The alkylation of toluene with methanol to selective formation of p-xylene has been systematically studied. ZSM-12 （MTW）/ZSM-5 co-crystalline zeolite in 40：60 proportions have been synthesized by the same molar gel...The alkylation of toluene with methanol to selective formation of p-xylene has been systematically studied. ZSM-12 （MTW）/ZSM-5 co-crystalline zeolite in 40：60 proportions have been synthesized by the same molar gel composition, but at different temperatures and periods than that of ZSM-12 and ZSM-5, separately. All the prepared samples are characterized by XRD, SEM, BET, and XRF. The activity of toluene alkylation was investigated with a mixture of toluene and methanol as a feed over the ZSM-12, ZSM-12/ZSM-5 co-crystalline, ZSM-5, and physical mixture of ZSM-12/ZSM-5. From characterization, it is observed that the ZSM-12/ZSM-5 co-crystalline material is different from that of ZSM-12, ZSM-5, and their physical mixture. Further, the ZSM-12/ZSM-5 co-crystalline zeolite produces the highest content of xylene and has better selectivity for p-xylene than ZSM-12, ZSM-5, and their physical mixture.展开更多
A ZSM-5/MOR co-crystalline zeolite was synthesized without using the template. The physico-chemical properties of the zeolite were characterized by XRD, FT-IR, SEM and TPD and then compared with the co-crystalline zeo...A ZSM-5/MOR co-crystalline zeolite was synthesized without using the template. The physico-chemical properties of the zeolite were characterized by XRD, FT-IR, SEM and TPD and then compared with the co-crystalline zeolite synthesized with a template. Analytical results indicated that they were similar in structure and composition. The influences ofpH value and Si/Al ratio on synthesis were studied. It was found that a high pH value or a low Si/AI ratio could provide better environment for mordenite （MOR） crystallization. The zeolites applied as catalysts in naphtha catalytic cracking for producing ethylene and propylene showed outstanding catalytic performance with the total yield of ethylene and propylene reaching 55 m%. The process could achieve most favorable efficiency when the catalyst contained 5 m% of MOR.展开更多
ZSM-5/β co-crystalline zeolites with different content of ZSM-5 have beensynthesized by adding different amount of ZSM-5 to the synthetic system of β zeolite with NaAlO_2,silica sol as the source of aluminum and sil...ZSM-5/β co-crystalline zeolites with different content of ZSM-5 have beensynthesized by adding different amount of ZSM-5 to the synthetic system of β zeolite with NaAlO_2,silica sol as the source of aluminum and silica, respectively, and TEA^+ as the template undercontrolled condition of the synthesis. The ZSM-5/β co-crystalline zeolite was studied by XRD, SEM,BET and NH_3-TPD. The reaction activity of toluene alkylation was investigated with a mixture oftoluene-methanol as the feedstock in a pulse micro-reactor over the ZSM-5/β co-crystalline zeolite.It is found that ZSM-5/β co-crystalline zeolite has two kinds of zeolite structure including ZSM-5and β zeolite, not in the form of a physical mixture. The pore structure of ZSM-5/βco-crystalline zeolites is different from that for β zeolite, ZSM-5 and their physical mixture. Inaddition, the peaks of both high and low temperature desorption of ammonia over the ZSM-5/βco-crystalline zeolite shift 23℃ to lower temperatures and the acid amount of its strong acid is 3%more than the physical mixture. So the ZSM-5/β co-crystalline zeolite produces the highest contentof xylene, which is 10.4% higher than the physical mixture. And the ZSM-5/β co-crystalline zeolitehas better selectivity for toluene alkylation and weaker de-methylation than β zeolite, ZSM-5 andtheir physical mixture.展开更多
Two co-crystalline compounds containing telluric acid and iodate,namely AIO_(3)·H_(6)TeO_(6)(A=Rb^(+),NH_(4)^(+)),were investigated as potential nonlinear optical materials.They crystallize into isostructural and...Two co-crystalline compounds containing telluric acid and iodate,namely AIO_(3)·H_(6)TeO_(6)(A=Rb^(+),NH_(4)^(+)),were investigated as potential nonlinear optical materials.They crystallize into isostructural and consist of isolated[IO_(3)]group and[H_(6)TeO_(6)]molecule linked by hydrogen bonds and charge interactions of Rb^(+)/NH_(4)^(+).They show phase-matching second harmonic generation responses with moderate intensity of 1.2×KDP(Rb^(+))and 1.1×KDP(NH_(4)^(+)).They also possess large optical band gaps over 4.25 eV and can be easily grown from aqueous so-lutions.The local dipole moment calculations based on the structures of AIO_(3)·H_(6)TeO_(6)(A=K+,Rb^(+),NH_(4)^(+))series of compounds indicate that the change of A+cation in their structural frame causes a slight change in the arrangement directions of[IO_(3)]and[Te(OH)_(6)]groups,and further induces their SHG responses of different in-tensities at the macroscopic level.展开更多
Endometriosis is an inflammatory oestrogen dependent disease defined by the presence of endometrial glands and stroma at extrauterine sites. The modern advance in treatment of endometriosis management is tackling the ...Endometriosis is an inflammatory oestrogen dependent disease defined by the presence of endometrial glands and stroma at extrauterine sites. The modern advance in treatment of endometriosis management is tackling the debilitating pain it causes, besides the infertility in patients desiring fertility in reproductive age group. This can be achieved by surgical or medical means, although in most cases a combination of both treatments is required. Usually, long term treatment is required in most cases. Unfortunately in most cases, pain symptoms recur between 6months and 12 months once treatment is stopped. A lot of research has gone in understanding the pathogenesis and further medical management of endometriosis besides surgery to be useful in relieving pain and use in patients desiring fertility besides hormonal treatments used earlier like hormonal contraceptives (oral, transdermal or vaginal administration), progestogens, danazol, Gonadotrophic releasing hormone agonist (GnRH), aromatase inhibitors. Newer agents like antiangiogenic drugs, phytochemical agents like resveratrol, TNF-α inhibitors, GnRH antagonists like egalogolix, statins, antiinflammatory agents like COX2 Inhibitors and PPARγ inhibitors like pioglitazone etc., with recent work of combined efficacy of telmesartan of both PPARγ partial agonism along with angiotensin 1 receptor agonism having more efficacy, role of immunomodulators like rapamycin, lipoxin 4 and pentoxyphylline, GnRH antagonists like egalogolix are still under study undergoing phase III trials although preliminary results show promising results with fewer side effects as compared to similar duration of GnRH agonist and much less BMD side effects. Increasing number of trials show the safety of SPRM’s, along with efficacy although disadvantage is suppression of fertility so cannot be used for women desiring fertility. Currently, only mifepristone and ulipristal have received FDA approval for indication in fibroid treatment, MTP and not for endometriosis as yet. The advantages and disadvantages of all the recent advances are discussed in an update in the pathophysiology as well medical treatment of endometriosis.展开更多
文摘The alkylation of toluene with methanol to selective formation of p-xylene has been systematically studied. ZSM-12 （MTW）/ZSM-5 co-crystalline zeolite in 40：60 proportions have been synthesized by the same molar gel composition, but at different temperatures and periods than that of ZSM-12 and ZSM-5, separately. All the prepared samples are characterized by XRD, SEM, BET, and XRF. The activity of toluene alkylation was investigated with a mixture of toluene and methanol as a feed over the ZSM-12, ZSM-12/ZSM-5 co-crystalline, ZSM-5, and physical mixture of ZSM-12/ZSM-5. From characterization, it is observed that the ZSM-12/ZSM-5 co-crystalline material is different from that of ZSM-12, ZSM-5, and their physical mixture. Further, the ZSM-12/ZSM-5 co-crystalline zeolite produces the highest content of xylene and has better selectivity for p-xylene than ZSM-12, ZSM-5, and their physical mixture.
基金funded by the National Basic Research Program of China (Project No. 2003CB615804) the joint funding of the National Natural Science Foundation of China and SINOPEC (NO.20736011)
文摘A ZSM-5/MOR co-crystalline zeolite was synthesized without using the template. The physico-chemical properties of the zeolite were characterized by XRD, FT-IR, SEM and TPD and then compared with the co-crystalline zeolite synthesized with a template. Analytical results indicated that they were similar in structure and composition. The influences ofpH value and Si/Al ratio on synthesis were studied. It was found that a high pH value or a low Si/AI ratio could provide better environment for mordenite （MOR） crystallization. The zeolites applied as catalysts in naphtha catalytic cracking for producing ethylene and propylene showed outstanding catalytic performance with the total yield of ethylene and propylene reaching 55 m%. The process could achieve most favorable efficiency when the catalyst contained 5 m% of MOR.
文摘ZSM-5/β co-crystalline zeolites with different content of ZSM-5 have beensynthesized by adding different amount of ZSM-5 to the synthetic system of β zeolite with NaAlO_2,silica sol as the source of aluminum and silica, respectively, and TEA^+ as the template undercontrolled condition of the synthesis. The ZSM-5/β co-crystalline zeolite was studied by XRD, SEM,BET and NH_3-TPD. The reaction activity of toluene alkylation was investigated with a mixture oftoluene-methanol as the feedstock in a pulse micro-reactor over the ZSM-5/β co-crystalline zeolite.It is found that ZSM-5/β co-crystalline zeolite has two kinds of zeolite structure including ZSM-5and β zeolite, not in the form of a physical mixture. The pore structure of ZSM-5/βco-crystalline zeolites is different from that for β zeolite, ZSM-5 and their physical mixture. Inaddition, the peaks of both high and low temperature desorption of ammonia over the ZSM-5/βco-crystalline zeolite shift 23℃ to lower temperatures and the acid amount of its strong acid is 3%more than the physical mixture. So the ZSM-5/β co-crystalline zeolite produces the highest contentof xylene, which is 10.4% higher than the physical mixture. And the ZSM-5/β co-crystalline zeolitehas better selectivity for toluene alkylation and weaker de-methylation than β zeolite, ZSM-5 andtheir physical mixture.
基金support from the National Natural Science Foundation of China(Grant No.22105046)the Natural Science Foundation of Guangxi Province(No.2022GXNSFBA035484)the Shanghai Pujiang Program(20PJ1412900).
文摘Two co-crystalline compounds containing telluric acid and iodate,namely AIO_(3)·H_(6)TeO_(6)(A=Rb^(+),NH_(4)^(+)),were investigated as potential nonlinear optical materials.They crystallize into isostructural and consist of isolated[IO_(3)]group and[H_(6)TeO_(6)]molecule linked by hydrogen bonds and charge interactions of Rb^(+)/NH_(4)^(+).They show phase-matching second harmonic generation responses with moderate intensity of 1.2×KDP(Rb^(+))and 1.1×KDP(NH_(4)^(+)).They also possess large optical band gaps over 4.25 eV and can be easily grown from aqueous so-lutions.The local dipole moment calculations based on the structures of AIO_(3)·H_(6)TeO_(6)(A=K+,Rb^(+),NH_(4)^(+))series of compounds indicate that the change of A+cation in their structural frame causes a slight change in the arrangement directions of[IO_(3)]and[Te(OH)_(6)]groups,and further induces their SHG responses of different in-tensities at the macroscopic level.
文摘Endometriosis is an inflammatory oestrogen dependent disease defined by the presence of endometrial glands and stroma at extrauterine sites. The modern advance in treatment of endometriosis management is tackling the debilitating pain it causes, besides the infertility in patients desiring fertility in reproductive age group. This can be achieved by surgical or medical means, although in most cases a combination of both treatments is required. Usually, long term treatment is required in most cases. Unfortunately in most cases, pain symptoms recur between 6months and 12 months once treatment is stopped. A lot of research has gone in understanding the pathogenesis and further medical management of endometriosis besides surgery to be useful in relieving pain and use in patients desiring fertility besides hormonal treatments used earlier like hormonal contraceptives (oral, transdermal or vaginal administration), progestogens, danazol, Gonadotrophic releasing hormone agonist (GnRH), aromatase inhibitors. Newer agents like antiangiogenic drugs, phytochemical agents like resveratrol, TNF-α inhibitors, GnRH antagonists like egalogolix, statins, antiinflammatory agents like COX2 Inhibitors and PPARγ inhibitors like pioglitazone etc., with recent work of combined efficacy of telmesartan of both PPARγ partial agonism along with angiotensin 1 receptor agonism having more efficacy, role of immunomodulators like rapamycin, lipoxin 4 and pentoxyphylline, GnRH antagonists like egalogolix are still under study undergoing phase III trials although preliminary results show promising results with fewer side effects as compared to similar duration of GnRH agonist and much less BMD side effects. Increasing number of trials show the safety of SPRM’s, along with efficacy although disadvantage is suppression of fertility so cannot be used for women desiring fertility. Currently, only mifepristone and ulipristal have received FDA approval for indication in fibroid treatment, MTP and not for endometriosis as yet. The advantages and disadvantages of all the recent advances are discussed in an update in the pathophysiology as well medical treatment of endometriosis.
