Visible light photocatalytic redox catalysis has become a powerful tool for organic synthesis, and has opened up new avenues for the formation of challenging structural skeletons and chemical bonds. In this respect, d...Visible light photocatalytic redox catalysis has become a powerful tool for organic synthesis, and has opened up new avenues for the formation of challenging structural skeletons and chemical bonds. In this respect, diverse photocatalysts, including ruthenium(II), iridium(Ⅲ), and organic dyes, have been most commonly applied.展开更多
A new kind of open type breakwaters was proposed based on the concept of wave energy conversion. The excellent feature of the structure is that it can absorb and utilize the wave energy to dissipate waves. The effects...A new kind of open type breakwaters was proposed based on the concept of wave energy conversion. The excellent feature of the structure is that it can absorb and utilize the wave energy to dissipate waves. The effects of some factors, such as the configuration insides, the geometrical parameters and the relative width (the ratio of the width to the wave length), on the performance of the breakwater were discussed based on a series of regular wave tests in the wave flume. The hydrodynamic characteristics of the new open type breakwater were analyzed in detail, and the structure was optimized to improve the performance of the breakwater to effectively dissipate the waves with long period. The variation of the coefficients of wave transmission and reflection along with attenuation with respect to relative width was examined. The results of the physical model tests indicate that the transmission coefficient significantly decreases by about twenty percent at the range of relative width from 0.1 to 0.2, compared with the traditional open type breakwaters.展开更多
In this paper the author first reviews 6 major advances in the study of Precambrian geologyand tectonics of South China during the last decade, and then proposes the following new modelof Late Precambrian scissors-typ...In this paper the author first reviews 6 major advances in the study of Precambrian geologyand tectonics of South China during the last decade, and then proposes the following new modelof Late Precambrian scissors-type opening-closing tectonic evolution in the region. (1) Besidesthe Middle-Late Proterozoic low-grade metamorphic basement, there existed a LateArchaean-Early Proterozoic medium- to high-garde metamorphic basement in South China;both of them formed the united Yangtze-Cathaysia (craton) at the end of the Early Proterozoic,with the Jiangxi-Anhui-Zhejiang palaeogulf extending into the inland and the Jiangxi-Anhui-Jiangsu Peninsula lying on the northern side of the palaeogulf.(2) From the Middle Proterozoic,the present Guangxi-Guizhou-Hunan area in the western-central oldland was subjected toextensional rifting and became a rift trough, thus resulting in counterclockwise rotation of the'Cathaysian block' and clockwise rotation of the 'Yangtze block'; moreover, the southwardcompression of the Dabie-Jiaonan block which split from the southern margin of the NorthChina plate and was accreted to the northern margin of the Jiangxi-Anhui-Jiangsu Peninsula ledto the scissors-type closing of the Jiangxi-Anhui-Zhejiang palaeogulf during the Middle-earlyLate Proterozoic, which further influenced the Early Palaeozoic tectonic evolution of the region.展开更多
Two kinds of 1,4-anhydroribose derivatives,1,4-anhydro-2,3-O-benzylidene-T-D-ribopyranose(ABRP)and 1,4-anhydro-2,3-O-isopropylidene-T-D-ribopyranose(AIRP)were prepared fromD-ribose.The ringopening copolymerizations of...Two kinds of 1,4-anhydroribose derivatives,1,4-anhydro-2,3-O-benzylidene-T-D-ribopyranose(ABRP)and 1,4-anhydro-2,3-O-isopropylidene-T-D-ribopyranose(AIRP)were prepared fromD-ribose.The ringopening copolymerizations of ABRP and AIRP in various feed ratios were carried out with SbCl_5 and BF_3OEt_2 as catalyst at low temperatures.The copolymer structure was characterized by means of ^(1)H,^(13)C NMR spectroscopy and specific rotation.When SbCl_(5)was used as catalyst,the copolymer obtained had completely 1,4-β-pyranosidic structure,i.e.,cellulosetype structure.However,when BF_(3)OEt_2 was used as catalyst,the copolymer had a mixed structure of furanosidic and pyranosidic units.展开更多
Thoracic endovascular aortic repair(TEVAR)has been considered as a first-choice treatment for type B aortic dissection(TBAD).However,some patients that is lack of optimal landing zones(<15 mm in dissected Z2,Z3 or ...Thoracic endovascular aortic repair(TEVAR)has been considered as a first-choice treatment for type B aortic dissection(TBAD).However,some patients that is lack of optimal landing zones(<15 mm in dissected Z2,Z3 or the presence of a lusorian artery)still pose significant challenges for TEVAR.We utilized a surgical stent-graft implantation in the descending aorta combined with supra-aortic vessels transposition through median sternotomy for these special TBAD patients.The short-and mid-term results showed that our procedure is a good and alternative therapy for such kind patients.展开更多
BACKGROUND Gustilo III fractures have a high incidence and are difficult to treat.Patients often experience difficulty in wound healing.Negative pressure drainage technology can help shorten wound healing time and has...BACKGROUND Gustilo III fractures have a high incidence and are difficult to treat.Patients often experience difficulty in wound healing.Negative pressure drainage technology can help shorten wound healing time and has positive value in improving patient prognosis.AIM To explore the clinical value of the negative pressure sealing drainage technique in wound healing of Gustilo IIIB and IIIC open fractures.METHODS Eighty patients with Gustilo IIIB and IIIC open fractures with skin and soft tissue injuries who were treated in the Second People’s Hospital of Dalian from March 2019 to December 2021 were selected as the research subjects.They were divided into a study group(n=40,healed with negative pressure closed drainage)and a control group(n=40,healed with conventional dressing changes)according to the variation in the healing they received.The efficacy of the clinical interventions,the variations in the regression indicators(time to wound healing,time to fracture healing,time to hospitalization),and the conversion and healing of bacterial wounds were compared 1-3 mo after the intervention.RESULTS The total effective rate of patients among the study group was 95.00%(38/40),which was notably higher than 75.00%(30/40)among the control group(P<0.05).The wound healing time,fracture healing time,and hospital stay of the patients in the study group was shorter than the control group(P<0.05).After the intervention,the negative bacterial culture at the wound site rate and wound healing rate of the patients among the study group increased compared to the control group(P<0.05).CONCLUSION Negative pressure sealing and drainage technology has a good therapeutic effect on patients with Gustilo IIIB and IIIC open fracture wounds with skin and soft tissue injury.It can notably enhance the wound healing rate and the negative rate of bacteria on the wound surface and help to speed up the recovery process of patients.展开更多
From the self-assembly of the typical Salen-type Schiff-base ligand H2L and Zn（OAc）2.2H20 in the molar ratio of 1：1 or 1：2, the mononuclear [Zn（L）（H2O）] （1） or binuclear [Zn2（L）（OAc）2（H2O）] （2） are o...From the self-assembly of the typical Salen-type Schiff-base ligand H2L and Zn（OAc）2.2H20 in the molar ratio of 1：1 or 1：2, the mononuclear [Zn（L）（H2O）] （1） or binuclear [Zn2（L）（OAc）2（H2O）] （2） are obtained, respectively. For both complexes 1 and 2, the unsaturated five-coordinate coordination environment to the catalytic active centers （Zn2＋ ions） permits the monomer insertion for the effective solution copolymerization of cyclohexene oxide and maleic anhydride. All the solution copolymerizations afford poly（ester-co-ether）s, while lower catalyst and co-catalyst concentrations are helpful for the formation of alternating polyester. Of the three co-catalysts, 4-（dimethylamino）pyridine is found to be the most efficient, while an excess thereof is detrimental for chain growth of the copolymers.展开更多
中点钳位(neutral point clamped,NPC)型三电平逆变器并网工作环境恶劣,IGBT面临单管与双管同时故障的挑战,这使得故障特征之间的差异变得非常微弱,进而导致双管故障的识别精度难以有效提升。为此,提出了一种新的故障诊断方法,该方法结...中点钳位(neutral point clamped,NPC)型三电平逆变器并网工作环境恶劣,IGBT面临单管与双管同时故障的挑战,这使得故障特征之间的差异变得非常微弱,进而导致双管故障的识别精度难以有效提升。为此,提出了一种新的故障诊断方法,该方法结合了多通道的二维递归融合图和轻量化多尺度残差(lightweightmultiscale convolutional residuals,LMCR)网络。首先,通过仿真获取三相电流信号作为故障信号;再利用递归图(recurrence plot,RP)将三相电流信号分别转化为二维图并进行多通道融合,以捕捉时间序列中的周期性、突变点和趋势等特征;最后,将递归融合图作为输入,输入到LMCR模型中进行故障识别,LMCR模型整合多级Inception结构和残差网络,用于提取不同尺度的特征并融合这些特征,从而保证网络的梯度消失和爆炸。实验结果显示,该方法在IGBT故障识别中表现出色,无噪声环境下平均识别准确率达100%,噪声环境中也达到了92.53%,充分证明了该方法具有较强的特征提取能力和优异的抗噪性能。展开更多
文摘Visible light photocatalytic redox catalysis has become a powerful tool for organic synthesis, and has opened up new avenues for the formation of challenging structural skeletons and chemical bonds. In this respect, diverse photocatalysts, including ruthenium(II), iridium(Ⅲ), and organic dyes, have been most commonly applied.
文摘A new kind of open type breakwaters was proposed based on the concept of wave energy conversion. The excellent feature of the structure is that it can absorb and utilize the wave energy to dissipate waves. The effects of some factors, such as the configuration insides, the geometrical parameters and the relative width (the ratio of the width to the wave length), on the performance of the breakwater were discussed based on a series of regular wave tests in the wave flume. The hydrodynamic characteristics of the new open type breakwater were analyzed in detail, and the structure was optimized to improve the performance of the breakwater to effectively dissipate the waves with long period. The variation of the coefficients of wave transmission and reflection along with attenuation with respect to relative width was examined. The results of the physical model tests indicate that the transmission coefficient significantly decreases by about twenty percent at the range of relative width from 0.1 to 0.2, compared with the traditional open type breakwaters.
文摘In this paper the author first reviews 6 major advances in the study of Precambrian geologyand tectonics of South China during the last decade, and then proposes the following new modelof Late Precambrian scissors-type opening-closing tectonic evolution in the region. (1) Besidesthe Middle-Late Proterozoic low-grade metamorphic basement, there existed a LateArchaean-Early Proterozoic medium- to high-garde metamorphic basement in South China;both of them formed the united Yangtze-Cathaysia (craton) at the end of the Early Proterozoic,with the Jiangxi-Anhui-Zhejiang palaeogulf extending into the inland and the Jiangxi-Anhui-Jiangsu Peninsula lying on the northern side of the palaeogulf.(2) From the Middle Proterozoic,the present Guangxi-Guizhou-Hunan area in the western-central oldland was subjected toextensional rifting and became a rift trough, thus resulting in counterclockwise rotation of the'Cathaysian block' and clockwise rotation of the 'Yangtze block'; moreover, the southwardcompression of the Dabie-Jiaonan block which split from the southern margin of the NorthChina plate and was accreted to the northern margin of the Jiangxi-Anhui-Jiangsu Peninsula ledto the scissors-type closing of the Jiangxi-Anhui-Zhejiang palaeogulf during the Middle-earlyLate Proterozoic, which further influenced the Early Palaeozoic tectonic evolution of the region.
文摘Two kinds of 1,4-anhydroribose derivatives,1,4-anhydro-2,3-O-benzylidene-T-D-ribopyranose(ABRP)and 1,4-anhydro-2,3-O-isopropylidene-T-D-ribopyranose(AIRP)were prepared fromD-ribose.The ringopening copolymerizations of ABRP and AIRP in various feed ratios were carried out with SbCl_5 and BF_3OEt_2 as catalyst at low temperatures.The copolymer structure was characterized by means of ^(1)H,^(13)C NMR spectroscopy and specific rotation.When SbCl_(5)was used as catalyst,the copolymer obtained had completely 1,4-β-pyranosidic structure,i.e.,cellulosetype structure.However,when BF_(3)OEt_2 was used as catalyst,the copolymer had a mixed structure of furanosidic and pyranosidic units.
基金supported by grants from the Young Program of National Natural Science Foundation of China(No.81600225)the Young Program of the Natural Science Foundation of Jiangsu Province(No.BK20160132)Jiangsu Province Special Program of Medical Science(BE2017610)
文摘Thoracic endovascular aortic repair(TEVAR)has been considered as a first-choice treatment for type B aortic dissection(TBAD).However,some patients that is lack of optimal landing zones(<15 mm in dissected Z2,Z3 or the presence of a lusorian artery)still pose significant challenges for TEVAR.We utilized a surgical stent-graft implantation in the descending aorta combined with supra-aortic vessels transposition through median sternotomy for these special TBAD patients.The short-and mid-term results showed that our procedure is a good and alternative therapy for such kind patients.
基金the Review Committee of Fuzhou Medical College of Nanchang University(Approval No.4445644).
文摘BACKGROUND Gustilo III fractures have a high incidence and are difficult to treat.Patients often experience difficulty in wound healing.Negative pressure drainage technology can help shorten wound healing time and has positive value in improving patient prognosis.AIM To explore the clinical value of the negative pressure sealing drainage technique in wound healing of Gustilo IIIB and IIIC open fractures.METHODS Eighty patients with Gustilo IIIB and IIIC open fractures with skin and soft tissue injuries who were treated in the Second People’s Hospital of Dalian from March 2019 to December 2021 were selected as the research subjects.They were divided into a study group(n=40,healed with negative pressure closed drainage)and a control group(n=40,healed with conventional dressing changes)according to the variation in the healing they received.The efficacy of the clinical interventions,the variations in the regression indicators(time to wound healing,time to fracture healing,time to hospitalization),and the conversion and healing of bacterial wounds were compared 1-3 mo after the intervention.RESULTS The total effective rate of patients among the study group was 95.00%(38/40),which was notably higher than 75.00%(30/40)among the control group(P<0.05).The wound healing time,fracture healing time,and hospital stay of the patients in the study group was shorter than the control group(P<0.05).After the intervention,the negative bacterial culture at the wound site rate and wound healing rate of the patients among the study group increased compared to the control group(P<0.05).CONCLUSION Negative pressure sealing and drainage technology has a good therapeutic effect on patients with Gustilo IIIB and IIIC open fracture wounds with skin and soft tissue injury.It can notably enhance the wound healing rate and the negative rate of bacteria on the wound surface and help to speed up the recovery process of patients.
基金financially supported by the National Natural Science Foundation of China(Nos.91222201,21173165 and 20871098)the Program for New Century Excellent Talents in Universities from the Ministry of Education of China(No.NCET-10-0936)+4 种基金the State Key Laboratory of Structure Chemistry(20100014)the Provincial Natural Foundation(2011JQ2011) of Shaanxithe Education Committee Foundation of Shaanxi Province(11JK0588,12JK0577)Graduate Innovation and Creativity Fund(YZZ12038) of Northwest UniversityHong Kong Research Grants Council(HKBU 202407 and FRG/06-07/II-16)
文摘From the self-assembly of the typical Salen-type Schiff-base ligand H2L and Zn（OAc）2.2H20 in the molar ratio of 1：1 or 1：2, the mononuclear [Zn（L）（H2O）] （1） or binuclear [Zn2（L）（OAc）2（H2O）] （2） are obtained, respectively. For both complexes 1 and 2, the unsaturated five-coordinate coordination environment to the catalytic active centers （Zn2＋ ions） permits the monomer insertion for the effective solution copolymerization of cyclohexene oxide and maleic anhydride. All the solution copolymerizations afford poly（ester-co-ether）s, while lower catalyst and co-catalyst concentrations are helpful for the formation of alternating polyester. Of the three co-catalysts, 4-（dimethylamino）pyridine is found to be the most efficient, while an excess thereof is detrimental for chain growth of the copolymers.
