GaN-based vertical P-i-N diode with mesa edge terminal structure due to electric field crowding effect, the breakdown voltage of the device is significantly reduced. This work investigates three terminal structures, i...GaN-based vertical P-i-N diode with mesa edge terminal structure due to electric field crowding effect, the breakdown voltage of the device is significantly reduced. This work investigates three terminal structures, including deeply etched, bevel, and stepped-mesas terminal structures, to suppress electric field crowding effects at the device and junction edges. Deeply-etched mesa terminal yields a breakdown voltage of 1205 V, i.e., 89% of the ideal voltage. The bevel-mesa terminal achieves about 89% of the ideal breakdown voltage, while the step-mesa terminal is less effective in mitigating electric field crowding, at about 32% of the ideal voltage. This work can provide an important reference for the design of high-power, high-voltage GaN-based P-i-N power devices, finding a terminal protection structure suitable for GaNPiN diodes to further enhance the breakdown performance of the device and to unleash the full potential of GaN semiconductor materials.展开更多
AIM:To investigate the clinical features and prognostic factors of advanced hepatocellular carcinoma (HCC)patients presenting with lung metastasis at initial diagnosis. METHODS:Between 2001 and 2010,we recruited 76 co...AIM:To investigate the clinical features and prognostic factors of advanced hepatocellular carcinoma (HCC)patients presenting with lung metastasis at initial diagnosis. METHODS:Between 2001 and 2010,we recruited 76 consecutive HCC patients initially presenting with lung metastasis,without co-existing metastasis from other sites.These patients were divided into three groups:untreated group(n=22),single treatment group(n= 19),and combined treatment group(n=35). RESULTS:Metastasis of bilateral lung lobes was common and noted in 35 patients(46.1%),and most of patients(59/76,77.6%)presented with multiple lung metastatic nodules.Nineteen patients(25.0%) received single-method treatment,including hepatectomy in 4,transcatheter arterial chemoembolization in 6,radiotherapy in 5,and oral sorafenib in 4.Thirty-five patients(46.1%)received combined treatment modalities.The overall median survival of the all patients was 8.7±0.6 mo;4.1±0.3,6.3±2.5 and 18.6±3.9 mo, respectively in the untreated group,single treatment group and combined treatment group,respectively, with a significant difference(log-rank test,P<0.001). Multivariate analysis revealed that Child-Pugh score, the absence or presence of portal vein tumor thrombus,and treatment modality were three independent prognostic factors affecting survival of patients with advanced HCC and concomitant lung metastasis. CONCLUSION:Combined treatment modalities tend to result in a better survival as compared with the conservative treatment or single treatment modality for HCC patients initially presenting with lung metastasis.展开更多
In response to the awareness of limited fossil resources and environmental concerns,catalytic conversion of renewable lignocellulose biomass to value-added chemicals and fuels is of great significance and attractive f...In response to the awareness of limited fossil resources and environmental concerns,catalytic conversion of renewable lignocellulose biomass to value-added chemicals and fuels is of great significance and attractive for sustainable chemistry.Division of Biomass Conversion and Bio-Energy attached to Dalian National Laboratory for Clean Energy has devoted themselves to valorization of lignocellulose biomass since launched in 2011.Our research interests focus on breeding of biomass resources(inulin and microalgae),exploration of catalytic and biological technologies,and production of energy chemicals and fuels.Although lignocellulose biomass is renewable and abundant,the way of utilization should be reasonable according to its structural characteristics in view of efficiency and economy.In this review,to celebrate the DICP's 70 th anniversary,we will highlight the major fundamental advances in DICP about the conversion of lignocellulose to value-added chemicals and liquid fuels.Particular attention will be paid to the transformation of cellulose and its derivatives to glycols,acids and nitrogen-containing chemicals,hemicellulose-derived platform molecule furfural to jet fuels and lignin to aromatics using catalytic technologies.展开更多
Efficient catalytic oxidation of ethylbenzene to acetophenone was realized using the catalytic system of cobalt zeolitic imidazolate framework ZIF-67/N-hydroxyphthalimide(NHPI) under mild conditions. 95.2% conversion ...Efficient catalytic oxidation of ethylbenzene to acetophenone was realized using the catalytic system of cobalt zeolitic imidazolate framework ZIF-67/N-hydroxyphthalimide(NHPI) under mild conditions. 95.2% conversion of ethylbenzene with 90.3% selectivity to acetophenone could be obtained at 373 K under 0.3 MPa O2 for 9 h. The results show that there exists synergetic effect between ZIF-67 and NHPI. 1-Phenylethyl hydroperoxide(PEHP) was generated via a radical process involving the hydrogen abstraction from ethylbenzene by phthalimide N-oxyl, and subsequently effectively decomposed to acetophenone by ZIF-67.展开更多
In order to study the effect of recycled plastic particles on the physical and mechanical properties of concrete,recycled plastic concrete with 0,3%,5%and 7%content(by weight)was designed.The compressive strength,spli...In order to study the effect of recycled plastic particles on the physical and mechanical properties of concrete,recycled plastic concrete with 0,3%,5%and 7%content(by weight)was designed.The compressive strength,splitting tensile strength and the change of mass caused by water absorption during curing were measured.The results show that the strength of concrete is increased by adding recycled plastic into concrete.Among them,the compressive strength and the splitting tensile strength of concrete is the best when the plastic content is 5%.With the increase of plastic content,the development speed of early strength slows down.Silane coupling agent plays a positive role in the strength of recycled plastic concrete.The water absorption saturation of concrete has been basically completed in the early stage.The addition of silane coupling agent makes the porosity of concrete reduce and the water absorption of concrete become poor.By summing up the physical and mechanical properties of recycled plastic concrete,it could be found that the addition of recycled plastic was effective for the modification of concrete materials.Under the control of the amount of recycled plastic,the strength of concrete with recycled plastic aggregates can meet the engineering requirements.展开更多
Oligo(methylsilylene)-ethynylene polymer with crosslinkable ethynyl unit in the main chain was synthesized by condensation ofα,ω-dicholorooligo(methylsilane) with dilithioacetylene.The as-synthesized polymer was cha...Oligo(methylsilylene)-ethynylene polymer with crosslinkable ethynyl unit in the main chain was synthesized by condensation ofα,ω-dicholorooligo(methylsilane) with dilithioacetylene.The as-synthesized polymer was characterized by GPC,FT-IR and NMR.The results showed ethynyl group was successfully introduced to the polymer main chain.The ceramic yield was dramatically increased by the cross-polymerization of ethynyl group,and the excess silicon of PMS was compensated.Nearstoichiometric (C/Si=1.17) and partial crystallizationβ-SiC monoliths were obtained by pressureless pyrolysing PSPA at 1200℃in a high yield(73.6 wt%).展开更多
BACKGROUND Children are a unique patient population.Anesthesia for pediatric abdominal surgery has long been achieved mainly with intravenous amiodarone and propofol alone or combined with other anesthetics.The incide...BACKGROUND Children are a unique patient population.Anesthesia for pediatric abdominal surgery has long been achieved mainly with intravenous amiodarone and propofol alone or combined with other anesthetics.The incidence of complications and postoperative adverse reactions is relatively high owing to the imperfect development of various protocols for children.Choosing the most appropriate anesthesia program is an important means of reducing adverse reactions.AIM To explore the clinical value of propofol combined with lidocaine-assisted anesthesia in pediatric surgery.METHODS A total of 120 children who underwent abdominal surgery at our hospital from January 2016 to March 2018 were selected and divided into groups A and B using the random number table method,with 60 patients in each group.Group B received ketamine for anesthesia,while group A received ketamine,propofol,and lidocaine.The pre-and postoperative heart rate(HR);mean arterial pressure(MAP);arterial oxygen saturation(SpO_(2));serum adrenocorticotropic hormone(ACTH),interleukin-6(IL-6),and cortisol(Cor)levels;restlessness score during the recovery period[Paediatric Anesthesia Emergence Delirium Scale(PAED)];and adverse reactions were compared between the two groups.RESULTS The HR,MAP,and SpO_(2) Level at five minutes before initiating anesthesia were compared between groups A and B,and the difference was not statistically significant(P>0.05).At 10 and 20 minutes after anesthesia initiation,the HR and MAP were lower in group A compared with group B(P<0.05).The differences in preoperative serum ACTH,IL-6,and Cor levels between groups A and B were not statistically significant(P>0.05);however,the postoperative serum ACTH,IL-6,and Cor levels in group A were lower compared with group B(P<0.05).Furthermore,the visual analog scale scores of group A at 2 h and 8 h postoperative were lower than those in group B,and the differences were statistically significant(P<0.05).The mean PAED score in group A was lower than that in group B(P<0.05),and the incidence of restlessness in group A was 23.33%lower than that in group B(36.67%)(P<0.05).The incidence of adverse reactions was lower in group A than in group B(6.25%vs 16.25%).CONCLUSION The anesthetic effect of propofol combined with lidocaine and ketamine in pediatric surgery was better than that of ketamine alone,and had less influence on hemodynamics and pediatric stress response indices,lower incidence of restlessness in the recovery period,and lower incidence of adverse reactions.展开更多
In this article,we study three types of new Yukawa couplings(the boson field is coupled to the fermion field).Two of them are quadratic Yukawa couplings(the boson field is in the form of a vector),and the other one is...In this article,we study three types of new Yukawa couplings(the boson field is coupled to the fermion field).Two of them are quadratic Yukawa couplings(the boson field is in the form of a vector),and the other one is the matrix Yukawa coupling(the boson field is in the form of a matrix).Based on the above three couplings,we introduce the Higgs mechanism,and find out the properties of the generated mass for the fermions with multiple flavors.For the matrix boson,we introduce its coupling with non-Abelian gauge field.It turns out that the generated mass of the gauge field through the Higgs mechanism is unique.In the large N limit,using the method of auxiliary field,we study the dynamical behaviors of the quadratic Yukawa couplings,including the poles of some dressed propagators.展开更多
文摘GaN-based vertical P-i-N diode with mesa edge terminal structure due to electric field crowding effect, the breakdown voltage of the device is significantly reduced. This work investigates three terminal structures, including deeply etched, bevel, and stepped-mesas terminal structures, to suppress electric field crowding effects at the device and junction edges. Deeply-etched mesa terminal yields a breakdown voltage of 1205 V, i.e., 89% of the ideal voltage. The bevel-mesa terminal achieves about 89% of the ideal breakdown voltage, while the step-mesa terminal is less effective in mitigating electric field crowding, at about 32% of the ideal voltage. This work can provide an important reference for the design of high-power, high-voltage GaN-based P-i-N power devices, finding a terminal protection structure suitable for GaNPiN diodes to further enhance the breakdown performance of the device and to unleash the full potential of GaN semiconductor materials.
基金supported by the National Natural Science Foundation of China (21790331,21603218)the Strategic Priority Research Program of Chinese Academy of Sciences (XDA21030400,XDB17020300)~~
基金Supported by Grants from National Natural Science Foundation of China,No.81000166Shanghai Science and Technology Development Commission,No.10411963300+1 种基金Shanghai Program for Excellent Talents in Health System,No.XYQ2011033Shanghai Health Bureau,No.ab8307000-2010-92
文摘AIM:To investigate the clinical features and prognostic factors of advanced hepatocellular carcinoma (HCC)patients presenting with lung metastasis at initial diagnosis. METHODS:Between 2001 and 2010,we recruited 76 consecutive HCC patients initially presenting with lung metastasis,without co-existing metastasis from other sites.These patients were divided into three groups:untreated group(n=22),single treatment group(n= 19),and combined treatment group(n=35). RESULTS:Metastasis of bilateral lung lobes was common and noted in 35 patients(46.1%),and most of patients(59/76,77.6%)presented with multiple lung metastatic nodules.Nineteen patients(25.0%) received single-method treatment,including hepatectomy in 4,transcatheter arterial chemoembolization in 6,radiotherapy in 5,and oral sorafenib in 4.Thirty-five patients(46.1%)received combined treatment modalities.The overall median survival of the all patients was 8.7±0.6 mo;4.1±0.3,6.3±2.5 and 18.6±3.9 mo, respectively in the untreated group,single treatment group and combined treatment group,respectively, with a significant difference(log-rank test,P<0.001). Multivariate analysis revealed that Child-Pugh score, the absence or presence of portal vein tumor thrombus,and treatment modality were three independent prognostic factors affecting survival of patients with advanced HCC and concomitant lung metastasis. CONCLUSION:Combined treatment modalities tend to result in a better survival as compared with the conservative treatment or single treatment modality for HCC patients initially presenting with lung metastasis.
基金supported by the National Natural Science Foundation of China(Projects 21790331,21603218,21703236 and 21872138)the Strategic Priority Research Program of the Chinese Academy of Sciences(Nos.XDB17020300 and XDA21030400)+1 种基金the Youth Innovation Promotion Association,CAS(2018219)DICP ZZBS201811
文摘In response to the awareness of limited fossil resources and environmental concerns,catalytic conversion of renewable lignocellulose biomass to value-added chemicals and fuels is of great significance and attractive for sustainable chemistry.Division of Biomass Conversion and Bio-Energy attached to Dalian National Laboratory for Clean Energy has devoted themselves to valorization of lignocellulose biomass since launched in 2011.Our research interests focus on breeding of biomass resources(inulin and microalgae),exploration of catalytic and biological technologies,and production of energy chemicals and fuels.Although lignocellulose biomass is renewable and abundant,the way of utilization should be reasonable according to its structural characteristics in view of efficiency and economy.In this review,to celebrate the DICP's 70 th anniversary,we will highlight the major fundamental advances in DICP about the conversion of lignocellulose to value-added chemicals and liquid fuels.Particular attention will be paid to the transformation of cellulose and its derivatives to glycols,acids and nitrogen-containing chemicals,hemicellulose-derived platform molecule furfural to jet fuels and lignin to aromatics using catalytic technologies.
基金supported by the National Natural Science Foundation of China(21233008,21103175 and 20803074)the"Strategic Priority Research Program-Climate Change:Carbon Budget and Related Issues"of the Chinese Academy of Sciences(XDA05010203)
文摘Efficient catalytic oxidation of ethylbenzene to acetophenone was realized using the catalytic system of cobalt zeolitic imidazolate framework ZIF-67/N-hydroxyphthalimide(NHPI) under mild conditions. 95.2% conversion of ethylbenzene with 90.3% selectivity to acetophenone could be obtained at 373 K under 0.3 MPa O2 for 9 h. The results show that there exists synergetic effect between ZIF-67 and NHPI. 1-Phenylethyl hydroperoxide(PEHP) was generated via a radical process involving the hydrogen abstraction from ethylbenzene by phthalimide N-oxyl, and subsequently effectively decomposed to acetophenone by ZIF-67.
文摘In order to study the effect of recycled plastic particles on the physical and mechanical properties of concrete,recycled plastic concrete with 0,3%,5%and 7%content(by weight)was designed.The compressive strength,splitting tensile strength and the change of mass caused by water absorption during curing were measured.The results show that the strength of concrete is increased by adding recycled plastic into concrete.Among them,the compressive strength and the splitting tensile strength of concrete is the best when the plastic content is 5%.With the increase of plastic content,the development speed of early strength slows down.Silane coupling agent plays a positive role in the strength of recycled plastic concrete.The water absorption saturation of concrete has been basically completed in the early stage.The addition of silane coupling agent makes the porosity of concrete reduce and the water absorption of concrete become poor.By summing up the physical and mechanical properties of recycled plastic concrete,it could be found that the addition of recycled plastic was effective for the modification of concrete materials.Under the control of the amount of recycled plastic,the strength of concrete with recycled plastic aggregates can meet the engineering requirements.
基金financial support of the National Science Foundation of China(No. 50903086)the Chinese Academy of Sciences
文摘Oligo(methylsilylene)-ethynylene polymer with crosslinkable ethynyl unit in the main chain was synthesized by condensation ofα,ω-dicholorooligo(methylsilane) with dilithioacetylene.The as-synthesized polymer was characterized by GPC,FT-IR and NMR.The results showed ethynyl group was successfully introduced to the polymer main chain.The ceramic yield was dramatically increased by the cross-polymerization of ethynyl group,and the excess silicon of PMS was compensated.Nearstoichiometric (C/Si=1.17) and partial crystallizationβ-SiC monoliths were obtained by pressureless pyrolysing PSPA at 1200℃in a high yield(73.6 wt%).
文摘BACKGROUND Children are a unique patient population.Anesthesia for pediatric abdominal surgery has long been achieved mainly with intravenous amiodarone and propofol alone or combined with other anesthetics.The incidence of complications and postoperative adverse reactions is relatively high owing to the imperfect development of various protocols for children.Choosing the most appropriate anesthesia program is an important means of reducing adverse reactions.AIM To explore the clinical value of propofol combined with lidocaine-assisted anesthesia in pediatric surgery.METHODS A total of 120 children who underwent abdominal surgery at our hospital from January 2016 to March 2018 were selected and divided into groups A and B using the random number table method,with 60 patients in each group.Group B received ketamine for anesthesia,while group A received ketamine,propofol,and lidocaine.The pre-and postoperative heart rate(HR);mean arterial pressure(MAP);arterial oxygen saturation(SpO_(2));serum adrenocorticotropic hormone(ACTH),interleukin-6(IL-6),and cortisol(Cor)levels;restlessness score during the recovery period[Paediatric Anesthesia Emergence Delirium Scale(PAED)];and adverse reactions were compared between the two groups.RESULTS The HR,MAP,and SpO_(2) Level at five minutes before initiating anesthesia were compared between groups A and B,and the difference was not statistically significant(P>0.05).At 10 and 20 minutes after anesthesia initiation,the HR and MAP were lower in group A compared with group B(P<0.05).The differences in preoperative serum ACTH,IL-6,and Cor levels between groups A and B were not statistically significant(P>0.05);however,the postoperative serum ACTH,IL-6,and Cor levels in group A were lower compared with group B(P<0.05).Furthermore,the visual analog scale scores of group A at 2 h and 8 h postoperative were lower than those in group B,and the differences were statistically significant(P<0.05).The mean PAED score in group A was lower than that in group B(P<0.05),and the incidence of restlessness in group A was 23.33%lower than that in group B(36.67%)(P<0.05).The incidence of adverse reactions was lower in group A than in group B(6.25%vs 16.25%).CONCLUSION The anesthetic effect of propofol combined with lidocaine and ketamine in pediatric surgery was better than that of ketamine alone,and had less influence on hemodynamics and pediatric stress response indices,lower incidence of restlessness in the recovery period,and lower incidence of adverse reactions.
基金supported in part by the National Natural Science Foundation of China(10935001,11275097 and11075075)the Research Fund for the Doctoral Program of Higher Education(2012009111002)
文摘In this article,we study three types of new Yukawa couplings(the boson field is coupled to the fermion field).Two of them are quadratic Yukawa couplings(the boson field is in the form of a vector),and the other one is the matrix Yukawa coupling(the boson field is in the form of a matrix).Based on the above three couplings,we introduce the Higgs mechanism,and find out the properties of the generated mass for the fermions with multiple flavors.For the matrix boson,we introduce its coupling with non-Abelian gauge field.It turns out that the generated mass of the gauge field through the Higgs mechanism is unique.In the large N limit,using the method of auxiliary field,we study the dynamical behaviors of the quadratic Yukawa couplings,including the poles of some dressed propagators.
