期刊文献+
共找到13篇文章
< 1 >
每页显示 20 50 100
Hereditary hemorrhagic telangiectasia involving portal venous system:A case report and review of the literature
1
作者 Jun-Ling Wu Zhi-Zhuang Zhao +7 位作者 Jun Chen Han-Wen Zhang Zhe Luan Cong-Yong Li Yi-Ming Zhao Yu-Jia Jing shu-fang wang Gang Sun 《World Journal of Gastrointestinal Surgery》 SCIE 2023年第10期2367-2375,共9页
BACKGROUND Hereditary hemorrhagic telangiectasia(HHT)is an autosomal dominant genetic disorder with an incidence of approximately 1 in 5000 in the general population.It is characterized by vasodilation,which affects s... BACKGROUND Hereditary hemorrhagic telangiectasia(HHT)is an autosomal dominant genetic disorder with an incidence of approximately 1 in 5000 in the general population.It is characterized by vasodilation,which affects specific organs,such as the skin,mucous membranes,brain,lungs,gastrointestinal tract,liver,and others.However,HHT rarely involves the portal venous system to cause serious clinical compli-cations.CASE SUMMARY A 68-year-old woman was admitted to the emergency department due to four consecutive days of abdominal pain and bloody stool and was subsequently diagnosed with HHT.Computed tomography angiography confirmed the presence of an arteriovenous fistula(AVFs).Considering this specific manifestation,whole exome sequencing was performed.After a comprehensive evaluation,a selective superior mesenteric artery embolization was prioritized to avoid intestinal ischemia.The postoperative symptoms of the patient were quickly relieved.Unfortunately,two months post-procedure the patient died from intestinal necrosis and abdominal infection related to remaining AVFs.CONCLUSION For patients with diffuse superior mesenteric AVFs,selective mesenteric arterial embolization may lead to positive short-term outcomes. 展开更多
关键词 Hereditary hemorrhagic telangiectasia Portal system Arteriovenous fistula Arteriovenous malformation Selective artery embolization Case report
下载PDF
Chinese physicians' perceptions of fecal microbiota transplantation 被引量:12
2
作者 Rong-Rong Ren Gang Sun +17 位作者 Yun-Sheng Yang Li-Hua Peng shu-fang wang Xiao-Hong Shi Jing-Quan Zhao Yong-Ling Ban Fei Pan Xue-Hong wang Wei Lu Jian-Lin Ren Ying Song Jiang-Bin wang Qi-Ming Lu Wen-Yuan Bai Xiao-Ping Wu Zi-Kai wang Xiao-Mei Zhang Ye Chen 《World Journal of Gastroenterology》 SCIE CAS 2016年第19期4757-4765,共9页
AIM: To explore Chinese physicians' perceptions towards fecal microbiota transplantation(FMT) and to provide information and an assessment of FMT development in China.METHODS: A self-administered questionnaire was... AIM: To explore Chinese physicians' perceptions towards fecal microbiota transplantation(FMT) and to provide information and an assessment of FMT development in China.METHODS: A self-administered questionnaire was developed according to the FMT practice guidelines and was distributed to physicians in hospitals via Internet Research Electronic Data Capture(REDcap) software and electronic mails to assess their attitudes toward and knowledge of FMT. The questionnaire included a brief introduction of FMT that was followed by 20 questions. The participants were required to respond voluntarily, under the condition of anonymity and without compensation. Except for the fill-in-the-blank questions, all of the other questions were required in the REDcap data collection systems, and the emailed questionnaires were completed based on eligibility.RESULTS: Up to December 9, 2014, 844 eligible questionnaires were received out of the 980 distributed questionnaires, with a response rate of 86.1%. Among the participants, 87.3% were from tertiary hospitals, and there were 647(76.7%) gastroenterologists and 197(23.3%) physicians in other departments(nongastroenterologists). Gastroenterologists' awareness of FMT prior to the survey was much higher than non-gastroenterologists'(54.3 vs 16.5%, P < 0.001); however, acceptance of FMT was not statistically different(92.4 vs 87.1%, P = 0.1603). Major concerns of FMT included the following: acceptability to patients(79.2%), absence of guidelines(56.9%), and administration and ethics(46.5%). On the basis of understanding, the FMT indications preferred byphysicians were recurrent Clostridium difficile infection(86.7%), inflammatory bowel disease combined with Clostridium difficile infection(78.6%), refractory ulcerative colitis(70.9%), ulcerative colitis(65.4%), Crohn's disease(59.4%), chronic constipation(43.7%), irritable bowel syndrome(39.1%), obesity(28.1%) and type 2 diabetes(23.9%). For donor selection, the majority of physicians preferred individuals with a similar gut flora environment to the recipients. 76.6% of physicians chose lower gastrointestinal tract as the administration approach. 69.2% of physicians considered FMT a safe treatment. CONCLUSION: Chinese physicians have awareness and a high acceptance of FMT, especially gastroenterologists, which provides the grounds and conditions for the development of this novel treatment in China. Physicians' greatest concerns were patient acceptability and absence of guidelines. 展开更多
关键词 FECAL MICROBIOTA TRANSPLANTATION CHINESE PHYSICIANS Gastroenterologists Perception Survey
下载PDF
Diagnosis of gastric intraepithelial neoplasia by narrow-band imaging and confocal laser endomicroscopy 被引量:10
3
作者 shu-fang wang Yun-Sheng Yang +7 位作者 Li-Xin Wei Zhong-Sheng Lu Ming-Zhou Guo Jin Huang Li-Hua Peng Gang Sun En-Qiang Ling-Hu Jiang-Yun Meng 《World Journal of Gastroenterology》 SCIE CAS CSCD 2012年第34期4771-4780,共10页
AIM:To evaluate the diagnosis of different differentiated gastric intraepithelial neoplasia (IN) by magnifica-tion endoscopy combined with narrow-band imaging (ME-NBI) and confocal laser endomicroscopy (CLE). METHODS:... AIM:To evaluate the diagnosis of different differentiated gastric intraepithelial neoplasia (IN) by magnifica-tion endoscopy combined with narrow-band imaging (ME-NBI) and confocal laser endomicroscopy (CLE). METHODS:Eligible patients with suspected gastric IN lesions previously diagnosed by endoscopy in secondary hospitals and scheduled for further diagnosis and tratment were recruited for this study. Excluded from the study were patients who had liver cirrhosis, impaired renal function, acute gastrointestinal (GI) bleeding, coagulopathy, esophageal varices, jaundice, and GI post-surgery. Also excluded were those who were pregnant, breastfeeding, were younger than 18 years old, or were unable to provide informed consent. All patients had all mucus and bile cleared from their stom-achs. They then received upper GI endoscopy. When a mucosal lesion is found during observation with whitelight imaging, the lesion is visualized using maximal magnification, employing gradual movement of the tip of the endoscope to bring the image into focus. Saved images are analyzed. Confocal images were evaluated by two endoscopists (Huang J and Li MY), who were familiar with CLE, blinded to the related information about the lesions, and asked to classify each lesion as either a low grade dysplasia (LGD) or high grade dysplasia (HGD) according to given criteria. The results were compared with the final histopathologic diagnosis. ME-NBI images were evaluated by two endoscopists (Lu ZS and Ling-Hu EQ) who were familiar with NBI, blinded to the related information about the lesions and CLE images, and were asked to classify each lesion as a LGD or HGD according to the "microvascular pattern and surface pattern" classification system. The results were compared with the final histopathologic diagnosis. RESULTS: The study included 32 pathology-proven low grade gastric IN and 26 pathology-proven high grade gastric IN that were detected with any of the modalities. CLE and ME-NBI enabled clear visualization of the vascular microsurface patterns and microvascular structures of the gastric mucosa. The accuracy of the CLE and the ME-NBI diagnosis was 88% (95% CI:78%-98%) and 81% (95% CI: 69%-93%), respectively. The kappa coefficient of agreement between the histopathology and the in vivo CLE imaging was 0.755; between the histopathology and the in vivo CLE imaging was 0.615. McNemar's test (binomial distribution used) indicated that the agreement was significant (P < 0.05). When patients were diagnosed by MENBI with CLE, the overall accuracy of the diagnosis was 86.21% (95% CI:73%-96%), and the kappa coefficient of agreement was 0.713, according to McNemar's test (P < 0.05). CONCLUSION:Higher diagnostic accuracy, sensitivityand specificity of CLE over ME-NBI indicate the feasibility of these two techniques for the efficacious diagnostic classification of gastric IN. 展开更多
关键词 胃的 intraepithelial 瘤形成 组织学的诊断 共焦的激光 endomicroscopy 放大内视镜检查法 狭窄乐队的成像 胃的 intraepithelial 瘤形成损害
下载PDF
Predictive factors of endoscopic submucosal dissection procedure time for gastric superficial neoplasia 被引量:6
4
作者 Zhong-Sheng Lu Yun-Sheng Yang +7 位作者 Dan Feng shu-fang wang Jing Yuan Jin Huang Xiang-Dong wang Jiang-Yun Meng Hong Du Hong-Bin wang 《World Journal of Gastroenterology》 SCIE CAS CSCD 2012年第47期7009-7014,共6页
AIM:To identify the determinants of endoscopic submucosal dissection(ESD) operation time.METHODS:This investigation was conducted as a single-center,prospective study in which ESD was performed by the same endoscopist... AIM:To identify the determinants of endoscopic submucosal dissection(ESD) operation time.METHODS:This investigation was conducted as a single-center,prospective study in which ESD was performed by the same endoscopist at the Chinese PLA General Hospital.A total of 173 patients underwent ESD operations performed by Dr.Lu from July 2007 to December 2011,and 183 lesions were enrolled.Patient gender,age,tumor location,gross type,tumor size,pathological type and adhesions were recorded prospectively.The order of treatment represented the experience of the operator.Univariate analysis and multivariate analysis were performed to evaluate the relationships between these factors and ESD procedure time.RESULTS:Univariate analysis showed the ESD time was closely related to the gender(P = 0.0210),tumor size(P < 0.0001),location(P < 0.0001),gross type(P < 0.0001) and adhesion(P = 0.0010).The surgical proficiency level was associated with ESD time in unit area(P < 0.0001).Multivariate analysis revealed that the ESD time was positively correlated with tumor size(P < 0.0001),adhesion(P < 0.0001) and location(P < 0.0001),but negatively correlated with surgical proficiency level(P = 0.0046).CONCLUSION:Large tumor size,adjacency to the cardia,and adhesion are predictors of a long ESD time,whereas high surgical proficiency level predicts a short ESD time. 展开更多
关键词 时间 肿瘤 手术 预测 内镜 剥离 膜下 单因素分析
下载PDF
Adipose-derived stromal cells resemble bone marrow stromal cells in hepatocyte differentiation potential in vitro and in vivo 被引量:7
5
作者 Li-juan Xu shu-fang wang +5 位作者 De-Qing wang Lian-jun Ma Zheng Chen Qian-Qian Chen Jun wang Li Yan 《World Journal of Gastroenterology》 SCIE CAS 2017年第38期6973-6982,共10页
AIM To investigate whether mesenchymal stem cells(MSCs) from adipose-derived stromal cells(ADSCs) and bone marrow stromal cells(BMSCs) have similar hepatic differentiation potential.METHODS Mouse ADSCs and BMSCs were ... AIM To investigate whether mesenchymal stem cells(MSCs) from adipose-derived stromal cells(ADSCs) and bone marrow stromal cells(BMSCs) have similar hepatic differentiation potential.METHODS Mouse ADSCs and BMSCs were isolated and cultured. Their morphological and phenotypic characteristics, as well as their multiple differentiation capacity were compared. A new culture system was established to induce ADSCs and BMSCs into functional hepatocytes. Reverse transcription polymerase chain reaction, Western blot, and immunofluorescence analyses were performed to identify the induced hepatocytelike cells. CM-Dil-labeled ADSCs and BMSCs were then transplanted into a mouse model of CCl4-induced acute liver failure. fluorescence microscopy was used to track the transplanted MSCs. Liver function was tested by an automatic biochemistry analyzer, and liver tissue histology was observed by hematoxylin and eosin(HE) staining.RESULTS ADSCs and BMSCs shared a similar morphology and multiple differentiation capacity, as well as a similar phenotype(with expression of CD29 and CD90 and no expression of CD11 b or CD45). Morphologically, ADSCs and BMSCs became round and epithelioid following hepatic induction. These two cell types differentiated into hepatocyte-like cells with similar expression of albumin, cytokeratin 18, cytokeratin 19, alpha fetoprotein, and cytochrome P450. fluorescence microscopy revealed that both ADSCs and BMSCs were observed in the mouse liver at different time points. Compared to the control group, both the function of the injured livers and HE staining showed significant improvement in the ADSC-and BMSC-transplanted mice. There was no significant difference between the two MSC groups.CONCLUSION ADSCs share a similar hepatic differentiation capacity and therapeutic effect with BMSCs in an acute liver failure model. ADSCs may represent an ideal seed cell type for cell transplantation or a bio-artificial liver support system. 展开更多
关键词 脂肪质导出 stromal 房间 骨头髓 stromal 房间 房间区别 Hepatocyte 区别
下载PDF
Gastric body diaphragm-like stricture as a rare complication of nonsteroidal anti-inflammatory drugs
6
作者 Li-Li Wu Yun-Sheng Yang +1 位作者 Feng-Chun Cai shu-fang wang 《World Journal of Gastroenterology》 SCIE CAS 2013年第23期3703-3706,共4页
Increased risk due to nonsteroidal anti-inflammatory drugs (NSAIDs) therapy has been observed in patients. Although diaphragm-like stricture in the small bowel and colon induced by NSAIDs therapy has been rarely repor... Increased risk due to nonsteroidal anti-inflammatory drugs (NSAIDs) therapy has been observed in patients. Although diaphragm-like stricture in the small bowel and colon induced by NSAIDs therapy has been rarely reported, gastric body diaphragm-like stricture has not been reported. We describe the first case of gastric body diaphragm-like stricture due to NSAIDs in a 44-year-old male patient who was successfully treated by an endoscopic approach to avoid complicated surgery. This case highlights new insight into the disadvantages of NSAIDs and provides new data for future clinical studies. 展开更多
关键词 Gastric GASTROSCOPY DIAPHRAGM STRICTURE NONSTEROIDAL ANTI-INFLAMMATORY drug
下载PDF
构建准层状自空穴掺杂SnSe取向薄膜获得优异热电功率因子和输出功率密度
7
作者 薛宇利 王晴 +7 位作者 高志 钱鑫 王江龙 闫国英 陈明敬 赵立东 王淑芳 李志亮 《Science Bulletin》 SCIE EI CAS CSCD 2023年第22期2769-2778,M0005,共11页
热电技术可以实现热能与电能的相互转换,其开发利用对于缓解能源危机具有重要意义.近10年来,SnSe因其潜在的高能量转换效率、绿色环保和低成本特性而备受关注.但SnSe的固有载流子浓度低(约10~(17)cm^(-3)),导致其功率因子偏低,从而限制... 热电技术可以实现热能与电能的相互转换,其开发利用对于缓解能源危机具有重要意义.近10年来,SnSe因其潜在的高能量转换效率、绿色环保和低成本特性而备受关注.但SnSe的固有载流子浓度低(约10~(17)cm^(-3)),导致其功率因子偏低,从而限制了SnSe基器件的输出功率密度.因此,探索新的载流子浓度优化策略对于SnSe的应用至关重要.此外,与三维块体相比,二维薄膜更易和现代半导体工艺相兼容,在热电微纳米器件的构筑和应用方面具有独特优势.本文报道了一种利用非原位硒化技术,通过电荷转移和自空穴掺杂效应来优化a轴取向SnSe基薄膜的载流子浓度.当硒化时间为20 min时,薄膜载流子浓度可提高至10~(18)cm^(-3)数量级,形成了准层状的自空穴掺杂SnSe基薄膜,其功率因子在600 K时达到了5.9μW cm^(-1)K^(-2).由硒化处理的SnSe基取向薄膜构筑的热电发电机在50和90 K的温差下分别具有约83、838μW cm^(-2)的超高功率密度.非原位硒化技术可以有效提高SnSe基薄膜的载流子浓度,为其他热电材料性能优化提供了一种新策略. 展开更多
关键词 Thermoelectric property Thin film Tin selenide Post-selenization Carrier concentration
原文传递
Enhancing thermoelectric performance of n-type AgBi_(3)S_(5)through synergistically optimizing the effective mass and carrier mobility
8
作者 Xin Qian Xiaoxue Zhang +5 位作者 Haoran Guo Bangfu Ding Mingjing Chen Jiang-Long wang Li-Dong Zhao shu-fang wang 《Journal of Materiomics》 SCIE CSCD 2023年第5期874-881,共8页
AgBi_(3)S_(5) is a new n-type thermoelectric material that is environmentally friendly and composed of elements of earth-abundant,non-toxic and high performance-cost ratio.This compound features an intrinsically low t... AgBi_(3)S_(5) is a new n-type thermoelectric material that is environmentally friendly and composed of elements of earth-abundant,non-toxic and high performance-cost ratio.This compound features an intrinsically low thermal conductivity derived from its complex monoclinic structure.However,the terrible electrical transport properties greatly limited the improvement of thermoelectric performance.Most previous studies considered that carrier concentration is the main reason for low electrical conductivity and focused on improving carrier concentration by aliovalent ion doping.In this work,we found that the critical parameter that restricts the electric transport performance of AgBi_(3)S_(5)was the extremely low carrier mobility instead of the carrier concentration.According to the Pisarenko relationships and density functional theory calculations,Nb doping can sharpen the conduction band of AgBi_(3)S_(5),which contributes to reducing the effective mass and improving the carrier mobility.With a further increase of the Nb doping content,the conduction band convergence can enlarge the effective mass and preserve the carrier mobility.Combined with the decrease in lattice thermal conductivity due to the intensive phone scattering,a maximum ZT value of~0.50 at 773 K was achieved in Ag_(0.97)Nb_(0.03)Bi_(3)S_(5),which was~109.6%higher than that of pure AgBi3S5.This work will stimulate the new exploration of high-performance thermoelectric materials in ternary metal sulfides. 展开更多
关键词 THERMOELECTRIC AgBi_(3)S_(5) Effective mass Carrier mobility ZT value
原文传递
Expression of Survivin Gene among Human Normal Endometrium,Atypical Hyperplasia of Endometrium and Endometrial Carcinoma 被引量:4
9
作者 Jian-ying XU shu-fang wang +1 位作者 Zhong-yan WAN Wei-jie ZHU 《Journal of Reproduction and Contraception》 CAS 2010年第3期129-135,共7页
Objective To investigate the expression of survivin gene among human normal endometrium,atypical hyperplasia of endometrium,and endometrial carcinoma.Methods Tissue samples of human normal endometrium during prolifera... Objective To investigate the expression of survivin gene among human normal endometrium,atypical hyperplasia of endometrium,and endometrial carcinoma.Methods Tissue samples of human normal endometrium during proliferative phase (NE,n=20),atypical hyperplasia of endometrium (AHE,n=11),and endometrial carcinoma (EC,n=9) were collected.Besides,Paraffin embedded sections of NE (n=20),AHE (n=20),and EC (n=20) were used.The expression of survivin gene was determined by immunohistochemistry and the real-time reverse transcription polymerase chain reaction.Results Survivin immunostaining appeared in the cytoplasm of endometrial epithelial cells.Both survivin staining and mRNA had higher levels in AHE or EC than those in NE (P〈0.01).No difference was found on survivin staining and mRNA between AHE and EC (P〉0.05).Conclusion High expression of survivin gene in human endometrium is associated with the risk of atypical hyperplasia progressing to endometrial carcinoma.The high level of survivin expression is useful as a predictive indicator for endometrial carcinoma. 展开更多
关键词 SURVIVIN ENDOMETRIUM atypical hyperplasia of endometrium endometrial carcinoma
原文传递
Identification and determination of major constituents in a traditional Chinese medicine compound recipe Xiongdankaiming tablet using HPLC-PDA/ESI-MS^n and HPLC-UV/ELSD 被引量:1
10
作者 shu-fang wang Jing LENG +1 位作者 Yi-min XU Mei-ling FENG 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE CAS CSCD 2013年第7期604-614,共11页
Xiongdankaiming tablet (XDKMT), a well-known compound in traditional Chinese medicine, is widely used for the treatment of acute iridocyclitis and primary open-angle glaucoma. In this paper, accurate and reliable meth... Xiongdankaiming tablet (XDKMT), a well-known compound in traditional Chinese medicine, is widely used for the treatment of acute iridocyclitis and primary open-angle glaucoma. In this paper, accurate and reliable methods were developed for the identification of 20 constituents using high-performance liquid chromatography with photodiode array and electron spray ionization-mass spectrometry (HPLC-PDA/ESI-MSn ), and determination of nine of the constituents (chlorogenic acid, gentiopicroside, isochlorogenic acid B, diosmetin-7-O-β-D-glucopyranoside, apigenin, diosmetin, tauroursodeoxycholic acid, acacetin, and taurochenodeoxycholic acid) was developed using HPLC with ultraviolet absorption detector and evaporative light scattering detector (HPLC-UV/ELSD) for the first time. The best results were obtained on a Zorbax SB-C18 column with gradient elution using water (0.1% formic acid) (A) and methanol (0.1% formic acid) (B) at a flow rate of 0.7 ml/min. Tauroursodeoxycholic acid and taurochenodeoxycholic acid, owing to their low UV absorption, were detected by ELSD. The other seven compounds were analyzed by HPLC-UV with variable wavelengths. The calibration curves of all nine constituents showed good linear regression (R2 >0.9996) within the linearity ranges. The limits of detection and quantification were in the ranges of 0.0460-9.90 μg/ml and 0.115-24.8 μg/ml, respectively. The accuracy, in terms of recovery, varied from 95.3% to 104.9% with relative standard deviations (RSDs) less than 4.4%. Precision (with the intra- and inter-day variations less than 4.4%) was also suitable for its intended use. The developed method was successfully applied for the analysis of major components in XDKMT, which provides an appropriate method for the quality control of XDKMT. 展开更多
关键词 Traditional Chinese medicine (TCM) COMPOUND RECIPE Xiongdankaiming TABLET HPLC-UV/ELSD HPLC-MS Quality control
原文传递
Improving electrical and thermal properties synchronously via introducing CsPbBr_(3)QDs into higher manganese silicides
11
作者 Qing wang Zhiliang Li +5 位作者 Xiaofeng Yang Xin Qian Linjuan Guo Jianglong wang Dan Zhang shu-fang wang 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2022年第16期279-286,共8页
Higher manganese silicide(HMS)is a P-type medium temperature thermoelectric(TE)material,which has attracted widespread attention over the past few decades due to its remarkable mechanical properties,excellent chemical... Higher manganese silicide(HMS)is a P-type medium temperature thermoelectric(TE)material,which has attracted widespread attention over the past few decades due to its remarkable mechanical properties,excellent chemical and thermal stability,as well as the non-toxicity,abundance and competitive price.The peak power factor(PF)of HMS is as high as~1.50×10^(-3)W m^(-1)K^(-2)because of its intrinsic high electrical conductivity and Seebeck coefficient.However,the thermal conductivity of HMS is also high,resulting in relatively low z T values.Introducing nano-dispersion in the matrix is one of the most effective methods to enhance the TE properties via reducing the lattice thermal conductivity significantly without drastic changes on the other parameters.In this study,Cs Pb BrQDs with uniform size were synthesized and introduced into HMS bulks.The PF(at 823 K)was enhanced to 1.71×10^(-3)W m^(-1)K^(-2),which is improved 14.0%approximately compared with that of pure HMS owing to the combined effect of element doping and energy filtering.The lattice thermal conductivity(at 823 K)decreased from 2.56W mKto 1.99 W mKsynchronously(~22.0%)due to the intensive phonon scattering caused by Cs doping,and the embedding of Pb riched CsPbBr_(3)QDs and Pb QDs.A maximum z T value of 0.57(823 K)is achieved in Cs Pb BrQDs/HMS composites,which is 36.0%higher than that of pure HMS.Predictably,for other TE materials,it is also feasible to improve the TE properties via introducing metastable quantum dots. 展开更多
关键词 Thermoelectric material Higher manganese silicide Quantum dot Figure of merit INCLUSION
原文传递
Ultrahigh power factors in P-type 1T-ZrX_2(X=S, Se)single layers
12
作者 Ying-Xiang Zhen Ming Yang +4 位作者 Hang Zhang Guang-Sheng Fu Jiang-Long wang shu-fang wang Rui-Ning wang 《Science Bulletin》 SCIE EI CAS CSCD 2017年第22期1530-1537,共8页
The thermoelectric performances of 1 T-ZrX_2(X=S and Se) single layers were investigated using a combination of density functional calculations and semi-classical Boltzmann transport theory. Because of the high hole m... The thermoelectric performances of 1 T-ZrX_2(X=S and Se) single layers were investigated using a combination of density functional calculations and semi-classical Boltzmann transport theory. Because of the high hole mobilities at 300 K, ultrahigh power factors(PF = S^2σ) were found in the P-type compounds;these values were ~ 11.95 and ~13.58 mWK ~2 m^1 for 1T-ZrS_2 and 1T-ZrSe_2 single layers, respectively.However, because of the Lorenz relation between the electrical conductivity(σ) and an electron's thermal conductivity(K_(el)) given by the Wiedemann-Franz law, the electronic figures of merit(Z_(el)T = PF T/K_(el)) at 300 K were approximately 0.67 and 0.75 for the N-and P-type 1T-ZrSe_2, respectively. In addition, the lattice thermal conductivities(K_(Ph)) were calculated, giving values of ~1.43 and ~0.97 W K ~1 m^1 for 1T-ZrS_2 and 1T-ZrSe_2 single layers, respectively. Therefore, because of the lower K_(Ph)/K_(el) ratio, the P-type 1T-ZrX_2 single layers possess higher fngure-of-merits(ZT = Z_(el)T/(1+(K_(Ph)/K_(el))) than their counterparts. This signifies that the P-type samples demonstrate better thermoelectric performance than the N-type ones. The thermoelectric properties of metastable 2H-ZrX_2(X = S and Se) single layers were also investigated. 展开更多
关键词 Thermoelectric property Zirconium dichalcogenides Density functional theory Boltzmann-transport theory
原文传递
Incorporating element doping and quantum dot embedding effects to enhance the thermoelectric properties of higher manganese silicides
13
作者 Qing wang Shiyu Song +7 位作者 Xiaofeng Yang Ziyang Liu Yufei Ma Xingyuan San Jianglong wang Dan Zhang shu-fang wang Zhiliang Li 《Journal of Materiomics》 SCIE EI 2021年第2期377-387,共11页
Element doping and nano-inclusion embedding are effective approaches to enhance the electrical conductivities and decrease the lattice thermal conductivities of thermoelectric(TE)materials,respectively.However,the int... Element doping and nano-inclusion embedding are effective approaches to enhance the electrical conductivities and decrease the lattice thermal conductivities of thermoelectric(TE)materials,respectively.However,the intrinsic low electrical thermal conductivities and high electrical properties are severely sacrificed,and the final figure of merit(ZT)is usually restricted.In this study,Ag doping and Pt quantum dot(QD)embedding were synchronously achieved via embedding Ag/Pt alloy QDs into the higher manganese silicides to avoid the conventional single-element doping strategy.The power factor(at 823 K)was enhanced from 1.57×10^(-3) W m^(-1) K^(-2) to 1.82×10^(-3) W m^(-1) K^(-2)(-16%)due to the-18%increase in carrier concentration that was derived from the Ag doping effect.Simultaneously,the lattice thermal conductivity(at 823 K)decreased from 2.65 W m^(-1) K^(-1) e1.92 W m^(-1) K^(-1)(-28%)because of the broadband phonon scattering effect that resulted from the residual Pt QDs inclusions.Synthetically,the optimal ZT value increased by-52%from 0.42 to 0.64 at 823 K.This study demonstrated that incorporating metastable alloy QDs to obtain element doping and nano-inclusion embedding effects is a novel and feasible means to enhance the ZT value of HMS.This method is also possibly applicable to other alloy QD/TE composites. 展开更多
关键词 Quantum dot Inclusion Higher manganese silicide Thermoelectric material Figure of merit
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部