Tong Hoang Lin, Che Quang Cong, Nguyen Thanh Hoai Nam, Hoang An, Nguyen Duy Hai, Ton That Buu, Thoi Le Nhat Binh, Hoang Le Minh, Lam Thanh Ngan, Hoang Thuy Kim Ngan, Du Chi Vi, Ta Dang Khoa, Nguyen Huu Hieu
{"title":"Green synthesis of three-dimensional magnesium ferrite/titanium dioxide/reduced graphene from Garcinia mangostana extract for crystal violet photodegradation and antibacterial activity","authors":"Tong Hoang Lin, Che Quang Cong, Nguyen Thanh Hoai Nam, Hoang An, Nguyen Duy Hai, Ton That Buu, Thoi Le Nhat Binh, Hoang Le Minh, Lam Thanh Ngan, Hoang Thuy Kim Ngan, Du Chi Vi, Ta Dang Khoa, Nguyen Huu Hieu","doi":"10.1088/1674-4926/44/12/122702","DOIUrl":"https://doi.org/10.1088/1674-4926/44/12/122702","url":null,"abstract":"In this study, three-dimensional porous magnesium ferrite/titanium dioxide/reduced graphene oxide (MgFe<sub>2</sub>O<sub>4</sub>-GM/TiO<sub>2</sub>/rGO (MGTG)) was successfully synthesized via green and hydrothermal-supported co-precipitation methods using the extract of <italic toggle=\"yes\">Garcinia mangostana </italic>(<italic toggle=\"yes\">G. mangostana</italic>) as a reducing agent. The characterization results indicate the successful formation of the nano/micro MgFe<sub>2</sub>O<sub>4</sub> (MFO) and TiO<sub>2</sub> on the structure of the reduced graphene oxide (rGO), which can also act as efficient support, alleviating the agglomeration of the nano/micro MFO and TiO<sub>2</sub>. The synergic effects of the adsorption and photodegradation activity of the material were investigated according to the removal of crystal violet (CV) under ultraviolet light. The effects of catalyst dosage, CV concentration, and pH on the CV removal efficiency of the MGTG were also investigated. According to the results, the CV photodegradation of the MGTG-200 corresponded to the pseudo-first-order kinetic model. The reusability of the material after 10 cycles also showed a removal efficiency of 92%. This happened because the materials can easily be recollected using external magnets. In addition, according to the effects of different free radicals <bold>·</bold>O<sub>2</sub>\u0000<sup>−</sup>, h<sup>+</sup>, and <bold>·</bold>OH on the photodegradation process, the photocatalysis mechanism of the MGTG was also thoroughly suggested. The antibacterial efficiency of the MGTG was also evaluated according to the inhibition of the Gram-positive bacteria strain <italic toggle=\"yes\">Staphylococcus aureus</italic> (<italic toggle=\"yes\">S. aureus</italic>). Concurrently, the antibacterial mechanism of the fabricated material was also proposed. These results confirm that the prepared material can be potentially employed in a wide range of applications, including wastewater treatment and antibacterial activity.","PeriodicalId":17038,"journal":{"name":"Journal of Semiconductors","volume":"18 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139761900","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Hyperfine splitting and ferromagnetism in CdS : Mn nanoparticles for optoelectronic device applications","authors":"Madhavi Sharad Darekar, Praveen Beekanahalli Mokshanatha","doi":"10.1088/1674-4926/44/12/122502","DOIUrl":"https://doi.org/10.1088/1674-4926/44/12/122502","url":null,"abstract":"Manganese (Mn) doped cadmium sulphide (CdS) nanoparticles were synthesized using a chemical method. It was possible to decrease CdS : Mn particle size by increasing Mn concentration. Investigation techniques such as ultraviolet−visible (UV−Vis) absorption spectroscopy and photoluminescence (PL) spectroscopy were used to determine optical properties of CdS : Mn nanoparticles. Size quantization effect was observed in UV−Vis absorption spectra. Quantum efficiency for luminescence or the internal magnetic field strength was increased by doping CdS nanoparticles with Mn element. Orange emission was observed at wavelength ~630 nm due to <sup>4</sup>T<sub>1</sub> → <sup>6</sup>A<sub>1</sub> transition. Isolated Mn<sup>2+</sup> ions arranged in tetrahedral coordination are mainly responsible for luminescence. Luminescence quenching and the effect of Mn doping on hyperfine interactions in the case of CdS nanoparticles were also discussed. The corresponding weight percentage of Mn element actually incorporated in doping process was determined by atomic absorption spectroscopy (AAS). Crystallinity was checked and the average size of nanoparticles was estimated using the X-ray diffraction (XRD) technique. CdS : Mn nanoparticles show ferromagnetism at room temperature. Transmission electron microscopy (TEM) images show spherical clusters of various sizes and selected area electron diffraction (SAED) patterns show the polycrystalline nature of the clusters. The electronic states of diluted magnetic semiconductors (DMS) of Ⅱ−Ⅵ group CdS nanoparticles give them great potential for applications due to quantum confinement. In this study, experimental results and discussions on these aspects have been given.","PeriodicalId":17038,"journal":{"name":"Journal of Semiconductors","volume":"20 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139761816","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A review of automatic detection of epilepsy based on EEG signals","authors":"Qirui Ren, Xiaofan Sun, Xiangqu Fu, Shuaidi Zhang, Yiyang Yuan, Hao Wu, Xiaoran Li, Xinghua Wang, Feng Zhang","doi":"10.1088/1674-4926/44/12/121401","DOIUrl":"https://doi.org/10.1088/1674-4926/44/12/121401","url":null,"abstract":"Epilepsy is a common neurological disorder that occurs at all ages. Epilepsy not only brings physical pain to patients, but also brings a huge burden to the lives of patients and their families. At present, epilepsy detection is still achieved through the observation of electroencephalography (EEG) by medical staff. However, this process takes a long time and consumes energy, which will create a huge workload to medical staff. Therefore, it is particularly important to realize the automatic detection of epilepsy. This paper introduces, in detail, the overall framework of EEG-based automatic epilepsy identification and the typical methods involved in each step. Aiming at the core modules, that is, signal acquisition analog front end (AFE), feature extraction and classifier selection, method summary and theoretical explanation are carried out. Finally, the future research directions in the field of automatic detection of epilepsy are prospected.","PeriodicalId":17038,"journal":{"name":"Journal of Semiconductors","volume":"67 ","pages":""},"PeriodicalIF":5.1,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138989073","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Switchable hidden spin polarization and negative Poisson's ratio in two-dimensional antiferroelectric wurtzite crystals","authors":"Zhuang Ma, Jingwen Jiang, Gui Wang, Peng Zhang, Yiling Sun, Zhengfang Qian, Jiaxin Zheng, Wen Xiong, Fei Wang, Xiuwen Zhang, Pu Huang","doi":"10.1088/1674-4926/44/12/122101","DOIUrl":"https://doi.org/10.1088/1674-4926/44/12/122101","url":null,"abstract":"Two-dimensional (2D) antiferroelectric materials have raised great research interest over the last decade. Here, we reveal a type of 2D antiferroelectric (AFE) crystal where the AFE polarization direction can be switched by a certain degree in the 2D plane. Such 2D functional materials are realized by stacking the exfoliated wurtzite (<italic toggle=\"yes\">wz</italic>) monolayers with “self-healable” nature, which host strongly coupled ferroelasticity/antiferroelectricity and benign stability. The AFE candidates, i.e., ZnX and CdX (X = S, Se, Te), are all semiconductors with direct bandgap at Γ point, which harbors switchable antiferroelectricity and ferroelasticity with low transition barriers, hidden spin polarization, as well as giant in-plane negative Poisson's ratio (NPR), enabling the co-tunability of hidden spin characteristics and auxetic magnitudes via AFE switching. The 2D AFE <italic toggle=\"yes\">wz</italic> crystals provide a platform to probe the interplay of 2D antiferroelectricity, ferroelasticity, NPR, and spin effects, shedding new light on the rich physics and device design in <italic toggle=\"yes\">wz</italic> semiconductors.","PeriodicalId":17038,"journal":{"name":"Journal of Semiconductors","volume":"9 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139761817","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yongqiang Sun, Guangzhou Cui, K. Guo, Jinchuan Zhang, N. Zhuo, Lijun Wang, Shuman Liu, Zhiwei Jia, Teng Fei, Kun Li, Jun-qi Liu, Feng-qi Liu, S. Zhai
{"title":"Quantum cascade lasers grown by MOCVD","authors":"Yongqiang Sun, Guangzhou Cui, K. Guo, Jinchuan Zhang, N. Zhuo, Lijun Wang, Shuman Liu, Zhiwei Jia, Teng Fei, Kun Li, Jun-qi Liu, Feng-qi Liu, S. Zhai","doi":"10.1088/1674-4926/44/12/121901","DOIUrl":"https://doi.org/10.1088/1674-4926/44/12/121901","url":null,"abstract":"Sharing the advantages of high optical power, high efficiency and design flexibility in a compact size, quantum cascade lasers (QCLs) are excellent mid-to-far infrared laser sources for gas sensing, infrared spectroscopic, medical diagnosis, and defense applications. Metalorganic chemical vapor deposition (MOCVD) is an important technology for growing high quality semiconductor materials, and has achieved great success in the semiconductor industry due to its advantages of high efficiency, short maintenance cycles, and high stability and repeatability. The utilization of MOCVD for the growth of QCL materials holds a significant meaning for promoting the large batch production and industrial application of QCL devices. This review summarizes the recent progress of QCLs grown by MOCVD. Material quality and the structure design together determine the device performance. Research progress on the performance improvement of MOCVD-grown QCLs based on the optimization of material quality and active region structure are mainly reviewed.","PeriodicalId":17038,"journal":{"name":"Journal of Semiconductors","volume":"2 4","pages":""},"PeriodicalIF":5.1,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139024228","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"From kesterite 2D nanosheets to wurtzite 1D nanorods: controllable synthesis of Cu−Zn−Sn−S and their application in electrocatalytic hydrogen evolution","authors":"Yu Li, Shuaibing Wang, Jie Chen, Ouyang Lin, Zhe Yin, Chunhe Yang, Aiwei Tang","doi":"10.1088/1674-4926/44/12/122701","DOIUrl":"https://doi.org/10.1088/1674-4926/44/12/122701","url":null,"abstract":"As typical quarternary copper-based chalcogenides, Cu–Zn–Sn–S nanocrystals (CZTS NCs) have emerged as a new-fashioned electrocatalyst in hydrogen evolution reactions (HERs). Oleylamine (OM), a reducing surfactant and solvent, plays a significant role in the assisting synthesis of CZTS NCs due to the ligand effect. Herein, we adopted a facile one-pot colloidal method for achieving the structure evolution of CZTS NCs from 2D nanosheets to 1D nanorods assisted through the continuous addition of OM. During the process, the mechanism of OM-induced morphology evolution was further discussed. When merely adding pure 1-dodecanethiol (DDT) as the solvent, the CZTS nanosheets were obtained. As OM was gradually added to the reaction, the CZTS NCs began to grow along the sides of the nanosheets and gradually shrink at the top, followed by the formation of stable nanorods. In acidic electrolytic conditions, the CZTS NCs with 1.0 OM addition display the optimal HER activity with a low overpotential of 561 mV at 10 mA/cm<sup>2</sup> and a small Tafel slope of 157.6 mV/dec compared with other CZTS samples. The enhancement of HER activity could be attributed to the contribution of the synergistic effect of the diverse crystal facets to the reaction.","PeriodicalId":17038,"journal":{"name":"Journal of Semiconductors","volume":"53 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139761868","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"<ArticleTitle xmlns:ns0=\"http://www.w3.org/1998/Math/MathML\">OASIS: An interpretable, finite-sample valid alternative to Pearson's <ns0:math><ns0:msup><ns0:mrow><ns0:mi>X</ns0:mi></ns0:mrow><ns0:mrow><ns0:mn>2</ns0:mn></ns0:mrow></ns0:msup></ns0:math> for scientific discovery.","authors":"Tavor Z Baharav, David Tse, Julia Salzman","doi":"10.1101/2023.03.16.533008","DOIUrl":"10.1101/2023.03.16.533008","url":null,"abstract":"<p><p>Contingency tables, data represented as counts matrices, are ubiquitous across quantitative research and data-science applications. Existing statistical tests are insufficient however, as none are simultaneously computationally efficient and statistically valid for a finite number of observations. In this work, motivated by a recent application in reference-free genomic inference (1), we develop OASIS (Optimized Adaptive Statistic for Inferring Structure), a family of statistical tests for contingency tables. OASIS constructs a test-statistic which is linear in the normalized data matrix, providing closed form p-value bounds through classical concentration inequalities. In the process, OASIS provides a decomposition of the table, lending interpretability to its rejection of the null. We derive the asymptotic distribution of the OASIS test statistic, showing that these finite-sample bounds correctly characterize the test statistic's p-value up to a variance term. Experiments on genomic sequencing data highlight the power and interpretability of OASIS. The same method based on OASIS significance calls detects SARS-CoV-2 and Mycobacterium Tuberculosis strains de novo, which cannot be achieved with current approaches. We demonstrate in simulations that OASIS is robust to overdispersion, a common feature in genomic data like single cell RNA-sequencing, where under accepted noise models OASIS still provides good control of the false discovery rate, while Pearson's <math><msup><mrow><mi>X</mi></mrow><mrow><mn>2</mn></mrow></msup></math> test consistently rejects the null. Additionally, we show on synthetic data that OASIS is more powerful than Pearson's <math><msup><mrow><mi>X</mi></mrow><mrow><mn>2</mn></mrow></msup></math> test in certain regimes, including for some important two group alternatives, which we corroborate with approximate power calculations.</p>","PeriodicalId":17038,"journal":{"name":"Journal of Semiconductors","volume":"37 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10634974/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82539827","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Development of a simple two-step lithography fabrication process for resonant tunneling diode using air-bridge technology","authors":"Swagata Samanta, Jue Wang, Edward Wasige","doi":"10.1088/1674-4926/44/11/114101","DOIUrl":"https://doi.org/10.1088/1674-4926/44/11/114101","url":null,"abstract":"This article reports on the development of a simple two-step lithography process for double barrier quantum well (DBQW) InGaAs/AlAs resonant tunneling diode (RTD) on a semi-insulating indium phosphide (InP) substrate using an air-bridge technology. This approach minimizes processing steps, and therefore the processing time as well as the required resources. It is particularly suited for material qualification of new epitaxial layer designs. A DC performance comparison between the proposed process and the conventional process shows approximately the same results. We expect that this novel technique will aid in the recent and continuing rapid advances in RTD technology.","PeriodicalId":17038,"journal":{"name":"Journal of Semiconductors","volume":"37 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138679796","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jiaxin Song, Malik Ashtar, Ying Yang, Yuan Liu, Mingming Chen, Dawei Cao
{"title":"Photocatalytic removal of heavy metal ions and antibiotics in agricultural wastewater: A review","authors":"Jiaxin Song, Malik Ashtar, Ying Yang, Yuan Liu, Mingming Chen, Dawei Cao","doi":"10.1088/1674-4926/44/11/111701","DOIUrl":"https://doi.org/10.1088/1674-4926/44/11/111701","url":null,"abstract":"In recent years, the treatment of agricultural wastewater has been an important aspect of environmental protection. The purpose of photocatalytic technology is to degrade pollutants by utilizing solar light energy to stimulate the migration of photocarriers to the surface of photocatalysts and occur reduction-oxidation reaction with pollutants in agricultural wastewater. Photocatalytic technology has the characteristics of high efficiency, sustainability, low-energy and free secondary pollution. It is an environmental and economical method to recover water quality that only needs sunlight. In this paper, the mechanism and research progress of photocatalytic removal of heavy metal ions and antibiotics from agricultural water pollution were reviewed by combining photocatalytic degradation process with agricultural treatment technology. The mechanism of influencing factors of photocatalytic degradation efficiency was discussed in detail and corresponding strategies were proposed, which has certain reference value for the development of photocatalytic degradation.","PeriodicalId":17038,"journal":{"name":"Journal of Semiconductors","volume":"1 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138679809","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}