ...Kaolin/metakaolin-insulating ceramic components fabricated using direct ink writing(DIW)have important ap-plication prospects in architecture and aerospace.The accuracy of the entire process including the forming and sintering accuracy of ceramics greatly limits the application scope,and high-accuracy ceramic samples can meet the usage requirements in many scenarios.The orthogonal experiment was designed with four process parame-ters,including nozzle internal diameter,filling rate,printing layer height/nozzle internal diameter,and printing speed,to investigate the evolution of the DIW forming accuracy,sintering shrinkage rate and surface roughness of metakaolin-based ceramics with different process parameters.The influence of each process parameter and its mechanism were analyzed to obtain the DIW parameters for high-accuracy metakaolin ceramics.Multiple linear regression models between the dimensional change rate,surface roughness,and process parameters of the ceramic samples were established and validated.The results show that comprehensively considering the forming accuracy of the ceramic green bodies,sintering shrinkage rate and surface roughness,the optimal DIW process parameters were a 0.41 mm nozzle internal diameter,100%filling rate,50%printing layer height/nozzle inter-nal diameter,and a 15 mm/s printing speed.Multiple linear regression models were developed for the process parameters and the printing accuracy,sintering shrinkage rate and surface roughness.The error rates between the theoretical results obtained by substituting the optimal process parameters into the multiple linear regression models and the actual results obtained by printing the samples with the optimal parameters were extremely small,all less than 0.8%.This verified the correctness and predictability of the multiple linear regression models.This work provides a reference basis for rapid fabrication of high-accuracy ceramics via DIW and accuracy prediction with different process parameters.展开更多
Many studies focus on mineralization of huge magnetite ore deposits and petrogenesis of their large-volume host rocks.However,magma generation of those small-scale intrusions with enrichment of magnetite is poorly rep...Many studies focus on mineralization of huge magnetite ore deposits and petrogenesis of their large-volume host rocks.However,magma generation of those small-scale intrusions with enrichment of magnetite is poorly reported and paid attention to.We here carry out an integrated study of magnetite chemistry,U-Pb zircon dating,geochemistry,and Sr-Nd-Hf isotopes for the magnetite-rich intermediate-mafic rocks from the Helishan pluton in the southwestern Alxa Block,Northwest China.This,together with several previously reported magnetite/iron-rich intrusions nearby,is capable of providing some constraints on magma generation of magnetite/iron-rich intrusive rocks.The Helishan pluton,dated at ca.290 Ma,consists of hornblende gabbro,diorite,and quartz monzodiorite with~3%-5%magnetite in all the lithologies.Study on magnetite chemistry manifests a magmatic origin for them.All the lithologies display high TFeO/MgO ratio (1.71-1.89),weakly fractionated REE patterns((La/Yb)_(N)=1.82-10.17),enrichment of Rb,Sr,and Pb,and depletion of high field strength elements.They have (^(87)Sr/^(86)Sr)_(i) values of 0.705 2 to 0.705 8,ε_(Nd)(t) values of+0.03 to+0.64,and zircon ε_(Hf)(t) values of +6.5 to+12.0.We propose that they were derived from partial melting of iron-rich metasomatized lithospheric mantle.The systematic variations of Sr/Y ratios and Nd-Hf isotopic compositions with time for the Paleozoic igneous rocks at the southwestern Alxa Block indicate ever existence of thinning and rebirth of lithospheric mantle.This geodynamic process could be the potential mechanism to give rise to the iron-rich signature of the reborn mantle sources of the Helishan pluton.For intermediatemafic intrusions at subduction zones,they are unlikely to form considerable magnetite ore deposits since their modest magmatic flux and early fractional crystallization of magnetite at a high oxygen fugacity and H_(2)O condition.展开更多
Comprehending the microscopic formation of nitrogen vacancy(NV)centers in nitrogen-doped diamonds is crucial for enhancing the controllable preparation of NV centers and quantum applications.Irradiation followed by an...Comprehending the microscopic formation of nitrogen vacancy(NV)centers in nitrogen-doped diamonds is crucial for enhancing the controllable preparation of NV centers and quantum applications.Irradiation followed by annealing simulations for a type-Ib diamond with a 900 ppm concentration of isolated nitrogen is conducted along different orientations and at different annealing temperatures.In these simulations,molecular dynamics(MD)with smoothly connected potential functions are implemented.MD simulations revealed the dynamic formation process of the NV center,which was subsequently verified by first-principles calculations and experiments.The results indicate that vacancies undergo one or multiple migrations by exchanging sites with neighboring atoms.There are three mechanisms for the formation of NV centers:direct irradiation-induced NV formation,irradiation with further annealing to form NV and vacancy migration(VM)during the annealing process.Furthermore,the results show that both VM and NV center formations are affected by orientations.This study clarifies the formation of NV centers across multiple scales and provides a solid foundation for the targeted preparation of NV centers.展开更多
基金supported by the major project of“Archaeological China”(Cultural Relics Guarantee[2020]No.444)China University of Geosciences(Wuhan)Gemmological Institute research project CIGTXM-04-S202145.
文摘Jade ware Jue is one of the most fashionable ornament in ancient China from the Neolithic Age to the Han Dynasty.In this study,the remnants of jade ware Jue,from Lijiashan ancient tomb group have been tested and analyzed respectively.The samples through a light etch surface showing glass luster and those with a severe etch surface showing earthen luster.With the aid of X-ray fluorescence Spectrometer(X-ray Fluorescence)test and X-ray diffraction(XRD)detection,the results show that tremolite is not the main mineral of the sample.The main components of the tested samples with light erosion are antigorite and talc,although the main components of the samples with severe erosion are calcite containing calcium carbonate barium.Furthermore,the research on jade ware Jue in Yunnan culture has not only contributed to our further understanding of the jade objects from Yunnan culture and the variety of jade material located in the Yunnan Province.It also provides a basis for the trace of the history and culture through the distribution and evolution of burial hierarchy laws.At the same time,the microscopic observation of the tested samples manifested a residual trace of“string”at the perforation,which has played a critical role in restoring the wearing of jade ware Jue from the tombs of the ancient Yunnan State and the handicraft skills at that time.
基金This paper is the phased results of the following projects,an undergraduate teaching reform research project of China University of Geosciences(Wuhan)General Teaching reform project(Project No.2021A36)the Key Project of Hubei Provincial Key Research Base of Humanities and Social Sciences(Project No.CJHIXM-02-202101)the Central University New Youth Research Foundation Project(Project No.G1323522065).
文摘Taking the wireless enamel(wireless enamel refers to make enamel works without filigree)production technique in jewelry practice course as the research object,combined with years of enamel teaching experience in the Gemmological Institute of China University of Geosciences(Wuhan),this study expounds the theoretical class,design preparation,creative idea and technique practice application from the course teaching objectives and the implementation,which also emphasizes the practical improvability of students’design practice ability and innovative thinking ability.During the period,it focuses on the core processes,such as wireless enamel glaze method,object correction,firing time,composite application and system integration,to help students solve the key and difficult problems in the wireless enamel firing process.
基金This research was funded by the Youth Foundation Project,Basic and Applied Research Foundation of Guangdong Province of China(2022A1515110780)China Postdoctoral Science Foundation(2023M743293)China Univerisity of Geosciences(Wuhan)Gemmological Institute research project(GICTXM-04-S202103).
文摘In gemmology,the term“Alexandrite effect”is used to describe colour change phenomenon when a gemstone is observed under different light sources,usually between daylight and incandescent light.The definition of the Alexandrite effect is constantly being broadened with new discovery of gem resource.The traditional definition of the Alexandrite effect attributing the colour change phenomenon to the presence of two maximum transmission regions and a maximum absorption region in the absorption spectra.In this study,7 blue spinels and 5 blue gemstones(including tanzanite,kyanite,fluorite,and 2 sapphires)showing the Alexandrite effect were investigated.The goal is to explain the cause of blue-to-violet Alexandrite effect and the spectral features causing such colour change.In the UV-Vis spectra,all samples showed a maximum absorption peak in the range of 534-610 nm,within the green region to orange region.The traditional explanation of green to red Alexandrite effect required a transmission window in the red region;however,some of our samples did not show this transmission window and the blue-to-violet Alexandrite effect was still visible.Therefore,it is incomplete to explain the mechanism of the Alexandrite effect according to their characteristic absorption spectra,a systematic study based on modern colour science and colour perception in human vision is required to elucidate the blue-to-violet Alexandrite effect.
基金the financial support from the National Key R&D Program of China(2018YFF0215400)grants from the Gemmological Institute of the China University of Geosciences in Wuhan。
文摘Amber can emit room temperature phosphorescence(RTP)under the well-known 365 nm fluorescence ultraviolet light.This paper is devoted to the phosphorescence study of 20 pieces of amber materials from the Dominican Republic,Mexico,Baltic sea,Myanmar,and Fushun,China.The results show that amber from the same geographic origin has similar shape in phosphorescence spectra.However,the shape of the amber phosphorescence spectra varies depending on their different localities.Burmite(amber from Myanmar)and Fushun amber have a bright yellow phosphorescence with a long lifetime,while the Dominican and Mexican ones are weaker and last shorter.The irradiation of Baltic amber becomes faint or even inert.Phosphorescence spectral Gaussian fitting results suggest an emission maximum near 550 nm in most amber samples.Their phosphorescence lifetime,analyzed through the exponential function fitting,is up to 1 second in Burmite and Fushun samples,shorter in the Dominican and Mexican ones,about 0.230 s,and the shortest in Baltic amber,close to 0.151 s.These variations of phosphorescence lifetime and intensity are related to the relative geological ages of these amber.It indicated that the phosphorescence agent was probably formed during the long geological time.While the anomaly occurred in Baltic amber,the only one found in a sea secondary deposit form,it demonstrated that the terrestrial geological environment these amber preserved has prevented the phosphorescence agent to be deactivated.
基金Hubei Jewelry Engineering Technology Research Center(CIGTXM-03-202001)Sub-project of Gem and Material Technology Engineering Research Center of Yunnan Provincial High School(ZX20200201)。
文摘Tengchong,an ancient border town located in southwest China,has more than 500years of history in the trading and processing of jadeite.It is an important distribution center for jadeite and the birthplace of China’s jadeite culture.Tengchong has three key advantages:location,culture and history,and is able to integrate local culture to form the unique style of“Yunnan Jade Carving”.This article combines physical objects with related results of previous studies,based on the different usage and functions of jadeite jewelry and products in Tengchong,in order to analyze and summarize their classification and application.The four aspects of pattern,material,colour and technique are also been analyzed,as well as the linguistic features of jadeite jewelry and products in Tengchong,with the hope of providing ideas and references for the creation of modern jadeite jewelry.
基金Under the auspices of National Natural Science Foundation of China(No.41471105,41430637,41701197)Program for Innovative Research Team(in Science and Technology)in University of Henan Province(No.16IRTSTHN012)+1 种基金Key Project of the Humanities and Social Sciences Research Base in Ministry of Education(No.15JJDZONGHE008)China Postdoctoral Science Foundation(No.2013M531667,2014T70672)
文摘Under the special background of China, the cooperative innovation between different government-industry-university-research institutes plays an increasingly important role in the agricultural field. However, the existing literature has paid little attention to it. Considering the cooperation patents, published in the agriculture field stemming from the Full-text Database of China Patents as the study object, the spatial and institutional attribute of the authors as the data source, and by combining the social network and spatial econometrics analysis, this paper analyzes the structure evolution characteristics of cooperative innovation networks of agricultural government-industry-university-research institute in the city level of China in 1985–2014, based on the triple helix theory, with the influence factors discussed. This shows that, 1) since 1985, China's agricultural innovation level has been substantially increased, but the development degree of the cooperative innovation network is low, and the patent cooperation mainly relies on authors in the same unit; 2) enterprises play a leading role in the agricultural cooperative innovation. The effect of the government and hybrid organizations driven by the government is not obvious; 3) the cooperative innovation in the province and city dominates, and a multi-pole pattern has been formed. The cooperative innovation network structure evolves from a single helix empty core and double helix multi core to a double helix hierarchical network; 4) the city's science, education funding and personnel investment are key factors determining the agricultural cooperative innovation, while the agricultural development of the city presents slight negative impacts on it. The spatial mismatch of supply and demand is present in the technical cooperative innovation of China's agriculture. Therefore, the science enhancement and education investment to big agricultural provinces should be promptly implemented.
基金funded by the Foundation of the Geological Survey of China(No.1212011121261)the National Natural Science Youth Foundation of China(Nos.41702118,41702363 and41602037)the China Postdoctoral Science Foundation(Nos.2014M552109 and 2015M582301)
文摘With a thick sequence of early Eocene to Pleistocene terrestrial records, the Qaidam Basin on the northern Tibetan Plateau provides an important sedimentary archive for understanding the paleoenvironmental evolution of the northeast Tibetan Plateau. In this study, specimens of fossil fish remains are collected from the late Middle Miocene（Serravallian, -12 Ma） of the middle member of the Shang Youshashan Formation, Dahonggou（DHG） section, in the northern Qaidam Basin. Based on a systematic study of these materials, the remains have assigned to Cyprinidae, with typical pharyngeal teeth and dorsal fin spines with serrations on the posterior edge. Our discovery improves understanding of the cyprinid fish distribution characteristics in the Qaidam Basin during the Cenozoic. Cooccurrences of terrestrial brackish ostracod species Cyprideis and long chain alkenonesin the layer indicate that the studied cyprinid fish lived in a generally large brackish to saline water body during the late middle Miocene（Serravallian）, when the climate of Qaidam Basin was still not sufficiently dry to form an extreme saline water lake.
基金supported by the National Natural Science Foundation of China(40272021)the Outstanding Young Teachers Project of China University of Geosciences(CUGQNL0319).
文摘Due to various courses of formation of zircons from kimbedites, different kinds of zircons can provide useful information about the mantle and the crystallization of kimberlites. We chose 9 typical ones out of 33 zircons from the Shengli- 1 kimberlite pipe in Mengyin County, Shandong Province to study their ages and formation by means of SHRIMP, CL, Raman spectroscopy, etc. The result shows that the ^207Pb/^206Pb ages of many zircons vary from 2567±13 Ma to 2636±42 Ma, which are close to the age of Archaean granitoid （2457.3±47 Ma） in the study area. The contents of U and Th in the samples are higher than those of zircons crystallized in kimbedite and vary from 89 to 398 ppm as well as from 10 to 283 ppm. Color zones are obvious in these samples under the CL. The inclusions are composed of feldspar, quartz, apatite, etc. The above results show that the zircon samples came from the crust of the earth, which means that the kimberlite magmas are contaminated by crustal substances. The position where a great deal of volatile escapes and even explodes during rapid rise of magmas is located at the boundary of the ancient basement and the Precambrian stratum.
基金the Crucial Plan of Technology of Hubei Province (2007AA201C31)
文摘In this study, Raman scattering measurements were obtained for momo corals covering their typical range of colors. Three different excitation wavelengths （785, 633, 514 nm） are used for the same samples at the same points. All the samples show the two major Raman features of polyenic compounds assigned to double carbon-carbon （C=C） stretching vibration at approximately 1 500 cm^-1 and single carbon-carbon （C-C） stretching vibration at approximately 1 130 cm^-1 bond stretching mode. These peaks are not detected in the corresponding white parts of momo corals. However, some changes in intensities, shape, and position of C=C stretching vibrations of the same point are observed by using different excitation wavelengths. The exact position of C-C stretching vibration of polyenic molecules depends strongly on the number of double bonds contained in their polyenic chain. In addition, the number of double bonds contained in the polyenic chains shows that different colors of the red momo coral are caused by different mixtures of polyenic compounds.
文摘Infrared （IR） absorption spectra and X-ray powder diffraction （XRD） patterrns of sexpenfine cat＇s eye from Sichuan Province have been investigated, and infrared absorption bands of the serpentine have been assigned in this paper. The results indicate that the bands near 3 600 - 3 700 cm^-1 belong to the stretching absorption band VOH, the bands in 948 - 1 100 cm^-1 axe assigned to the stretching vibraling band Usvo, and the bands at 600 570 and 440 cm^-1 respectively belong to the bending vibration band VOH, δMg-O and δSi-O. The serpentine cat＇ s eye includes two types： chrysotile and antigorite. Chrysotile has a sharp and intensive band at 3 688 cm^-1 and a weak band at 3 643 cm^-1 , while antigorite has only one intensive band in the region. At vibration band VSi-O, chrysotile and antigorite have a similar feature at 1 071 cm^-1, but the band at 980 cm^-1 in anfigorite has been split into two bands in chrysotile - a strong one at 1 027 cm^-1 and a weak one at 949 cm^-1. In addition, antigorite has a characteristic bending vibrating band δMg-O at 570 cm^-1. Based on the analysis of the feature of crystal structure, their IR differences axe well explained.
基金supported by the Fundamental Research Funds for the Central Universities(CUG2106117)Hubei Jewelry Engineering Technology Research Center(CIGTXM03202301)+1 种基金Hubei Provincial Natural Science Foundation(20241350053)GuangDong Basic and Applied Basic Research Foundation(2023A1515110043).
文摘Negative temperature coefficient(NTC)thermistor plays a crucial role in science research and engineering applications for precise temperature monitoring.Although great progress has been achieved in NTC materials,enhancing sensitivity and maintaining this high sensitivity along with linearity across extensive temperature ranges remain a significant challenge.In this study,we introduce a diamondbased thermistor(DT)characterized by its outstanding sensitivity,swift response time,and broad temperature monitoring capabilities.The temperature constant B for this DT,measured from 30 to 300°C(B30/300),achieves an exceptional value of 8012 K,which notably exceeds the temperature sensing capabilities of previously reported NTC thermistors within this extensive range.Moreover,diamond’s unique thermal conductivity and stability significantly boost the response speed and durability of the DT,offering substantial advantages over traditional ceramic thermistors.The enhanced temperature-sensitive properties of the DT are attributed to the presence of impurity elements in polycrystalline diamond.Impedance analysis indicates a hopping conduction mechanism,likely involving C-H or C-N dipoles at the diamond grain boundaries.This study marks a significant leap forward in diamond thermistor technology and sheds light on the mechanisms of thermal active conduction in diamond materials.
基金supported by National Key Research and Develop-ment Program of China(Grant.No.2022YFB4602502)Free Exploration Basic Research Project of Local Science and Technology Development Funds Guided by the Central Government of China(Grant.Nos.2021Szvup158,2021Szvup159)+5 种基金National Nature Science Foundation of China(Grant.No.52375395)Shenzhen Fundamental Research Program of China(Grant.No.JCYJ20220818102601004)Research Project of the Fundamental Research Funds for the Central Universities,China University of Geosciences(Wuhan)(Grant.No.CUG2106346)Science and Technology Reveal System Project of Hubei Province of China(Grant.No.2021BEC010)Research Project of State Key Laboratory of Materials Processing and Die&Mould Technology of China(Grant.No.P2021-020)the Scientific Compass Testing Institute for the SEM images.
文摘Kaolin/metakaolin-insulating ceramic components fabricated using direct ink writing(DIW)have important ap-plication prospects in architecture and aerospace.The accuracy of the entire process including the forming and sintering accuracy of ceramics greatly limits the application scope,and high-accuracy ceramic samples can meet the usage requirements in many scenarios.The orthogonal experiment was designed with four process parame-ters,including nozzle internal diameter,filling rate,printing layer height/nozzle internal diameter,and printing speed,to investigate the evolution of the DIW forming accuracy,sintering shrinkage rate and surface roughness of metakaolin-based ceramics with different process parameters.The influence of each process parameter and its mechanism were analyzed to obtain the DIW parameters for high-accuracy metakaolin ceramics.Multiple linear regression models between the dimensional change rate,surface roughness,and process parameters of the ceramic samples were established and validated.The results show that comprehensively considering the forming accuracy of the ceramic green bodies,sintering shrinkage rate and surface roughness,the optimal DIW process parameters were a 0.41 mm nozzle internal diameter,100%filling rate,50%printing layer height/nozzle inter-nal diameter,and a 15 mm/s printing speed.Multiple linear regression models were developed for the process parameters and the printing accuracy,sintering shrinkage rate and surface roughness.The error rates between the theoretical results obtained by substituting the optimal process parameters into the multiple linear regression models and the actual results obtained by printing the samples with the optimal parameters were extremely small,all less than 0.8%.This verified the correctness and predictability of the multiple linear regression models.This work provides a reference basis for rapid fabrication of high-accuracy ceramics via DIW and accuracy prediction with different process parameters.
基金supported by the National Natural Science Foundation of China(No.41573021)the Most Special Fund from the State Key Laboratory of Geological Processes and Mineral Resources(No.MSFGPMR201601-2)。
文摘Many studies focus on mineralization of huge magnetite ore deposits and petrogenesis of their large-volume host rocks.However,magma generation of those small-scale intrusions with enrichment of magnetite is poorly reported and paid attention to.We here carry out an integrated study of magnetite chemistry,U-Pb zircon dating,geochemistry,and Sr-Nd-Hf isotopes for the magnetite-rich intermediate-mafic rocks from the Helishan pluton in the southwestern Alxa Block,Northwest China.This,together with several previously reported magnetite/iron-rich intrusions nearby,is capable of providing some constraints on magma generation of magnetite/iron-rich intrusive rocks.The Helishan pluton,dated at ca.290 Ma,consists of hornblende gabbro,diorite,and quartz monzodiorite with~3%-5%magnetite in all the lithologies.Study on magnetite chemistry manifests a magmatic origin for them.All the lithologies display high TFeO/MgO ratio (1.71-1.89),weakly fractionated REE patterns((La/Yb)_(N)=1.82-10.17),enrichment of Rb,Sr,and Pb,and depletion of high field strength elements.They have (^(87)Sr/^(86)Sr)_(i) values of 0.705 2 to 0.705 8,ε_(Nd)(t) values of+0.03 to+0.64,and zircon ε_(Hf)(t) values of +6.5 to+12.0.We propose that they were derived from partial melting of iron-rich metasomatized lithospheric mantle.The systematic variations of Sr/Y ratios and Nd-Hf isotopic compositions with time for the Paleozoic igneous rocks at the southwestern Alxa Block indicate ever existence of thinning and rebirth of lithospheric mantle.This geodynamic process could be the potential mechanism to give rise to the iron-rich signature of the reborn mantle sources of the Helishan pluton.For intermediatemafic intrusions at subduction zones,they are unlikely to form considerable magnetite ore deposits since their modest magmatic flux and early fractional crystallization of magnetite at a high oxygen fugacity and H_(2)O condition.
基金Hubei Provincial Jewelry Engineering Technology Research Center,Gemological Institute,China University of Geosciences(Wuhan)for its support(Grant No.CIGTXM-04-S202301)The project was supported by the National Natural Science Foundation of China(Grant Nos.52302046 and 52202045)+4 种基金the Natural Science Foundation of Hubei Province(Grant No.2022CFB606)the Knowledge Innovation Program of Wuhan-Shuguang(Grant No.2023010201020255)the Fundamental Research Funds for the Central Universities(Grant Nos.2042023kf0116 and 2042023kf0112)the Fundamental Research Funds for National University,China University of Geosciences(Wuhan)(Grant No.CUGDCJJ202225)the Open Fund of Hubei Key Laboratory of Electronic Manufacturing and Packaging Integration(Wuhan University)(Grant No.EMPI2023016).
文摘Comprehending the microscopic formation of nitrogen vacancy(NV)centers in nitrogen-doped diamonds is crucial for enhancing the controllable preparation of NV centers and quantum applications.Irradiation followed by annealing simulations for a type-Ib diamond with a 900 ppm concentration of isolated nitrogen is conducted along different orientations and at different annealing temperatures.In these simulations,molecular dynamics(MD)with smoothly connected potential functions are implemented.MD simulations revealed the dynamic formation process of the NV center,which was subsequently verified by first-principles calculations and experiments.The results indicate that vacancies undergo one or multiple migrations by exchanging sites with neighboring atoms.There are three mechanisms for the formation of NV centers:direct irradiation-induced NV formation,irradiation with further annealing to form NV and vacancy migration(VM)during the annealing process.Furthermore,the results show that both VM and NV center formations are affected by orientations.This study clarifies the formation of NV centers across multiple scales and provides a solid foundation for the targeted preparation of NV centers.
