A direct tunneling model through gate dielectric s in CMOS devices in the frame of WKB approximation is reported.In the model,an im proved one-band effective mass approximation is used for the hole quantization, wher...A direct tunneling model through gate dielectric s in CMOS devices in the frame of WKB approximation is reported.In the model,an im proved one-band effective mass approximation is used for the hole quantization, where valence band mixing is taken into account.By comparing to the experiments, the model is demonstrated to be applicable to both electron and hole tunneling c urrents in CMOS devices.The effect of the dispersion in oxide energy gap on the tunneling current is also studied.This model can be further extended to study th e direct tunneling current in future high-k materials.展开更多
Objective:To observe the anti-tumor effect of matrine combined with cisplatin on U14 rat models of cervical cancer.Methods:A total of 80 female Kunming rats were used to establish U14 rat models of cervical cancer and...Objective:To observe the anti-tumor effect of matrine combined with cisplatin on U14 rat models of cervical cancer.Methods:A total of 80 female Kunming rats were used to establish U14 rat models of cervical cancer and then divided into groups Ⅰ,Ⅱ,Ⅲ and Ⅳ,with 20 rats in each.For Group Ⅰ,the control group,injection of normal saline was given around the tumors.For Group Ⅱ,injection of 2 mg/kg cisplatin was given around the tumors.For Group Ⅲ,injection of 75 mg/kg matrine was given around the tumors while the combined injection of matrine and cisplatin was given for Group Ⅳ with the same doses as Groups Ⅱand Ⅲ.The animals were sacrificed 10 d after the injection and tumors were taken out for the comparisons of tumor weights after injection and calculation of anti-tumor rates,while thymus and spleen were taken for thymus index and spleen index.Blood in eyeball was collected for determination of changes in serum creatinine and urea nitrogen levels.Sections of tumor issue were prepared and morphological changes in tumor tissue cells were observed by using immunohistochemistry technique.Results:After injection,the thymus index and spleen index in Groups Ⅲ and Ⅳ were significantly higher than those in Groups Ⅰ and Ⅱ(P<0.05)while the two indexes in Group Ⅱ were significantly lower than Group Ⅰ(P<0.05).The tumor weights in Groups Ⅱ and Ⅳ were significantly smaller than those in Groups Ⅰ and Ⅲ(P<0.05) with significantly higher anti-tumor rates than Groups Ⅰ and Ⅲ(P<0.05).The serum creatinine and urea nitrogen levels in Groups Ⅲ and Ⅳ were significantly lower than Group Ⅱ(P<0.05) and the two indicators in Group Ⅲ were significantly lower than those in Group Ⅳ(P<0.05).The observation under the histological microscope showed densely arranged tumor cells in Group Ⅰ,growing as a crumby structure and diffuse appearance,with hyperchromatic and large nuclei,and abundant cytoplasm.In the case of Group Ⅱ,it showed less tumor cells,with extensive degenerative necrosis,sparse arrangement and karyopyknosis as well as karyoclasis.For Group Ⅲ,necrosis of tumor cells in different sizes and heterogeneous color in nuclei were observed.For Group Ⅳ,the number of tumor cells was significantly smaller than Groups Ⅰ and Ⅲ and the tumor cells presented an appearance of crumby structure as cancer nests,with more proliferation of connective tissue.Conclusions:The treatment of matrine combined with cisplatin can significantly improve the anti-tumor effect on U14 rats with cervical cancer,which can be a new option for the treatment for cervical cancer.展开更多
Between 1984-1989,the authors treat-ed 81 cases of paralytic strabismus,in-cluding 53 cases treated in the Arab Repub-lic of Yemen where the authors worked for 3years.The results of treatment were satisfac-tory as rep...Between 1984-1989,the authors treat-ed 81 cases of paralytic strabismus,in-cluding 53 cases treated in the Arab Repub-lic of Yemen where the authors worked for 3years.The results of treatment were satisfac-tory as reported in the following.Clinical DataThis series of 81 patients (81 eyes) con-sisted of Yemenis 49 cases,Somalis 2 cases,Ethiopians 2 cases,and Chinese 28 cases.There were 47 males and 34 females。展开更多
The cooperative principle is an important theory of pragmatics,concerning how to maximally achieve communicative goal.While translation serves as a communicative medium,it should also observe the conversational rules...The cooperative principle is an important theory of pragmatics,concerning how to maximally achieve communicative goal.While translation serves as a communicative medium,it should also observe the conversational rules—cooperative principle to achieve the equivalent effect.This paper tries to explore the issue from the perspective of cooperative principle.展开更多
Totally 20 cases of mental depression were treated by needling extrachannel points with an effec-tive rate of 90%; comparison of these cases with 21 controls treated with amitriptyline, showed no significant differenc...Totally 20 cases of mental depression were treated by needling extrachannel points with an effec-tive rate of 90%; comparison of these cases with 21 controls treated with amitriptyline, showed no significant difference in effect (P】0.05). Measured with Hamilton’s scale, factors of anxiety somatization, cognitive disturbance, retardation, sleep disturbance and feeling of despair in both the needling and control groups showed obvious decrease in the mean value, and the change in anxiety somatization was markedly significant in the needling group as compared with that in the controls (P【 0.01). Our studies revealed that after 6 weeks of needling the power of slow wave 5 decreased while that of the fast wave a increased, all significantly different as compared with that before and during the treatment (P 【 0.05).展开更多
The incidence of obesity has been ap-parently increasing in recent years.Accord-ing to the statistics of 34,006 individuals in-vestigated in 1987 in Beijing,3,560 wereobese,accounting for 10.47%.The incidenceof obesit...The incidence of obesity has been ap-parently increasing in recent years.Accord-ing to the statistics of 34,006 individuals in-vestigated in 1987 in Beijing,3,560 wereobese,accounting for 10.47%.The incidenceof obesity in Nanjing in 1986 reached26.95% (971 individuals investigated).Aretrospective analysis of 3,160 newborns inShenyang City of China indicated a 7.05%incidence of obsesity in newborns.Thetreatment of obesity by means of traditionalChinese medicine (TCM) has proved effec-tive and thus drawn increasing展开更多
Asthma in children is often refractorywith frequent recurrences. In recent years,external modalities for treatment of this dis-ease have been used because they are effec-tive and also well accepted by children.
Experimental assessments were made on the anti-HSV-Ⅱ action of 500 herbs by determinations of thevirus inhibition logarithm(VIL).13 highly effectiveherbs (VIL■4.00)were screened cut,providing a ra-tional basis for c...Experimental assessments were made on the anti-HSV-Ⅱ action of 500 herbs by determinations of thevirus inhibition logarithm(VIL).13 highly effectiveherbs (VIL■4.00)were screened cut,providing a ra-tional basis for clinical therapy.Among these effec-tive herbs,10 were aqueous extracts of Artemisiaanomala,Centella asiatica,Epimedium Sagittatum,Hibiscus mutabills,Hosta plantaginea,Hypericumjaponicum,Inula japonica.Mosla punctata,Rhodo-dendron simsii,and Rhus chinenses,while 3 werealcohol extracts of Epimedium Sagittatum,Hypericumjaponicum,and Mosla punctata.展开更多
Headaches of the neurofunctional type,blood vascular type,neuro-vascular type,andmusculotonic type are commonly encounteredclinically.The authors report a nasal inhalantof Chinese herbal drugs which has been effec-tiv...Headaches of the neurofunctional type,blood vascular type,neuro-vascular type,andmusculotonic type are commonly encounteredclinically.The authors report a nasal inhalantof Chinese herbal drugs which has been effec-tive in the treatment of these varieties ofheadache.展开更多
The fabrication of LPFG in single mode fiber （SMF） was fabricated using amplitude mask writing techniques. The birefringence effect of LPFG for sensing the transverse strain was discussed in detail. The experimented...The fabrication of LPFG in single mode fiber （SMF） was fabricated using amplitude mask writing techniques. The birefringence effect of LPFG for sensing the transverse strain was discussed in detail. The experimented results shou that it exhibits a very high sensitivity and a good linearity to transverse strain, with a sensitivity some hundred times greater than what has been achieved using FBG sensor.展开更多
A basic glucoprotein named α-momorcharin(Mr:29000) that was isolated andpurified from the seeds of MomordicaCharantia was proved to have an obviousinhibitory effect on early pregnacy of
在高二英语课本中相继出现了 affect 和 effect。这两个词虽说都有“影响”之意,但词性不同,而且用法也各异。此外,由于它们发音相似而易于混淆。现辨异如下:一、affect 只用怍动词。使用时常有以下几个意义。1.表示“影响”,“对……有...在高二英语课本中相继出现了 affect 和 effect。这两个词虽说都有“影响”之意,但词性不同,而且用法也各异。此外,由于它们发音相似而易于混淆。现辨异如下:一、affect 只用怍动词。使用时常有以下几个意义。1.表示“影响”,“对……有(产生)影响”。例如;Smoking affects health.吸烟影响健康。The war and the sufferinu that it caused affected him greatly.(SB Ⅱ p.105)这场战争及其所造成的苦难对他影响很大。展开更多
Objective:To systematically evaluate the effects of MBSR on psychological health intervention in nurses.Methods:The randomized controlled trial(RCT)and self-controlled trial(SC)investigating the application of mindful...Objective:To systematically evaluate the effects of MBSR on psychological health intervention in nurses.Methods:The randomized controlled trial(RCT)and self-controlled trial(SC)investigating the application of mindfulness-based stress reduction in nursing staff were retrieved from CNKI,WanFang,VIP,PubMed,Cochrane Library,Web of Science,EMBASE databases.The retrieval time was set from the establishment of the database to April 2020.The Review Manager 5.3 software were used for meta-analysis.Result:9 RCTs and 5 self-control trails were included with 1421,712 subjects in the experimental group and 709 subjects in the control group.The results of the meta-analysis showed that compared with the control group,mindfulness-based stress reduction therapy can effectively reduce the psychological symptoms of clinical nurses[SMD=-0.96,95%CI(-1.51,-0.38),P=0.001],reduces nurses'anxiety levels[SMD=-1.28,95%CI(-2.18,-0.38),P=0.005],relieve the nurse's depression[SMD=-1.08,95%CI(-2.15,-0.02),P=0.005],improve the mental resilience of nurse[SMD=7.05,95%CI(3.93,10.17),P=0.03],showing a statistical meaning.Conclusion:The mental health of nurses is often neglected by themselves and there is insufficient awareness that MBSR can improve mental health.There has been a debate about whether MBSR actually improves the mental health of nurses,so it is necessary to further explore this issue and seek better methods and opportunities for practice.展开更多
930537 Preliminary report on portal hyperten-tion in liver cirrhosis treated by transjugular in-trahepatic portosystemic stent shunt(analysis of8 cases).XU Ke(徐克),et al.Dept Radiol,lst Hosp,China Med Univ,Shenyang,1...930537 Preliminary report on portal hyperten-tion in liver cirrhosis treated by transjugular in-trahepatic portosystemic stent shunt(analysis of8 cases).XU Ke(徐克),et al.Dept Radiol,lst Hosp,China Med Univ,Shenyang,110001.Chin J Radiol 1993;25(5):294—297.Transjugular intrahepatic portosystemic stentshunt(TIPPS)was performed in 8 cases of livercirrhosis with portal hypertention.Moderate orsevere hemorrhage from gastroesophageal variceshad happened in all patients for 2～5 times beforTIPSS.The average pressure of portal veindropped from 3.80±0.50kPa to 2.58±0.26kPa.The diameter of the shunt established be-tween portal and hepatic veins was 10～12mm.Gastrointestinal bleeding and ascites were effec-展开更多
970228 The therapeutic effect of purified human leu-cocytic interferon-a on hemorrhagic fever with renalsyndrome. BAI Jingyu(白敬羽), et al. Changzhou 3rdPeople’s Hosp, Changzhou, 213001. Chin J Intern Med1997; 36(2)...970228 The therapeutic effect of purified human leu-cocytic interferon-a on hemorrhagic fever with renalsyndrome. BAI Jingyu(白敬羽), et al. Changzhou 3rdPeople’s Hosp, Changzhou, 213001. Chin J Intern Med1997; 36(2): 90-93. Objective:To explore the therapeutic effect of puri-展开更多
The in-orbit verification of a refueling test system has been completed successfully.The test system based on a surface tension tank was developed by the Beijing Institute of Control Engineering（BICE）,CAST and launc...The in-orbit verification of a refueling test system has been completed successfully.The test system based on a surface tension tank was developed by the Beijing Institute of Control Engineering（BICE）,CAST and launched into spacewith the Tianyuan 1 satellite aboard a LM-7 carrier rocket on June 25.The lifetime of any spacecraft is constrained by fuel it carried.展开更多
The application of nanoscale zero-valent iron (nZVI) in the remediation of contaminated groundwater or wastewater is limited due to its lack of stability, easy aggregation and iron leaching. To address this issue, nZV...The application of nanoscale zero-valent iron (nZVI) in the remediation of contaminated groundwater or wastewater is limited due to its lack of stability, easy aggregation and iron leaching. To address this issue, nZVI was distributed on oak sawdust-derived biochar (BC) to obtain the nZVI/BC composite for the highly efficient reduction of nitrobenzene (NB). nZVI, BC and nZVI/BC were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). For nZVI/BC, nZVI particles were uniformly dispersed on BC. nZVI/BC exhibited higher removal efficiency for NB than the simple summation of bare nZVI and BC. The removal mechanism was investigated through the analyses of UV-Visible spectra, mass balance and XPS. NB was quickly adsorbed on the surface of nZVI/BC, and then gradually reduced to aniline (AN), accompanied by the oxidation of nZVI to magnetite. The effects of several reaction parameters, e.g., NB concentration, reaction pH and nZVI/BC aging time, on the removal of NB were also studied. In addition to high reactivity, the loading of nZVI on biochar significantly alleviated Fe leaching and enhanced the durability of nZVI.展开更多
The Portevin-Le Chatelier(PLC) effects in a wrought Ni-base superalloy with different γ' precipitates contents have been investigated. Detailed analysis on the serration type of the tensile curves indicates that ...The Portevin-Le Chatelier(PLC) effects in a wrought Ni-base superalloy with different γ' precipitates contents have been investigated. Detailed analysis on the serration type of the tensile curves indicates that the γ' precipitates have a decisive influence on the transformation from normal to inverse PLC behavior, which is rarely proposed in other works. It is considered that the γ' precipitates play the same role in PLC effect as temperature and strain rate for the investigated wrought Ni-base superalloy.展开更多
文摘A direct tunneling model through gate dielectric s in CMOS devices in the frame of WKB approximation is reported.In the model,an im proved one-band effective mass approximation is used for the hole quantization, where valence band mixing is taken into account.By comparing to the experiments, the model is demonstrated to be applicable to both electron and hole tunneling c urrents in CMOS devices.The effect of the dispersion in oxide energy gap on the tunneling current is also studied.This model can be further extended to study th e direct tunneling current in future high-k materials.
基金Supported by special program of molecular genetics medicine for women and children's health,National Center for Women and Children's Health.China Centers for Disease Control with Grant No.FY-ZX-ZD-0059
文摘Objective:To observe the anti-tumor effect of matrine combined with cisplatin on U14 rat models of cervical cancer.Methods:A total of 80 female Kunming rats were used to establish U14 rat models of cervical cancer and then divided into groups Ⅰ,Ⅱ,Ⅲ and Ⅳ,with 20 rats in each.For Group Ⅰ,the control group,injection of normal saline was given around the tumors.For Group Ⅱ,injection of 2 mg/kg cisplatin was given around the tumors.For Group Ⅲ,injection of 75 mg/kg matrine was given around the tumors while the combined injection of matrine and cisplatin was given for Group Ⅳ with the same doses as Groups Ⅱand Ⅲ.The animals were sacrificed 10 d after the injection and tumors were taken out for the comparisons of tumor weights after injection and calculation of anti-tumor rates,while thymus and spleen were taken for thymus index and spleen index.Blood in eyeball was collected for determination of changes in serum creatinine and urea nitrogen levels.Sections of tumor issue were prepared and morphological changes in tumor tissue cells were observed by using immunohistochemistry technique.Results:After injection,the thymus index and spleen index in Groups Ⅲ and Ⅳ were significantly higher than those in Groups Ⅰ and Ⅱ(P<0.05)while the two indexes in Group Ⅱ were significantly lower than Group Ⅰ(P<0.05).The tumor weights in Groups Ⅱ and Ⅳ were significantly smaller than those in Groups Ⅰ and Ⅲ(P<0.05) with significantly higher anti-tumor rates than Groups Ⅰ and Ⅲ(P<0.05).The serum creatinine and urea nitrogen levels in Groups Ⅲ and Ⅳ were significantly lower than Group Ⅱ(P<0.05) and the two indicators in Group Ⅲ were significantly lower than those in Group Ⅳ(P<0.05).The observation under the histological microscope showed densely arranged tumor cells in Group Ⅰ,growing as a crumby structure and diffuse appearance,with hyperchromatic and large nuclei,and abundant cytoplasm.In the case of Group Ⅱ,it showed less tumor cells,with extensive degenerative necrosis,sparse arrangement and karyopyknosis as well as karyoclasis.For Group Ⅲ,necrosis of tumor cells in different sizes and heterogeneous color in nuclei were observed.For Group Ⅳ,the number of tumor cells was significantly smaller than Groups Ⅰ and Ⅲ and the tumor cells presented an appearance of crumby structure as cancer nests,with more proliferation of connective tissue.Conclusions:The treatment of matrine combined with cisplatin can significantly improve the anti-tumor effect on U14 rats with cervical cancer,which can be a new option for the treatment for cervical cancer.
文摘Between 1984-1989,the authors treat-ed 81 cases of paralytic strabismus,in-cluding 53 cases treated in the Arab Repub-lic of Yemen where the authors worked for 3years.The results of treatment were satisfac-tory as reported in the following.Clinical DataThis series of 81 patients (81 eyes) con-sisted of Yemenis 49 cases,Somalis 2 cases,Ethiopians 2 cases,and Chinese 28 cases.There were 47 males and 34 females。
文摘The cooperative principle is an important theory of pragmatics,concerning how to maximally achieve communicative goal.While translation serves as a communicative medium,it should also observe the conversational rules—cooperative principle to achieve the equivalent effect.This paper tries to explore the issue from the perspective of cooperative principle.
文摘Totally 20 cases of mental depression were treated by needling extrachannel points with an effec-tive rate of 90%; comparison of these cases with 21 controls treated with amitriptyline, showed no significant difference in effect (P】0.05). Measured with Hamilton’s scale, factors of anxiety somatization, cognitive disturbance, retardation, sleep disturbance and feeling of despair in both the needling and control groups showed obvious decrease in the mean value, and the change in anxiety somatization was markedly significant in the needling group as compared with that in the controls (P【 0.01). Our studies revealed that after 6 weeks of needling the power of slow wave 5 decreased while that of the fast wave a increased, all significantly different as compared with that before and during the treatment (P 【 0.05).
文摘The incidence of obesity has been ap-parently increasing in recent years.Accord-ing to the statistics of 34,006 individuals in-vestigated in 1987 in Beijing,3,560 wereobese,accounting for 10.47%.The incidenceof obesity in Nanjing in 1986 reached26.95% (971 individuals investigated).Aretrospective analysis of 3,160 newborns inShenyang City of China indicated a 7.05%incidence of obsesity in newborns.Thetreatment of obesity by means of traditionalChinese medicine (TCM) has proved effec-tive and thus drawn increasing
文摘Asthma in children is often refractorywith frequent recurrences. In recent years,external modalities for treatment of this dis-ease have been used because they are effec-tive and also well accepted by children.
文摘Experimental assessments were made on the anti-HSV-Ⅱ action of 500 herbs by determinations of thevirus inhibition logarithm(VIL).13 highly effectiveherbs (VIL■4.00)were screened cut,providing a ra-tional basis for clinical therapy.Among these effec-tive herbs,10 were aqueous extracts of Artemisiaanomala,Centella asiatica,Epimedium Sagittatum,Hibiscus mutabills,Hosta plantaginea,Hypericumjaponicum,Inula japonica.Mosla punctata,Rhodo-dendron simsii,and Rhus chinenses,while 3 werealcohol extracts of Epimedium Sagittatum,Hypericumjaponicum,and Mosla punctata.
文摘Headaches of the neurofunctional type,blood vascular type,neuro-vascular type,andmusculotonic type are commonly encounteredclinically.The authors report a nasal inhalantof Chinese herbal drugs which has been effec-tive in the treatment of these varieties ofheadache.
文摘The fabrication of LPFG in single mode fiber （SMF） was fabricated using amplitude mask writing techniques. The birefringence effect of LPFG for sensing the transverse strain was discussed in detail. The experimented results shou that it exhibits a very high sensitivity and a good linearity to transverse strain, with a sensitivity some hundred times greater than what has been achieved using FBG sensor.
文摘A basic glucoprotein named α-momorcharin(Mr:29000) that was isolated andpurified from the seeds of MomordicaCharantia was proved to have an obviousinhibitory effect on early pregnacy of
文摘在高二英语课本中相继出现了 affect 和 effect。这两个词虽说都有“影响”之意,但词性不同,而且用法也各异。此外,由于它们发音相似而易于混淆。现辨异如下:一、affect 只用怍动词。使用时常有以下几个意义。1.表示“影响”,“对……有(产生)影响”。例如;Smoking affects health.吸烟影响健康。The war and the sufferinu that it caused affected him greatly.(SB Ⅱ p.105)这场战争及其所造成的苦难对他影响很大。
文摘Objective:To systematically evaluate the effects of MBSR on psychological health intervention in nurses.Methods:The randomized controlled trial(RCT)and self-controlled trial(SC)investigating the application of mindfulness-based stress reduction in nursing staff were retrieved from CNKI,WanFang,VIP,PubMed,Cochrane Library,Web of Science,EMBASE databases.The retrieval time was set from the establishment of the database to April 2020.The Review Manager 5.3 software were used for meta-analysis.Result:9 RCTs and 5 self-control trails were included with 1421,712 subjects in the experimental group and 709 subjects in the control group.The results of the meta-analysis showed that compared with the control group,mindfulness-based stress reduction therapy can effectively reduce the psychological symptoms of clinical nurses[SMD=-0.96,95%CI(-1.51,-0.38),P=0.001],reduces nurses'anxiety levels[SMD=-1.28,95%CI(-2.18,-0.38),P=0.005],relieve the nurse's depression[SMD=-1.08,95%CI(-2.15,-0.02),P=0.005],improve the mental resilience of nurse[SMD=7.05,95%CI(3.93,10.17),P=0.03],showing a statistical meaning.Conclusion:The mental health of nurses is often neglected by themselves and there is insufficient awareness that MBSR can improve mental health.There has been a debate about whether MBSR actually improves the mental health of nurses,so it is necessary to further explore this issue and seek better methods and opportunities for practice.
文摘930537 Preliminary report on portal hyperten-tion in liver cirrhosis treated by transjugular in-trahepatic portosystemic stent shunt(analysis of8 cases).XU Ke(徐克),et al.Dept Radiol,lst Hosp,China Med Univ,Shenyang,110001.Chin J Radiol 1993;25(5):294—297.Transjugular intrahepatic portosystemic stentshunt(TIPPS)was performed in 8 cases of livercirrhosis with portal hypertention.Moderate orsevere hemorrhage from gastroesophageal variceshad happened in all patients for 2～5 times beforTIPSS.The average pressure of portal veindropped from 3.80±0.50kPa to 2.58±0.26kPa.The diameter of the shunt established be-tween portal and hepatic veins was 10～12mm.Gastrointestinal bleeding and ascites were effec-
文摘970228 The therapeutic effect of purified human leu-cocytic interferon-a on hemorrhagic fever with renalsyndrome. BAI Jingyu(白敬羽), et al. Changzhou 3rdPeople’s Hosp, Changzhou, 213001. Chin J Intern Med1997; 36(2): 90-93. Objective:To explore the therapeutic effect of puri-
文摘The in-orbit verification of a refueling test system has been completed successfully.The test system based on a surface tension tank was developed by the Beijing Institute of Control Engineering（BICE）,CAST and launched into spacewith the Tianyuan 1 satellite aboard a LM-7 carrier rocket on June 25.The lifetime of any spacecraft is constrained by fuel it carried.
基金financially supported by Postgraduate Research & Practice Innovation Program of Jiangsu Province (No. SJCX17 0120)the National Natural Science Foundation of China (Grant Nos. 41471267 and 41601527)+1 种基金Natural Science Foundation of Guangdong Province, China (Nos. 2014A030313704 and 2014A030310141)Technology Program of Guangzhou, China (Grant No. 201607010236).
文摘The application of nanoscale zero-valent iron (nZVI) in the remediation of contaminated groundwater or wastewater is limited due to its lack of stability, easy aggregation and iron leaching. To address this issue, nZVI was distributed on oak sawdust-derived biochar (BC) to obtain the nZVI/BC composite for the highly efficient reduction of nitrobenzene (NB). nZVI, BC and nZVI/BC were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). For nZVI/BC, nZVI particles were uniformly dispersed on BC. nZVI/BC exhibited higher removal efficiency for NB than the simple summation of bare nZVI and BC. The removal mechanism was investigated through the analyses of UV-Visible spectra, mass balance and XPS. NB was quickly adsorbed on the surface of nZVI/BC, and then gradually reduced to aniline (AN), accompanied by the oxidation of nZVI to magnetite. The effects of several reaction parameters, e.g., NB concentration, reaction pH and nZVI/BC aging time, on the removal of NB were also studied. In addition to high reactivity, the loading of nZVI on biochar significantly alleviated Fe leaching and enhanced the durability of nZVI.
基金financially supported by the National Natural Science Foundation of China(Nos.51601192,51671188,51671189and 11332010)the High Technology Research and Development Program of China(No.2014AA041701)
文摘The Portevin-Le Chatelier(PLC) effects in a wrought Ni-base superalloy with different γ' precipitates contents have been investigated. Detailed analysis on the serration type of the tensile curves indicates that the γ' precipitates have a decisive influence on the transformation from normal to inverse PLC behavior, which is rarely proposed in other works. It is considered that the γ' precipitates play the same role in PLC effect as temperature and strain rate for the investigated wrought Ni-base superalloy.
