In extended-reach or long-horizontal drilling,cuttings usually deposit at the bottom of the annulus.Once cuttings accumulate to a certain thickness,complex problems such as excessive torque and drag,tubing buckling,an...In extended-reach or long-horizontal drilling,cuttings usually deposit at the bottom of the annulus.Once cuttings accumulate to a certain thickness,complex problems such as excessive torque and drag,tubing buckling,and pipe stuck probably occur,which results in a lot of non-productive time and remedial operations.Cuttings bed remover can efficiently destroy deposited cuttings in time through hydraulic and mechanical stirring effects.This paper aims to build a method for hole cleaning evaluation and installation spacing optimization of cuttings bed remover to improve the wellbore cleaning effect.Firstly,a Computational Fluid Dynamics approach with Eulerian—Eulerian multiphase model was utilized to investigate the mechanism of cuttings transportation,and a new type of cuttings bed remover was designed.Next,an evaluation method of hole cleaning effect of remover was established.After that,the effects of several drilling parameters on hole cleaning including flow rate of drilling fluid,rotational speed of drillpipe,rate of penetration,wellbore size,rheological property of drilling fluid,and remover eccentricity on the performance of cuttings bed remover were investigated.The results demonstrate that the new type of remover with streamline blade performs better than conventional removers.The efficiency of hole cleaning is greatly improved by increasing the rotational speed of drillpipe,flow rate of drilling fluid,remover eccentricity,and 6 rpm Fann dial reading for drilling fluid.While higher rate of penetration and large wellbore size result in worse hole cleaning.These findings can serve as an important guide for the structure optimization design of cuttings bed remover and installation spacing of removers.展开更多
Cuttings accumulation in horizontal drilling of a shale gas well is one of the main reasons for high drilling torque and drag and serious backing pressure and consequently influencing the rate of penetration(ROP),so i...Cuttings accumulation in horizontal drilling of a shale gas well is one of the main reasons for high drilling torque and drag and serious backing pressure and consequently influencing the rate of penetration(ROP),so inhibiting the generation of a cuttings bed and keeping the hole clean is an important prerequisite to ensure the smooth and safe drilling of horizontal section.In order to improve the hole cleaning efficiency of horizontal sections,this paper studied the decay laws of helical flow induced by helix angles and rotation speed of a newly developed cuttings bed remover with V-shaped blades for horizontal wells and their influences on the resuspension distribution of cuttings particles by virtue of the CFD numerical simulation method and EulereEuler binary-fluid model,combined with the theory of particle dynamics.Then,the parameters such as blade rotation speed and blade helix angle were optimized.And the following research results were obtained.First,with the increase of the rotation speed,cuttings deposit at the bottom of the annulus deflects to a certain degree.And the higher the rotation speed,the more obvious the deflection.Second,annulus pressure drop loss increases with the increase of the helix angle.And this phenomenon is more obvious when the helix angle is larger.Third,the field test results in Well Changning H25-7 of the southern Sichuan Basin show that after the application of the newly developed cuttings bed remover for horizontal wells,the drilling friction is decreased by 33%,the tripping is smooth without sticking.And in the process of its application,no complex downhole accident happened.Obviously,it provides good hole cleaning to ensure the safe and smooth implementation of the later casing running operation.In conclusion,this newly developed cuttings bed remover can satisfy the demand of cutting bed cleaning and drilling cost reduction and efficiency improvement of horizontal wells,so it is worth popularizing and applying.What's more,it provides guidance and reference for the design of similar cuttings bed removers.展开更多
In order to solve the problem of limited makeup removal ability of a single surfactant of Peg-20 glyceryl triisostearate in makeup remover,an efficient system was prepared which contained PEG-20 glyceryl triisostearat...In order to solve the problem of limited makeup removal ability of a single surfactant of Peg-20 glyceryl triisostearate in makeup remover,an efficient system was prepared which contained PEG-20 glyceryl triisostearate and a combination of Sorbeth-30 tetraoleate and Peg-5 glyceryl triisostearate.Leather test,skin colorimeter test and consumer self-evaluation were used to assess the makeup removal ability,rinsing performance and softness skin feel of the efficient makeup remover base.The results showed that a 7%combination of Sorbeth-30 tetraoleate and PEG-5 glyceryl triisostearate could significantly improve the comprehensive performance of single PEG-20 glyceryl triisostearate makeup remover system,furthermore,they performed best at the ratio of 6:1.We hope the findings can have guiding significance for the development of makeup remover products.展开更多
With the extensive application of polymer flooding technology in offshore oilfields,the plugging in polymer injection wells has become more and more severe,which seriously affects the oil displacement effect and regul...With the extensive application of polymer flooding technology in offshore oilfields,the plugging in polymer injection wells has become more and more severe,which seriously affects the oil displacement effect and regular production of oilfields.In this paper,a new kind of blockage remover has been developed and evaluated by rheological behavior experiments,dissolution experiments and core flooding experiments.The results reveal that this new blockage remover can effectively reduce the viscosity of polymer and completely degrade the reservoir blockage with low corrosion rate.It is beneficial to long-term production of oil wells in offshore oilfield.Results of core flooding experiments show that this new blockage remover can relieve polymer damage and improve permeability.The agent has been applied in LD10-1 oilfield in 2016,the daily injection rate increased significantly after stimulation.展开更多
Ultrasonic-Assisted Grinding(UAG)is a novel manufacturing technology that shows promising promise for use in processing Ceramic Matrix Composites(CMCs).Nevertheless,analyzing the material removal process of CMCs with ...Ultrasonic-Assisted Grinding(UAG)is a novel manufacturing technology that shows promising promise for use in processing Ceramic Matrix Composites(CMCs).Nevertheless,analyzing the material removal process of CMCs with multidirectional structure during UAG is challenging,impeding the progress and improvement of the UAG process.This work examined the impact of ultrasonic vibration on the dynamic mechanical characteristics during processing.Additionally,we experimentally elucidated the material removal mechanism of CMCs during the scratching process under the influence of vertical vibration.The results indicate that the introduction of ultrasonic vibration causes a strain rate effect,resulting in a modification of the material removal mechanism,subsequently impacting the processing quality.Ultrasonic vibration increases the dynamic strength and brittleness of the fibers in CMCs,leading to more cracks at fracture,which changes from the original bending fracture to shear fracture.In addition,ultrasonic vibration can effectively inhibit the impact of scratching depth and anisotropy on the removal mechanism of CMCs,resulting in a more uniform surface of CMCs after processing.展开更多
It is crucial to develop arsenic removal adsorbents with strong sulfur resistance under middle-low-temperature flue gas conditions(<400℃).In this work,five Fe-Ce-La oxides were prepared by co-precipitation method,...It is crucial to develop arsenic removal adsorbents with strong sulfur resistance under middle-low-temperature flue gas conditions(<400℃).In this work,five Fe-Ce-La oxides were prepared by co-precipitation method,and FeCeLaO/SiO_(2)-Al_(2)O_(3) composite adsorbents were prepared by coupling fly ash-based Si-Al carriers.The active components Fe-Ce-La oxides and Si-Al carriers were characterized by TPD,TG,XRF,BET and XPS,respectively.The effects of temperature,Si/Al ratio and FeCeLaO loading rate on the sulfur resistance were investigated.Results show that the SO_(2) promotes the arsenic removal of Fe_(2)O_(3),CeLaO and FeCeLaO.At 400℃,the arsenic removal efficiencies of the three oxides increase from 45.3%,72.5% and 81.3% without SO_(2) to 62.6%,80.5%and 91.0%,respectively.The SO_(2) inhibits the arsenic removal of La_(2)O_(2)CO_(3) and FeLaO,and the inhibition effect is pronounced at high temperatures.The sulfur poisoning resistance of Si-Al carriers increases with the increase of Si/Al ratio.When the Si/Al ratio is increased to 9.74,the arsenic removal efficiency in the SO_(2) environment is 13.9% higher than that in the absence of SO_(2).Introducing FeCeLaO active components is beneficial for enhancing the SO_(2) poisoning resistance of Si-Al carriers.The strong sulfur resistance of the FeCeLaO/SiO_(2)-Al_(2)O_(3) composite adsorbent results from multiple factors:protective effects of Ce on Fe,La and Al;sulfation-induced generation of Ce^(3+)and surface-adsorbed oxygen;and strong surface acidity of SiO_(2).展开更多
Acid is commonly used to separate phosphorus-containing solid solutions from steelmaking slag.However,the acid leaching solution obtained from this process cannot be directly utilized and thus requires purification.Th...Acid is commonly used to separate phosphorus-containing solid solutions from steelmaking slag.However,the acid leaching solution obtained from this process cannot be directly utilized and thus requires purification.The effect of different conditions on the calcium and iron removal characteristics of modified steelmaking slag leaching solution was investigated.Additionally,the removal mechanism was analyzed by thermodynamic calculations.The results indicated that the addition of soybean straw ash in steelmaking slag modification enabled K_(2)O to enter the phosphorus-containing solid solution,promoting phosphorus enrichment.Valuable elements such as phosphorus and potassium were more easily dissolved in the mixed acid.The oxalic acid concentration had a significant effect on the calcium removal rate,whereas the effects of temperature,stirring rate,and time on the calcium removal rate were minor.The main component of the calcium removal precipitate was CaC_(2)O_(4)·H_(2)O,with a removal rate up to 94.48%.During the iron removal process,when the pH value of the solution was low,Fe^(3+)mainly reacted to form the iron hydroxide precipitate for removal.Increasing the pH value of the solution would cause Fe^(3+)to combine with H_(2)PO_(4)^(-),forming FePO_(4)·2H_(2)O precipitate,leading to a reduction in the phosphorus content of the leaching solution.展开更多
To explore the adaptive mechanisms of the partial nitritation-anammox(PNA)process under high salinity stress during kitchen wastewater treatment,focusing on their physiological and molecular responses through metageno...To explore the adaptive mechanisms of the partial nitritation-anammox(PNA)process under high salinity stress during kitchen wastewater treatment,focusing on their physiological and molecular responses through metagenomic analysis.An airlift inner-circulation partition bioreactor(AIPBR)was developed,featuring an inner cylinder and a flow guide tube to create distinct oxygen gradients,facilitating the study of microbial adaptation under varying salt conditions.The AIPBR was operated with synthetic wastewater containing ammonium concentrations of 1800±100 mg/L and salinity gradients ranging from 1 to 10 g/L,followed by a fixed salinity period at 6 g/L,with ammonium concentrations approximately 850 mg/L.High-throughput metagenomic analysis revealed shifts in functional genes and metabolic pathways in response to salinity stress.Anammox bacteria adapted by enriching genes involved in the synthesis of osmoprotective compounds and activating energy-producing pathways like the tricarboxylic acid cycle(TCA).These adaptations,along with modifications in membrane composition,were essential for sustaining system stability under elevated salinity.Under prolonged high salinity stress,anaerobic ammonium oxidizing(AnAOB)exhibited improved salt tolerance,maintaining a total nitrogen removal efficiency above 85%and stabilizing after an adaptation phase.The metagenomic data revealed a marked enrichment of genes associated with ion transport,stress response mechanisms,and DNA repair pathways.Changes in microbial community composition favored salt-tolerant species,supporting system stability.These findings highlight the applicability of the developed bioreactor for scaling up the PNA process to handle high-salinity wastewater,providing a promising avenue for sustainable nitrogen removal in challenging environments.展开更多
To address the problems with catalytic degradation,such as poisoning and inactivation,a simple and efficient gas purging regeneration technique was developed for iron-based catalyst in-situ regeneration.Specifically,t...To address the problems with catalytic degradation,such as poisoning and inactivation,a simple and efficient gas purging regeneration technique was developed for iron-based catalyst in-situ regeneration.Specifically,the effects of carrier gas types,regeneration temperatures,and granular activated carbon(GAC)addition on iron-based catalyst regeneration were investigated.The Fe_(3)O_(4)/𝛾-Al_(2)O_(3) regenerated at 550°C with additional GAC and 15%water vapor exhibited the optimal degradation efficiency towards polychlorinated biphenyls(PCBs),with an increase from 41.2%to 93.5%,compared with non-regenerated Fe_(3)O_(4)/𝛾-Al_(2)O_(3).In addition,the 60-hour stability test revealed a well-recovered catalytic activity.During the Fe_(3)O_(4)/𝛾-Al_(2)O_(3) regeneration,the coke on the catalyst surface was oxidized and removed in the form of CO_(2),and meanwhile the oxidized Fe(III)was reduced into Fe(II)in the catalyst.This study provides a safe and efficient iron-based catalyst regeneration technology for PCB off-gas degradation and reveals the catalytic activity recovery mechanism during catalyst regeneration.展开更多
The discharge of micro-polluted water from sources such as agricultural runoff,urban stormwater,and treated effluents presents significant challenges to aquatic ecosystems.Constructed wetlands(CWs)have gained recog-ni...The discharge of micro-polluted water from sources such as agricultural runoff,urban stormwater,and treated effluents presents significant challenges to aquatic ecosystems.Constructed wetlands(CWs)have gained recog-nition as an eco-friendly solution for removing pollutants from various wastewater sources and are increasingly applied for micro-polluted water treatment.By reviewing 78 full-scale CW studies from Web of Science,it is summarized that the ranges of ammonium nitrogen(NH4+-N)concentrations in runoff,wastewater treatment plant effluent and polluted river were 0.1–6.6,0.3–12.3,and 0.2–41.1 mg/L,respectively.The ranges of ni-trate nitrogen concentrations were 0.2–14.2,0–5.7,and 0–2.6 mg/L,respectively.Removal efficiencies of CWs for micro-polluted water varied by CW types.The total nitrogen removal efficiencies for subsurface-flow CWs,free-water surface-flow CWs,and hybrid CWs ranged from 27.4%to 66.5%,16.8%to 89.8%,and 19.4%to 88.2%,respectively.The NH4+-N removal efficiencies ranged from 34.2%to 73.6%,38.4%to 89.4%and 13.5%to 94.2%,respectively.Additionally,other factors influencing contaminant removal efficiency such as hydraulic retention time,vegetation types,redox micro-environment and influent water quality were evaluated.Based on these findings,two strategies for improving the purification performance of CWs were proposed:the selection of incorporating electron donor substrates and the optimization of operation parameters.This paper serves as a synthesis of information to guide future research and full-scale CW applications in micro-polluted water treatment.展开更多
Abstract:Graphene-Based separation membranes hold promise for water treatment.However,their practical deployment in high-salinity brines remains challenging due to structural instability.Herein,a defect-free Na^(+)-Cu...Abstract:Graphene-Based separation membranes hold promise for water treatment.However,their practical deployment in high-salinity brines remains challenging due to structural instability.Herein,a defect-free Na^(+)-Cu^(2+)/GO-PEI nanocomposite membrane was fabricated via a pH-controlled cross-linking polymerization strategy.Polyethyleneimine(PEI)serves as a critical interfacial stabilizer,enhancing the connection between the Na^(+)-GO and Cu^(2+)-GO layers through amide bond formation with GO nanosheets while facilitating Cu^(2+)chelation.The Na^(+)/GO layer modifies the pore structure of the polyether sulfone(PES)substrate,synergistically optimizing the membrane’s microstructure.Performances evaluation revealed that the as-prepared membrane achieved exceptional separation efficiency(>98%)for tributyl phosphate,sulfonated kerosene,and bis(2-ethylhexyl)phosphate in high-salinity brine,accompanied by a high flux of 160~224 L·m^(-2)·h^(-1).Notably,it exhibited robust chemical stability in corrosive environment and maintained mechanical durability after 500 folding cycles coupled with consistent separation performances over 10 recycles.This study presents a novel multi-component modification approach for constructing high-performance GObased membrane,promising practical applications in organic pollutant removal from high salt solution.展开更多
Environmental pollution,energy consumption,and greenhouse gas emissions are critical global issues.To address these challenges,optimizing skimmer coatings is a major step in commercializing cleaning oil stains.This re...Environmental pollution,energy consumption,and greenhouse gas emissions are critical global issues.To address these challenges,optimizing skimmer coatings is a major step in commercializing cleaning oil stains.This research presents a novel approach to creating and refining oil absorbent coatings,introducing a unique oil spill removal skimmer enhanced with a super hydrophobic polyaniline(PANI)nanofiber coating.The goal of this study was to improve oil absorption performance,increase the contact angle,lower drag,reduce energy consumption,achieve high desirability,and lower production costs.PANI treated with hydrochloric acid was a key focus as it resulted in higher porosity and smaller pore diameters,providing a larger surface area,which are crucial factors for boosting oil absorption and minimizing drag.To optimize optimal nanofiber morphology,PANI synthesized with methanesulfonic acid was first dedoped and then redoped with hydrochloric acid.After optimization,the most effective skimmer coating was achieved using a formulation consisting of 0.1%PANI,an ammonium persulfate/aniline ratio of 0.4,and an acid/aniline ratio of 9.689,along with redoped PANI nanofibers.The optimized skimmer exhibited a remarkable contact angle of 177.477°.The coating achieved drag reduction of 32%,oil absorption of 88.725%,a cost of$1.710,and a desirability rating of 78.5%.In this study,an optimized skimmer coat containing super hydrophobic coat-PANI nanofibers was fabricated.By enhancing contact angle and reducing drag,these coatings increased the skimmer performance by improving oil absorption and reducing fuel consumption.展开更多
Behind the removal of tariffs lies a multiplication of benefits for both China and Africa A transformative policy is set to significantly reshape economic relations between China and Africa.China’s policy to grant ze...Behind the removal of tariffs lies a multiplication of benefits for both China and Africa A transformative policy is set to significantly reshape economic relations between China and Africa.China’s policy to grant zero-tariff treatment to imports from the 53 African nations with diplomatic ties will go into effect on 1 May this year.This initiative,which Chinese Foreign Minister Wang Yi likened to an arithmetic operation during this year’s Two Sessions,marks a further step in China’s efforts to boost imports from Africa.展开更多
Excessive phosphorus and arsenic in water bodies not only destroy ecosystems but also pose a serious threat to human health.In this study,a series of Al-doped modified metal-organic frameworks(Zr-Al-MOF)were prepared ...Excessive phosphorus and arsenic in water bodies not only destroy ecosystems but also pose a serious threat to human health.In this study,a series of Al-doped modified metal-organic frameworks(Zr-Al-MOF)were prepared by solvothermal method,which achieved efficient removal of phosphate and arsenate in water.Due to the use of inexpensive Al salts,the material has a lower cost and is more economical.The molar ratio of metal salts,adsorption time,solution pH,initial concentration,temperature and coexisting anions were studied,and it was found that when the molar ratio of Zr:Al was 2,Zr-Al-MOF had the best adsorption performance for phosphate and arsenate,and the maximum adsorption capacity was 93.04 mg P/g and 173.83 mg As/g,respectively.It traps phosphate and arsenate at a fast reaction rate and can be recycled repeatedly.In addition,0.15 g/L of 2Zr-Al-MOF can effectively reduce the phosphate and arsenate content in the contaminated spring water samples of Yangzonghai Lake to the standard range of drinking water,which further confirms the application potential of 2Zr-Al-MOF.By FT-IR and XPS analysis,it was found that the adsorption mechanism was ligand exchange,electrostatic attraction and hydrogen bond formation.The theoretical calculation shows that the adsorption energy is negative,which indicates that 2Zr-Al-MOF is attractive to phosphate and arsenate,and the adsorption state is stable.The results show that 2Zr-Al-MOF is an effective phosphate and arsenate adsorbent and has broad application prospects in eutrophication water treatment.展开更多
Photocatalysis—a green and energy-efficient technology for environmental remediation and energy conversion—has recently demonstrated broad application potential in intelligent building materials.This review systemat...Photocatalysis—a green and energy-efficient technology for environmental remediation and energy conversion—has recently demonstrated broad application potential in intelligent building materials.This review systematically summarizes recent advancements in incorporating photocatalytic materials into building applications,focusing on two main scenarios:pavement and wall surfaces.In pavement systems,photocatalytic materials are primarily employed to degrade pollutants such as NO_(x)and volatile organic compounds,thereby actively reducing emissions.In wall applications,the emphasis is on imparting intelligent maintenance functions,including self-cleaning,antibacterial activity,and air purification.We provide a comprehensive analysis of the performance of various photocatalytic materials,their incorporation methods,and their effects on mechanical properties and environmental durability.Building on this analysis,we propose design principles for photocatalytic building materials that balance catalytic efficiency with cost,enhance mechanical stability,and preserve the intrinsic functions of building components.Finally,we outline future research directions,emphasizing the significant potential of photocatalytic building materials in advancing green construction and sustainable development.展开更多
Organic pollutants,a pivotal factor in water pollution,have persistently menaced the aquatic ecosystem,as well as the sustainable development of human health,economy,and society.Consequently,there is an urgent need fo...Organic pollutants,a pivotal factor in water pollution,have persistently menaced the aquatic ecosystem,as well as the sustainable development of human health,economy,and society.Consequently,there is an urgent need for advanced techniques to efficiently eliminate organic micropollutants from water.Here,we present the synthesis of three nonporous cavitand-crosslinked polymers capable of adsorbing diverse organic pollutants from aqueous solutions.These polymeric adsorbents exhibit outstanding adsorptive performance towards the tested micropollutants,characterized by high apparent adsorption rate constants(kobs)and maximum adsorption capacities(qmax,e).Notably,Compound NCCP-1 demonstrated a remarkable qmax,e of 459 mg/g for bisphenol A(BPA),ranking among the highest values reported for organic polymer adsorbents.In-depth investigation of the adsorption mechanism of the nonporous polymer revealed that it involves the recognition of pollutants by the deep cavities of the cavitand moieties and the interstitial spaces between them,primarily mediated by the hydrophobic effect.Furthermore,NCCP-1 was applied in situ water purification simulations and was proven to maintain its removal efficiency over more than four cycles,highlighting its potential for practical applications in water treatment.展开更多
In recent years,an increase in the content of Zn,the impurity element,in ironmaking raw materials has led to the deterioration of iron-bearing resources and has introduced new challenges to sintering dezincification.A...In recent years,an increase in the content of Zn,the impurity element,in ironmaking raw materials has led to the deterioration of iron-bearing resources and has introduced new challenges to sintering dezincification.A thorough understanding of the reaction behavior of Zn during the sintering process can form a theoretical foundation for the development of efficient dezincification technology.Therefore,the reaction behavior of Zn was investigated under different temperatures and atmospheres using thermodynamic calculations and experimental simulations,and the phase transformation of Zn in each pre-reductive sintering zone was investigated.The results showed that Zn-containing materials were mainly converted into ZnO when the temperature reached 700℃,and ZnO began to combine with Fe_(2)O_(3)to form ZnFe_(2)O_(4)at approximately 800℃.At low CO concentration,ZnFe_(2)O_(4)was stable,while ZnO combined with iron oxide to form Fe_(0.85-x)Zn_(x)O in a strong reduction atmosphere.ZnFe_(2)O_(4)could also be converted into Fe_(0.85-x)Zn_(x)O and FeO.A part of Zn was converted to elemental Zn,which was volatilized and removed into the gas phase above 1000℃.Therefore,the feasibility of dezincification via pre-reductive sintering was confirmed.At the coke ratio of 18.0 wt.%of the sintering material,the Zn removal rate reached 62.3 wt.%.展开更多
Microglia are the macrophages that populate the brain parenchyma.Research in the past decades has identified them as both essential guardians of the brain and significant contributors to various neurological diseases....Microglia are the macrophages that populate the brain parenchyma.Research in the past decades has identified them as both essential guardians of the brain and significant contributors to various neurological diseases.A highly versatile cell type,microglia have been shown to fulfill a multitude of critical roles in the central nervous system,including facilitating neurogenesis and myelination,pruning synapses,removing debris and waste,modulating neuronal activity,supporting the blood-brain barrier,repairing tissue damage,and surveilling against microbial invasions under physiological conditions(Prinz et al.,2021;Paolicelli et al.,2022).展开更多
基金the financial support from the Natural Science Foundation of China(Grant Nos.52222401,52234002,52394250,52394255)Science Foundation of China University of Petroleum,Beijing(Grant No.ZXZX20230083)other projects(ZLZX2020-01-07-01)。
文摘In extended-reach or long-horizontal drilling,cuttings usually deposit at the bottom of the annulus.Once cuttings accumulate to a certain thickness,complex problems such as excessive torque and drag,tubing buckling,and pipe stuck probably occur,which results in a lot of non-productive time and remedial operations.Cuttings bed remover can efficiently destroy deposited cuttings in time through hydraulic and mechanical stirring effects.This paper aims to build a method for hole cleaning evaluation and installation spacing optimization of cuttings bed remover to improve the wellbore cleaning effect.Firstly,a Computational Fluid Dynamics approach with Eulerian—Eulerian multiphase model was utilized to investigate the mechanism of cuttings transportation,and a new type of cuttings bed remover was designed.Next,an evaluation method of hole cleaning effect of remover was established.After that,the effects of several drilling parameters on hole cleaning including flow rate of drilling fluid,rotational speed of drillpipe,rate of penetration,wellbore size,rheological property of drilling fluid,and remover eccentricity on the performance of cuttings bed remover were investigated.The results demonstrate that the new type of remover with streamline blade performs better than conventional removers.The efficiency of hole cleaning is greatly improved by increasing the rotational speed of drillpipe,flow rate of drilling fluid,remover eccentricity,and 6 rpm Fann dial reading for drilling fluid.While higher rate of penetration and large wellbore size result in worse hole cleaning.These findings can serve as an important guide for the structure optimization design of cuttings bed remover and installation spacing of removers.
基金Project supported by the National Major Science and Technology Project“Research and application of key technologies for factory-like well drilling”(No.:2016ZX05022-001)the National Major Science and Technology Project“Test and application of 3-D optimized and fast drilling technology for cluster horizontal well in shale gas reservoirs”(No.:2016ZX05062003)CNPC Major Scientific Research and Technical Development Project“Integration and demonstration of drilling speed/efficiency improvement technologies for deep well and horizontal well”(No.:2018E-2108)。
文摘Cuttings accumulation in horizontal drilling of a shale gas well is one of the main reasons for high drilling torque and drag and serious backing pressure and consequently influencing the rate of penetration(ROP),so inhibiting the generation of a cuttings bed and keeping the hole clean is an important prerequisite to ensure the smooth and safe drilling of horizontal section.In order to improve the hole cleaning efficiency of horizontal sections,this paper studied the decay laws of helical flow induced by helix angles and rotation speed of a newly developed cuttings bed remover with V-shaped blades for horizontal wells and their influences on the resuspension distribution of cuttings particles by virtue of the CFD numerical simulation method and EulereEuler binary-fluid model,combined with the theory of particle dynamics.Then,the parameters such as blade rotation speed and blade helix angle were optimized.And the following research results were obtained.First,with the increase of the rotation speed,cuttings deposit at the bottom of the annulus deflects to a certain degree.And the higher the rotation speed,the more obvious the deflection.Second,annulus pressure drop loss increases with the increase of the helix angle.And this phenomenon is more obvious when the helix angle is larger.Third,the field test results in Well Changning H25-7 of the southern Sichuan Basin show that after the application of the newly developed cuttings bed remover for horizontal wells,the drilling friction is decreased by 33%,the tripping is smooth without sticking.And in the process of its application,no complex downhole accident happened.Obviously,it provides good hole cleaning to ensure the safe and smooth implementation of the later casing running operation.In conclusion,this newly developed cuttings bed remover can satisfy the demand of cutting bed cleaning and drilling cost reduction and efficiency improvement of horizontal wells,so it is worth popularizing and applying.What's more,it provides guidance and reference for the design of similar cuttings bed removers.
文摘In order to solve the problem of limited makeup removal ability of a single surfactant of Peg-20 glyceryl triisostearate in makeup remover,an efficient system was prepared which contained PEG-20 glyceryl triisostearate and a combination of Sorbeth-30 tetraoleate and Peg-5 glyceryl triisostearate.Leather test,skin colorimeter test and consumer self-evaluation were used to assess the makeup removal ability,rinsing performance and softness skin feel of the efficient makeup remover base.The results showed that a 7%combination of Sorbeth-30 tetraoleate and PEG-5 glyceryl triisostearate could significantly improve the comprehensive performance of single PEG-20 glyceryl triisostearate makeup remover system,furthermore,they performed best at the ratio of 6:1.We hope the findings can have guiding significance for the development of makeup remover products.
基金The work is supported by National Science and Technology Major Project of the Ministry of Science and Technology of China“High Efficiency Oil Production and Supporting Technology Demonstration on Bohai Oilfield”(No.2016ZX05058-003).
文摘With the extensive application of polymer flooding technology in offshore oilfields,the plugging in polymer injection wells has become more and more severe,which seriously affects the oil displacement effect and regular production of oilfields.In this paper,a new kind of blockage remover has been developed and evaluated by rheological behavior experiments,dissolution experiments and core flooding experiments.The results reveal that this new blockage remover can effectively reduce the viscosity of polymer and completely degrade the reservoir blockage with low corrosion rate.It is beneficial to long-term production of oil wells in offshore oilfield.Results of core flooding experiments show that this new blockage remover can relieve polymer damage and improve permeability.The agent has been applied in LD10-1 oilfield in 2016,the daily injection rate increased significantly after stimulation.
基金supported by the National Science Foundation for Distinguished Young Scholars of China(No.52325506)the Fundamental Research Funds for the Central Universities(No.DUT22LAB501)。
文摘Ultrasonic-Assisted Grinding(UAG)is a novel manufacturing technology that shows promising promise for use in processing Ceramic Matrix Composites(CMCs).Nevertheless,analyzing the material removal process of CMCs with multidirectional structure during UAG is challenging,impeding the progress and improvement of the UAG process.This work examined the impact of ultrasonic vibration on the dynamic mechanical characteristics during processing.Additionally,we experimentally elucidated the material removal mechanism of CMCs during the scratching process under the influence of vertical vibration.The results indicate that the introduction of ultrasonic vibration causes a strain rate effect,resulting in a modification of the material removal mechanism,subsequently impacting the processing quality.Ultrasonic vibration increases the dynamic strength and brittleness of the fibers in CMCs,leading to more cracks at fracture,which changes from the original bending fracture to shear fracture.In addition,ultrasonic vibration can effectively inhibit the impact of scratching depth and anisotropy on the removal mechanism of CMCs,resulting in a more uniform surface of CMCs after processing.
文摘It is crucial to develop arsenic removal adsorbents with strong sulfur resistance under middle-low-temperature flue gas conditions(<400℃).In this work,five Fe-Ce-La oxides were prepared by co-precipitation method,and FeCeLaO/SiO_(2)-Al_(2)O_(3) composite adsorbents were prepared by coupling fly ash-based Si-Al carriers.The active components Fe-Ce-La oxides and Si-Al carriers were characterized by TPD,TG,XRF,BET and XPS,respectively.The effects of temperature,Si/Al ratio and FeCeLaO loading rate on the sulfur resistance were investigated.Results show that the SO_(2) promotes the arsenic removal of Fe_(2)O_(3),CeLaO and FeCeLaO.At 400℃,the arsenic removal efficiencies of the three oxides increase from 45.3%,72.5% and 81.3% without SO_(2) to 62.6%,80.5%and 91.0%,respectively.The SO_(2) inhibits the arsenic removal of La_(2)O_(2)CO_(3) and FeLaO,and the inhibition effect is pronounced at high temperatures.The sulfur poisoning resistance of Si-Al carriers increases with the increase of Si/Al ratio.When the Si/Al ratio is increased to 9.74,the arsenic removal efficiency in the SO_(2) environment is 13.9% higher than that in the absence of SO_(2).Introducing FeCeLaO active components is beneficial for enhancing the SO_(2) poisoning resistance of Si-Al carriers.The strong sulfur resistance of the FeCeLaO/SiO_(2)-Al_(2)O_(3) composite adsorbent results from multiple factors:protective effects of Ce on Fe,La and Al;sulfation-induced generation of Ce^(3+)and surface-adsorbed oxygen;and strong surface acidity of SiO_(2).
基金supported by the National Natural Science Foundation of China(52074004 and 51604003)Anhui Provincial Natural Science Foundation(2508085Y032).
文摘Acid is commonly used to separate phosphorus-containing solid solutions from steelmaking slag.However,the acid leaching solution obtained from this process cannot be directly utilized and thus requires purification.The effect of different conditions on the calcium and iron removal characteristics of modified steelmaking slag leaching solution was investigated.Additionally,the removal mechanism was analyzed by thermodynamic calculations.The results indicated that the addition of soybean straw ash in steelmaking slag modification enabled K_(2)O to enter the phosphorus-containing solid solution,promoting phosphorus enrichment.Valuable elements such as phosphorus and potassium were more easily dissolved in the mixed acid.The oxalic acid concentration had a significant effect on the calcium removal rate,whereas the effects of temperature,stirring rate,and time on the calcium removal rate were minor.The main component of the calcium removal precipitate was CaC_(2)O_(4)·H_(2)O,with a removal rate up to 94.48%.During the iron removal process,when the pH value of the solution was low,Fe^(3+)mainly reacted to form the iron hydroxide precipitate for removal.Increasing the pH value of the solution would cause Fe^(3+)to combine with H_(2)PO_(4)^(-),forming FePO_(4)·2H_(2)O precipitate,leading to a reduction in the phosphorus content of the leaching solution.
基金supported by China Hunan Provincial Science&Technology Department(No.2023NK2031)the Natural Science Foundation of Hunan Province(No.2023JJ40031)the Ministry of Human Resources and Social Security(No.H20240365).
文摘To explore the adaptive mechanisms of the partial nitritation-anammox(PNA)process under high salinity stress during kitchen wastewater treatment,focusing on their physiological and molecular responses through metagenomic analysis.An airlift inner-circulation partition bioreactor(AIPBR)was developed,featuring an inner cylinder and a flow guide tube to create distinct oxygen gradients,facilitating the study of microbial adaptation under varying salt conditions.The AIPBR was operated with synthetic wastewater containing ammonium concentrations of 1800±100 mg/L and salinity gradients ranging from 1 to 10 g/L,followed by a fixed salinity period at 6 g/L,with ammonium concentrations approximately 850 mg/L.High-throughput metagenomic analysis revealed shifts in functional genes and metabolic pathways in response to salinity stress.Anammox bacteria adapted by enriching genes involved in the synthesis of osmoprotective compounds and activating energy-producing pathways like the tricarboxylic acid cycle(TCA).These adaptations,along with modifications in membrane composition,were essential for sustaining system stability under elevated salinity.Under prolonged high salinity stress,anaerobic ammonium oxidizing(AnAOB)exhibited improved salt tolerance,maintaining a total nitrogen removal efficiency above 85%and stabilizing after an adaptation phase.The metagenomic data revealed a marked enrichment of genes associated with ion transport,stress response mechanisms,and DNA repair pathways.Changes in microbial community composition favored salt-tolerant species,supporting system stability.These findings highlight the applicability of the developed bioreactor for scaling up the PNA process to handle high-salinity wastewater,providing a promising avenue for sustainable nitrogen removal in challenging environments.
基金supported by the Fundamental Research Funds for the Central Publicinterest Scientific Institution(No.2024YSKY-44)the National Key R&D Program of China(No.2023YFC3708003).
文摘To address the problems with catalytic degradation,such as poisoning and inactivation,a simple and efficient gas purging regeneration technique was developed for iron-based catalyst in-situ regeneration.Specifically,the effects of carrier gas types,regeneration temperatures,and granular activated carbon(GAC)addition on iron-based catalyst regeneration were investigated.The Fe_(3)O_(4)/𝛾-Al_(2)O_(3) regenerated at 550°C with additional GAC and 15%water vapor exhibited the optimal degradation efficiency towards polychlorinated biphenyls(PCBs),with an increase from 41.2%to 93.5%,compared with non-regenerated Fe_(3)O_(4)/𝛾-Al_(2)O_(3).In addition,the 60-hour stability test revealed a well-recovered catalytic activity.During the Fe_(3)O_(4)/𝛾-Al_(2)O_(3) regeneration,the coke on the catalyst surface was oxidized and removed in the form of CO_(2),and meanwhile the oxidized Fe(III)was reduced into Fe(II)in the catalyst.This study provides a safe and efficient iron-based catalyst regeneration technology for PCB off-gas degradation and reveals the catalytic activity recovery mechanism during catalyst regeneration.
基金supported by the Natural Science Foundation of China(No.52470105)the Young Taishan Scholars Program of Shandong Province(No.358202103017).
文摘The discharge of micro-polluted water from sources such as agricultural runoff,urban stormwater,and treated effluents presents significant challenges to aquatic ecosystems.Constructed wetlands(CWs)have gained recog-nition as an eco-friendly solution for removing pollutants from various wastewater sources and are increasingly applied for micro-polluted water treatment.By reviewing 78 full-scale CW studies from Web of Science,it is summarized that the ranges of ammonium nitrogen(NH4+-N)concentrations in runoff,wastewater treatment plant effluent and polluted river were 0.1–6.6,0.3–12.3,and 0.2–41.1 mg/L,respectively.The ranges of ni-trate nitrogen concentrations were 0.2–14.2,0–5.7,and 0–2.6 mg/L,respectively.Removal efficiencies of CWs for micro-polluted water varied by CW types.The total nitrogen removal efficiencies for subsurface-flow CWs,free-water surface-flow CWs,and hybrid CWs ranged from 27.4%to 66.5%,16.8%to 89.8%,and 19.4%to 88.2%,respectively.The NH4+-N removal efficiencies ranged from 34.2%to 73.6%,38.4%to 89.4%and 13.5%to 94.2%,respectively.Additionally,other factors influencing contaminant removal efficiency such as hydraulic retention time,vegetation types,redox micro-environment and influent water quality were evaluated.Based on these findings,two strategies for improving the purification performance of CWs were proposed:the selection of incorporating electron donor substrates and the optimization of operation parameters.This paper serves as a synthesis of information to guide future research and full-scale CW applications in micro-polluted water treatment.
基金Special Research Assistant Program,China(2024000020)the Science and Technology Department of Qinghai Province,China(2024-ZJ-918)the“Kunlun Talents”Program of Qinghai(2024000075)。
文摘Abstract:Graphene-Based separation membranes hold promise for water treatment.However,their practical deployment in high-salinity brines remains challenging due to structural instability.Herein,a defect-free Na^(+)-Cu^(2+)/GO-PEI nanocomposite membrane was fabricated via a pH-controlled cross-linking polymerization strategy.Polyethyleneimine(PEI)serves as a critical interfacial stabilizer,enhancing the connection between the Na^(+)-GO and Cu^(2+)-GO layers through amide bond formation with GO nanosheets while facilitating Cu^(2+)chelation.The Na^(+)/GO layer modifies the pore structure of the polyether sulfone(PES)substrate,synergistically optimizing the membrane’s microstructure.Performances evaluation revealed that the as-prepared membrane achieved exceptional separation efficiency(>98%)for tributyl phosphate,sulfonated kerosene,and bis(2-ethylhexyl)phosphate in high-salinity brine,accompanied by a high flux of 160~224 L·m^(-2)·h^(-1).Notably,it exhibited robust chemical stability in corrosive environment and maintained mechanical durability after 500 folding cycles coupled with consistent separation performances over 10 recycles.This study presents a novel multi-component modification approach for constructing high-performance GObased membrane,promising practical applications in organic pollutant removal from high salt solution.
文摘Environmental pollution,energy consumption,and greenhouse gas emissions are critical global issues.To address these challenges,optimizing skimmer coatings is a major step in commercializing cleaning oil stains.This research presents a novel approach to creating and refining oil absorbent coatings,introducing a unique oil spill removal skimmer enhanced with a super hydrophobic polyaniline(PANI)nanofiber coating.The goal of this study was to improve oil absorption performance,increase the contact angle,lower drag,reduce energy consumption,achieve high desirability,and lower production costs.PANI treated with hydrochloric acid was a key focus as it resulted in higher porosity and smaller pore diameters,providing a larger surface area,which are crucial factors for boosting oil absorption and minimizing drag.To optimize optimal nanofiber morphology,PANI synthesized with methanesulfonic acid was first dedoped and then redoped with hydrochloric acid.After optimization,the most effective skimmer coating was achieved using a formulation consisting of 0.1%PANI,an ammonium persulfate/aniline ratio of 0.4,and an acid/aniline ratio of 9.689,along with redoped PANI nanofibers.The optimized skimmer exhibited a remarkable contact angle of 177.477°.The coating achieved drag reduction of 32%,oil absorption of 88.725%,a cost of$1.710,and a desirability rating of 78.5%.In this study,an optimized skimmer coat containing super hydrophobic coat-PANI nanofibers was fabricated.By enhancing contact angle and reducing drag,these coatings increased the skimmer performance by improving oil absorption and reducing fuel consumption.
文摘Behind the removal of tariffs lies a multiplication of benefits for both China and Africa A transformative policy is set to significantly reshape economic relations between China and Africa.China’s policy to grant zero-tariff treatment to imports from the 53 African nations with diplomatic ties will go into effect on 1 May this year.This initiative,which Chinese Foreign Minister Wang Yi likened to an arithmetic operation during this year’s Two Sessions,marks a further step in China’s efforts to boost imports from Africa.
基金supported by the NSFC-Yunnan Joint Fund(No.U2102210)the National Natural Science Foundation of China(No.22168044)+1 种基金Yunnan Provincial Department of Science and Technology(No.202201BF070001-013)the Research Innovation Fund for Graduate Students of Yunnan University(No.KC-23234004).
文摘Excessive phosphorus and arsenic in water bodies not only destroy ecosystems but also pose a serious threat to human health.In this study,a series of Al-doped modified metal-organic frameworks(Zr-Al-MOF)were prepared by solvothermal method,which achieved efficient removal of phosphate and arsenate in water.Due to the use of inexpensive Al salts,the material has a lower cost and is more economical.The molar ratio of metal salts,adsorption time,solution pH,initial concentration,temperature and coexisting anions were studied,and it was found that when the molar ratio of Zr:Al was 2,Zr-Al-MOF had the best adsorption performance for phosphate and arsenate,and the maximum adsorption capacity was 93.04 mg P/g and 173.83 mg As/g,respectively.It traps phosphate and arsenate at a fast reaction rate and can be recycled repeatedly.In addition,0.15 g/L of 2Zr-Al-MOF can effectively reduce the phosphate and arsenate content in the contaminated spring water samples of Yangzonghai Lake to the standard range of drinking water,which further confirms the application potential of 2Zr-Al-MOF.By FT-IR and XPS analysis,it was found that the adsorption mechanism was ligand exchange,electrostatic attraction and hydrogen bond formation.The theoretical calculation shows that the adsorption energy is negative,which indicates that 2Zr-Al-MOF is attractive to phosphate and arsenate,and the adsorption state is stable.The results show that 2Zr-Al-MOF is an effective phosphate and arsenate adsorbent and has broad application prospects in eutrophication water treatment.
基金supported by National Natural Science Foundation of China(No.22408235)Tianchi Talent Program of Xinjiang.
文摘Photocatalysis—a green and energy-efficient technology for environmental remediation and energy conversion—has recently demonstrated broad application potential in intelligent building materials.This review systematically summarizes recent advancements in incorporating photocatalytic materials into building applications,focusing on two main scenarios:pavement and wall surfaces.In pavement systems,photocatalytic materials are primarily employed to degrade pollutants such as NO_(x)and volatile organic compounds,thereby actively reducing emissions.In wall applications,the emphasis is on imparting intelligent maintenance functions,including self-cleaning,antibacterial activity,and air purification.We provide a comprehensive analysis of the performance of various photocatalytic materials,their incorporation methods,and their effects on mechanical properties and environmental durability.Building on this analysis,we propose design principles for photocatalytic building materials that balance catalytic efficiency with cost,enhance mechanical stability,and preserve the intrinsic functions of building components.Finally,we outline future research directions,emphasizing the significant potential of photocatalytic building materials in advancing green construction and sustainable development.
基金supported by the National Natural Science Foundation of China(Nos.22322107,22101169 and 22071144)by Shanghai Scientific and Technological Committee(No.22010500300).
文摘Organic pollutants,a pivotal factor in water pollution,have persistently menaced the aquatic ecosystem,as well as the sustainable development of human health,economy,and society.Consequently,there is an urgent need for advanced techniques to efficiently eliminate organic micropollutants from water.Here,we present the synthesis of three nonporous cavitand-crosslinked polymers capable of adsorbing diverse organic pollutants from aqueous solutions.These polymeric adsorbents exhibit outstanding adsorptive performance towards the tested micropollutants,characterized by high apparent adsorption rate constants(kobs)and maximum adsorption capacities(qmax,e).Notably,Compound NCCP-1 demonstrated a remarkable qmax,e of 459 mg/g for bisphenol A(BPA),ranking among the highest values reported for organic polymer adsorbents.In-depth investigation of the adsorption mechanism of the nonporous polymer revealed that it involves the recognition of pollutants by the deep cavities of the cavitand moieties and the interstitial spaces between them,primarily mediated by the hydrophobic effect.Furthermore,NCCP-1 was applied in situ water purification simulations and was proven to maintain its removal efficiency over more than four cycles,highlighting its potential for practical applications in water treatment.
基金the National Key Research and Development Program of China(No.2023YFC3707001).
文摘In recent years,an increase in the content of Zn,the impurity element,in ironmaking raw materials has led to the deterioration of iron-bearing resources and has introduced new challenges to sintering dezincification.A thorough understanding of the reaction behavior of Zn during the sintering process can form a theoretical foundation for the development of efficient dezincification technology.Therefore,the reaction behavior of Zn was investigated under different temperatures and atmospheres using thermodynamic calculations and experimental simulations,and the phase transformation of Zn in each pre-reductive sintering zone was investigated.The results showed that Zn-containing materials were mainly converted into ZnO when the temperature reached 700℃,and ZnO began to combine with Fe_(2)O_(3)to form ZnFe_(2)O_(4)at approximately 800℃.At low CO concentration,ZnFe_(2)O_(4)was stable,while ZnO combined with iron oxide to form Fe_(0.85-x)Zn_(x)O in a strong reduction atmosphere.ZnFe_(2)O_(4)could also be converted into Fe_(0.85-x)Zn_(x)O and FeO.A part of Zn was converted to elemental Zn,which was volatilized and removed into the gas phase above 1000℃.Therefore,the feasibility of dezincification via pre-reductive sintering was confirmed.At the coke ratio of 18.0 wt.%of the sintering material,the Zn removal rate reached 62.3 wt.%.
基金funded by NIH grants HL154720-03S1, AG057587, AG074283, DK122708-03S1, BrightFocus ADR A20183775Brown Foundation 2020 Healthy Aging Initiative (to WC)
文摘Microglia are the macrophages that populate the brain parenchyma.Research in the past decades has identified them as both essential guardians of the brain and significant contributors to various neurological diseases.A highly versatile cell type,microglia have been shown to fulfill a multitude of critical roles in the central nervous system,including facilitating neurogenesis and myelination,pruning synapses,removing debris and waste,modulating neuronal activity,supporting the blood-brain barrier,repairing tissue damage,and surveilling against microbial invasions under physiological conditions(Prinz et al.,2021;Paolicelli et al.,2022).
