Multifunctional architecture with intriguing structural design is highly desired for realizing the promising performances in wearable sensors and flexible energy storage devices.Cellulose nanofiber(CNF)is employed for...Multifunctional architecture with intriguing structural design is highly desired for realizing the promising performances in wearable sensors and flexible energy storage devices.Cellulose nanofiber(CNF)is employed for assisting in building conductive,hyperelastic,and ultralight Ti_(3)C_(2)T_(x)MXene hybrid aerogels with oriented tracheid-like texture.The biomimetic hybrid aerogels are constructed by a facile bidirectional freezing strategy with CNF,carbon nanotube(CNT),and MXene based on synergistic electrostatic interaction and hydrogen bonding.Entangled CNF and CNT“mortars”bonded with MXene“bricks”of the tracheid structure produce good interfacial binding,and superior mechanical strength(up to 80%compressibility and extraordinary fatigue resistance of 1000 cycles at 50%strain).Benefiting from the biomimetic texture,CNF/CNT/MXene aerogel shows ultralow density of 7.48 mg cm^(-3)and excellent electrical conductivity(~2400 S m^(-1)).Used as pressure sensors,such aerogels exhibit appealing sensitivity performance with the linear sensitivity up to 817.3 kPa^(-1),which affords their application in monitoring body surface information and detecting human motion.Furthermore,the aerogels can also act as electrode materials of compressive solid-state supercapacitors that reveal satisfactory electrochemical performance(849.2 mF cm^(-2)at 0.8 mA cm^(-2))and superior long cycle compression performance(88%after 10,000 cycles at a compressive strain of 30%).展开更多
In-situ pressure-preserved coring(IPP-Coring)is considered to be the most reliable and efficient method for the identification of the scale of oil and gas resources.During IPP-Coring,because the rotation behavior of t...In-situ pressure-preserved coring(IPP-Coring)is considered to be the most reliable and efficient method for the identification of the scale of oil and gas resources.During IPP-Coring,because the rotation behavior of the pressure controller valve cover in different medium environments is unclear,interference between the valve cover and inner pipe may occur and negatively affect the IPP-Coring success rate.To address this issue,we conducted a series of indoor experiments employing a high-speed camera to gain greater insights into the valve cover rotation behavior in different medium environments,e.g.,air,water,and simulated drilling fluids.The results indicated that the variation in the valve cover rotation angle in the air and fluid environments can be described by a one-phase exponential decay function with a constant time parameter and by biphasic dose response function,respectively.The rotation behavior in the fluid environments exhibited distinct elastic and gravitational acceleration zones.In the fluid environments,the density clearly impacted the valve cover closing time and rotation behavior,whereas the effect of viscosity was very slight.This can be attributed to the negligible influence of the fluid viscosity on the drag coefficient found in this study;meanwhile,the density can increase the buoyancy and the time period during which the valve cover experienced a high drag coefficient.Considering these results,control schemes for the valve cover rotation behavior during IPP-Coring were proposed for different layers and geological conditions in which the different drilling fluids should be used,e.g.,the use of a high-density valve cover in high-pore pressure layers.展开更多
To provide a more accurate evaluation of the scale of deep underground resources,a new pressure coring system was carefully developed and its strength and safety of the engineering were verified by theoretical analyse...To provide a more accurate evaluation of the scale of deep underground resources,a new pressure coring system was carefully developed and its strength and safety of the engineering were verified by theoretical analyses and numerical simulation.The designed pressure coring system can obtain cores with length of 3 m and diameter of 50 mm at 70 MPa.The results of the ball-drop operation experiment demonstrate that differential motion assembly can effectively cut a safety pin by applying a tensile force of 4852 N,and it can lift the core tube through the center pole to complete a series of mechanical actions to seal the pressure.Additionally,by maintaining pressures at 70 MPa for 30 min,the pressure sealing capacity of the system was proven.Furthermore,a core sample with a diameter of 50 mm was obtained through a core drilling experiment and the coring performance of the pressure coring system was verified.This study can not only enrich the existing onshore coring technology but also provide a theoretical guide and design criteria for the development of similar pressure coring systems to meet the demand for deeper underground exploration.展开更多
Lignin is the most abundant aromatic compound found in nature.The rich functional groups of lignin are responsible for its antibacterial,antioxidant,anti-ultraviolet,and biocompatible properties.As modified lignin has...Lignin is the most abundant aromatic compound found in nature.The rich functional groups of lignin are responsible for its antibacterial,antioxidant,anti-ultraviolet,and biocompatible properties.As modified lignin has a higher molecular weight,water solubility,and better surface activity,it is a good candidate for the construction of new biological materials.Ligninbased hydrogels are a type of functional materials with broad application prospects in the biomedical field.This review aimed to introduce the biological properties of lignin and the application of lignin-based hydrogels in the biological field.展开更多
Lignin,the second most abundant bio-renewable polymer in the world after cellulose,is widely used in industrial production.In recent years,nanoparticles have attracted increasing attention due to their excellent prope...Lignin,the second most abundant bio-renewable polymer in the world after cellulose,is widely used in industrial production.In recent years,nanoparticles have attracted increasing attention due to their excellent properties.Therefore,the preparation of lignin nanoparticles to obtain valueadded products is an effective way to utilize their potential completely.This article describes the preparation methods of micro/nanosized lignin with different sizes and shapes,and provides a detailed introduction to their applications in biomedicine.展开更多
The paper presents a novel control design,which is based on the idea of active disturbance rejection control(ADRC),for a kind of flexible aerocraft whose contolled variable cannot be measured directly.Since the origin...The paper presents a novel control design,which is based on the idea of active disturbance rejection control(ADRC),for a kind of flexible aerocraft whose contolled variable cannot be measured directly.Since the original frame of ADRC can-not be directly applied,the paper puts forward a new extended state observer(ESO)and the corresponding ADRC law.In order to assign the poles of the closed loop system to ideal positions such that the vibration can be quickly suppressed,an elastic damping term is added into feedback law.The advantages of the new ESO for fectively estimating both the rigid mode and elastic mode from the measurements are discussed.Moreover,the analysis on the stabiliy.the relative stability and the steady state of the closed-loop system is given.Finally,the efectiveness and robustness of the proposed ADRC are verified by simulations.展开更多
Basil(Ocimum basilicum),an edible and medicinal plant with high nutritional value and therapeutic efficacy,was used as a potential source of total flavonoids in this study.Heat reflux extractions were performed using ...Basil(Ocimum basilicum),an edible and medicinal plant with high nutritional value and therapeutic efficacy,was used as a potential source of total flavonoids in this study.Heat reflux extractions were performed using aqueous ethanol.The optimized extraction conditions of total flavonoids from O.basilicum were determined by Box-Behnken design with response surface methodology.Response surface plots showed that the optional four independent variables significantly influenced the extraction yield of total flavonoids.The extraction parameters for the highest total flavonoids yield were optimized as:extraction temperature of 79.74℃,ethanol concentration of 77.63%,ratio of liquid to material of 29.72:1(mL/g),and extraction time of 2.06 h.The average yield of total flavonoids under above optimum parameters was 42.61 mg of rutin equivalents per g of extract dry matter,which was in good agreement with the predicted value of 40.23 mg/g.These optimized conditions could be useful for the extraction of flavonoids from O.basilicum.展开更多
Dear Editor:Florid cystic endosalpingiosis(FCE)is a rare type of endosalpingiosis that presents as a mass-like lesion.It may rarely involve the uterus and present as a cystic or tumor-like mass.Herein we report an unu...Dear Editor:Florid cystic endosalpingiosis(FCE)is a rare type of endosalpingiosis that presents as a mass-like lesion.It may rarely involve the uterus and present as a cystic or tumor-like mass.Herein we report an unusual case of FCE.The patient is a 43-year-old woman presented with pelvic cystic mass,which was diagnosed as an ovarian cyst by ultrasonic examination,and diagnosed as a uterine leiomyoma with cystic degeneration by laparoscopy.Pathologic findings show FCE of the uterine subserosa.Preoperative diagnosis of uterine cystic endosalpingiosis is usually difficult.Thus,awareness about this condition in clinicians may help in preventing misdiagnosis and overtreatment.A 43-year-old woman,gravida 6 para 1,presented a cystic formation at the left adnexal area.展开更多
Dear editor:Cavernous hemangioma is an extremely rare disease in female genital tract,most of which diffusely involves the myometrium.Localized cavernous hemangioma of the uterus is even more uncommon.We hereby report...Dear editor:Cavernous hemangioma is an extremely rare disease in female genital tract,most of which diffusely involves the myometrium.Localized cavernous hemangioma of the uterus is even more uncommon.We hereby report a new bona file case of endometrial cavernous hemangiomatous polyp in a 34-yr-old woman.The diagnosis of this patient was confirmed by histopathologic examination.This case is of interest because it indicates that this condition could be found in the vagina,mimicking cervical polyp.Based on previous research articles,1,2 this is the third report of endometrial cavernous hemangiomatous polyp,and it is also the first reported one that presenting as a cervical polyp.Clinicians should keep in mind that a cervical lesion may not only originate from the cervix,rather,the differential diagnosis should be broadened to include cavernous hemangioma,especially when bleeding occurs.展开更多
基金supported by the Project of Jinan City(202228044)National Natural Science Foundation of China(32071720,32271814)+1 种基金the China Postdoctoral Science Foundation(2021M702456)China Scholarship Council for supporting their PhD program。
文摘Multifunctional architecture with intriguing structural design is highly desired for realizing the promising performances in wearable sensors and flexible energy storage devices.Cellulose nanofiber(CNF)is employed for assisting in building conductive,hyperelastic,and ultralight Ti_(3)C_(2)T_(x)MXene hybrid aerogels with oriented tracheid-like texture.The biomimetic hybrid aerogels are constructed by a facile bidirectional freezing strategy with CNF,carbon nanotube(CNT),and MXene based on synergistic electrostatic interaction and hydrogen bonding.Entangled CNF and CNT“mortars”bonded with MXene“bricks”of the tracheid structure produce good interfacial binding,and superior mechanical strength(up to 80%compressibility and extraordinary fatigue resistance of 1000 cycles at 50%strain).Benefiting from the biomimetic texture,CNF/CNT/MXene aerogel shows ultralow density of 7.48 mg cm^(-3)and excellent electrical conductivity(~2400 S m^(-1)).Used as pressure sensors,such aerogels exhibit appealing sensitivity performance with the linear sensitivity up to 817.3 kPa^(-1),which affords their application in monitoring body surface information and detecting human motion.Furthermore,the aerogels can also act as electrode materials of compressive solid-state supercapacitors that reveal satisfactory electrochemical performance(849.2 mF cm^(-2)at 0.8 mA cm^(-2))and superior long cycle compression performance(88%after 10,000 cycles at a compressive strain of 30%).
基金The authors are grateful for the financial support from the National Natural Science Foundation of China(No.51827901&No.52274133)the Program for Guangdong Introducing Innovative and Enterpreneurial Teams(No.2019ZT08G315)the Shenzhen National Science Fund for Distinguished Young Scholars(RCJC20210706091948015).
文摘In-situ pressure-preserved coring(IPP-Coring)is considered to be the most reliable and efficient method for the identification of the scale of oil and gas resources.During IPP-Coring,because the rotation behavior of the pressure controller valve cover in different medium environments is unclear,interference between the valve cover and inner pipe may occur and negatively affect the IPP-Coring success rate.To address this issue,we conducted a series of indoor experiments employing a high-speed camera to gain greater insights into the valve cover rotation behavior in different medium environments,e.g.,air,water,and simulated drilling fluids.The results indicated that the variation in the valve cover rotation angle in the air and fluid environments can be described by a one-phase exponential decay function with a constant time parameter and by biphasic dose response function,respectively.The rotation behavior in the fluid environments exhibited distinct elastic and gravitational acceleration zones.In the fluid environments,the density clearly impacted the valve cover closing time and rotation behavior,whereas the effect of viscosity was very slight.This can be attributed to the negligible influence of the fluid viscosity on the drag coefficient found in this study;meanwhile,the density can increase the buoyancy and the time period during which the valve cover experienced a high drag coefficient.Considering these results,control schemes for the valve cover rotation behavior during IPP-Coring were proposed for different layers and geological conditions in which the different drilling fluids should be used,e.g.,the use of a high-density valve cover in high-pore pressure layers.
基金the Shenzhen National Science Fund for Distinguished Young Scholars(No.RCJC20210706091948015)National Science Fund for Distinguished Young Scholars(No.52225403)the National Natural Science Foundation of China(No.51827901).
文摘To provide a more accurate evaluation of the scale of deep underground resources,a new pressure coring system was carefully developed and its strength and safety of the engineering were verified by theoretical analyses and numerical simulation.The designed pressure coring system can obtain cores with length of 3 m and diameter of 50 mm at 70 MPa.The results of the ball-drop operation experiment demonstrate that differential motion assembly can effectively cut a safety pin by applying a tensile force of 4852 N,and it can lift the core tube through the center pole to complete a series of mechanical actions to seal the pressure.Additionally,by maintaining pressures at 70 MPa for 30 min,the pressure sealing capacity of the system was proven.Furthermore,a core sample with a diameter of 50 mm was obtained through a core drilling experiment and the coring performance of the pressure coring system was verified.This study can not only enrich the existing onshore coring technology but also provide a theoretical guide and design criteria for the development of similar pressure coring systems to meet the demand for deeper underground exploration.
基金the financial support from the National Natural Science Foundation of China(32171717)the Young Elite Scientists Sponsorship Program(YESS20200389).
文摘Lignin is the most abundant aromatic compound found in nature.The rich functional groups of lignin are responsible for its antibacterial,antioxidant,anti-ultraviolet,and biocompatible properties.As modified lignin has a higher molecular weight,water solubility,and better surface activity,it is a good candidate for the construction of new biological materials.Ligninbased hydrogels are a type of functional materials with broad application prospects in the biomedical field.This review aimed to introduce the biological properties of lignin and the application of lignin-based hydrogels in the biological field.
基金The authors are grateful for the financial support from the National Natural Science Foundation of China(32071720)the Young Elite Scientists Sponsorship Program of Tianjin(TJSQNTJ-2017-19).
文摘Lignin,the second most abundant bio-renewable polymer in the world after cellulose,is widely used in industrial production.In recent years,nanoparticles have attracted increasing attention due to their excellent properties.Therefore,the preparation of lignin nanoparticles to obtain valueadded products is an effective way to utilize their potential completely.This article describes the preparation methods of micro/nanosized lignin with different sizes and shapes,and provides a detailed introduction to their applications in biomedicine.
基金This work was supported by the National Key R&D Program of China(No.2018YFA0703800)the National Center for Mathematics and Interdisciplinary Sciences,Chinese Acad-emy of Sciences.
文摘The paper presents a novel control design,which is based on the idea of active disturbance rejection control(ADRC),for a kind of flexible aerocraft whose contolled variable cannot be measured directly.Since the original frame of ADRC can-not be directly applied,the paper puts forward a new extended state observer(ESO)and the corresponding ADRC law.In order to assign the poles of the closed loop system to ideal positions such that the vibration can be quickly suppressed,an elastic damping term is added into feedback law.The advantages of the new ESO for fectively estimating both the rigid mode and elastic mode from the measurements are discussed.Moreover,the analysis on the stabiliy.the relative stability and the steady state of the closed-loop system is given.Finally,the efectiveness and robustness of the proposed ADRC are verified by simulations.
基金This project was financially supported by National Natural Science Foundation of China(31260400)the foundations of Jiangsu Province Biomass Energy and Materials Laboratory in Institute of Chemical Industry of Forest Products,CAF(JSBEM201601)+2 种基金State Key Laboratory of Pulp&Paper Engineering(201611,201503)Jiangsu Provincial Key Laboratory of Pulp and Paper Science and Technology,Nanjing Forestry University(201531)P.R.China,Natural Science Foundation of Tianjin City(16JCQNJC05900)for financial support。
文摘Basil(Ocimum basilicum),an edible and medicinal plant with high nutritional value and therapeutic efficacy,was used as a potential source of total flavonoids in this study.Heat reflux extractions were performed using aqueous ethanol.The optimized extraction conditions of total flavonoids from O.basilicum were determined by Box-Behnken design with response surface methodology.Response surface plots showed that the optional four independent variables significantly influenced the extraction yield of total flavonoids.The extraction parameters for the highest total flavonoids yield were optimized as:extraction temperature of 79.74℃,ethanol concentration of 77.63%,ratio of liquid to material of 29.72:1(mL/g),and extraction time of 2.06 h.The average yield of total flavonoids under above optimum parameters was 42.61 mg of rutin equivalents per g of extract dry matter,which was in good agreement with the predicted value of 40.23 mg/g.These optimized conditions could be useful for the extraction of flavonoids from O.basilicum.
文摘Dear Editor:Florid cystic endosalpingiosis(FCE)is a rare type of endosalpingiosis that presents as a mass-like lesion.It may rarely involve the uterus and present as a cystic or tumor-like mass.Herein we report an unusual case of FCE.The patient is a 43-year-old woman presented with pelvic cystic mass,which was diagnosed as an ovarian cyst by ultrasonic examination,and diagnosed as a uterine leiomyoma with cystic degeneration by laparoscopy.Pathologic findings show FCE of the uterine subserosa.Preoperative diagnosis of uterine cystic endosalpingiosis is usually difficult.Thus,awareness about this condition in clinicians may help in preventing misdiagnosis and overtreatment.A 43-year-old woman,gravida 6 para 1,presented a cystic formation at the left adnexal area.
文摘Dear editor:Cavernous hemangioma is an extremely rare disease in female genital tract,most of which diffusely involves the myometrium.Localized cavernous hemangioma of the uterus is even more uncommon.We hereby report a new bona file case of endometrial cavernous hemangiomatous polyp in a 34-yr-old woman.The diagnosis of this patient was confirmed by histopathologic examination.This case is of interest because it indicates that this condition could be found in the vagina,mimicking cervical polyp.Based on previous research articles,1,2 this is the third report of endometrial cavernous hemangiomatous polyp,and it is also the first reported one that presenting as a cervical polyp.Clinicians should keep in mind that a cervical lesion may not only originate from the cervix,rather,the differential diagnosis should be broadened to include cavernous hemangioma,especially when bleeding occurs.
