With the increasing demand for oil exploration and subsurface resource development,density imaging plays an increasingly important role in identifying thin layers.However,conventional density imaging tools are limited...With the increasing demand for oil exploration and subsurface resource development,density imaging plays an increasingly important role in identifying thin layers.However,conventional density imaging tools are limited by poor vertical resolution and therefore suffer from errors in accurately estimating the thickness and relative dip angle of thin layers.This affects the accurate evaluation of thin layer oil and gas reserves.To address this issue,this study evaluates the feasibility of employing novel methods based on advanced tool design.First,an electronically controllable X-ray source is selected to replace the traditional Cs-137 source,aiming to improve the tool's vertical resolution while reducing the radioactive risks commonly associated with chemical sources.Simulation results show that the X-ray tool provides sufficient depth of investigation with better vertical resolution while maintaining the same level of measurement sensitivity.Once the tool design is established,Fisher's optimal segmentation method is improved to enhance the estimation of thin layer thickness and relative dip angle.This is completed by transforming identifying thin layer interface into a mathematical clustering problem.The thin layer interface is fitted using the nonlinear least squares method,which enables the calculation of its parameters.The results demonstrate a 38.5%reduction in RMSE(root mean square error)for thin layer thickness and a 33.7%reduction in RMSE for relative dip angle,demonstrating the superior performance of enhanced X-ray tool in thin layer identification.This study provides a new perspective on the design of density imaging tools and assessment of thin layer,which can help in future thin layer hydrocarbon reserves evaluation and development decisions.展开更多
[Objectives]To establish the quality standard of hospital preparation Jiedu Shengxue granules.[Methods]Scleromitrion diffusum and Prunella vulgaris in Jiedu Shengxue granules were qualitatively identified by thin laye...[Objectives]To establish the quality standard of hospital preparation Jiedu Shengxue granules.[Methods]Scleromitrion diffusum and Prunella vulgaris in Jiedu Shengxue granules were qualitatively identified by thin layer chromatography(TLC).A high performance liquid chromatography(HPLC)was established to determine the content of notoginsenoside R1 in the granule.[Results]The traditional Chinese medicinal materials in Jiedu Shengxue granules could be identified by TLC,and the characteristic spots were stable and clear.Notoginsenoside R1 had a good linear relationship in the range of 10.45-104.5μg/mL,with an average recovery of 98.52%and RSD=2.36%.[Conclusions]TLC and HPLC,as the quality control methods of Jiedu Shengxue granules,have high accuracy and good repeatability,which lays a foundation for the quality control of this mixture.展开更多
The intricate distribution of oil and water in tight rocks makes pinpointing oil layers challenging.While conventional identification methods offer potential solutions,their limited accuracy precludes them from being ...The intricate distribution of oil and water in tight rocks makes pinpointing oil layers challenging.While conventional identification methods offer potential solutions,their limited accuracy precludes them from being effective in their applications to unconventional reservoirs.This study employed nuclear magnetic resonance(NMR)spectrum decomposition to dissect the NMR T_(2)spectrum into multiple subspectra.Furthermore,it employed laboratory NMR experiments to ascertain the fluid properties of these sub-spectra,aiming to enhance identification accuracy.The findings indicate that fluids of distinct properties overlap in the T_(2)spectra,with bound water,movable water,bound oil,and movable oil appearing sequentially from the low-value zone to the high-value zone.Consequently,an oil layer classification scheme was proposed,which considers the physical properties of reservoirs,oil-bearing capacity,and the characteristics of both mobility and the oil-water two-phase flow.When applied to tight oil layer identification,the scheme's outcomes align closely with actual test results.A horizontal well,deployed based on these findings,has produced high-yield industrial oil flow,underscoring the precision and dependability of this new approach.展开更多
The emerging Au-assisted exfoliation technique enables the production of a wealth of large-area and high-quality ultrathin two dimensional(2D)crystals.Fast,damage-free,and reliable determination of the layer number of...The emerging Au-assisted exfoliation technique enables the production of a wealth of large-area and high-quality ultrathin two dimensional(2D)crystals.Fast,damage-free,and reliable determination of the layer number of such 2D films can greatly promote layer-dependent physical studies and device applications.Here,an optical method has been developed for simple,high throughput,and accurate determination of the layer number for Au-assisted exfoliated MoS_(2)and WS_(2)films in a broad thickness range.The method is based on quantitative analysis of layer-dependent white light reflection spectra(WLRS),revealing that the intensity of exciton-induced reflection peaks can be used as a clear indicator for identifying the layer number.The simple yet robust method will facilitate fundamental studies on layer-dependent optical,electrical,and thermal properties and device applications of 2D materials.The technique can also be readily combined with photoluminescence(PL)and Raman spectroscopies to study other layer-dependent physical properties of 2D materials.展开更多
MoS2, MoSe2 and WSe2 thin flakes were fabricated by the standard micromechanical cleavage procedures. The thickness and the optical contrast of the atomic thin dichalcogenide flakes on SiO2/Si substrates were measured...MoS2, MoSe2 and WSe2 thin flakes were fabricated by the standard micromechanical cleavage procedures. The thickness and the optical contrast of the atomic thin dichalcogenide flakes on SiO2/Si substrates were measured by atomic force microscopy（AFM） and spectroscopic ellipsometer. A rapid and nondestructive method by using reflection spectra was proposed to identify the layer number of 2D layered transition metal dichalcogenides on SiO2（275 nm）/Si substrates. The contrast spectra of 2D nanosheets with different layer numbers are in agreement with theoretical calculations based on Fresnel＇s law, indicating that this method provides an unambiguous and nondestructive contrast spectra fingerprint for identifying single-and few-layered transition metal dichalcogenides. The results will greatly help in fundamental research and application.展开更多
Using melting layer(ML)and non-melting layer(NML)data observed with the X-band dual linear polarization Doppler weather radar(X-POL)in Shunyi,Beijing,the reflectivity(ZH),differential reflectivity(ZDR),and correlation...Using melting layer(ML)and non-melting layer(NML)data observed with the X-band dual linear polarization Doppler weather radar(X-POL)in Shunyi,Beijing,the reflectivity(ZH),differential reflectivity(ZDR),and correlation coefficient(CC)in the ML and NML are obtained in several stable precipitation processes.The prior probability density distributions(PDDs)of the ZH,ZDR and CC are calculated first,and then the probabilities of ZH,ZDR and CC at each radar gate are determined(PBB in the ML and PNB in the NML)by the Bayesian method.When PBB>PNB the gate belongs to the ML,and when PBB<PNB the gate belongs to the NML.The ML identification results with the Bayesian method are contrasUsing melting layer(ML)and non-melting layer(NML)data observed with the X-band dual linear polarization Doppler weather radar(X-POL)in Shunyi,Beijing,the reflectivity(ZH),differential reflectivity(ZDR),and correlation coefficient(CC)in the ML and NML are obtained in several stable precipitation processes.The prior probability density distributions(PDDs)of the ZH,ZDR and CC are calculated first,and then the probabilities of ZH,ZDR and CC at each radar gate are determined(PBB in the ML and PNB in the NML)by the Bayesian method.When PBB>PNB the gate belongs to the ML,and when PBB<PNB the gate belongs to the NML.The ML identification results with the Bayesian method are contrasted under the conditions of the independent PDDs and joint PDDs of the ZH,ZDR and CC.The results suggest that MLs can be identified effectively,although there are slight differences between the two methods.Because the values of the polarization parameters are similar in light rain and dry snow,it is difficult for the polarization radar to distinguish them.After using the Bayesian method to identify the ML,light rain and dry snow can be effectively separated with the X-POL observed data.ted under the conditions of the independent PDDs and joint PDDs of the ZH,ZDR and CC.The results suggest that MLs can be identified effectively,although there are slight differences between the two methods.Because the values of the polarization parameters are similar in light rain and dry snow,it is difficult for the polarization radar to distinguish them.After using the Bayesian method to identify the ML,light rain and dry snow can be effectively separated with the X-POL observed data.展开更多
Engineering equipment served in harsh environments for a long time will inevitably corrode,resulting in a loss of mechanical performance and a reduction in a lifetime,and even threatening production safety.Although co...Engineering equipment served in harsh environments for a long time will inevitably corrode,resulting in a loss of mechanical performance and a reduction in a lifetime,and even threatening production safety.Although conventional post-treatment anti-corrosion technologies can slow down the corrosion rate,it is important to consider the corrosion effect on the structural performance in design.This paper proposes a topology optimization method with prior consideration of structural corrosion resistance during the design phase,so the structures designed by the approach can have excellent corrosion resistance,considerably reducing the cost of post-treatment anti-corrosion technologies.First,an erosion-based method is utilized to identify the structural surface layer.In the procedure,the initial structure is eroded to generate a reduced-scale eroded structure,and then,the eroded regions are specified as the surface layer.Second,dual-material interpolation is used to create the corrosion model by modifying the material properties of elements on the structural surface layer,which is set to 0 to simulate uniform corrosion.Finally,the topology optimization method with structural surface corrosion considered is enforced through a two-step filtering/projection process.After the entire lifetime corrosion analysis,various numerical examples indicate that the structural performance of the proposed method is superior to that of the standard method(SIMP interpolation)without considering the influence of corrosion,demonstrating the effectiveness of the proposed method.展开更多
[Objectives]To establish the quality standard for Hibiscus trionum L.[Methods]The moisture,total ash,acid insoluble ash and extract of H.trionum L.were determined by the method of Chinese Pharmacopoeia 2020 edition.Th...[Objectives]To establish the quality standard for Hibiscus trionum L.[Methods]The moisture,total ash,acid insoluble ash and extract of H.trionum L.were determined by the method of Chinese Pharmacopoeia 2020 edition.The medicinal materials were qualitatively identified by microscopic identification and TLC,and the content of quercetin was determined by HPLC.[Results]The moisture,total ash,acid insoluble ash and extract contents of the 12 batches of samples were 7.69%-12.94%,10.44%-14.62%,1.89%-3.64%,16.56%-21.81%,microscopic characteristic was obvious,and a method for TLC and content determination of H.trionum L.was established.[Conclusions]A perfect quality standard was established,which can be used for the quality control of H.trionum L.展开更多
基金the support of theNational Natural Science Foundation of China(U23B20151 and52171253)。
文摘With the increasing demand for oil exploration and subsurface resource development,density imaging plays an increasingly important role in identifying thin layers.However,conventional density imaging tools are limited by poor vertical resolution and therefore suffer from errors in accurately estimating the thickness and relative dip angle of thin layers.This affects the accurate evaluation of thin layer oil and gas reserves.To address this issue,this study evaluates the feasibility of employing novel methods based on advanced tool design.First,an electronically controllable X-ray source is selected to replace the traditional Cs-137 source,aiming to improve the tool's vertical resolution while reducing the radioactive risks commonly associated with chemical sources.Simulation results show that the X-ray tool provides sufficient depth of investigation with better vertical resolution while maintaining the same level of measurement sensitivity.Once the tool design is established,Fisher's optimal segmentation method is improved to enhance the estimation of thin layer thickness and relative dip angle.This is completed by transforming identifying thin layer interface into a mathematical clustering problem.The thin layer interface is fitted using the nonlinear least squares method,which enables the calculation of its parameters.The results demonstrate a 38.5%reduction in RMSE(root mean square error)for thin layer thickness and a 33.7%reduction in RMSE for relative dip angle,demonstrating the superior performance of enhanced X-ray tool in thin layer identification.This study provides a new perspective on the design of density imaging tools and assessment of thin layer,which can help in future thin layer hydrocarbon reserves evaluation and development decisions.
基金Supported by Guangxi Hospital Preparation Quality Improvement Project of Zhuang and Yao Ethnic Medicines(GZZJ202015)Key Research and Development Plan of Guangxi Department of Science and Technology(GK AB21196057)+3 种基金High-level TCM Key Discipline(Zhuang Pharmacology)Construction Project of State Administration of Traditional Chinese Medicine(GZYYRJH[2022]226)Guangxi TCM Multidisciplinary Innovative Team Project(GZKJ2309)"Qingmiao Engineering"Talent Cultivation Project of Guangxi International Zhuang Medical Hospital(2022001)"High-level Talent Cultivation and Innovation Team"Project of Guangxi University of Chinese Medicine(2022A008).
文摘[Objectives]To establish the quality standard of hospital preparation Jiedu Shengxue granules.[Methods]Scleromitrion diffusum and Prunella vulgaris in Jiedu Shengxue granules were qualitatively identified by thin layer chromatography(TLC).A high performance liquid chromatography(HPLC)was established to determine the content of notoginsenoside R1 in the granule.[Results]The traditional Chinese medicinal materials in Jiedu Shengxue granules could be identified by TLC,and the characteristic spots were stable and clear.Notoginsenoside R1 had a good linear relationship in the range of 10.45-104.5μg/mL,with an average recovery of 98.52%and RSD=2.36%.[Conclusions]TLC and HPLC,as the quality control methods of Jiedu Shengxue granules,have high accuracy and good repeatability,which lays a foundation for the quality control of this mixture.
基金funded by a major special project of PetroChina Company Limited(No.2021DJ1003No.2023ZZ2).
文摘The intricate distribution of oil and water in tight rocks makes pinpointing oil layers challenging.While conventional identification methods offer potential solutions,their limited accuracy precludes them from being effective in their applications to unconventional reservoirs.This study employed nuclear magnetic resonance(NMR)spectrum decomposition to dissect the NMR T_(2)spectrum into multiple subspectra.Furthermore,it employed laboratory NMR experiments to ascertain the fluid properties of these sub-spectra,aiming to enhance identification accuracy.The findings indicate that fluids of distinct properties overlap in the T_(2)spectra,with bound water,movable water,bound oil,and movable oil appearing sequentially from the low-value zone to the high-value zone.Consequently,an oil layer classification scheme was proposed,which considers the physical properties of reservoirs,oil-bearing capacity,and the characteristics of both mobility and the oil-water two-phase flow.When applied to tight oil layer identification,the scheme's outcomes align closely with actual test results.A horizontal well,deployed based on these findings,has produced high-yield industrial oil flow,underscoring the precision and dependability of this new approach.
基金the Key-Area Research and Development Program of Guangdong Province(No.2020B010169002)the Natural Science Foundation of Guangdong Province(No.2020A1515010885)+1 种基金the Science and Technology Planning Project of Shenzhen Municipality(No.JCYJ20190806142614541)the Key Laboratory Fund(No.61428060205).
文摘The emerging Au-assisted exfoliation technique enables the production of a wealth of large-area and high-quality ultrathin two dimensional(2D)crystals.Fast,damage-free,and reliable determination of the layer number of such 2D films can greatly promote layer-dependent physical studies and device applications.Here,an optical method has been developed for simple,high throughput,and accurate determination of the layer number for Au-assisted exfoliated MoS_(2)and WS_(2)films in a broad thickness range.The method is based on quantitative analysis of layer-dependent white light reflection spectra(WLRS),revealing that the intensity of exciton-induced reflection peaks can be used as a clear indicator for identifying the layer number.The simple yet robust method will facilitate fundamental studies on layer-dependent optical,electrical,and thermal properties and device applications of 2D materials.The technique can also be readily combined with photoluminescence(PL)and Raman spectroscopies to study other layer-dependent physical properties of 2D materials.
基金financially supported by the National Natural Science Foundation of China(Nos.11304381 and 11174366)
文摘MoS2, MoSe2 and WSe2 thin flakes were fabricated by the standard micromechanical cleavage procedures. The thickness and the optical contrast of the atomic thin dichalcogenide flakes on SiO2/Si substrates were measured by atomic force microscopy（AFM） and spectroscopic ellipsometer. A rapid and nondestructive method by using reflection spectra was proposed to identify the layer number of 2D layered transition metal dichalcogenides on SiO2（275 nm）/Si substrates. The contrast spectra of 2D nanosheets with different layer numbers are in agreement with theoretical calculations based on Fresnel＇s law, indicating that this method provides an unambiguous and nondestructive contrast spectra fingerprint for identifying single-and few-layered transition metal dichalcogenides. The results will greatly help in fundamental research and application.
基金supported by a Beijing Municipal Science and Technology Project (Grant No. Z171100004417008)the National Key R&D Program of China (Grant No. 2018YFF0300102)the National Natural Science Foundation of China (Grant Nos. 41375038 and 41575050)
文摘Using melting layer(ML)and non-melting layer(NML)data observed with the X-band dual linear polarization Doppler weather radar(X-POL)in Shunyi,Beijing,the reflectivity(ZH),differential reflectivity(ZDR),and correlation coefficient(CC)in the ML and NML are obtained in several stable precipitation processes.The prior probability density distributions(PDDs)of the ZH,ZDR and CC are calculated first,and then the probabilities of ZH,ZDR and CC at each radar gate are determined(PBB in the ML and PNB in the NML)by the Bayesian method.When PBB>PNB the gate belongs to the ML,and when PBB<PNB the gate belongs to the NML.The ML identification results with the Bayesian method are contrasUsing melting layer(ML)and non-melting layer(NML)data observed with the X-band dual linear polarization Doppler weather radar(X-POL)in Shunyi,Beijing,the reflectivity(ZH),differential reflectivity(ZDR),and correlation coefficient(CC)in the ML and NML are obtained in several stable precipitation processes.The prior probability density distributions(PDDs)of the ZH,ZDR and CC are calculated first,and then the probabilities of ZH,ZDR and CC at each radar gate are determined(PBB in the ML and PNB in the NML)by the Bayesian method.When PBB>PNB the gate belongs to the ML,and when PBB<PNB the gate belongs to the NML.The ML identification results with the Bayesian method are contrasted under the conditions of the independent PDDs and joint PDDs of the ZH,ZDR and CC.The results suggest that MLs can be identified effectively,although there are slight differences between the two methods.Because the values of the polarization parameters are similar in light rain and dry snow,it is difficult for the polarization radar to distinguish them.After using the Bayesian method to identify the ML,light rain and dry snow can be effectively separated with the X-POL observed data.ted under the conditions of the independent PDDs and joint PDDs of the ZH,ZDR and CC.The results suggest that MLs can be identified effectively,although there are slight differences between the two methods.Because the values of the polarization parameters are similar in light rain and dry snow,it is difficult for the polarization radar to distinguish them.After using the Bayesian method to identify the ML,light rain and dry snow can be effectively separated with the X-POL observed data.
基金the financial support to this work by the National Natural Science Foundation of China(Grant Nos.U1808215 and 11821202)the 111 Project(B14013)the Fundamental Research Funds for the Central Universities of China(DUT21GF101).
文摘Engineering equipment served in harsh environments for a long time will inevitably corrode,resulting in a loss of mechanical performance and a reduction in a lifetime,and even threatening production safety.Although conventional post-treatment anti-corrosion technologies can slow down the corrosion rate,it is important to consider the corrosion effect on the structural performance in design.This paper proposes a topology optimization method with prior consideration of structural corrosion resistance during the design phase,so the structures designed by the approach can have excellent corrosion resistance,considerably reducing the cost of post-treatment anti-corrosion technologies.First,an erosion-based method is utilized to identify the structural surface layer.In the procedure,the initial structure is eroded to generate a reduced-scale eroded structure,and then,the eroded regions are specified as the surface layer.Second,dual-material interpolation is used to create the corrosion model by modifying the material properties of elements on the structural surface layer,which is set to 0 to simulate uniform corrosion.Finally,the topology optimization method with structural surface corrosion considered is enforced through a two-step filtering/projection process.After the entire lifetime corrosion analysis,various numerical examples indicate that the structural performance of the proposed method is superior to that of the standard method(SIMP interpolation)without considering the influence of corrosion,demonstrating the effectiveness of the proposed method.
基金Supported by National Key R&D Plan(2018YFC1706101)Sichuan Science and Technology Plan Project(2021YFS0043)+1 种基金2021 State Ethnic Affairs Commission Leading Talent Support PlanBasic Scientific Research Project for Central Universities—Special Project of School-level Innovation Team(ZYN2022067)。
文摘[Objectives]To establish the quality standard for Hibiscus trionum L.[Methods]The moisture,total ash,acid insoluble ash and extract of H.trionum L.were determined by the method of Chinese Pharmacopoeia 2020 edition.The medicinal materials were qualitatively identified by microscopic identification and TLC,and the content of quercetin was determined by HPLC.[Results]The moisture,total ash,acid insoluble ash and extract contents of the 12 batches of samples were 7.69%-12.94%,10.44%-14.62%,1.89%-3.64%,16.56%-21.81%,microscopic characteristic was obvious,and a method for TLC and content determination of H.trionum L.was established.[Conclusions]A perfect quality standard was established,which can be used for the quality control of H.trionum L.
