[Objectives] The aim was to study the antioxidant activity of different solvent extracts of Blumea Megacephala in vitro. [Methods] The removal rates of DPPH free radicals and ABTS free radicals and the reduction capac...[Objectives] The aim was to study the antioxidant activity of different solvent extracts of Blumea Megacephala in vitro. [Methods] The removal rates of DPPH free radicals and ABTS free radicals and the reduction capacity of Fe^(3+) by ethanol extract( EE),acetone extract( AE) and ethyl acetate extract( EAE) of Blumea Megacephala were detected. [Results]The three extracts of Blumea Megacephala had certain antioxidant activity,of which the antioxidant activity of ethyl acetate extract was the strongest and has great potential for development.[Conclusions]The study can provide scientific reference for the deep research on the antioxidant activity of Blumea Megacephala.展开更多
The geological environment is important for the development of coal enterprises. In the Guqiao coalmine, the information of coal mining subsidence, terrain landform, coal gangue utilization, mine water treatment and s...The geological environment is important for the development of coal enterprises. In the Guqiao coalmine, the information of coal mining subsidence, terrain landform, coal gangue utilization, mine water treatment and several on-site investigations have been analyzed. It holds that its geological environment can be evaluated from three aspects, i.e., geological disasters, terrain and landform destruction, and influence on water and soil environment. The results show that mining activities have serious impacts on geological disasters and terrain landform, while lighter impacts on the water and soil envir</span><span style="font-family:Verdana;">onment. According to the research results, a set of corresponding gove</span><span style="font-family:Verdana;">rnance strategies are given. The findings can provide theoretical support for the geological environmental protection and restoration of the Guqiao coalmine.展开更多
The layered heterometallic halide perovskites, as a newly explored material, have attracted great scientific attention. As one of the representatives of perovskite, lead-free or lead-substituted perovskite materials a...The layered heterometallic halide perovskites, as a newly explored material, have attracted great scientific attention. As one of the representatives of perovskite, lead-free or lead-substituted perovskite materials are widely applied in photovoltaic, sensors, catalysis, detectors and other fields. Therefore, it is urgent to carry out more systematic exploration and expand applicable preresearch, so as to make more interesting discoveries in this new hot spot. As an interesting candidate, heterometallic compounds will introduce more structural adjustability and novel physical properties, which is the main feature to be selected as the research hotspot. Here, we reported a lead-free bilayer heterometallic Ruddlesden-Popper(RP) type perovskite, [(MACH)_(2)CsAgBiBr_(7)](MACH = cyclohexanemethylamine), which possesses a reversible phase transition at 379.6 K/375.1 K during heating-cooling cycle. Besides, it exhibits reddish-brown light emission under 365 nm, meanwhile, CIE chromaticity coordinate is(0.32, 0.45) on the yellow side and correlated color temperature is about 6000 K. Moreover, both the experimental data and theoretical calculation results suggest that [(MACH)_(2)CsAgBiBr_(7)] shows indirect semiconducting characteristics. In summary, this work will inspire the design of lead-free heterometallic perovskite materials for the application of sensors and light-emitting diodes(LEDs) fields.展开更多
Gut microbial communities are likely remodeled in tandem with accumulated physiological decline during aging,yet there is limited understanding of gut microbiome variation in advanced age.Here,we performed a metagenom...Gut microbial communities are likely remodeled in tandem with accumulated physiological decline during aging,yet there is limited understanding of gut microbiome variation in advanced age.Here,we performed a metagenomics-based enterotype analysis in a geographically homogeneous cohort of 367 enrolled Chinese individuals between the ages of 60 and 94 years,with the goal of characterizing the gut microbiome of elderly individuals and identifying factors linked to enterotype variations.In addition to two adult-like enterotypes dominated by Bacteroides(ET-Bacteroides)and Prevotella(ET-Prevotella),we identified a novel enterotype dominated by Escherichia(ET-Escherichia),whose prevalence increased in advanced age.Our data demonstrated that age explained more of the variance in the gut microbiome than previously identified factors such as type 2 diabetes mellitus(T2DM)or diet.We characterized the distinct taxonomic and functional profiles of ET-Escherichia,and found the strongest cohesion and highest robustness of the microbial co-occurrence network in this enterotype,as well as the lowest species diversity.In addition,we carried out a series of correlation analyses and co-abundance network analyses,which showed that several factors were likely linked to the overabundance of Escherichia members,including advanced age,vegetable intake,and fruit intake.Overall,our data revealed an enterotype variation characterized by Escherichia enrichment in the elderly population.Considering the different age distribution of each enterotype,these findings provide new insights into the changes that occur in the gut microbiome with age and highlight the importance of microbiome-based stratification of elderly individuals.展开更多
Opposed multi-burner(OMB)gasification technology is the first large-scale gasification technology developed in China with completely independent intellectual property rights.It has been widely used around the world,in...Opposed multi-burner(OMB)gasification technology is the first large-scale gasification technology developed in China with completely independent intellectual property rights.It has been widely used around the world,involving synthetic ammonia,methanol,ethylene glycol,coal liquefaction,hydrogen production and other fields.This paper summarizes the research and development process of OMB gasification technology from the perspective of the cold model experiment and process simulation,pilotscale study and industrial demonstration.The latest progress of fundamental research in nozzle atomization and dispersion,mixing enhancement of impinging flow,multiscale reaction of different carbonaceous feedstocks,spectral characteristic of impinging flame and particle characteristics inside gasifier,and comprehensive gasification model are reviewed.The latest industrial application progress of ultralarge-scale OMB gasifier and radiant syngas cooler(RSC)combined with quenching chamber OMB gasifier are introduced,and the prospects for the future technical development are proposed as well.展开更多
This article puts forward the gray markov prediction model to predict mine gas emission by combining grey system theory and markov chain theory. And GM (1, 1) model is established in the first place for grey data by t...This article puts forward the gray markov prediction model to predict mine gas emission by combining grey system theory and markov chain theory. And GM (1, 1) model is established in the first place for grey data by the model. To eliminate the error, and improve the prediction accuracy of the model, secondary parameters fitting was done on the basis of GM (1, 1) model. And we get second parameter fitting for trend prediction. Then using Markov state transfer probability matrix prediction method to do quadratic fitting for its predictive value, which can improve the prediction precision of the volatile random variables. It proves the prediction results of the model are satisfactory by analyzing history data of gas emission prediction. This conclusion broadens the application scope of grey forecast model and provides a new method for mine gas emission scientific forecast.展开更多
For electric vehicles (EVs),it is necessary to improve endurance mileage by improving the efficiency.There exists a trend towards increasing the system voltage and switching frequency,contributing to improve charging ...For electric vehicles (EVs),it is necessary to improve endurance mileage by improving the efficiency.There exists a trend towards increasing the system voltage and switching frequency,contributing to improve charging speed and power density.However,this trend poses significant challenges for high-voltage and high-frequency motor controllers,which are plagued by increased switching losses and pronounced switching oscillations as consequences of hard switching.The deployment of soft switching technology presents a viable solution to mitigate these issues.This paper reviews the applications of soft switching technologies for three-phase inverters and classifies them based on distinct characteristics.For each type of inverter,the advantages and disadvantages are evaluated.Then,the paper introduces the research progress and control methods of soft switching inverters (SSIs).Moreover,it presents a comparative analysis among the conventional hard switching inverters (HSIs),an active clamping resonant DC link inverter (ACRDCLI) and an auxiliary resonant commuted pole inverter (ARCPI).Finally,the problems and prospects of soft switching technology applied to motor controllers for EVs are put forward.展开更多
It is of great significance to analyze the chemical indexes of mine water and develop a rapid identification system of water source, which can quickly and accurately distinguish the causes of water inrush and identify...It is of great significance to analyze the chemical indexes of mine water and develop a rapid identification system of water source, which can quickly and accurately distinguish the causes of water inrush and identify the source of water inrush, so as to reduce casualties and economic losses and prevent and control water inrush disasters. Taking Ca<sup>2+</sup>, Mg<sup>2+</sup>, Na<sup>+</sup> + K<sup>+</sup>, , , Cl<sup>-</sup>, pH value and TDS as discriminant indexes, the principal component analysis method was used to reduce the dimension of data, and the identification model of mine water inrush source based on PCA-BP neural network was established. 96 sets of data of different aquifers in Panxie mining area were selected for prediction analysis, and 20 sets of randomly selected data were tested, with an accuracy rate of 95%. The model can effectively reduce data redundancy, has a high recognition rate, and can accurately and quickly identify the water source of mine water inrush.展开更多
A phenoxazine based molecule termed SP has been synthesized and used as selective sensor for halogenated solvents. This molecule shows selective fast response towards halogenated solvent via naked-eye detectable chrom...A phenoxazine based molecule termed SP has been synthesized and used as selective sensor for halogenated solvents. This molecule shows selective fast response towards halogenated solvent via naked-eye detectable chromism. SP shows colorless solution when dissolved in most solvents initially but changes to blue color in chloroform under UV irradiation(λ = 365 nm) within 5 s. The luminescence spectra of SP in halogenated solvent show a large bathochromic shift(> 100 nm) with 60-fold enhanced emission intensity compared to that in halogen-free solvents. It is also worth mentioning that the photoinduced reaction between SP molecule and the halogenated solvents occurred. Based on the detailed NMR, fluorescence and mass spectra, the possible radical reaction mechanism was proposed.Different from the majority of solvatochromic sensors that based on the polarity of solvents for detection of halogenated solvents, our sensor system worked in a special展开更多
With the increasing of coal mining depth, the coal seam floor is threatened more and more seriously with the limestone aquifer of Taiyuan Formation. In order to make the coal seam floor water inrush accident to be eff...With the increasing of coal mining depth, the coal seam floor is threatened more and more seriously with the limestone aquifer of Taiyuan Formation. In order to make the coal seam floor water inrush accident to be effectively prevented, it is very important to ascertain the hydro-geological condition of the research area and adequately gain hydro-geological parameters. Based on the theory of chemical dynamics, the chemical dynamical equation of the mineral was obtained. The chemical dynamical equation of the mineral and the Darcy’s Law were combined to derive the expression of permeability coefficient and transmissibility coefficient that was indicated by hydro-chemistry index. Based on the data of water quality analysis in the research area, the hydro-geology parameter of the aquifer of Taiyuan Formation was calculated. And it was compared with what the hydro-geology parameter was determined by the data of pumping test. The results show that the permeability coefficient (K) of the research area is 1.7512 m/d, and transmissibility coefficient (T) is 42.0282 m2/d. The calculated results of chemical dynamics and pumping test results are little different between them. And it has certain practical significance in the mine water control. It provides an effective method for obtaining hydro-geological parameters.展开更多
With the depletion of coal resources due to excessive exploitation and the increasing adjustment of the national energy structure, in response to the call of national policy, some mines are forced to close, and the re...With the depletion of coal resources due to excessive exploitation and the increasing adjustment of the national energy structure, in response to the call of national policy, some mines are forced to close, and the reuse of abandoned mine resources plays an important role in the sustainable development of mining industry. This paper analyzes the general situation of abandoned mines in Huainan and Huaibei, elaborates the research methods of geothermal temperature and calculation methods of geothermal reserves in abandoned mines, analyzes and studies the utilization prospect of geothermal resources in abandoned mines in Huainan and Huaibei, and draws the following conclusions: the temperature of geothermal resources in abandoned mines in Huainan and Huaibei is 25℃- 60℃, which belongs to the moderate-hot water and warm water resources in low-temperature geothermal resources, and can be used for geothermal heating, industrial geothermal and entertainment industries. Based on the previous experience in geothermal resource utilization mode, this paper provides theoretical and technical support for the demonstration project of resource utilization and development of abandoned mines in the Huainan and Huaibei mining areas.展开更多
of main observation and conclusion We report herein a practical approach for synthesis of an electrophilic trifluoroethylthiolation reagent PhSO2SCH2CF3(1)from easily available materials.The reaction proceeded through...of main observation and conclusion We report herein a practical approach for synthesis of an electrophilic trifluoroethylthiolation reagent PhSO2SCH2CF3(1)from easily available materials.The reaction proceeded through a protonation and nucleophilic substitution cascade of the in situ formed trifluorodiazoethane.This bench-stable reagent could easily be applied to introduce trifluoroethylthio group into small organic molecules.展开更多
In the past few decades,the role of the microbiome in human health and disease has received unprecedented attention internation ally.The intestinal microbiome has been acknowledged as an im portant metabolic,1 immune2...In the past few decades,the role of the microbiome in human health and disease has received unprecedented attention internation ally.The intestinal microbiome has been acknowledged as an im portant metabolic,1 immune2 and endocrine organ.3 Alterations in microbiome composition have been proposed as indicators of the host’s pathophysiology,4,5 and an understanding of the gut microbi ota composition has been proven valuable in augmenting disease diagnosis.6 Furthermore,the core microbial community is being in vestigated as a potential preclinical biomarker for various diseases,including cancer,7 metabolic disturbances,8 immune disorders9 and neurodegenerative diseases.展开更多
Sutures,as necessary medical devices for postoperative treatment,are no longer merely supportive but are required to have advanced functions to promote repair.Here,we report an absorbable self-powered electrical stimu...Sutures,as necessary medical devices for postoperative treatment,are no longer merely supportive but are required to have advanced functions to promote repair.Here,we report an absorbable self-powered electrical stimulation suture.The suture is composed entirely of absorbable materials(magnesium,polylactic acid,and polycaprolactone)and can be used in vivo for incision closure and repair.The suture has the capacity to generate spontaneous electrical stimulation in response to body movement,allowing for accelerated tissue reconstruction.An in vivo muscle incision repair model demonstrated that the wound healing rate under treatment with this suture was 1.6 times faster than that of commercial sutures,proving its postoperative therapeutic capability.展开更多
The conventional treatment method of soybean wastewater is expensive and generates waste sludge that requires further handling.Purple nonsulfur bacteria(PNSB)wastewater treatment is a clean technology and can generate...The conventional treatment method of soybean wastewater is expensive and generates waste sludge that requires further handling.Purple nonsulfur bacteria(PNSB)wastewater treatment is a clean technology and can generate single cell protein while degrading pollutants.A wild strain of PNSB,Rhodobacter sphaeroides Z08,was isolated from local soil and was used to treat soybean wastewater.To develop a cost-effective process,the work was performed under natural conditions without artificial light,aeration,nutrients addition,or pH and temperature adjustment.The results showed that the wild strain Rhodobacter sphaeroides Z08 could grow well under natural conditions.The growth curve showed two quickgrowth periods and a turning point.The Z08 treatment of soybean wastewater was zero order reaction and COD reduction was 96%after 10 d.The major byproducts of the process were C2-C5 organic acids,predominantly butyric acid.No alcohol was found in the effluent.The initial COD/bacterial-mass ratio(F/M)had a significant effect on soybean wastewater treatment efficiency.When the initial F/M was lower than 10 mg-COD/mg-bacteria,a sufficient amount of time to achieve 90%of COD reduction was only three days.The Z08 biomass yield was 0.28 g·g^(–1),and the bacterial protein content was 52%.展开更多
Understanding the effect of immunosuppressive agents on intestinal microbiota is important to reduce the mortality and morbidity from orthotopic liver transplantation (OLT). We investigated the relationship between th...Understanding the effect of immunosuppressive agents on intestinal microbiota is important to reduce the mortality and morbidity from orthotopic liver transplantation (OLT). We investigated the relationship between the commonly used immunosuppressive agent cyclosporine A (CSA) and the intestinal microbial variation in an OLT model. The rat samples were divided as follows:(1) N group (normal control);(2) I group (isograft LT, Brown Norway [BN] rat to BN);(3) R group (allograft LT, Lewis to BN rat);and (4) CSA group (R group treated with CSA). The intestinal microbiota was assayed by denaturing gradient gel electrophoresis profiles and by using real-time polymerase chain reaction. The liver histopathology and the alanine/aspartate aminotransferase ratio after LT were both ameliorated by CSA. In the CSA group, the numbers of rDNA gene copies of Clostridium cluster I, Clostridium cluster XIV, and Enterobacteriaceae decreased, whereas those of Faecalibacterium prausnitzii increased compared with the R group. Cluster analysis indicated that the samples from the N, I, and CSA groups were clustered, whereas the other clusters contained the samples from the R group. Hence, CSA ameliorates hepatic graft injury and partially restores gut microbiota following LT, and these may benefit hepatic graft rejection.展开更多
Molecularly imprinted polymers(MIPs),as important mimics of antibodies,are chemically synthesized by polymerization in the presence of a target compound.MIPs have found wide applications in important fileds.However,th...Molecularly imprinted polymers(MIPs),as important mimics of antibodies,are chemically synthesized by polymerization in the presence of a target compound.MIPs have found wide applications in important fileds.However,the current molecular imprinting technology suffers from a dilemma;there is often a compromise between the best affinity and the best specificity for MIPs prepared under optimized condi-tions.Herein,we proposed a new strategy called molecular imprinting and cladding(MIC)to solve this issue.The principle is straightforward;after molecular imprinting,a chemically inert cladding thinlayer is generated to precisely cover non-imprinted area.We further proposed a special MIC approach for con-trollably engineering protein binders.The prepared cladded MIPs(cMIPs)exhibited significantly improved affinity and specificity.The general applicability of the proposed strategy and method was ver-ified by engineering of cMIPs for the recognition of a variety of different proteins.The feasibility of cMIPs for real applications was demonstrated by fluorescence imaging of cancer cells against normal cells and immunoassay of C-peptide in human urine.This study opened up a new avenue for controllably engi-neering protein-specific antibody mimics with excellent recognition properties,holding great prospective in important applications such as disease diagnosis and nanomedicine.展开更多
基金Supported by National Innovation Planning Project for University Students in 2017(201710599021)Chemical Construction Project for Key Subjects of Traditional Chinese Medicine in the"12th Five-Year Plan"Period of State Administration of Traditional Chinese Medicine([2012]32)+1 种基金Chemical Construction Project of Drugs for Key Subjects in Guangxi([2017]22)Guangxi Key Discipline Drug Chemistry Construction Project
文摘[Objectives] The aim was to study the antioxidant activity of different solvent extracts of Blumea Megacephala in vitro. [Methods] The removal rates of DPPH free radicals and ABTS free radicals and the reduction capacity of Fe^(3+) by ethanol extract( EE),acetone extract( AE) and ethyl acetate extract( EAE) of Blumea Megacephala were detected. [Results]The three extracts of Blumea Megacephala had certain antioxidant activity,of which the antioxidant activity of ethyl acetate extract was the strongest and has great potential for development.[Conclusions]The study can provide scientific reference for the deep research on the antioxidant activity of Blumea Megacephala.
文摘The geological environment is important for the development of coal enterprises. In the Guqiao coalmine, the information of coal mining subsidence, terrain landform, coal gangue utilization, mine water treatment and several on-site investigations have been analyzed. It holds that its geological environment can be evaluated from three aspects, i.e., geological disasters, terrain and landform destruction, and influence on water and soil environment. The results show that mining activities have serious impacts on geological disasters and terrain landform, while lighter impacts on the water and soil envir</span><span style="font-family:Verdana;">onment. According to the research results, a set of corresponding gove</span><span style="font-family:Verdana;">rnance strategies are given. The findings can provide theoretical support for the geological environmental protection and restoration of the Guqiao coalmine.
基金supported by the National Natural Science Foundation of China (No. 21991141)Zhejiang Normal University。
文摘The layered heterometallic halide perovskites, as a newly explored material, have attracted great scientific attention. As one of the representatives of perovskite, lead-free or lead-substituted perovskite materials are widely applied in photovoltaic, sensors, catalysis, detectors and other fields. Therefore, it is urgent to carry out more systematic exploration and expand applicable preresearch, so as to make more interesting discoveries in this new hot spot. As an interesting candidate, heterometallic compounds will introduce more structural adjustability and novel physical properties, which is the main feature to be selected as the research hotspot. Here, we reported a lead-free bilayer heterometallic Ruddlesden-Popper(RP) type perovskite, [(MACH)_(2)CsAgBiBr_(7)](MACH = cyclohexanemethylamine), which possesses a reversible phase transition at 379.6 K/375.1 K during heating-cooling cycle. Besides, it exhibits reddish-brown light emission under 365 nm, meanwhile, CIE chromaticity coordinate is(0.32, 0.45) on the yellow side and correlated color temperature is about 6000 K. Moreover, both the experimental data and theoretical calculation results suggest that [(MACH)_(2)CsAgBiBr_(7)] shows indirect semiconducting characteristics. In summary, this work will inspire the design of lead-free heterometallic perovskite materials for the application of sensors and light-emitting diodes(LEDs) fields.
基金supported by the National Natural Science Foundation of China(Nos.82101665,82271588,82200665,and 82100795)the Zhejiang Provincial Natural Science Foundation of China(No.LY22H030009)+1 种基金the Zhejiang Provincial Science and Technology Program of Traditional Chinese Medicine(No.2023ZL480)the Medical and Health Research Project of Zhejiang Province(No.2023RC153),China.
文摘Gut microbial communities are likely remodeled in tandem with accumulated physiological decline during aging,yet there is limited understanding of gut microbiome variation in advanced age.Here,we performed a metagenomics-based enterotype analysis in a geographically homogeneous cohort of 367 enrolled Chinese individuals between the ages of 60 and 94 years,with the goal of characterizing the gut microbiome of elderly individuals and identifying factors linked to enterotype variations.In addition to two adult-like enterotypes dominated by Bacteroides(ET-Bacteroides)and Prevotella(ET-Prevotella),we identified a novel enterotype dominated by Escherichia(ET-Escherichia),whose prevalence increased in advanced age.Our data demonstrated that age explained more of the variance in the gut microbiome than previously identified factors such as type 2 diabetes mellitus(T2DM)or diet.We characterized the distinct taxonomic and functional profiles of ET-Escherichia,and found the strongest cohesion and highest robustness of the microbial co-occurrence network in this enterotype,as well as the lowest species diversity.In addition,we carried out a series of correlation analyses and co-abundance network analyses,which showed that several factors were likely linked to the overabundance of Escherichia members,including advanced age,vegetable intake,and fruit intake.Overall,our data revealed an enterotype variation characterized by Escherichia enrichment in the elderly population.Considering the different age distribution of each enterotype,these findings provide new insights into the changes that occur in the gut microbiome with age and highlight the importance of microbiome-based stratification of elderly individuals.
基金supported by the National Natural Science Foundation of China(21776086,21761132034)。
文摘Opposed multi-burner(OMB)gasification technology is the first large-scale gasification technology developed in China with completely independent intellectual property rights.It has been widely used around the world,involving synthetic ammonia,methanol,ethylene glycol,coal liquefaction,hydrogen production and other fields.This paper summarizes the research and development process of OMB gasification technology from the perspective of the cold model experiment and process simulation,pilotscale study and industrial demonstration.The latest progress of fundamental research in nozzle atomization and dispersion,mixing enhancement of impinging flow,multiscale reaction of different carbonaceous feedstocks,spectral characteristic of impinging flame and particle characteristics inside gasifier,and comprehensive gasification model are reviewed.The latest industrial application progress of ultralarge-scale OMB gasifier and radiant syngas cooler(RSC)combined with quenching chamber OMB gasifier are introduced,and the prospects for the future technical development are proposed as well.
文摘This article puts forward the gray markov prediction model to predict mine gas emission by combining grey system theory and markov chain theory. And GM (1, 1) model is established in the first place for grey data by the model. To eliminate the error, and improve the prediction accuracy of the model, secondary parameters fitting was done on the basis of GM (1, 1) model. And we get second parameter fitting for trend prediction. Then using Markov state transfer probability matrix prediction method to do quadratic fitting for its predictive value, which can improve the prediction precision of the volatile random variables. It proves the prediction results of the model are satisfactory by analyzing history data of gas emission prediction. This conclusion broadens the application scope of grey forecast model and provides a new method for mine gas emission scientific forecast.
基金funded by Tsinghua University-Weichai Power Intelligent Manufacturing Joint Research Institute (WCDL-GH-2022-0131)。
文摘For electric vehicles (EVs),it is necessary to improve endurance mileage by improving the efficiency.There exists a trend towards increasing the system voltage and switching frequency,contributing to improve charging speed and power density.However,this trend poses significant challenges for high-voltage and high-frequency motor controllers,which are plagued by increased switching losses and pronounced switching oscillations as consequences of hard switching.The deployment of soft switching technology presents a viable solution to mitigate these issues.This paper reviews the applications of soft switching technologies for three-phase inverters and classifies them based on distinct characteristics.For each type of inverter,the advantages and disadvantages are evaluated.Then,the paper introduces the research progress and control methods of soft switching inverters (SSIs).Moreover,it presents a comparative analysis among the conventional hard switching inverters (HSIs),an active clamping resonant DC link inverter (ACRDCLI) and an auxiliary resonant commuted pole inverter (ARCPI).Finally,the problems and prospects of soft switching technology applied to motor controllers for EVs are put forward.
文摘It is of great significance to analyze the chemical indexes of mine water and develop a rapid identification system of water source, which can quickly and accurately distinguish the causes of water inrush and identify the source of water inrush, so as to reduce casualties and economic losses and prevent and control water inrush disasters. Taking Ca<sup>2+</sup>, Mg<sup>2+</sup>, Na<sup>+</sup> + K<sup>+</sup>, , , Cl<sup>-</sup>, pH value and TDS as discriminant indexes, the principal component analysis method was used to reduce the dimension of data, and the identification model of mine water inrush source based on PCA-BP neural network was established. 96 sets of data of different aquifers in Panxie mining area were selected for prediction analysis, and 20 sets of randomly selected data were tested, with an accuracy rate of 95%. The model can effectively reduce data redundancy, has a high recognition rate, and can accurately and quickly identify the water source of mine water inrush.
基金the Natural Science Foundation of Shandong Province (Nos. BS2014CL042, ZR2014EEP021, ZR2017MB033)the Key Research and Development Program of Shandong Province, China (Nos. 2016GSF116014 and 2017CXGC1113)+1 种基金the Start-up Grant of Shandong Jiaotong University and the National Undergraduate Innovation Training Program (No. 201611510109)the financial support from the government of Shandong Province for visiting abroad
文摘A phenoxazine based molecule termed SP has been synthesized and used as selective sensor for halogenated solvents. This molecule shows selective fast response towards halogenated solvent via naked-eye detectable chromism. SP shows colorless solution when dissolved in most solvents initially but changes to blue color in chloroform under UV irradiation(λ = 365 nm) within 5 s. The luminescence spectra of SP in halogenated solvent show a large bathochromic shift(> 100 nm) with 60-fold enhanced emission intensity compared to that in halogen-free solvents. It is also worth mentioning that the photoinduced reaction between SP molecule and the halogenated solvents occurred. Based on the detailed NMR, fluorescence and mass spectra, the possible radical reaction mechanism was proposed.Different from the majority of solvatochromic sensors that based on the polarity of solvents for detection of halogenated solvents, our sensor system worked in a special
文摘With the increasing of coal mining depth, the coal seam floor is threatened more and more seriously with the limestone aquifer of Taiyuan Formation. In order to make the coal seam floor water inrush accident to be effectively prevented, it is very important to ascertain the hydro-geological condition of the research area and adequately gain hydro-geological parameters. Based on the theory of chemical dynamics, the chemical dynamical equation of the mineral was obtained. The chemical dynamical equation of the mineral and the Darcy’s Law were combined to derive the expression of permeability coefficient and transmissibility coefficient that was indicated by hydro-chemistry index. Based on the data of water quality analysis in the research area, the hydro-geology parameter of the aquifer of Taiyuan Formation was calculated. And it was compared with what the hydro-geology parameter was determined by the data of pumping test. The results show that the permeability coefficient (K) of the research area is 1.7512 m/d, and transmissibility coefficient (T) is 42.0282 m2/d. The calculated results of chemical dynamics and pumping test results are little different between them. And it has certain practical significance in the mine water control. It provides an effective method for obtaining hydro-geological parameters.
文摘With the depletion of coal resources due to excessive exploitation and the increasing adjustment of the national energy structure, in response to the call of national policy, some mines are forced to close, and the reuse of abandoned mine resources plays an important role in the sustainable development of mining industry. This paper analyzes the general situation of abandoned mines in Huainan and Huaibei, elaborates the research methods of geothermal temperature and calculation methods of geothermal reserves in abandoned mines, analyzes and studies the utilization prospect of geothermal resources in abandoned mines in Huainan and Huaibei, and draws the following conclusions: the temperature of geothermal resources in abandoned mines in Huainan and Huaibei is 25℃- 60℃, which belongs to the moderate-hot water and warm water resources in low-temperature geothermal resources, and can be used for geothermal heating, industrial geothermal and entertainment industries. Based on the previous experience in geothermal resource utilization mode, this paper provides theoretical and technical support for the demonstration project of resource utilization and development of abandoned mines in the Huainan and Huaibei mining areas.
基金We are grateful for financial support from the Natural Science Foundation of China and Shandong province(Nos.21971149,ZR2018MB010,ZR2019ZD45,ZR2017MB033)the Key Researchand Development Program of Shandong Province(No.2017CXGC1113)Tang scholar award and the Fundamental Research Funds of Shandong University.
文摘of main observation and conclusion We report herein a practical approach for synthesis of an electrophilic trifluoroethylthiolation reagent PhSO2SCH2CF3(1)from easily available materials.The reaction proceeded through a protonation and nucleophilic substitution cascade of the in situ formed trifluorodiazoethane.This bench-stable reagent could easily be applied to introduce trifluoroethylthio group into small organic molecules.
基金supported by the National Key Research and Development Program of China(2022YFC3602000)the National Natural Science Foundation of China(81874038)the Research Project of Jinan Microecological Biomedicine ShandongLaboratory(JNL-2022001A).
文摘In the past few decades,the role of the microbiome in human health and disease has received unprecedented attention internation ally.The intestinal microbiome has been acknowledged as an im portant metabolic,1 immune2 and endocrine organ.3 Alterations in microbiome composition have been proposed as indicators of the host’s pathophysiology,4,5 and an understanding of the gut microbi ota composition has been proven valuable in augmenting disease diagnosis.6 Furthermore,the core microbial community is being in vestigated as a potential preclinical biomarker for various diseases,including cancer,7 metabolic disturbances,8 immune disorders9 and neurodegenerative diseases.
基金financially supported by the National Natural Science Foundation of China(82301331)。
文摘Sutures,as necessary medical devices for postoperative treatment,are no longer merely supportive but are required to have advanced functions to promote repair.Here,we report an absorbable self-powered electrical stimulation suture.The suture is composed entirely of absorbable materials(magnesium,polylactic acid,and polycaprolactone)and can be used in vivo for incision closure and repair.The suture has the capacity to generate spontaneous electrical stimulation in response to body movement,allowing for accelerated tissue reconstruction.An in vivo muscle incision repair model demonstrated that the wound healing rate under treatment with this suture was 1.6 times faster than that of commercial sutures,proving its postoperative therapeutic capability.
基金the Chinese Ministry of Science&Technology(No.2006BAC19B04)the National Natural Science Foundation of China(Grant No.50978072).
文摘The conventional treatment method of soybean wastewater is expensive and generates waste sludge that requires further handling.Purple nonsulfur bacteria(PNSB)wastewater treatment is a clean technology and can generate single cell protein while degrading pollutants.A wild strain of PNSB,Rhodobacter sphaeroides Z08,was isolated from local soil and was used to treat soybean wastewater.To develop a cost-effective process,the work was performed under natural conditions without artificial light,aeration,nutrients addition,or pH and temperature adjustment.The results showed that the wild strain Rhodobacter sphaeroides Z08 could grow well under natural conditions.The growth curve showed two quickgrowth periods and a turning point.The Z08 treatment of soybean wastewater was zero order reaction and COD reduction was 96%after 10 d.The major byproducts of the process were C2-C5 organic acids,predominantly butyric acid.No alcohol was found in the effluent.The initial COD/bacterial-mass ratio(F/M)had a significant effect on soybean wastewater treatment efficiency.When the initial F/M was lower than 10 mg-COD/mg-bacteria,a sufficient amount of time to achieve 90%of COD reduction was only three days.The Z08 biomass yield was 0.28 g·g^(–1),and the bacterial protein content was 52%.
基金This work was supported by the China Postdoctoral Science Foundation (No. 2017M610374)Zhejiang Medical Health Technology Project (No. 2019313269)+2 种基金Innovative Research Groups of the National Natural Science Foundation of China (No. 81421062)National Natural Science Foundation of China (No. 81470891)Science and Technology Bureau of Zhejiang Province, China (No. 2016C33145).
文摘Understanding the effect of immunosuppressive agents on intestinal microbiota is important to reduce the mortality and morbidity from orthotopic liver transplantation (OLT). We investigated the relationship between the commonly used immunosuppressive agent cyclosporine A (CSA) and the intestinal microbial variation in an OLT model. The rat samples were divided as follows:(1) N group (normal control);(2) I group (isograft LT, Brown Norway [BN] rat to BN);(3) R group (allograft LT, Lewis to BN rat);and (4) CSA group (R group treated with CSA). The intestinal microbiota was assayed by denaturing gradient gel electrophoresis profiles and by using real-time polymerase chain reaction. The liver histopathology and the alanine/aspartate aminotransferase ratio after LT were both ameliorated by CSA. In the CSA group, the numbers of rDNA gene copies of Clostridium cluster I, Clostridium cluster XIV, and Enterobacteriaceae decreased, whereas those of Faecalibacterium prausnitzii increased compared with the R group. Cluster analysis indicated that the samples from the N, I, and CSA groups were clustered, whereas the other clusters contained the samples from the R group. Hence, CSA ameliorates hepatic graft injury and partially restores gut microbiota following LT, and these may benefit hepatic graft rejection.
基金the Key Program of the National Natural Science Foundation of China(21834003)the National Science Fund for Distinguished Young Scholars(21425520)the Excellent Research Program(ZYJH004)from Nanjing University to ZL。
文摘Molecularly imprinted polymers(MIPs),as important mimics of antibodies,are chemically synthesized by polymerization in the presence of a target compound.MIPs have found wide applications in important fileds.However,the current molecular imprinting technology suffers from a dilemma;there is often a compromise between the best affinity and the best specificity for MIPs prepared under optimized condi-tions.Herein,we proposed a new strategy called molecular imprinting and cladding(MIC)to solve this issue.The principle is straightforward;after molecular imprinting,a chemically inert cladding thinlayer is generated to precisely cover non-imprinted area.We further proposed a special MIC approach for con-trollably engineering protein binders.The prepared cladded MIPs(cMIPs)exhibited significantly improved affinity and specificity.The general applicability of the proposed strategy and method was ver-ified by engineering of cMIPs for the recognition of a variety of different proteins.The feasibility of cMIPs for real applications was demonstrated by fluorescence imaging of cancer cells against normal cells and immunoassay of C-peptide in human urine.This study opened up a new avenue for controllably engi-neering protein-specific antibody mimics with excellent recognition properties,holding great prospective in important applications such as disease diagnosis and nanomedicine.
