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用于H_(2)PO_(4)^(-)检测的比率型荧光探针合成及性能研究
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作者 郭昌晟 陈君霞 +3 位作者 刘忆茹 卢钰盛 董智云 席福贵 《化学试剂》 CAS 2024年第6期33-38,共6页
设计合成了一种基于吖啶-苯并咪唑鎓的大环受体ABIM,可作为H_(2)PO_(4)^(-)的荧光比率传感器。借助荧光光谱研究了受体ABIM对H_(2)PO_(4)^(-)的选择性识别,在大环受体ABIM的乙腈溶液中加入H_(2)PO_(4)^(-)后,在426 nm处荧光发射明显“... 设计合成了一种基于吖啶-苯并咪唑鎓的大环受体ABIM,可作为H_(2)PO_(4)^(-)的荧光比率传感器。借助荧光光谱研究了受体ABIM对H_(2)PO_(4)^(-)的选择性识别,在大环受体ABIM的乙腈溶液中加入H_(2)PO_(4)^(-)后,在426 nm处荧光发射明显“关闭”,506 nm处荧光发射明显“打开”,溶液荧光颜色由蓝色变为蓝绿色,新的荧光发射峰可能是由于H_(2)PO_(4)^(-)诱导两个受体中的吖啶环之间形成Excimer产生的。ABIM与H_(2)PO_(4)^(-)以1∶1的化学计量比结合,结合常数为(7.13±0.48)×10^(6)L/mol,检出限为2.38×10-7 mol/L,最佳响应时间为2 min。回收实验表明,ABIM可应用于样品中H_(2)PO_(4)^(-)的检测。 展开更多
关键词 吖啶 苯并咪唑鎓 h 2po-4 大环 比率型荧光探针
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C2H2/CH4燃烧特性实验及反应动力学研究
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作者 刘宇 罗蒙蒙 +3 位作者 田富超 谷午 王凯 梁运涛 《燃烧科学与技术》 CAS CSCD 北大核心 2024年第5期473-480,共8页
随着煤矿开采深度的增加,极易出现瓦斯与煤自燃灾害交织共生现象,增大灾害风险.为阐明煤与瓦斯共生灾害发生时的火焰传播特性,有必要开展煤自燃气体掺混对瓦斯燃烧特性的影响研究.乙炔气体(C_(2)H_(2))是煤高温氧化时产生的主要气体之一... 随着煤矿开采深度的增加,极易出现瓦斯与煤自燃灾害交织共生现象,增大灾害风险.为阐明煤与瓦斯共生灾害发生时的火焰传播特性,有必要开展煤自燃气体掺混对瓦斯燃烧特性的影响研究.乙炔气体(C_(2)H_(2))是煤高温氧化时产生的主要气体之一,甲烷(CH_(4))是瓦斯的主要成分,本文研究了0~2%体积分数C_(2)H_(2)掺混对CH_(4)层流燃烧速度的影响规律.结果表明,随着C_(2)H_(2)体积分数的增加,C_(2)H_(2)/CH_(4)混合燃料层流燃烧速度增大.层流燃烧速度受质热扩散作用、动力学和热力学效应的综合影响,当C_(2)H_(2)体积分数增加至2%时,混合燃料的(αLe)^(1/2)、T_(ad)分别增加了1.54%、2.98%,T_(a)减少了26.93%,说明动力学效应是C_(2)H_(2)促进CH_(4)层流燃烧速度增加的主导因素.由活性自由基体积分数分析可知,随着C_(2)H_(2)体积分数的增加,H、O、OH和CH_(3)等活性自由基体积分数均出现增加趋势,从而促进了CH_(4)的燃烧. 展开更多
关键词 C2h2/Ch4混合燃料 层流燃烧速度 动力学效应 敏感性分析 活性自由基
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Bi2O3/CaFe2O4Z型异质结材料光催化降解氧氟沙星
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作者 叶红勇 杜佳 +2 位作者 杨培渊 王明辉 左广玲 《南阳理工学院学报》 2024年第4期114-119,共6页
利用溶剂热法合成了Z型异质结Bi2O3/CaFe2O4复合催化剂。采用多种表征手段对其晶体结构、形貌和性能进行了表征,并以氧氟沙星(OFX)为降解对象考察了Bi2O3/CaFe2O4复合催化剂的光催化活性。结果表明:Bi2O3负载在CaFe2O4表面,构建了Z型异... 利用溶剂热法合成了Z型异质结Bi2O3/CaFe2O4复合催化剂。采用多种表征手段对其晶体结构、形貌和性能进行了表征,并以氧氟沙星(OFX)为降解对象考察了Bi2O3/CaFe2O4复合催化剂的光催化活性。结果表明:Bi2O3负载在CaFe2O4表面,构建了Z型异质结构,这种结构能加速无效光生载流子的复合,促进有效光生载流子的分离,提升Bi2O3/CaFe2O4复合催化剂的可见光催化活性;Bi2O3/CaFe2O4复合催化剂对OFX的降解效果明显优于纯Bi2O3和CaFe2O4。在Bi2O3负载量为5%时,Bi2O3/CaFe2O4对OFX的降解效果最好,降解率可达78.7%,经过4次循环,依然可达到62.5%,说明其理化性能稳定,能够长期稳定循环使用。 展开更多
关键词 Ag3po4 caFe2O4 光催化 氧氟沙星
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CF_(3)H和CO_(2)抑制CH_(4)爆炸实验研究
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作者 白洁琪 白纪成 +3 位作者 梁运涛 王琳 宋双林 田富超 《煤矿安全》 CAS 北大核心 2024年第5期122-130,共9页
为对比研究CF_(3)H和CO_(2)对CH_(4)爆炸特性的抑制效果,使用20 L球型爆炸压力测试系统分别测量对比2种抑制剂对CH_(4)在空气中爆炸极限范围的影响;研究了不同体积分数的2种抑制剂对CH_(4)体积分数9.5%爆炸压力参数影响,分析了2种抑制... 为对比研究CF_(3)H和CO_(2)对CH_(4)爆炸特性的抑制效果,使用20 L球型爆炸压力测试系统分别测量对比2种抑制剂对CH_(4)在空气中爆炸极限范围的影响;研究了不同体积分数的2种抑制剂对CH_(4)体积分数9.5%爆炸压力参数影响,分析了2种抑制剂针对CH_(4)在空气中爆炸的爆炸三角形。结果表明:CF_(3)H和CO_(2)均能缩小CH_(4)在空气中的爆炸极限范围,抑制CH_(4)至失爆所需CF_(3)H和CO_(2)体积分数分别为12.5%和21.5%;对比抑制CH_(4)体积分数9.5%的爆炸参数(反应峰值压力和升压速率),10%CF_(3)H的抑爆能力是等量CO_(2)的1.95倍和1.3倍,但是低于体积分数4%的CF_(3)H单独使用时对CH_(4)爆炸存在微弱的促进作用;2种抑制剂作用下的爆炸三角形显示CF_(3)H抑制下的可爆区域面积小于CO_(2),安全区域内CF_(3)H的窒息比是CO_(2)的57%。 展开更多
关键词 Ch_(4)爆炸 瓦斯爆炸 CO_(2) CF_(3)h 爆炸极限 抑爆剂 爆炸压力 爆炸三角形
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6-氟-4-羟基-3-氧代-3,4-二氢喹喔啉-1(2 H)-羧酸叔丁酯的合成、晶体结构及抗肿瘤活性研究
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作者 毛云虹 赵春深 《人工晶体学报》 CAS 北大核心 2024年第7期1257-1268,共12页
喹喔啉类化合物由于具有显著的生物活性而被广泛应用于医药、化工领域,特别是抗癌药物研发领域。本文通过四步反应法首次合成了6-氟-4-羟基-3-氧代-3,4-二氢喹喔啉-1(2 H)-羧酸叔丁酯,经溶液结晶法获得其单晶体。晶体学分析表明,该化合... 喹喔啉类化合物由于具有显著的生物活性而被广泛应用于医药、化工领域,特别是抗癌药物研发领域。本文通过四步反应法首次合成了6-氟-4-羟基-3-氧代-3,4-二氢喹喔啉-1(2 H)-羧酸叔丁酯,经溶液结晶法获得其单晶体。晶体学分析表明,该化合物属单斜晶系,空间群C2/c,晶胞常数a=1.28663(10)nm,b=2.25249(17)nm,c=1.01564(7)nm,Z=8,ρ_(c)=1.359 g·cm^(-3),R=0.0538,R_(w)=0.1406。在B3LYP/6-311+G(2d,p)模式下使用密度泛函理论(DFT)计算了该化合物的最佳结构,与X射线单晶衍射确定的晶体结构基本一致。抗肿瘤活性研究表明其有良好的抗肿瘤作用。此外,通过DFT计算了分子的静电势和前沿分子轨道。 展开更多
关键词 喹喔啉类化合物 6-氟-4-羟基-3-氧代-3 4-二氢喹喔啉-1(2 h)-羧酸叔丁酯 晶体结构 密度泛函理论 合成 抗肿瘤活性
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β-细辛醚通过抑制TRPV4的表达缓解谷氨酸诱导的Ca^(2+)超载
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作者 蒋兰兰 陈向涛 +3 位作者 储涛 蔡静雯 刘浩宇 尹兰香 《合肥工业大学学报(自然科学版)》 CAS 北大核心 2024年第2期263-269,共7页
谷氨酸处理会导致Ca^(2+)超载,瞬时受体电位香草素受体4(transient receptor potential vanilloid 4,TRPV4)在其中的作用及可能机制尚不清楚。β-细辛醚能快速透过血脑屏障,对兴奋性毒性具有较强的神经保护作用。文章以高分化的PC12细... 谷氨酸处理会导致Ca^(2+)超载,瞬时受体电位香草素受体4(transient receptor potential vanilloid 4,TRPV4)在其中的作用及可能机制尚不清楚。β-细辛醚能快速透过血脑屏障,对兴奋性毒性具有较强的神经保护作用。文章以高分化的PC12细胞为研究对象,探究β-细辛醚(15、30、60μmol/L)预处理4 h,40 mmol/L谷氨酸处理实时记录对PC12细胞Ca^(2+)浓度的影响,采用钙成像技术检测Ca^(2+)浓度的变化;采用实时荧光定量聚合酶链式反应(polymerase chain reaction,PCR)、Western Blot及免疫荧光技术检测TRPV4的mRNA和蛋白的表达;采用Lipofectiamine 2000脂质体实验转染TRPV4-siRNA和pEX-3-TRPV4,观察沉默和过表达TRPV4对谷氨酸引起Ca^(2+)超载的影响。结果表明:与正常对照组相比,谷氨酸处理5 min可诱导Ca^(2+)超载,显著提高TRPV4的mRNA和蛋白的表达;与模型组相比,β-细辛醚能够剂量依赖性地降低谷氨酸诱导的Ca^(2+)超载和TRPV4的表达;沉默TRPV4抑制细胞Ca^(2+)超载;过表达TRPV4则部分逆转β-细辛醚抑制谷氨酸诱导的Ca^(2+)超载。该研究证明,谷氨酸处理PC12细胞5 min通过上调TRPV4的表达诱导Ca^(2+)超载,β-细辛醚作为TRPV4的拮抗剂,是一种潜在的抑制兴奋性毒性的药物。 展开更多
关键词 谷氨酸 兴奋性毒性 Β-细辛醚 瞬时受体电位香草素受体4(TRPV4) ca^(2+)超载
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miR-361介导PI3K/Akt/Ca^(2+)通路对大鼠肥大细胞增殖情况及组胺与IL-4表达水平的影响
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作者 蒙金秋 简华慧 +7 位作者 蒙安定 陈丽 林淼鑫 周伟杰 黄爱良 罗慧秋 林峻慰 唐秀生 《医药前沿》 2024年第10期1-3,7,共4页
目的:探讨miR-361介导PI3K/AKt/Ca^(2+)通路对活化大鼠肥大细胞增殖情况及组胺与白细胞介素-4(IL-4)表达水平的影响。方法:将大鼠肥大细胞(RBL-2H3细胞)分为miR-361过表达组、miR-361抑制组、miR-361对照组和正常对照组,miR-361过表达组... 目的:探讨miR-361介导PI3K/AKt/Ca^(2+)通路对活化大鼠肥大细胞增殖情况及组胺与白细胞介素-4(IL-4)表达水平的影响。方法:将大鼠肥大细胞(RBL-2H3细胞)分为miR-361过表达组、miR-361抑制组、miR-361对照组和正常对照组,miR-361过表达组、miR-361抑制组、miR-361对照组细胞分别转染miR-361过表达、miR-361抑制及miR-361无义序列寡核苷酸片段,测定并比较各组细胞miR-361 mRNA、组胺、IL-4及PI3K/AKt/Ca^(2+)通路相关蛋白水平。结果:miR-361过表达组细胞miR-361 mRNA相对表达水平高于miR-361抑制组、miR-361对照组及正常对照组,差异均有统计学意义(P<0.05)。CCK-8法检测结果显示,miR-361过表达组24、48、72 h细胞增值率均低于miR-361抑制组、miR-361对照组及正常对照组,差异均有统计学意义(P<0.05)。ELISA法检测结果显示,miR-361过表达组细胞组胺和IL-4水平的表达水平低于miR-361抑制组、miR-361对照组及正常对照组,差异均有统计学意义(P<0.05)。Western印迹法检测结果显示,miR-361过表达组细胞p-AKT、AKT、p-PI3K、PI3K蛋白表达水平均高于miR-361抑制组、miR-361对照组及正常对照组,差异均有统计学意义(P<0.05)。结论:miR-361过表达可抑制大鼠肥大细胞的增殖,降低组胺与IL-4的表达水平,其作用机制可能与其能够提高PI3K/AKt/Ca^(2+)通路活性有关。 展开更多
关键词 miR-361 肥大细胞 组胺 白细胞介素-4 PI3K/AKt/ca^(2+)通路
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微生物合成4-羟基-2,5-二甲基-3(2H)-呋喃酮的研究进展
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作者 宋金鹏 仲秀芳 +3 位作者 李学思 曹振华 彭新辉 范光森 《中国酿造》 CAS 北大核心 2024年第4期14-21,共8页
4-羟基-2,5-二甲基-3(2H)-呋喃酮(HDMF)是一种具有焦糖味的安全优良的甜味香料和增香剂,其阈值低、香势好且特征性强,被广泛应用于食品、烟草等产品中,市场需求量大,尤其是天然来源的HDMF受到人们更多的青睐。然而,天然来源的HDMF产量较... 4-羟基-2,5-二甲基-3(2H)-呋喃酮(HDMF)是一种具有焦糖味的安全优良的甜味香料和增香剂,其阈值低、香势好且特征性强,被广泛应用于食品、烟草等产品中,市场需求量大,尤其是天然来源的HDMF受到人们更多的青睐。然而,天然来源的HDMF产量较低,尚不能满足当前市场的需求。该文从其应用、检测、生产方法、合成HDMF微生物的种类、微生物合成HDMF的机制与关键酶及其发酵培养影响因素进行简述,重点侧重于已报道的具有合成HDMF的微生物种类、微生物合成HDMF的内在机制及其影响其发酵的培养因素,旨在为后续筛选、改造获得优良高产HDMF微生物菌株,并优化微生物发酵条件实现生物法高效制备天然HDMF提供参考。 展开更多
关键词 4-羟基-2 5-二甲基-3(2h)-呋喃酮 微生物合成 合成机制 培养条件
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Preparation of Na_(3)V_(2)(PO_(4))_(3) Cathode Materials by Hydrothermal Assisted Sol-Gel Method for Sodium -Ion Batteries
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作者 Jiayu LI 《Research and Application of Materials Science》 2023年第1期5-10,共6页
Na_(3)V_(2)(PO_(4))_(3)(NVP)cathode material of the sodium ion battery(1 C=117 mAh g-1)has a NASICON-type structure,which not only facilitates the rapid migration of sodium ions,but also has a small volume deformation... Na_(3)V_(2)(PO_(4))_(3)(NVP)cathode material of the sodium ion battery(1 C=117 mAh g-1)has a NASICON-type structure,which not only facilitates the rapid migration of sodium ions,but also has a small volume deformation during sodium ion de-intercalation and the main frame mechanism remains unchanged,and thus is seen as an energy storage material for a wide range of applications,but has a limited electronic conductivity due to its structure.In this paper,NVP cathode materials with finer primary particles are successfully prepared using a simple hydrothermal treatment-assisted sol-gel method.The increased pore size of the NVP materials prepared under the hydrothermal process allows for more active sites and more effective resistance to the volume deformation of sodium ions during insertion/extraction processes,effectively facilitating the diffusion of ions and electrons.The Na_(3)V_(2)(PO_(4))_(3) material obtained by the optimized process exhibited good crystallinity in XRD characterization,as well as superior electrochemical properties in a series of electrochemical tests.A specific capacitance of 106.3 mAh g^(-1) at 0.2 C is demonstrated,compared to 96.5 mAh g^(-1) for Na_(3)V_(2)(PO_(4))_(3) without hydrothermal treatment,and cycling performance is also improved with 93%capacity retention.The calculated sodium ion diffusion coefficient(DNa=5.68×10^(-14))obtained after EIS curve fitting of the improved sample illustrates that the pore structure is beneficial to the performance of the Na_(3)V_(2)(PO_(4))_(3)cathode material. 展开更多
关键词 Na3V2(po4)3 hydrothermal assisted Sodium ion poROSITY
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转录因子HNF1A、HNF4A和FOXA2调节肝细胞蛋白质N-糖基化
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作者 Vedrana Vicic Bockor Nika Foglar +7 位作者 Goran Josipovic Marija Klasic Ana Vujic Branimir Plavsa Toma Keser Samira Smajlovic Aleksandar Vojta Vlatka Zoldos 《Engineering》 SCIE EI CAS CSCD 2024年第1期57-68,共12页
Hepatocyte nuclear factor 1 alpha(HNF1A),hepatocyte nuclear factor 4 alpha(HNF4A),and forkhead box protein A2(FOXA2)are key transcription factors that regulate a complex gene network in the liver,cre-ating a regulator... Hepatocyte nuclear factor 1 alpha(HNF1A),hepatocyte nuclear factor 4 alpha(HNF4A),and forkhead box protein A2(FOXA2)are key transcription factors that regulate a complex gene network in the liver,cre-ating a regulatory transcriptional loop.The Encode and ChIP-Atlas databases identify the recognition sites of these transcription factors in many glycosyltransferase genes.Our in silico analysis of HNF1A,HNF4A.and FOXA2 binding to the ten candidate glyco-genes studied in this work confirms a significant enrich-ment of these transcription factors specifically in the liver.Our previous studies identified HNF1A as a master regulator of fucosylation,glycan branching,and galactosylation of plasma glycoproteins.Here,we aimed to functionally validate the role of the three transcription factors on downstream glyco-gene transcriptional expression and the possible effect on glycan phenotype.We used the state-of-the-art clus-tered regularly interspaced short palindromic repeats/dead Cas9(CRISPR/dCas9)molecular tool for the downregulation of the HNF1A,HNF4A,and FOXA2 genes in HepG2 cells-a human liver cancer cell line.The results show that the downregulation of all three genes individually and in pairs affects the transcrip-tional activity of many glyco-genes,although downregulation of glyco-genes was not always followed by an unambiguous change in the corresponding glycan structures.The effect is better seen as an overall change in the total HepG2 N-glycome,primarily due to the extension of biantennary glycans.We propose an alternative way to evaluate the N-glycome composition via estimating the overall complexity of the glycome by quantifying the number of monomers in each glycan structure.We also propose a model showing feedback loops with the mutual activation of HNF1A-FOXA2 and HNF4A-FOXA2 affecting glyco-genes and protein glycosylation in HepG2 cells. 展开更多
关键词 Clustered regularly interspaced short palindromic repeats/dead cas9(CRISPR/dcas9) EPIGENETICS hepatocyte nuclear factor 1 alpha(hNF1A) hepatocyte nuclear factor 4 alpha(hNF4A) Forkhead box protein A2(FOXA2) N-GLYCOSYLATION hepG2 cells
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可见光下g-C_(3)N_(4)催化诱导C(sp^(2))-H芳基化喹喔啉-2(1H)-酮
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作者 赵能选 李兰杰 +1 位作者 徐宏烈 王涛 《化学研究与应用》 CAS 北大核心 2024年第2期299-305,共7页
建立了一种有效且简单的可见光诱导的g-C_(3)N_(4)催化的喹喔啉-2(1H)-酮的芳基化反应。该反应以乙腈为溶剂,K_(2)S_(2)O_(8)为氧化剂,具有反应条件温和、环境友好和官能团耐受性好等优点。该策略提供了一种简单的操作方法,可以获得各... 建立了一种有效且简单的可见光诱导的g-C_(3)N_(4)催化的喹喔啉-2(1H)-酮的芳基化反应。该反应以乙腈为溶剂,K_(2)S_(2)O_(8)为氧化剂,具有反应条件温和、环境友好和官能团耐受性好等优点。该策略提供了一种简单的操作方法,可以获得各种中等到良好产率的3-苯基喹喔啉-2(1H)-酮化合物,最高产率达77%。 展开更多
关键词 光催化 3-苯基喹喔啉-2(1h)-酮 g-C_(3)N_(4)
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New 4-imino-4H-Chromeno[2,3-d]Pyrimidin-3(5H)-Amine: Synthesis, Cytotoxic Effects on Tumoral Cell Lines and in Silico ADMET Properties
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作者 Marwa Dhiabi Sirine Karoui +7 位作者 Mehdi Fakhfakh Souhir Abid Emmanuelle Limanton Rémy Le Guével Thierry Charlier Ludovic Paquin Jean-Pierre Bazureau Houcine Ammar 《International Journal of Organic Chemistry》 2024年第3期107-122,共16页
The synthesis of new 4-imino-4H-chromeno[2,3-d]pyrimidin-3(5H)-amine in four steps including one step under microwave dielectric heating is reported. The structural identity of the synthesized compounds was establishe... The synthesis of new 4-imino-4H-chromeno[2,3-d]pyrimidin-3(5H)-amine in four steps including one step under microwave dielectric heating is reported. The structural identity of the synthesized compounds was established according to their spectroscopic analysis, such as FT-IR, NMR and mass spectroscopy. These new compounds were tested for their antiproliferative activities on seven representative human tumoral cell lines (Huh7 D12, Caco2, MDA-MB231, MDA-MB468, HCT116, PC3 and MCF7) and also on fibroblasts. Among them, only the compounds 6c showed micromolar cytotoxic activity on tumor cell lines (1.8 50 50 > 25 μM). Finally, in silico ADMET studies ware performed to investigate the possibility of using of the identified compound 6c as potential anti-tumor compound. 展开更多
关键词 2-Amino-4h-Chromene 4h-Chromeno[2 3-d]Pyrimidin-3(5h)-Amine Microwave Irradiation Tumoral Cell Line in Silico ADMET
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不同温度下三元体系NH_(4)H_(2)PO4-NH_(4)Cl-H_(2)O的相平衡测定与关联
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作者 孟泽宇 朱静 +2 位作者 陈丽琼 张杰 李天祥 《化学工业与工程》 CAS CSCD 北大核心 2023年第1期127-137,共11页
采用等温溶解平衡法研究了三元体系NH_(4)H_(2)PO4-NH_(4)Cl-H_(2)O在303.15、323.15、333.15和343.15 K下的固液相平衡关系。通过湿渣法与X射线衍射法相结合鉴定了平衡固相组成,绘制了该三元体系在不同温度下的平衡相图。结果表明:该... 采用等温溶解平衡法研究了三元体系NH_(4)H_(2)PO4-NH_(4)Cl-H_(2)O在303.15、323.15、333.15和343.15 K下的固液相平衡关系。通过湿渣法与X射线衍射法相结合鉴定了平衡固相组成,绘制了该三元体系在不同温度下的平衡相图。结果表明:该体系在各温度下的相图中都包含1个共饱和点,2条单变量曲线,3个结晶区。采用Pitzer-Harvie-Weare模型对实验数据关联计算,计算值与实验值的平均相对偏差(RAD)和均方根差(RMSD)最大分别为3.18和0.98,实验值与计算值吻合。实验结果可为该体系的共结晶研究提供必要的热力学数据。 展开更多
关键词 固液相平衡 Pitzer-harvie-Weare模型 Nh_(4)h_(2)po4 Nh_(4)Cl
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Effects of H_3PO_4 and Ca(H_2PO_4)_2 on mechanical properties and water resistance of thermally decomposed magnesium oxychloride cement 被引量:14
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作者 文静 余红发 +3 位作者 李颖 吴成友 董金美 郑利娜 《Journal of Central South University》 SCIE EI CAS 2013年第12期3729-3735,共7页
The effects of H3PO4 and Ca(H2PO4)2 on compressive strength, water resistance, hydration process of thermally decomposed magnesium oxychloride cement (TDMOC) pastes were studied. The mineral composition, hydration... The effects of H3PO4 and Ca(H2PO4)2 on compressive strength, water resistance, hydration process of thermally decomposed magnesium oxychloride cement (TDMOC) pastes were studied. The mineral composition, hydration products and hydration heat release were analyzed by XRD, FT-IR, SEM and TAM air isothermal calorimeter, etc. After being modified by H3PO4 and Ca(HzPO4)2, the properties of the TDMOC are improved obviously. The compressive strength increases from 14.8 MPa to 48.1 MPa and 37.1 MPa, respectively. The strength retention coefficient (Kn) increases from 0.38 to 0.99 and 0.94, respectively. The 24 h hydration heat release decreases by 10% and 4% and the time of hydration peak appearing is delayed from 1 h to about 10 h. The XRD, FT-IR and SEM results show that the main composition is 5Mg(OH)z'MgCIz'8H20 in the modified TDMOC pastes. The possible mechanism for the strength enhancement was discussed. The purposes are to extend the potential applications of the salt lake magnesium resources and to improve the mechanical properties of TDMOC. 展开更多
关键词 thermally decomposed magnesium oxychloride cement (TDMOC) h3po4 ca(h2po4)2 STRENGTh water resistance hydration heat
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CaO+KH_2PO_4在高氟地下水水质处理中的应用 被引量:4
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作者 尹国勋 郑明凯 朱利霞 《水资源保护》 CAS 北大核心 2007年第4期82-84,共3页
采用CaO+KH2PO4工艺对焦作市高氟区地下水进行降氟处理。通过实验研究,分析了该工艺的除氟机理和最佳设计参数。实验结果表明,CaO+KH2PO4工艺应用于当地高氟水的水质处理中,CaO/KH2PO4=0.4/0.625为最佳的药量配比,即针对氟质量浓度为1.7... 采用CaO+KH2PO4工艺对焦作市高氟区地下水进行降氟处理。通过实验研究,分析了该工艺的除氟机理和最佳设计参数。实验结果表明,CaO+KH2PO4工艺应用于当地高氟水的水质处理中,CaO/KH2PO4=0.4/0.625为最佳的药量配比,即针对氟质量浓度为1.75 mg/L的地下水,每吨水最佳投药量为:CaO/KH2PO4=0.8 kg/1.25 kg。 展开更多
关键词 地下水 水质处理 高氟区 caO Kh2po4
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Influence of pH value and chelating reagent on performance of Li_3V_2(PO_4)3/C cathode material 被引量:2
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作者 向伟 唐艳 +4 位作者 王雁英 钟本和 方为茂 刘恒 郭孝东 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2013年第5期1395-1402,共8页
The Li3V2(PO4)3/C composite cathode material was synthesized via sol-gel method using three different chelating agents (citric acid, salicylic acid and polyacrylic acid) at pH value of 3 or 7. The crystal structur... The Li3V2(PO4)3/C composite cathode material was synthesized via sol-gel method using three different chelating agents (citric acid, salicylic acid and polyacrylic acid) at pH value of 3 or 7. The crystal structure, morphology, specific surface area and electrochemical performance of the prepared samples were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and galvanostatic charge/discharge test. The results show that the effects of pH value on the performance of the prepared materials are greatly related to the chelating agents. With salicylic acid or polyacrylic acid as the chelating reagent, the structure, morphology and electrochemical performance of the samples are greatly influenced by the pH values. However, the structure of the materials with citric acid as the chelating agent does not change as pH value changes, and the materials own uniform particle size distribution and good electrochemical performance. It delivers an initial discharge capacity of 113.58 mA·h/g at 10C, remaining as high as 108.48 mA·h/g after 900 cycles, with a capacity retention of 95.51%. 展开更多
关键词 Li3V2po4)3 cathode material sol-gel method chelating agents ph value
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风化煤腐植酸与Ca(H_2PO_4)_2相互作用机理的研究 被引量:4
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作者 李丽 武丽萍 成绍鑫 《燃料化学学报》 EI CAS CSCD 北大核心 2000年第4期314-319,共6页
采用化学法及IR、XRD、XPS等综合解析手段 ,研究了风化煤腐植酸 (HA)、腐植酸钾 (HA -K)与磷酸一钙[Ca(H2 PO4 ) 2 ]之间的反应特征 ,探讨了二者的反应机理。结果表明 ,磷酸一钙与HA基本未发生反应 ,而与HA -K反应后生成KH2 PO4 以及HA... 采用化学法及IR、XRD、XPS等综合解析手段 ,研究了风化煤腐植酸 (HA)、腐植酸钾 (HA -K)与磷酸一钙[Ca(H2 PO4 ) 2 ]之间的反应特征 ,探讨了二者的反应机理。结果表明 ,磷酸一钙与HA基本未发生反应 ,而与HA -K反应后生成KH2 PO4 以及HA与CaHPO4 的有机 -无机复合物 ,但该复合物不太稳定 ,在水溶液中易水解生成腐植酸钙 (HA -Ca)和Ca(H2 PO4 ) 2 。本研究将为研制以煤炭腐植酸为基础的长效、缓效磷肥提供理论依据。 展开更多
关键词 风化煤 腐植酸 磷酸一钙 磷酸盐复合物 磷肥
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Effect of Mn-doping on performance of Li_3V_2(PO_4)_3/C cathode material for lithium ion batteries 被引量:3
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作者 翟静 赵敏寿 王丹丹 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2011年第3期523-528,共6页
Li3V2-2/3xMnx(PO4)3(0≤x≤0.12) powders were synthesized by sol-gel method. The effect of Mn2+-doping on the structure and electrochemical performances of Li3V2(PO4)3/C was characterized by XRD, SEM, XPS, galva... Li3V2-2/3xMnx(PO4)3(0≤x≤0.12) powders were synthesized by sol-gel method. The effect of Mn2+-doping on the structure and electrochemical performances of Li3V2(PO4)3/C was characterized by XRD, SEM, XPS, galvanostatic charge /discharge and electrochemical impedance spectroscopy(EIS). The XRD study shows that a small amount of Mn2+-doped does not alter the structure of Li3V2(PO4)3/C materials, and all Mn2+-doped samples are of pure single phase with a monoclinic structure (space group P21/n). The XPS analysis indicates that valences state of V and Mn are +3 and +2 in Li3V1.94Mn0.09(PO4)3/C, respectively, and the citric acid in raw materials was decomposed into carbon during calcination, and residual carbon exists in Li3V1.94Mn0.09(PO4)/C. The results of electrochemical measurements show that Mn2+-doping can improve the cyclic stability and rate performance of these cathode materials. The Li3V1.94Mn0.09(PO4)3/C cathode material shows the best cyclic stability and rate performance. For example, at the discharge current density of 40 mA/g, after 100 cycles, the discharge capacity of Li3V1.94Mn0.09(PO4)3/C declines from initial 158.8 mA·h/g to 120.5 mA·h/g with a capacity retention of 75.9%; however, that of the Mn-undoed sample declines from 164.2 mA·h/g to 72.6 mA·h/g with a capacity retention of 44.2%. When the discharge current is increased up to 1C, the intial discharge capacity of Li3V1.94Mn0.09(PO4)3/C still reaches 146.4 mA·h/g, and the discharge capacity maintains at 107.5 mA·h/g after 100 cycles. The EIS measurement indicates that Mn2+-doping with a appropriate amount of Mn2+ decreases the charge transfer resistance, which is favorable for the insertion/extraction of Li+. 展开更多
关键词 lithium ion batteries cathode materials Li3V2po4)3 SOL-GEL doping
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The Initial Reactions of HaPO4 and NaH2PO4 Supported on Silica: A Joint Experimental and Theoretical Study 被引量:1
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作者 张志强 屈一新 +1 位作者 王水 王际东 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2009年第3期315-321,340,共8页
A combination of X-ray powder diffraction, thermogravimetric analysis, diffuse reflection infrared Fourier transform, and ^31p magic-angle spinning nuclear magnetic resonance techniques with density function computati... A combination of X-ray powder diffraction, thermogravimetric analysis, diffuse reflection infrared Fourier transform, and ^31p magic-angle spinning nuclear magnetic resonance techniques with density function computation was used to elucidate the products and mecha- nism of the reactions among silica, H3PO4, and NaH2PO4 during the preparation of silica supported H3PO4 and NaH2PO4 catalysts. The spectral test results indicate that besides polyphosphoric acid, silicon phosphates on silica supported H3PO4 are also formed. On silica supported NaH2PO4 only sodium polyphosphates are present. Density functional theory (DFT) simulations indicate that in the initial stage, reaction of H3PO4 with silanol groups on the silica support is more favorable than that between H3PO4 itself. In contrast, dimerization and trimerization of NaH2PO4 are predicted to be the predominant initial reactions for the silica supported NaH2PO4 catalyst. 展开更多
关键词 h3po4 Nah2po4 CONDENSATION SILIca DFT
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Electrochemical performance of LiFePO_(4)-Li_(3)V_(2)(PO_4)_3 composite material prepared by solid-hydrothermal method 被引量:1
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作者 郭孝东 钟本和 +3 位作者 刘恒 宋杨 文嘉杰 唐艳 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2011年第8期1761-1766,共6页
LiFePO4-Li3V2(PO4)3 composites were synthesized by solid-hydrothermal method and by ball milling,respectively.The electrochemical performance of the solid-hydrothermally obtained materials(C-LFVP) was significantl... LiFePO4-Li3V2(PO4)3 composites were synthesized by solid-hydrothermal method and by ball milling,respectively.The electrochemical performance of the solid-hydrothermally obtained materials(C-LFVP) was significantly improved compared with LiFePO4(LFP) and Li3V2(PO4)3(LVP),and it was also much better than that of the ball-milled LiFePO4-Li3V2(PO4)3(P-LFVP).C-LFVP and P-LFVP both had four REDOX peaks(voltage plateaus),which coincided with that of LFP and LVP.Some new trace substances were found in C-LFVP which had more perfect morphology,this was responsible for the better electrochemical performance of C-LFVP than P-LFVP. 展开更多
关键词 LIFEpo4 Li3V2po4)3 composite materials solid-hydrothermal
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