We have discussed the materials of solar cell based on hybrid organic–inorganic halide perovskites with formamidinium(NH_2CH = NH_2^+or FA) lead iodide. Firstly, we build the structure of formamidinium lead iodide(FA...We have discussed the materials of solar cell based on hybrid organic–inorganic halide perovskites with formamidinium(NH_2CH = NH_2^+or FA) lead iodide. Firstly, we build the structure of formamidinium lead iodide(FAPbI_3) by using the material studio. By using the first-principles calculations, the energy band structure, density of states(DOS), and partial DOS(PDOS) of the hydrazine-iodide lead halide are obtained. Then, we theoretically analyze a design scheme for perovskite solar cell materials, published in [Science 354, 861(2016)], with the photoelectric conversion efficiency that can reach 20.3%. Also, we use non-toxic elements to replace lead in FAPbI_3 without affecting its photoelectric conversion efficiency. Here in this work, we explore the energy band structure, lattice constant, light absorption efficiency, etc. After the Ca, Zn, Ge Sr, Sn, and Ta atoms replacing lead(Pb) and through comparing the spectral distributions of the solar spectrum, it can be found that FAGeI_3, FASnI_3, and FAZnI_3 have better absorbance characteristics in the solar spectrum range. If the band gap structure is taken into account, FAGeI_3 will become an ideal material to replace FAPbI_3, although its performance is slightly lower than that of FAPbI_3. The toxicity of Pb is taken into account, and the Ge element can be used as a substitute element for Pb. Furthermore, we explore one of the perovskite materials, i.e., FA0.75Cs_(0.25)Sn_(0.25)Ge_(0.75)I_3 whose photovoltaic properties are close to those of FA_(0.75)Cs_(0.25)Sn_(0.5)Pb_(0.5)I_3, but the former does not contain toxic atoms.Our results pave the way for further investigating the applications of these materials in relevant technologies.展开更多
Nanomaterials provide an ideal platform for biomolecular display due to their dimensions approach the molecular scale,facilitating binding behavior akin to that observed in solution-based processes.DNA nanoprobes hold...Nanomaterials provide an ideal platform for biomolecular display due to their dimensions approach the molecular scale,facilitating binding behavior akin to that observed in solution-based processes.DNA nanoprobes hold great promise as miniature detectives capable of detecting mi RNAs within cells.However,current nanoprobes face a challenge in achieving the required precision for accurate miRNA detection,particularly within the intricate confines of the cellular microenvironment,due to interference with biological autofluorescence,off-target effects,and a lack of spatiotemporal control.Here,we have designed a dual-stimuli responsive DNA tracker,synergistically utilizing specific intracellular cues and external triggers,which enables spatiotemporal-controlled and precise detection and imaging of miRNAs"on demand".The tracker,which combines zeolitic imidazolate framework-67(ZIF-67)and unique hairpin DNA structures,effectively anchored onto the ZIF-67 through electrostatic interactions,remains in a dormant state until activated by abundant cellular ATP,resulting in the release of the hairpin structures that include a PC linker incorporated into the loop region.Subsequent irradiation triggers specific recognition of the target miRNA.The newly developed HP-PC-BT@ZIF-67 tracker demonstrates precise spatiotemporal mi RNA detection and exhibits excellent biocompatibility,enabling specific mi RNA recognition"on demand"within cancer cells.This research presents a reliable mi RNA imaging platform in the intricate cellular environment,opening up the possibilities for precise biomedical analysis and disease diagnosis.展开更多
Shaking table tests are widely used to evaluate seismic effects on railway structures,but accurately measuring rail displacement remains a significant challenge owing to the nonlinear characteristics of large displace...Shaking table tests are widely used to evaluate seismic effects on railway structures,but accurately measuring rail displacement remains a significant challenge owing to the nonlinear characteristics of large displacements,ambient noise interference,and limitations in displacement meter installation.In this paper,a novel method that integrates the Kanade-Lucas-Tomasi(KLT)feature tracker with an extended Kalman filter(EKF)is presented for measuring rail displacement during shaking table tests.The method employs KLT feature tracker and a random sample consensus algorithm to extract and track key feature points,while EKF optimally estimates dynamic states by accounting for system noise and observation errors.Shaking table test results demonstrate that the proposed method achieves an acceleration root mean square error of 0.300 m/s^(2)and a correlation with accelerometer data exceeding 99.7%,significantly outper-forming the original KLT approach.This innovative method provides a more efficient and reliable solution for measuring rail displacement under large nonlinear vibrations.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.11164004)the Industrial Research Project of Guizhou Province,China(Grant No.GY[2012]3060)+1 种基金the Project of Education Department of Guizhou Province,China(Grant No.[2016]215)the Special Laboratory Fund of Education Department of Guizhou Province,China(Grant No.GY[2014]217)
文摘We have discussed the materials of solar cell based on hybrid organic–inorganic halide perovskites with formamidinium(NH_2CH = NH_2^+or FA) lead iodide. Firstly, we build the structure of formamidinium lead iodide(FAPbI_3) by using the material studio. By using the first-principles calculations, the energy band structure, density of states(DOS), and partial DOS(PDOS) of the hydrazine-iodide lead halide are obtained. Then, we theoretically analyze a design scheme for perovskite solar cell materials, published in [Science 354, 861(2016)], with the photoelectric conversion efficiency that can reach 20.3%. Also, we use non-toxic elements to replace lead in FAPbI_3 without affecting its photoelectric conversion efficiency. Here in this work, we explore the energy band structure, lattice constant, light absorption efficiency, etc. After the Ca, Zn, Ge Sr, Sn, and Ta atoms replacing lead(Pb) and through comparing the spectral distributions of the solar spectrum, it can be found that FAGeI_3, FASnI_3, and FAZnI_3 have better absorbance characteristics in the solar spectrum range. If the band gap structure is taken into account, FAGeI_3 will become an ideal material to replace FAPbI_3, although its performance is slightly lower than that of FAPbI_3. The toxicity of Pb is taken into account, and the Ge element can be used as a substitute element for Pb. Furthermore, we explore one of the perovskite materials, i.e., FA0.75Cs_(0.25)Sn_(0.25)Ge_(0.75)I_3 whose photovoltaic properties are close to those of FA_(0.75)Cs_(0.25)Sn_(0.5)Pb_(0.5)I_3, but the former does not contain toxic atoms.Our results pave the way for further investigating the applications of these materials in relevant technologies.
基金supported by the National Natural Science Foundation of China(Nos.21904095,22004089)Peiyang Talents Project of Tianjin University+1 种基金Young Thousand Talented ProgramProgram of Tianjin Science and Technology Major Project and Engineering(No.19ZXYXSY00090)。
文摘Nanomaterials provide an ideal platform for biomolecular display due to their dimensions approach the molecular scale,facilitating binding behavior akin to that observed in solution-based processes.DNA nanoprobes hold great promise as miniature detectives capable of detecting mi RNAs within cells.However,current nanoprobes face a challenge in achieving the required precision for accurate miRNA detection,particularly within the intricate confines of the cellular microenvironment,due to interference with biological autofluorescence,off-target effects,and a lack of spatiotemporal control.Here,we have designed a dual-stimuli responsive DNA tracker,synergistically utilizing specific intracellular cues and external triggers,which enables spatiotemporal-controlled and precise detection and imaging of miRNAs"on demand".The tracker,which combines zeolitic imidazolate framework-67(ZIF-67)and unique hairpin DNA structures,effectively anchored onto the ZIF-67 through electrostatic interactions,remains in a dormant state until activated by abundant cellular ATP,resulting in the release of the hairpin structures that include a PC linker incorporated into the loop region.Subsequent irradiation triggers specific recognition of the target miRNA.The newly developed HP-PC-BT@ZIF-67 tracker demonstrates precise spatiotemporal mi RNA detection and exhibits excellent biocompatibility,enabling specific mi RNA recognition"on demand"within cancer cells.This research presents a reliable mi RNA imaging platform in the intricate cellular environment,opening up the possibilities for precise biomedical analysis and disease diagnosis.
基金The National Key Research and Development Program of China(No.2021YFB2600600,2021YFB2600601)the National Natural Science Foundation of China(No.52408456)+2 种基金China Postdoctoral Science Foundation(No.2022M720533)College Students’Innovative Entrepreneurial Training Plan Program(No.202410710009)Key Research and Development Program of Shaanxi,China(No.2024SF-YBXM-659).
文摘Shaking table tests are widely used to evaluate seismic effects on railway structures,but accurately measuring rail displacement remains a significant challenge owing to the nonlinear characteristics of large displacements,ambient noise interference,and limitations in displacement meter installation.In this paper,a novel method that integrates the Kanade-Lucas-Tomasi(KLT)feature tracker with an extended Kalman filter(EKF)is presented for measuring rail displacement during shaking table tests.The method employs KLT feature tracker and a random sample consensus algorithm to extract and track key feature points,while EKF optimally estimates dynamic states by accounting for system noise and observation errors.Shaking table test results demonstrate that the proposed method achieves an acceleration root mean square error of 0.300 m/s^(2)and a correlation with accelerometer data exceeding 99.7%,significantly outper-forming the original KLT approach.This innovative method provides a more efficient and reliable solution for measuring rail displacement under large nonlinear vibrations.
