The macroporous anion exchangers with long-chained cross-linking agents were investigated for the tungsten recovery from salt solutions.The physical-chemical characteristics of these sorbents were studied by means of ...The macroporous anion exchangers with long-chained cross-linking agents were investigated for the tungsten recovery from salt solutions.The physical-chemical characteristics of these sorbents were studied by means of sorption-desorption experiment aswell as electron and IR-spectroscopy.The anion exchangers on the basis of macroporous copolymers of methylacrylate and divinyl-ester of diethyleneglycol or tetravinyl-ester of pentaerythritol possess the exchange capacity to tungsten 2--5 times greater than the porous anion exchangers on the basis of styrene and divinylbenzene,therefore they can be used for selective tungsten recovery from comulex salt solutions.展开更多
To improve the tensile bond strength of denim bonding agents, the adhesion between denim and MMA resin was investigated by applying initiator systems containing 1-cyclohexyl-5-ethyl barbituric acid (CEB), copper acety...To improve the tensile bond strength of denim bonding agents, the adhesion between denim and MMA resin was investigated by applying initiator systems containing 1-cyclohexyl-5-ethyl barbituric acid (CEB), copper acetyl acetonate (CAA), quaternary ammonium chloride (QAC). cupric ion, with the addition of TEGDMA, an.d pretreatment solution for denim, and an HEMA primer. The effects of a cross-linking agent on barbituric acid-initiated denim bonding resin were examined by measuring degree of conversion, molecular weight, hardness of bonding resin, and tensile bond strengths.展开更多
The development of unconventional petroleum resources has gradually become an important succession for increasing oil production.However,the related engineers and researchers are paying more and more attention to the ...The development of unconventional petroleum resources has gradually become an important succession for increasing oil production.However,the related engineers and researchers are paying more and more attention to the application of temporary plugging agents(TPAs)for their efficient development.TPAs can expand the stimulated reservoir volume(SRV)and facilitate the flow of oil and gas to the bottom of the well.Particle-gels used as temporary plugging agents have the characteristics of the simple injection process,good deformation,high plugging strength,and complete self-degradation performance,which have been widely applied in recent years.In this paper,five samples of DPPG polymerized by different molecular weights of cross-linking agents were prepared.In addition,infrared spectroscopy analysis,differential calorimetry scanning(DSC)analysis,static particle gel swelling and degradation performance evaluation experiments,and dynamic temporary plugging performance experiments in cores were conducted at 34°C.Results show that as the molecular weight of the cross-linking agent(at 0.01 g)in the DPPG molecule decreased from 1,000 to 200 Da,the fewer cross-linking sites of DPPG,the looser the microscopic three-dimensional mesh structure formed.The swelling ratio increased from 7 to 33 times.However,the complete degradation time increased from 40 to 210 min.Moreover,the DSC results confirmed that the higher the molecular weight of the cross-linking agent,the worse is chemical stability and the more prone it to self-degradation.DPPG samples had good temporary plugging performance in reservoir cores.DPPGs prepared by the cross-linking agent with smaller molecular weight has a stronger swelling ratio,higher gel strength,and greater plugging strength in the core permeabilities.Moreover,the degraded DPPG is less damaging to the cores.However,their slower degradation rates take a slightly longer times to reach complete degradation.The results of this paper can provide new ideas and a theoretical basis for the development of particle gel-type temporary plugging agents(TPA)with controllable degradation time in low-temperature reservoirs.It can help to expand the application range of existing DPPG reservoir conditions.展开更多
In this study,a hydrophobic material,ethylcellulose,which was used as its aqueous suspension Surelease^(®),was combined with a swelling agent as the swelling layer to prepare delayed-release pellets for Danshensu...In this study,a hydrophobic material,ethylcellulose,which was used as its aqueous suspension Surelease^(®),was combined with a swelling agent as the swelling layer to prepare delayed-release pellets for Danshensu,which is a hydrophilic drug with low MW.A rupturable,delayed-release pellet consists of a drug core,a swelling layer containing a swelling agent(cross-linked sodium carboxymethyl cellulose)with a hydrophobic agent(Surelease^(®)),and a controlled layer composed by an insoluble,water-permeable polymeric coating(aqueous ethylcellulose dispersions)was developed in a fluidised bed.Results showed that blending Surelease^(®)into the swelling layer could effectively extend the release of Danshensu from the pellets,which may be attributed to the slowed swelling rate by reduction of water penetration and improvement of mechanical integrity of the swelling layer.Drug in the delayed pellets showed sustained release in beagle dogs after oral administration with comparable in-vivo exposure to the uncoated drug pellets.In conclusion,blends of hydrophobic and swelling agents in the swelling layer in doublemembrane pellets could achieve a delayed drug-release profile in vitro,as well as delayed and sustained absorption in vivo for highly soluble,low-MW drug.The present study highlighted the potential use of a delayed-release system for other hydrophilic,low-MW drugs to meet the formulation requirements for chronopharmacological diseases.展开更多
The conventional foaming agents have the problems of poor adaptability and high cost during the application in different types of gas fields,especially in high temperature,high salinity,high acidic gas and high conden...The conventional foaming agents have the problems of poor adaptability and high cost during the application in different types of gas fields,especially in high temperature,high salinity,high acidic gas and high condensate oil and gas fields.In this study,the Gemini foaming agent was used as the main agent to enhance foaming and foam stability of the foaming agent,the grafted nanoparticles were used as foam stabilizer to further improve the foam stability,and the characteristic auxiliaries were added to make the foaming agent suitable for different types of gas reservoirs.Two types and six subtypes of nanoparticle foaming agents have been prepared for the main gas fields of China.The experimental evaluation results show that the overall temperature resistance,salinity resistance,H2S resistance,CO2 resistance and condensate resistance of the nanoparticle foaming agents can reach 160℃,250000 mg/L,100 mg/L,100%and 40%,respectively.The new foaming agents have been used in 8685 wells in China.Compared with conventional foaming agent,the average gas flow rate per well increased by 62.48%,the pressure difference(casing-tubing)decreased by 18.9%,and the cost dropped by 45%.The effect of reducing cost and increasing efficiency is obvious.展开更多
In order to prepare the polyethylene materials with controlling properties,we developed two kinds of controllable cross-linking polyethylene foaming system.2,5-dimethyl-2,5-bis (tert-butyl peroxy) hexane was used as c...In order to prepare the polyethylene materials with controlling properties,we developed two kinds of controllable cross-linking polyethylene foaming system.2,5-dimethyl-2,5-bis (tert-butyl peroxy) hexane was used as cross-linking agent and TEMPO as cross-linking inhibitor,azodicarbonamide (AC) was used as foaming agent and citric acid as foaming promoter.The density,expansion ratio,cellular structure and mechanical property of these two kinds of controllable materials were studied.Experimental results show that,properties of these two kinds of materials appear similar trend:cellular size and expansion ratio are enlarged with the amount of cross-linking inhibitor or foaming promoter increasing,while density and mechanical strength appear decreasing trend.Through comparing those two material systems’ properties,cross-linking polyethelene foaming system with citric acid as foaming promoter has better properties.展开更多
A study for further improving the suspension rate of alcohol-based coatings using a new nano-dispersing agent has been presented in this paper. The results of experiments show that the new nano-dispersing agent should...A study for further improving the suspension rate of alcohol-based coatings using a new nano-dispersing agent has been presented in this paper. The results of experiments show that the new nano-dispersing agent should be used in combination with organic auxiliary agent which significantly increases the suspension effect of alcohol-based coatings. By the methods, the suspension rates of 99%, 98%, 96% and 94% can be achieved at 2h, 2h, 48h and 72h, respectively. These alcohol-based coatings have characters of higher strength, lower gas evolution, better brush ability and no blister after ignition.展开更多
A method for the treatment of hazardous waste drilling fluids,potentially leading to environmental pollution,is considered.The waste drilling fluid is treated with an inorganic flocculant,an organic flocculant,and a p...A method for the treatment of hazardous waste drilling fluids,potentially leading to environmental pollution,is considered.The waste drilling fluid is treated with an inorganic flocculant,an organic flocculant,and a pH regulator.The profile control agent consists of partially hydrolyzed polyacrylamide,formaldehyde,hexamethylenetetramine,resorcinol,phenol,and the treated waste drilling fluid itself.For a waste drilling fluid concentration of 2500 mg/L,the gelling time of the profile control agent is 25 h,and the gelling strength is 32,000 mPa.s.Compared with the profile control agent prepared by recirculated water under the same conditions,the present profile control agent displays better stability,salt-resistance,and performance.展开更多
At present, the use of rare earth elements(REEs) has become an inevitable necessity in many modern industries. In general, liquid extraction is the best commercial method for extracting REEs due to its ability to co...At present, the use of rare earth elements(REEs) has become an inevitable necessity in many modern industries. In general, liquid extraction is the best commercial method for extracting REEs due to its ability to control high volumes of liquids with electrical load. With the aim of improving a separation technology that would be superior to the existing extraction systems, the extraction behaviors of La(Ⅲ),Pr(Ⅲ), and Nd(Ⅲ) from an HCI medium with Cyanex 272 in the presence of the complexing agent lactic acid(HLac) and auxiliary agents citric acid(H3 Cit), acetic acid(HAc), and Titriplex Ⅲ have been reported.The effect of pH and lactic acid concentration has been examined. The use of lactic acid as a complexing agent leading to a high extraction of REEs with Cyanex 272 at pH = 5 was compared with systems without lactic acid. The results show that the use of acetic acid along with lactic acid leads to an increase in the extraction percentage of LREEs. While use of citric acid and Titriplex Ⅲ reduces the extraction percentage of LREEs. Finally, the presence of Titriplex Ⅲ together with lactic acid could lead to an increase in the separation factor of Pr and Nd.展开更多
文摘The macroporous anion exchangers with long-chained cross-linking agents were investigated for the tungsten recovery from salt solutions.The physical-chemical characteristics of these sorbents were studied by means of sorption-desorption experiment aswell as electron and IR-spectroscopy.The anion exchangers on the basis of macroporous copolymers of methylacrylate and divinyl-ester of diethyleneglycol or tetravinyl-ester of pentaerythritol possess the exchange capacity to tungsten 2--5 times greater than the porous anion exchangers on the basis of styrene and divinylbenzene,therefore they can be used for selective tungsten recovery from comulex salt solutions.
文摘To improve the tensile bond strength of denim bonding agents, the adhesion between denim and MMA resin was investigated by applying initiator systems containing 1-cyclohexyl-5-ethyl barbituric acid (CEB), copper acetyl acetonate (CAA), quaternary ammonium chloride (QAC). cupric ion, with the addition of TEGDMA, an.d pretreatment solution for denim, and an HEMA primer. The effects of a cross-linking agent on barbituric acid-initiated denim bonding resin were examined by measuring degree of conversion, molecular weight, hardness of bonding resin, and tensile bond strengths.
基金supported by the Research Foundation of China University of Petroleum-Beijing at Karamay (No. YJ2018B02002 and XQZX20200010)the Natural Science Foundation of Xinjiang Uygur Autonomous Region (No. 2021D01E23 and 2019D01B57)+3 种基金the University Scientific Research Project of Xinjiang Uygur Autonomous Region (No. XJEDU2019Y067)the Xinjiang Uygur Autonomous Region Innovation Environment Construction Project (No. 2019Q025)the Sichuan Province Regional Innovation Cooperation Project (No. 2020YFQ0036)the CNPC Strategic Cooperation Science and Technology Project (ZLZX2020-01-04-04)
文摘The development of unconventional petroleum resources has gradually become an important succession for increasing oil production.However,the related engineers and researchers are paying more and more attention to the application of temporary plugging agents(TPAs)for their efficient development.TPAs can expand the stimulated reservoir volume(SRV)and facilitate the flow of oil and gas to the bottom of the well.Particle-gels used as temporary plugging agents have the characteristics of the simple injection process,good deformation,high plugging strength,and complete self-degradation performance,which have been widely applied in recent years.In this paper,five samples of DPPG polymerized by different molecular weights of cross-linking agents were prepared.In addition,infrared spectroscopy analysis,differential calorimetry scanning(DSC)analysis,static particle gel swelling and degradation performance evaluation experiments,and dynamic temporary plugging performance experiments in cores were conducted at 34°C.Results show that as the molecular weight of the cross-linking agent(at 0.01 g)in the DPPG molecule decreased from 1,000 to 200 Da,the fewer cross-linking sites of DPPG,the looser the microscopic three-dimensional mesh structure formed.The swelling ratio increased from 7 to 33 times.However,the complete degradation time increased from 40 to 210 min.Moreover,the DSC results confirmed that the higher the molecular weight of the cross-linking agent,the worse is chemical stability and the more prone it to self-degradation.DPPG samples had good temporary plugging performance in reservoir cores.DPPGs prepared by the cross-linking agent with smaller molecular weight has a stronger swelling ratio,higher gel strength,and greater plugging strength in the core permeabilities.Moreover,the degraded DPPG is less damaging to the cores.However,their slower degradation rates take a slightly longer times to reach complete degradation.The results of this paper can provide new ideas and a theoretical basis for the development of particle gel-type temporary plugging agents(TPA)with controllable degradation time in low-temperature reservoirs.It can help to expand the application range of existing DPPG reservoir conditions.
基金Financial support was provided by a research grant from the University of Macao(Research Grant RG085/09-10S/ZY/ICMS and UL016/09-Y4/CMS/WYT01/ICMS).
文摘In this study,a hydrophobic material,ethylcellulose,which was used as its aqueous suspension Surelease^(®),was combined with a swelling agent as the swelling layer to prepare delayed-release pellets for Danshensu,which is a hydrophilic drug with low MW.A rupturable,delayed-release pellet consists of a drug core,a swelling layer containing a swelling agent(cross-linked sodium carboxymethyl cellulose)with a hydrophobic agent(Surelease^(®)),and a controlled layer composed by an insoluble,water-permeable polymeric coating(aqueous ethylcellulose dispersions)was developed in a fluidised bed.Results showed that blending Surelease^(®)into the swelling layer could effectively extend the release of Danshensu from the pellets,which may be attributed to the slowed swelling rate by reduction of water penetration and improvement of mechanical integrity of the swelling layer.Drug in the delayed pellets showed sustained release in beagle dogs after oral administration with comparable in-vivo exposure to the uncoated drug pellets.In conclusion,blends of hydrophobic and swelling agents in the swelling layer in doublemembrane pellets could achieve a delayed drug-release profile in vitro,as well as delayed and sustained absorption in vivo for highly soluble,low-MW drug.The present study highlighted the potential use of a delayed-release system for other hydrophilic,low-MW drugs to meet the formulation requirements for chronopharmacological diseases.
基金Supported by the PetroChina Scientifc Research and Technological Development Project(kt2017-21-14-1).
文摘The conventional foaming agents have the problems of poor adaptability and high cost during the application in different types of gas fields,especially in high temperature,high salinity,high acidic gas and high condensate oil and gas fields.In this study,the Gemini foaming agent was used as the main agent to enhance foaming and foam stability of the foaming agent,the grafted nanoparticles were used as foam stabilizer to further improve the foam stability,and the characteristic auxiliaries were added to make the foaming agent suitable for different types of gas reservoirs.Two types and six subtypes of nanoparticle foaming agents have been prepared for the main gas fields of China.The experimental evaluation results show that the overall temperature resistance,salinity resistance,H2S resistance,CO2 resistance and condensate resistance of the nanoparticle foaming agents can reach 160℃,250000 mg/L,100 mg/L,100%and 40%,respectively.The new foaming agents have been used in 8685 wells in China.Compared with conventional foaming agent,the average gas flow rate per well increased by 62.48%,the pressure difference(casing-tubing)decreased by 18.9%,and the cost dropped by 45%.The effect of reducing cost and increasing efficiency is obvious.
基金Funded by National Natural Science Foundation of China (No.21975108)Fundamental Research Funds for the Central Universities of China (No.JUSRP121033)。
文摘In order to prepare the polyethylene materials with controlling properties,we developed two kinds of controllable cross-linking polyethylene foaming system.2,5-dimethyl-2,5-bis (tert-butyl peroxy) hexane was used as cross-linking agent and TEMPO as cross-linking inhibitor,azodicarbonamide (AC) was used as foaming agent and citric acid as foaming promoter.The density,expansion ratio,cellular structure and mechanical property of these two kinds of controllable materials were studied.Experimental results show that,properties of these two kinds of materials appear similar trend:cellular size and expansion ratio are enlarged with the amount of cross-linking inhibitor or foaming promoter increasing,while density and mechanical strength appear decreasing trend.Through comparing those two material systems’ properties,cross-linking polyethelene foaming system with citric acid as foaming promoter has better properties.
文摘A study for further improving the suspension rate of alcohol-based coatings using a new nano-dispersing agent has been presented in this paper. The results of experiments show that the new nano-dispersing agent should be used in combination with organic auxiliary agent which significantly increases the suspension effect of alcohol-based coatings. By the methods, the suspension rates of 99%, 98%, 96% and 94% can be achieved at 2h, 2h, 48h and 72h, respectively. These alcohol-based coatings have characters of higher strength, lower gas evolution, better brush ability and no blister after ignition.
文摘A method for the treatment of hazardous waste drilling fluids,potentially leading to environmental pollution,is considered.The waste drilling fluid is treated with an inorganic flocculant,an organic flocculant,and a pH regulator.The profile control agent consists of partially hydrolyzed polyacrylamide,formaldehyde,hexamethylenetetramine,resorcinol,phenol,and the treated waste drilling fluid itself.For a waste drilling fluid concentration of 2500 mg/L,the gelling time of the profile control agent is 25 h,and the gelling strength is 32,000 mPa.s.Compared with the profile control agent prepared by recirculated water under the same conditions,the present profile control agent displays better stability,salt-resistance,and performance.
基金Project supported by Anguran Lead and Zinc Company(55/G/93)
文摘At present, the use of rare earth elements(REEs) has become an inevitable necessity in many modern industries. In general, liquid extraction is the best commercial method for extracting REEs due to its ability to control high volumes of liquids with electrical load. With the aim of improving a separation technology that would be superior to the existing extraction systems, the extraction behaviors of La(Ⅲ),Pr(Ⅲ), and Nd(Ⅲ) from an HCI medium with Cyanex 272 in the presence of the complexing agent lactic acid(HLac) and auxiliary agents citric acid(H3 Cit), acetic acid(HAc), and Titriplex Ⅲ have been reported.The effect of pH and lactic acid concentration has been examined. The use of lactic acid as a complexing agent leading to a high extraction of REEs with Cyanex 272 at pH = 5 was compared with systems without lactic acid. The results show that the use of acetic acid along with lactic acid leads to an increase in the extraction percentage of LREEs. While use of citric acid and Titriplex Ⅲ reduces the extraction percentage of LREEs. Finally, the presence of Titriplex Ⅲ together with lactic acid could lead to an increase in the separation factor of Pr and Nd.