In order to reduce the waste of resources and environmental pollution caused by excessive application of chemical fertilizers, improve the utilization rate of fertilizers, and promote the large-scale and high-quality ...In order to reduce the waste of resources and environmental pollution caused by excessive application of chemical fertilizers, improve the utilization rate of fertilizers, and promote the large-scale and high-quality development of the Chinese rose industry. In this experiment, corn stover biochar, phosphoric acid modified biochar and organic fertilizer were used as test materials, and the effects of mixed application of modified biochar and organic fertilizer on the growth and development of Chinese rose as well as soil physicochemical properties were investigated by using the method of pot planting test. The results showed that modified biochar with organic fertilizer had the most significant effect on the enhancement of soil pH, organic matter content and soil carbon-to-nitrogen ratio. After 120 d of planting, modified biochar with organic fertilizer had the most significant effect on the enhancement of plant height and crown width of Chinese rose;both organic fertilizer and modified biochar with organic fertilizer significantly increased the chlorophyll content of Chinese rose. The number of flowers and the number of branches were the highest in the modified biochar with organic fertilizer treatment. In conclusion, the application of modified biochar with organic fertilizer can better improve the soil pH, and increase the soil organic matter content and carbon-to-nitrogen ratio to change the biological traits of Chinese rose. The results of this study provide a theoretical basis for the reduction of chemical fertilizers and the resource utilization of agricultural wastes and guarantee the sustainable development of the cut flower industry.展开更多
Nickel-rich layered oxide cathode(LiNi_(x)Co_(y)Mn_(1−x−y)O_(2),x>0.5,NCM)shows substantial potential for applications in longer-range electrical vehicles.However,the rapid capacity decay and serious safety concern...Nickel-rich layered oxide cathode(LiNi_(x)Co_(y)Mn_(1−x−y)O_(2),x>0.5,NCM)shows substantial potential for applications in longer-range electrical vehicles.However,the rapid capacity decay and serious safety concerns impede its practical viability.This work provides a hydrogen-bonded organic framework(HOF)modification strategy to simultaneously improve the electrochemical performance,thermal stability and incombustibility of separator.Melamine cyanurate(MCA),as a low-cost and reliable flame-retardant HOF,was implemented in the separator modification layer,which can prevent the battery short circuit even at a high temperature.In addition,the supermolecule properties of MCA provide unique physical and chemical microenvironment for regulating ion-transport behavior in electrolyte.The MCA coating layer enabled the nickel-rich layered oxide cathode with a high-capacity retention of 90.3%after 300 cycles at 1.0 C.Collectively,the usage of MCA in lithium-ion batteries(LIBs)affords a simple,low-cost and efficient strategy to improve the security and service life of nickel-rich layered cathodes.展开更多
The small angle X-ray scattering of organically modified MSU-X silica prepared by co-condensation of tetraethoxysilane (TEOS) and methyltriethoxysilane (MTES) show negative deviation from Debye’s theory due to the ...The small angle X-ray scattering of organically modified MSU-X silica prepared by co-condensation of tetraethoxysilane (TEOS) and methyltriethoxysilane (MTES) show negative deviation from Debye’s theory due to the existence of the organic interface layer. By exerting correction of the scattering negative deviation, Debye relation may be recovered, and the average wall thickness of the material may be evaluated.展开更多
In this paper,organic montmorillonite(OMMT)was added into crumb rubber modified asphalt(CRMA)to improve its high temperature performance,anti-aging performance and storage stability.The effects of different OMMT conte...In this paper,organic montmorillonite(OMMT)was added into crumb rubber modified asphalt(CRMA)to improve its high temperature performance,anti-aging performance and storage stability.The effects of different OMMT content on properties of CRMA were studied.The rutting factor obtained by dynamic shear rheological(DSR)test was adopted to evaluate the high-temperature performance.The creep stiffness and m value determined by the bending beam rheometer(BBR)test were employed to evaluate the low-temperature performance.The softening point,ductility,rutting factor before and after rolling thin film ovens test(RTFOT)and pressure aging vessel test(PAV)were compared to characterize the aging properties.Moreover,the segregation test after being reserved for 48 h and 7 d was conducted,and the softening point and rutting factor of upper and lower layers of segregation pipe were adopted to evaluate the storage stability.The results indicated that the high-temperature performance and anti-aging performance were developed with the increasing content of OMMT,while the low-temperature performance deteriorated.The storage stability was improved with the increasing content of OMMT before the content exceeded 4%,after which the storage stability declined.Taking account of all factors,it is suggested that the optimum content of OMMT is 3%−4%.展开更多
The production of foods with genetically modified organisms (GMOs) has risen rapidly over the past three decades to comprise nearly 90% of crops grown in the United States today. Currently, there are no mandates for l...The production of foods with genetically modified organisms (GMOs) has risen rapidly over the past three decades to comprise nearly 90% of crops grown in the United States today. Currently, there are no mandates for labeling foods containing GMOs. GMO agricultural crops contain the insertion of genes encoding for pesticides, pesticide resistance, growth factors, or other substances not normally present. In addition to the foreign genes that are inserted, hundreds to thousands of mutations disrupt normal genes in GMO plants. Recently, animal studies have demonstrated toxicity of GMO foods causing organ failure, infertility, carcinomas and death. The FDA requirement of ingredients added to foods be labeled on the product is not applied to GMO foods, precluding the consumer’s right to know. GMOs provide an economic incentive to companies because the seeds can be patented, driving up costs and creating the potential for monopolies. Herbicide-resistance conferred by GMOs has resulted in higher pesticide applications, which correlate with higher human cancer rates, and the emergence of pesticide-resistant weeds and insects. GMO toxins are spreading into to non-target insects, waterways and aquatic organisms, with toxicity to non-target organisms and resultant contamination of disparate ecosystems in the food chain. The appropriateness of mandatory GMO labeling of foods in the United States is discussed.展开更多
Objective To develop a technique for simultaneous detection of various target genes in Roundup Ready soybean by combining multiplex PCR and low-density DNA microarray. Methods Two sets of the multiplex PCR system were...Objective To develop a technique for simultaneous detection of various target genes in Roundup Ready soybean by combining multiplex PCR and low-density DNA microarray. Methods Two sets of the multiplex PCR system were used to amplify the target genes in genetically modified （GM） soybean. Seventeen capture probes （PCR products） and 17 pairs of corresponding primers were designed according to the genetic characteristics of Rroundup Ready soybean （GTS40-3-2）, maize （MonS10, Nk603, GA21）, canola （T45, MS1/RF1）, and rice （SCK） in many identified GM crops. All of the probes were categorized and identified as species-specific probes. One negative probe and one positive control probe were used to assess the efficiency of all reactions, and therefore eliminate any false positive and negative results. After multiplex PCR reaction, amplicons were adulterated with Cy5-dUTP and hybridized with DNA microarray. The array was then scanned to display the specific hybridization signals of target genes. The assay was applied to the analysis of sample of certified transgenic soybean （Roundup Ready GTS40-3-2） and canola （MS1/RF1）. Results A combination technique of multiplex PCR and DNA microarray was successfully developed to identify multi-target genes in Roundup Ready soybean and MS 1/RF1 canola with a great specificity and reliability. Reliable identification of genetic characteristics of Roundup Ready of GM soybean from genetically modified crops was achieved at 0.5% transgenic events, indicating a high sensitivity. Conclusion A combination technique of multiplex PCR and low-density DNA microarray can reliably detect and identify the genetically modified crops.展开更多
Zero-valent iron(ZVI),an ideal reductant treating persistent pollutants,is hampered by issues like corrosion,passivation,and suboptimal utilization.Recent advancements in nonmetallic modified ZVI(NM-ZVI)show promising...Zero-valent iron(ZVI),an ideal reductant treating persistent pollutants,is hampered by issues like corrosion,passivation,and suboptimal utilization.Recent advancements in nonmetallic modified ZVI(NM-ZVI)show promising potential in circumventing these challenges by modifying ZVI's surface and internal physicochemical properties.Despite its promise,a thorough synthesis of research advancements in this domain remains elusive.Here we review the innovative methodologies,regulatory principles,and reduction-centric mechanisms underpinning NM-ZVI's effectiveness against two prevalent persistent pollutants:halogenated organic compounds and heavy metals.We start by evaluating different nonmetallic modification techniques,such as liquid-phase reduction,mechanical ball milling,and pyrolysis,and their respective advantages.The discussion progresses towards a critical analysis of current strategies and mechanisms used for NM-ZVI to enhance its reactivity,electron selectivity,and electron utilization efficiency.This is achieved by optimizing the elemental compositions,content ratios,lattice constants,hydrophobicity,and conductivity.Furthermore,we propose novel approaches for augmenting NM-ZVI's capability to address complex pollution challenges.This review highlights NM-ZVI's potential as an alternative to remediate water environments contaminated with halogenated organic compounds or heavy metals,contributing to the broader discourse on green remediation technologies.展开更多
Increases in the number of cases of identified genetically modified （GM） rice contamination can be traced back to the first Rapid Alert System for Food and Feed （RASFF） in 2006. In response to the lack of reliable...Increases in the number of cases of identified genetically modified （GM） rice contamination can be traced back to the first Rapid Alert System for Food and Feed （RASFF） in 2006. In response to the lack of reliable detection methods, Decision 2011/884/EU proposed that new screening methods replace Decision 2008/289/EC, to identify all possible GM rice products originating in China. However, the synergy brands （SYBR） Green real-time PCR assay proposed by Decision 2011/884/EU has been shown to lack conformity with other TaqMan methods currently in use. To evaluate the specificity and repeatability of the methods recommended in Decision 2011/884/EU and Decision 2008/289/EC, we collected 74 rice products originating from six countries or districts. The 74 rice samples were tested using the Decision 2011/884/EU and Decision 2008/289/ EC methods. The parallel use of different instruments and reagents were used for testing in parallel, and the results were analyzed statistically. To avoid the limitations of specific laboratories, eight GM organism detection laboratories in China participated in a collaborative trial. In our tests, 24.3% （18/74） of the samples tested were positive with the SYBR Green real-time PCR assay using the Decision 2011/884/EU method, but were negative with the TaqMan real-time PCR assay using the Decision 2011/884/EU and Decision 2008/289/EC methods. Sequencing the PCR-amplified CrylA（b/c） genes in three samples （6, 30 and 43） showed that the products consisted of primer dimers rather than the targeted sequence. The combined experimental results showed that testing for the nopaline synthase gene （NOS） of Agrobacterium tumefasciens terminator and CrylA（b/c） produced false-positive results when the Decision 2011/884/EU method was used. Because of the high rate of false-positive results, the Decision 2011/884/EU SYBR Green method to detect GM rice requires improvement.展开更多
Dimethyldistearylammonium Bromide (DODMAB) is a bentonite modifier with good performance. In this experiment, 1-Bromooctadecane is the raw material, and completes tertiary amination and quaternization successively by ...Dimethyldistearylammonium Bromide (DODMAB) is a bentonite modifier with good performance. In this experiment, 1-Bromooctadecane is the raw material, and completes tertiary amination and quaternization successively by changing the condition of experiment. The result is that the productivity can achieve 78.94% in the synthesis of DODMAB. It has been used in the experiment of bentonite modification and achieves good results;compared with using trimethylstearylammonium bromide as the organic modifier, the synthetic organic bentonite has better performance than the common organic modifier when used in the oil base drilling fluid of oilfield operation.展开更多
For the official surveillance of genetically modified crops, efficient and simple detection methods need to be on hand to implement the strict requirements regarding approval, labelling and traceability determined by ...For the official surveillance of genetically modified crops, efficient and simple detection methods need to be on hand to implement the strict requirements regarding approval, labelling and traceability determined by the European Union. Therefore, a multiplex ligation dependent probe amplification (MLPA) module was developed for simultaneous detection of five genetically modified rapeseed events (MS8, RF3, GT73, Falcon GS40/90 and T45). Probes were designed and concentrations were adapted in order to obtain high sensitivity and specificity. This MLPA module was validated using certified reference materials and its applicability was tested analyzing routine honey, mustard and rapeseed samples. The limit of detection was determined by analyzing a dilution series (n = 16 for each concentration) of respective transgenic DNA. After optimization, the MLPA revealed limits of detection between 10 to 50 copies of the transgene DNA/assay. The method proved to be sensitive and highly reproducible. When analyzing routine samples, results obtained applying the MLPA module were similar compared to real-time PCR.展开更多
Poly (vinyl chloride)/ethylene-vinyl acetate/montmorillonite (PVC/EVA/OMMT) composites were prepared by melt blending method. Two kinds of montmorillonites were organically modified by trimethyloctadecyl ammonium and ...Poly (vinyl chloride)/ethylene-vinyl acetate/montmorillonite (PVC/EVA/OMMT) composites were prepared by melt blending method. Two kinds of montmorillonites were organically modified by trimethyloctadecyl ammonium and dimethyl bis (hydrogenated tallow) ammonium, respectively. The morphology and tensile properties of the resultant composites were discussed in terms of the modifier type and OMMT content. The PVC/EVA/OMMT composites have intercalated structure, which is independent of the polarity of the modifiers, while the tensile properties show strong dependence on the modifier type. The OMMT modified by polar modifier gives higher tensile ductile and strength of PVC/EVA/OMMT composites.展开更多
金属离子过量使用会造成环境污染,危及人类健康。因此,对相关金属离子进行检测显得尤为重要。发光金属有机框架(Luminescent metal-organic frameworks,LMOFs)因其具备高色纯度、超高孔隙率和可调结构等优势,被视为简单有效且有前途的...金属离子过量使用会造成环境污染,危及人类健康。因此,对相关金属离子进行检测显得尤为重要。发光金属有机框架(Luminescent metal-organic frameworks,LMOFs)因其具备高色纯度、超高孔隙率和可调结构等优势,被视为简单有效且有前途的荧光传感材料。本文以3,5-二(4-咪唑-1-基)吡啶(Bip)为主配体,1,4-萘二甲酸(1,4-ndc)为辅助配体,Ni^(2+)为中心离子,采取溶剂热法合成了一例二维金属有机框架[Ni_(2)(Bip)_(2)(1,4-ndc)_(2)(H_(2)O)_(6)](记为CUST-756,其中CUST是Changchun University of Science and Technology缩写),并通过合成后修饰法制备了Eu^(3+)@CUST-756复合发光材料。利用XRD、FT-IR和XPS对合成的CUST-756和Eu^(3+)@CUST-756复合材料进行了基础表征。并且采用荧光光谱对样品进行了发光特性、金属离子传感性能及其机理研究。实验结果表明,Eu^(3+)@CUST-756在甲醇溶液中具备优异的发光性能和良好的稳定性,Eu^(3+)的引入使得材料可用于金属阳离子Cr^(3+)、Fe^(3+)检测。Cr^(3+)离子的检出限(limit of detection,LOD)为5.44µmol·L^(-1);Fe^(3+)离子的LOD为7.51µmol·L^(-1),与大多数LMOFs性能相近。展开更多
文摘In order to reduce the waste of resources and environmental pollution caused by excessive application of chemical fertilizers, improve the utilization rate of fertilizers, and promote the large-scale and high-quality development of the Chinese rose industry. In this experiment, corn stover biochar, phosphoric acid modified biochar and organic fertilizer were used as test materials, and the effects of mixed application of modified biochar and organic fertilizer on the growth and development of Chinese rose as well as soil physicochemical properties were investigated by using the method of pot planting test. The results showed that modified biochar with organic fertilizer had the most significant effect on the enhancement of soil pH, organic matter content and soil carbon-to-nitrogen ratio. After 120 d of planting, modified biochar with organic fertilizer had the most significant effect on the enhancement of plant height and crown width of Chinese rose;both organic fertilizer and modified biochar with organic fertilizer significantly increased the chlorophyll content of Chinese rose. The number of flowers and the number of branches were the highest in the modified biochar with organic fertilizer treatment. In conclusion, the application of modified biochar with organic fertilizer can better improve the soil pH, and increase the soil organic matter content and carbon-to-nitrogen ratio to change the biological traits of Chinese rose. The results of this study provide a theoretical basis for the reduction of chemical fertilizers and the resource utilization of agricultural wastes and guarantee the sustainable development of the cut flower industry.
基金supported by the National Key Research and Development Program of China(No.2022YFA1504100)the National Natural Science Foundation of China(Nos.22005215,22279089,and 22178251).
文摘Nickel-rich layered oxide cathode(LiNi_(x)Co_(y)Mn_(1−x−y)O_(2),x>0.5,NCM)shows substantial potential for applications in longer-range electrical vehicles.However,the rapid capacity decay and serious safety concerns impede its practical viability.This work provides a hydrogen-bonded organic framework(HOF)modification strategy to simultaneously improve the electrochemical performance,thermal stability and incombustibility of separator.Melamine cyanurate(MCA),as a low-cost and reliable flame-retardant HOF,was implemented in the separator modification layer,which can prevent the battery short circuit even at a high temperature.In addition,the supermolecule properties of MCA provide unique physical and chemical microenvironment for regulating ion-transport behavior in electrolyte.The MCA coating layer enabled the nickel-rich layered oxide cathode with a high-capacity retention of 90.3%after 300 cycles at 1.0 C.Collectively,the usage of MCA in lithium-ion batteries(LIBs)affords a simple,low-cost and efficient strategy to improve the security and service life of nickel-rich layered cathodes.
文摘The small angle X-ray scattering of organically modified MSU-X silica prepared by co-condensation of tetraethoxysilane (TEOS) and methyltriethoxysilane (MTES) show negative deviation from Debye’s theory due to the existence of the organic interface layer. By exerting correction of the scattering negative deviation, Debye relation may be recovered, and the average wall thickness of the material may be evaluated.
基金Projects(51838001,51878070,51908069)supported by the National Natural Science Foundation of China。
文摘In this paper,organic montmorillonite(OMMT)was added into crumb rubber modified asphalt(CRMA)to improve its high temperature performance,anti-aging performance and storage stability.The effects of different OMMT content on properties of CRMA were studied.The rutting factor obtained by dynamic shear rheological(DSR)test was adopted to evaluate the high-temperature performance.The creep stiffness and m value determined by the bending beam rheometer(BBR)test were employed to evaluate the low-temperature performance.The softening point,ductility,rutting factor before and after rolling thin film ovens test(RTFOT)and pressure aging vessel test(PAV)were compared to characterize the aging properties.Moreover,the segregation test after being reserved for 48 h and 7 d was conducted,and the softening point and rutting factor of upper and lower layers of segregation pipe were adopted to evaluate the storage stability.The results indicated that the high-temperature performance and anti-aging performance were developed with the increasing content of OMMT,while the low-temperature performance deteriorated.The storage stability was improved with the increasing content of OMMT before the content exceeded 4%,after which the storage stability declined.Taking account of all factors,it is suggested that the optimum content of OMMT is 3%−4%.
文摘The production of foods with genetically modified organisms (GMOs) has risen rapidly over the past three decades to comprise nearly 90% of crops grown in the United States today. Currently, there are no mandates for labeling foods containing GMOs. GMO agricultural crops contain the insertion of genes encoding for pesticides, pesticide resistance, growth factors, or other substances not normally present. In addition to the foreign genes that are inserted, hundreds to thousands of mutations disrupt normal genes in GMO plants. Recently, animal studies have demonstrated toxicity of GMO foods causing organ failure, infertility, carcinomas and death. The FDA requirement of ingredients added to foods be labeled on the product is not applied to GMO foods, precluding the consumer’s right to know. GMOs provide an economic incentive to companies because the seeds can be patented, driving up costs and creating the potential for monopolies. Herbicide-resistance conferred by GMOs has resulted in higher pesticide applications, which correlate with higher human cancer rates, and the emergence of pesticide-resistant weeds and insects. GMO toxins are spreading into to non-target insects, waterways and aquatic organisms, with toxicity to non-target organisms and resultant contamination of disparate ecosystems in the food chain. The appropriateness of mandatory GMO labeling of foods in the United States is discussed.
基金National Basic Research Program of China (No. 2001CB109001)National High-Tech Research Program of China (No. 2002AA212041)
文摘Objective To develop a technique for simultaneous detection of various target genes in Roundup Ready soybean by combining multiplex PCR and low-density DNA microarray. Methods Two sets of the multiplex PCR system were used to amplify the target genes in genetically modified （GM） soybean. Seventeen capture probes （PCR products） and 17 pairs of corresponding primers were designed according to the genetic characteristics of Rroundup Ready soybean （GTS40-3-2）, maize （MonS10, Nk603, GA21）, canola （T45, MS1/RF1）, and rice （SCK） in many identified GM crops. All of the probes were categorized and identified as species-specific probes. One negative probe and one positive control probe were used to assess the efficiency of all reactions, and therefore eliminate any false positive and negative results. After multiplex PCR reaction, amplicons were adulterated with Cy5-dUTP and hybridized with DNA microarray. The array was then scanned to display the specific hybridization signals of target genes. The assay was applied to the analysis of sample of certified transgenic soybean （Roundup Ready GTS40-3-2） and canola （MS1/RF1）. Results A combination technique of multiplex PCR and DNA microarray was successfully developed to identify multi-target genes in Roundup Ready soybean and MS 1/RF1 canola with a great specificity and reliability. Reliable identification of genetic characteristics of Roundup Ready of GM soybean from genetically modified crops was achieved at 0.5% transgenic events, indicating a high sensitivity. Conclusion A combination technique of multiplex PCR and low-density DNA microarray can reliably detect and identify the genetically modified crops.
基金supported by the NSFC-JSPS joint research program(No.51961145202)the National Natural Science Foundation of China(No.52370163,52321005,and 52293443)the State Key Laboratory of Urban Water Resource and Environment(Harbin Institute of Technology)(No.2022TS42).
文摘Zero-valent iron(ZVI),an ideal reductant treating persistent pollutants,is hampered by issues like corrosion,passivation,and suboptimal utilization.Recent advancements in nonmetallic modified ZVI(NM-ZVI)show promising potential in circumventing these challenges by modifying ZVI's surface and internal physicochemical properties.Despite its promise,a thorough synthesis of research advancements in this domain remains elusive.Here we review the innovative methodologies,regulatory principles,and reduction-centric mechanisms underpinning NM-ZVI's effectiveness against two prevalent persistent pollutants:halogenated organic compounds and heavy metals.We start by evaluating different nonmetallic modification techniques,such as liquid-phase reduction,mechanical ball milling,and pyrolysis,and their respective advantages.The discussion progresses towards a critical analysis of current strategies and mechanisms used for NM-ZVI to enhance its reactivity,electron selectivity,and electron utilization efficiency.This is achieved by optimizing the elemental compositions,content ratios,lattice constants,hydrophobicity,and conductivity.Furthermore,we propose novel approaches for augmenting NM-ZVI's capability to address complex pollution challenges.This review highlights NM-ZVI's potential as an alternative to remediate water environments contaminated with halogenated organic compounds or heavy metals,contributing to the broader discourse on green remediation technologies.
基金supported by the Science and Technology Project of Yangtze River Delta,China (16395810100)the National Transgenic Major Project,China (2012ZX080110031)the Special Subject of Shanghai Technical Barriers to Trade,China (13TBT001)
文摘Increases in the number of cases of identified genetically modified （GM） rice contamination can be traced back to the first Rapid Alert System for Food and Feed （RASFF） in 2006. In response to the lack of reliable detection methods, Decision 2011/884/EU proposed that new screening methods replace Decision 2008/289/EC, to identify all possible GM rice products originating in China. However, the synergy brands （SYBR） Green real-time PCR assay proposed by Decision 2011/884/EU has been shown to lack conformity with other TaqMan methods currently in use. To evaluate the specificity and repeatability of the methods recommended in Decision 2011/884/EU and Decision 2008/289/EC, we collected 74 rice products originating from six countries or districts. The 74 rice samples were tested using the Decision 2011/884/EU and Decision 2008/289/ EC methods. The parallel use of different instruments and reagents were used for testing in parallel, and the results were analyzed statistically. To avoid the limitations of specific laboratories, eight GM organism detection laboratories in China participated in a collaborative trial. In our tests, 24.3% （18/74） of the samples tested were positive with the SYBR Green real-time PCR assay using the Decision 2011/884/EU method, but were negative with the TaqMan real-time PCR assay using the Decision 2011/884/EU and Decision 2008/289/EC methods. Sequencing the PCR-amplified CrylA（b/c） genes in three samples （6, 30 and 43） showed that the products consisted of primer dimers rather than the targeted sequence. The combined experimental results showed that testing for the nopaline synthase gene （NOS） of Agrobacterium tumefasciens terminator and CrylA（b/c） produced false-positive results when the Decision 2011/884/EU method was used. Because of the high rate of false-positive results, the Decision 2011/884/EU SYBR Green method to detect GM rice requires improvement.
文摘Dimethyldistearylammonium Bromide (DODMAB) is a bentonite modifier with good performance. In this experiment, 1-Bromooctadecane is the raw material, and completes tertiary amination and quaternization successively by changing the condition of experiment. The result is that the productivity can achieve 78.94% in the synthesis of DODMAB. It has been used in the experiment of bentonite modification and achieves good results;compared with using trimethylstearylammonium bromide as the organic modifier, the synthetic organic bentonite has better performance than the common organic modifier when used in the oil base drilling fluid of oilfield operation.
文摘For the official surveillance of genetically modified crops, efficient and simple detection methods need to be on hand to implement the strict requirements regarding approval, labelling and traceability determined by the European Union. Therefore, a multiplex ligation dependent probe amplification (MLPA) module was developed for simultaneous detection of five genetically modified rapeseed events (MS8, RF3, GT73, Falcon GS40/90 and T45). Probes were designed and concentrations were adapted in order to obtain high sensitivity and specificity. This MLPA module was validated using certified reference materials and its applicability was tested analyzing routine honey, mustard and rapeseed samples. The limit of detection was determined by analyzing a dilution series (n = 16 for each concentration) of respective transgenic DNA. After optimization, the MLPA revealed limits of detection between 10 to 50 copies of the transgene DNA/assay. The method proved to be sensitive and highly reproducible. When analyzing routine samples, results obtained applying the MLPA module were similar compared to real-time PCR.
文摘Poly (vinyl chloride)/ethylene-vinyl acetate/montmorillonite (PVC/EVA/OMMT) composites were prepared by melt blending method. Two kinds of montmorillonites were organically modified by trimethyloctadecyl ammonium and dimethyl bis (hydrogenated tallow) ammonium, respectively. The morphology and tensile properties of the resultant composites were discussed in terms of the modifier type and OMMT content. The PVC/EVA/OMMT composites have intercalated structure, which is independent of the polarity of the modifiers, while the tensile properties show strong dependence on the modifier type. The OMMT modified by polar modifier gives higher tensile ductile and strength of PVC/EVA/OMMT composites.
文摘金属离子过量使用会造成环境污染,危及人类健康。因此,对相关金属离子进行检测显得尤为重要。发光金属有机框架(Luminescent metal-organic frameworks,LMOFs)因其具备高色纯度、超高孔隙率和可调结构等优势,被视为简单有效且有前途的荧光传感材料。本文以3,5-二(4-咪唑-1-基)吡啶(Bip)为主配体,1,4-萘二甲酸(1,4-ndc)为辅助配体,Ni^(2+)为中心离子,采取溶剂热法合成了一例二维金属有机框架[Ni_(2)(Bip)_(2)(1,4-ndc)_(2)(H_(2)O)_(6)](记为CUST-756,其中CUST是Changchun University of Science and Technology缩写),并通过合成后修饰法制备了Eu^(3+)@CUST-756复合发光材料。利用XRD、FT-IR和XPS对合成的CUST-756和Eu^(3+)@CUST-756复合材料进行了基础表征。并且采用荧光光谱对样品进行了发光特性、金属离子传感性能及其机理研究。实验结果表明,Eu^(3+)@CUST-756在甲醇溶液中具备优异的发光性能和良好的稳定性,Eu^(3+)的引入使得材料可用于金属阳离子Cr^(3+)、Fe^(3+)检测。Cr^(3+)离子的检出限(limit of detection,LOD)为5.44µmol·L^(-1);Fe^(3+)离子的LOD为7.51µmol·L^(-1),与大多数LMOFs性能相近。
