This paper proposes a design of passive cooling system for CPR1000 spent fuel pool(SFP). Our design can effectively manage the SFP temperature not to exceed80 C. Then the transient analysis of the CPR1000 SFP with des...This paper proposes a design of passive cooling system for CPR1000 spent fuel pool(SFP). Our design can effectively manage the SFP temperature not to exceed80 C. Then the transient analysis of the CPR1000 SFP with designed passive cooling system is carried out in station blackout(SBO) accident by the best-estimate thermal-hydraulic system code RELAP5. The simulation results show that to maintain the temperature of CPR1000 SFP under 80 C, the numbers of the SFP and air cooling heat exchangers tubes are 6627 and 19 086, respectively.The height difference between the bottom of the air cooling heat exchanger and the top of the SFP heat exchanger is3.8 m. The number of SFP heat exchanger tubes decreases as the height difference increases, while the number of the air cooling heat exchanger tubes increases. The transient analysis results show that after the SBO accident, a stable natural cooling circulation is established. The surface temperature of CPR1000 SFP increases continually until 80 C, which indicates that the design of the passive air cooling system for CPR1000 SFP is capable of removing the decay heat to maintain the temperature of the SFP around 80 C after losing the heat sink.展开更多
Chemically modified carbonaceous materials have attained utmost attention in the fields of renewable energy storage and conversion,due to the controllable physicochemical properties,tailorable micro-/nanostructures,an...Chemically modified carbonaceous materials have attained utmost attention in the fields of renewable energy storage and conversion,due to the controllable physicochemical properties,tailorable micro-/nanostructures,and respectable stability.Herein,P-doped mesoporous carbons were synthesized by using F127 as the soft template,organophosphonic acid as the P source and phenolic resin as the carbon source.Small amounts of iron species were introduced to act as a graphitization catalyst.The synthesized carbons exhibit the well-defined wormhole-like pore structure featuring high specific surface area and homogenously doped P heteroatoms.Notably,introducing iron species during the synthesis process can optimize the textural properties and the degree of graphitization of carbon materials.The doping amount of P has an important effect on the porous structure and the defect degree,which correspondingly influence the active sites and the oxygen reduction reaction(ORR)activity.The resultant material presents superior catalytic activity for the ORR,together with remarkably enhanced durability and methanol tolerance in comparison with the commercial Platinum catalyst,demonstrating the possibility for its use in electrode materials and electronic nanodevices for metal-air batteries and fuel cells.展开更多
The exploration of cost-effective non-noble-metal electrocatalysts is highly imperative to replace the state-of-the-art platinum-based catalysts for oxygen reduction reaction(ORR). Here, we prepared cobalt phosphonate...The exploration of cost-effective non-noble-metal electrocatalysts is highly imperative to replace the state-of-the-art platinum-based catalysts for oxygen reduction reaction(ORR). Here, we prepared cobalt phosphonate-derived N-doped cobalt phosphate/carbon nanotube hybrids(Co Pi C-N/CNTs) by hydrothermal treatment of N-containing cobalt phosphonate and oxidized carbon nanotubes(o-CNT) followed by high-temperature calcination under nitrogen atmosphere. The resultant Co Pi C-N/CNT exhibits a superior electrocatalytic performance for the ORR in alkaline media, which is equal to the commercial Pt/C catalyst in the aspect of half-wave potential, onset potential and diffuse limiting current density. Furthermore, the excellent tolerance to methanol and strong durability outperform those of commercial Pt/C. It is found that cobalt phosphonate-derived N-doped cobalt phosphate and the in-situ formed graphitic carbons play key roles on the activity enhancement. Besides, introducing a suitable amount of CNTs enhances the electronic conductivity and further contributes to the improved ORR performance.展开更多
The Bohai Sea is one of the southernmost areas for sea ice formation in the northern hemisphere.Sea ice disasters in this body of water severely affect marine activities and the safety of coastal residents.In this stu...The Bohai Sea is one of the southernmost areas for sea ice formation in the northern hemisphere.Sea ice disasters in this body of water severely affect marine activities and the safety of coastal residents.In this study,we analyze the variation characteristics of the sea ice in the Bohai Sea and establish an annual regression model based on predictable mode analysis method.The results show the following:1)From 1970 to 2018,the average ice grade is(2.6±0.8),with a maximum of 4.5 and a minimum of 1.0.Liaodong Bay(LDB)has the heaviest ice conditions in the Bohai Sea,followed by Bohai Bay(BHB)and Laizhou Bay(LZB).Interannual variation is obvious in all three bays,but the linear decreasing trend is significant only in BHB.2)Three modes are obtained from empirical orthogonal function analysis,namely,single polarity mode with the same sign of anomaly in all of the three bays and strong interannual variability(82.0%),the north–south dipole mode with BHB and LZB showing an opposite sign of anomalies to that in LDB and strong decadal variations(14.5%),and a linear trend mode(3.5%).Critical factors are analyzed and regression equations are established for all the principal components,and then an annual hindcast model is established by synthesizing the results of the three modes.This model provides an annual spatial prediction of the sea ice in the Bohai Sea for the first time,and meets the demand of operational sea ice forecasting.展开更多
Objective To investigate the clinicopathological characteristics and clinical treatment outcomes of patients with papillary serous carcinoma of the uterine cervix(PSCC).Methods In this study, 4 patients with histologi...Objective To investigate the clinicopathological characteristics and clinical treatment outcomes of patients with papillary serous carcinoma of the uterine cervix(PSCC).Methods In this study, 4 patients with histologically confirmed papillary serous carcinoma of the uterine cervix were retrospectively investigated. Pap smears, human papillomavirus(HPV) screening, tumor marker status, biopsy analysis, and relevant imaging examinations were conducted for the confirmation of primary diagnosis and recurrence. Patients underwent surgery, chemotherapy, or radiotherapy, and survival were the main endpoint.Results The 4 patients were diagnosed with IB1, IB1, IIA, or IIIB disease. Two patients(2/4) presented with recurrence within 18 months after primary therapy. Compared with chemotherapy alone(progressionfree survival(PFS): 11 months), radiotherapy combined with adjuvant chemotherapy showed favorable PFS rates(PFS: 20, 36, 13 months in 3 cases), although valid statistical analysis was not feasible because of the small sample size. The 5-year survival rate was 0%, and the 3-year survival rate was 75%. Our data, in agreement with the literature evidence, showed that the number of moderate-risk and high-risk factors in patients diagnosed with PSCC at an early stage was higher than that in patients diagnosed with common adenocarcinoma/squamous carcinoma of the uterine cervix.Conclusion PSCC has a poor clinical prognosis, and compared with chemotherapy alone, radiotherapy combined with adjuvant chemotherapy may lead to improved PFS.展开更多
Objective To contrast and analyze the difference of metabolites of intestinal flora between patients with type 2diabetes and normal blood glucose human in Xinjiang Uygur and Kazak.Methods Uygur fecal samples and Kazak...Objective To contrast and analyze the difference of metabolites of intestinal flora between patients with type 2diabetes and normal blood glucose human in Xinjiang Uygur and Kazak.Methods Uygur fecal samples and Kazak fecal samples were collected,and short-chain fatty acids(SCFA)were extracted by water from feces,then the content of SCFA in fecal samples was analyzed by gas-chromatography mass-spectrometry(GC-MS).Results Both Uygurs and Kazaks,in their feces,the content of SCFA in the feces showed significantly decreased in patients with type 2diabetes,and a significant negative linear correlation was shown between the fasting plasma glucose and the concentration of SCFA in the fecal samples.But,there was no statistical differences between uygurs and kazaks,in not only normal blood glucose group,but also type 2 diabetes group.Conclusion The feces of patients with type 2diabetes has an decreased concentration of SCFA.Between Uygurs and Kazaks,the metabolic changes of intestinal flora was similar in patients with type 2diabetes.展开更多
Recent years, pronunciation of being native-like is more and more stressed in China; so many scholars have done researches on this area. Researchers explore disparate ways linked with prosody acquisition to try to loo...Recent years, pronunciation of being native-like is more and more stressed in China; so many scholars have done researches on this area. Researchers explore disparate ways linked with prosody acquisition to try to look out the factors that give influence to the English prosody acquisition. Generally concluding, two aspects are taken into account by researchers: linguistics ways and sociolinguistics ways. For instances, the whole features of learning prosody acquisition, semantic ways to learn the prosody; input and output frequency, age and gender effect on the prosody are the important factors.展开更多
基金supported by National High-tech R&D Program of China(No.2012AA050905)
文摘This paper proposes a design of passive cooling system for CPR1000 spent fuel pool(SFP). Our design can effectively manage the SFP temperature not to exceed80 C. Then the transient analysis of the CPR1000 SFP with designed passive cooling system is carried out in station blackout(SBO) accident by the best-estimate thermal-hydraulic system code RELAP5. The simulation results show that to maintain the temperature of CPR1000 SFP under 80 C, the numbers of the SFP and air cooling heat exchangers tubes are 6627 and 19 086, respectively.The height difference between the bottom of the air cooling heat exchanger and the top of the SFP heat exchanger is3.8 m. The number of SFP heat exchanger tubes decreases as the height difference increases, while the number of the air cooling heat exchanger tubes increases. The transient analysis results show that after the SBO accident, a stable natural cooling circulation is established. The surface temperature of CPR1000 SFP increases continually until 80 C, which indicates that the design of the passive air cooling system for CPR1000 SFP is capable of removing the decay heat to maintain the temperature of the SFP around 80 C after losing the heat sink.
基金supported by the National Natural Science Foundation of China(21421001,21573115)
文摘Chemically modified carbonaceous materials have attained utmost attention in the fields of renewable energy storage and conversion,due to the controllable physicochemical properties,tailorable micro-/nanostructures,and respectable stability.Herein,P-doped mesoporous carbons were synthesized by using F127 as the soft template,organophosphonic acid as the P source and phenolic resin as the carbon source.Small amounts of iron species were introduced to act as a graphitization catalyst.The synthesized carbons exhibit the well-defined wormhole-like pore structure featuring high specific surface area and homogenously doped P heteroatoms.Notably,introducing iron species during the synthesis process can optimize the textural properties and the degree of graphitization of carbon materials.The doping amount of P has an important effect on the porous structure and the defect degree,which correspondingly influence the active sites and the oxygen reduction reaction(ORR)activity.The resultant material presents superior catalytic activity for the ORR,together with remarkably enhanced durability and methanol tolerance in comparison with the commercial Platinum catalyst,demonstrating the possibility for its use in electrode materials and electronic nanodevices for metal-air batteries and fuel cells.
基金supported by the National Natural Science Foundation of China(21421001,21573115)~~
文摘The exploration of cost-effective non-noble-metal electrocatalysts is highly imperative to replace the state-of-the-art platinum-based catalysts for oxygen reduction reaction(ORR). Here, we prepared cobalt phosphonate-derived N-doped cobalt phosphate/carbon nanotube hybrids(Co Pi C-N/CNTs) by hydrothermal treatment of N-containing cobalt phosphonate and oxidized carbon nanotubes(o-CNT) followed by high-temperature calcination under nitrogen atmosphere. The resultant Co Pi C-N/CNT exhibits a superior electrocatalytic performance for the ORR in alkaline media, which is equal to the commercial Pt/C catalyst in the aspect of half-wave potential, onset potential and diffuse limiting current density. Furthermore, the excellent tolerance to methanol and strong durability outperform those of commercial Pt/C. It is found that cobalt phosphonate-derived N-doped cobalt phosphate and the in-situ formed graphitic carbons play key roles on the activity enhancement. Besides, introducing a suitable amount of CNTs enhances the electronic conductivity and further contributes to the improved ORR performance.
基金supported by the National Natural Science Foundation of China(Nos.U1706216 and 41575067)the National Key Research and Development Program(Nos.2015CB953904,2016YFC1402000,and 2016YFC 1401500)
文摘The Bohai Sea is one of the southernmost areas for sea ice formation in the northern hemisphere.Sea ice disasters in this body of water severely affect marine activities and the safety of coastal residents.In this study,we analyze the variation characteristics of the sea ice in the Bohai Sea and establish an annual regression model based on predictable mode analysis method.The results show the following:1)From 1970 to 2018,the average ice grade is(2.6±0.8),with a maximum of 4.5 and a minimum of 1.0.Liaodong Bay(LDB)has the heaviest ice conditions in the Bohai Sea,followed by Bohai Bay(BHB)and Laizhou Bay(LZB).Interannual variation is obvious in all three bays,but the linear decreasing trend is significant only in BHB.2)Three modes are obtained from empirical orthogonal function analysis,namely,single polarity mode with the same sign of anomaly in all of the three bays and strong interannual variability(82.0%),the north–south dipole mode with BHB and LZB showing an opposite sign of anomalies to that in LDB and strong decadal variations(14.5%),and a linear trend mode(3.5%).Critical factors are analyzed and regression equations are established for all the principal components,and then an annual hindcast model is established by synthesizing the results of the three modes.This model provides an annual spatial prediction of the sea ice in the Bohai Sea for the first time,and meets the demand of operational sea ice forecasting.
文摘Objective To investigate the clinicopathological characteristics and clinical treatment outcomes of patients with papillary serous carcinoma of the uterine cervix(PSCC).Methods In this study, 4 patients with histologically confirmed papillary serous carcinoma of the uterine cervix were retrospectively investigated. Pap smears, human papillomavirus(HPV) screening, tumor marker status, biopsy analysis, and relevant imaging examinations were conducted for the confirmation of primary diagnosis and recurrence. Patients underwent surgery, chemotherapy, or radiotherapy, and survival were the main endpoint.Results The 4 patients were diagnosed with IB1, IB1, IIA, or IIIB disease. Two patients(2/4) presented with recurrence within 18 months after primary therapy. Compared with chemotherapy alone(progressionfree survival(PFS): 11 months), radiotherapy combined with adjuvant chemotherapy showed favorable PFS rates(PFS: 20, 36, 13 months in 3 cases), although valid statistical analysis was not feasible because of the small sample size. The 5-year survival rate was 0%, and the 3-year survival rate was 75%. Our data, in agreement with the literature evidence, showed that the number of moderate-risk and high-risk factors in patients diagnosed with PSCC at an early stage was higher than that in patients diagnosed with common adenocarcinoma/squamous carcinoma of the uterine cervix.Conclusion PSCC has a poor clinical prognosis, and compared with chemotherapy alone, radiotherapy combined with adjuvant chemotherapy may lead to improved PFS.
基金National natural science foundation project(NO.30760288)
文摘Objective To contrast and analyze the difference of metabolites of intestinal flora between patients with type 2diabetes and normal blood glucose human in Xinjiang Uygur and Kazak.Methods Uygur fecal samples and Kazak fecal samples were collected,and short-chain fatty acids(SCFA)were extracted by water from feces,then the content of SCFA in fecal samples was analyzed by gas-chromatography mass-spectrometry(GC-MS).Results Both Uygurs and Kazaks,in their feces,the content of SCFA in the feces showed significantly decreased in patients with type 2diabetes,and a significant negative linear correlation was shown between the fasting plasma glucose and the concentration of SCFA in the fecal samples.But,there was no statistical differences between uygurs and kazaks,in not only normal blood glucose group,but also type 2 diabetes group.Conclusion The feces of patients with type 2diabetes has an decreased concentration of SCFA.Between Uygurs and Kazaks,the metabolic changes of intestinal flora was similar in patients with type 2diabetes.
文摘Recent years, pronunciation of being native-like is more and more stressed in China; so many scholars have done researches on this area. Researchers explore disparate ways linked with prosody acquisition to try to look out the factors that give influence to the English prosody acquisition. Generally concluding, two aspects are taken into account by researchers: linguistics ways and sociolinguistics ways. For instances, the whole features of learning prosody acquisition, semantic ways to learn the prosody; input and output frequency, age and gender effect on the prosody are the important factors.
