Antimony trisulfide(Sb_(2)S_(3)) solar cells suffer from large open circuit voltage deficits due to their intrinsic defects which limit the power conversion efficiency.Thus,it is important to elucidate these defects’...Antimony trisulfide(Sb_(2)S_(3)) solar cells suffer from large open circuit voltage deficits due to their intrinsic defects which limit the power conversion efficiency.Thus,it is important to elucidate these defects’ origin and defects at the interface.Here,we discover that sulfide radical defects have a significant impact on the performance of Sb_(2)S_(3)solar cells.Moreover,it has been illustrated that these defects at the CdS/Sb_(2)S_(3)interface can be reduced by optimizing the deposition process.A trap distribution model is used to quantify the defect density at the CdS/Sb_(2)S_(3)interface.It shows that the interface defects can be reduced by24% by improving the deposition process.This work reveals the importance of interface defects and guides the future optimization of Sb_(2)S_(3)solar cells.展开更多
BACKGROUND： Previous studies about blood oxygenation-level dependent （BOLD） functional MRI （fMRI） have indicated that the poststroke recovery of motor function is accompanied by the selective activation of motor ...BACKGROUND： Previous studies about blood oxygenation-level dependent （BOLD） functional MRI （fMRI） have indicated that the poststroke recovery of motor function is accompanied by the selective activation of motor cortexes with high correlation. OBJECTIVE： To evaluate the short-term outcomes after rehabilitative interventions with BOLD fMRI in hemiplegic patients with acute stroke, and analyze the correlation of the excitement of brain function in the passive and active movements of the affected limb with the recovery of motor function. DESIGN ： A case observation.SETTING： Department of Neurology, Baotou Central Hospital.PARTICIPANTS： Thirty hemiplegic inpatients with ischemic stroke were selected from the Department of Neurology, Baotou Central Hospital from January to December in 2005, including 16 males and 14 females, aging 44-71 years with an average age of （56±5） years, and the disease course ranged from 12 to 72 hours. Inclusive criteria： In accordance with the diagnostic standard of ischemic stroke revised by the Fourth National Academic Meeting for Cerebrovascular Disease; Confirmed by cranial CT or MRI. They were all informed agreed with the detected items. METHODS ： ① The Bobath technique was adopted in the rehabilitative interventions of the 30 patients, 30 minutes for each time, twice a day for three weeks continuously. ② The hand motor recovery of the stroke patients was graded by the Brunnstrom stages （ Ⅰ -Ⅵ）, and be able to grasp various objects and extend for the whole range was taken as grade Ⅵ. ③ The patients were examined with fMRI BOLD before rehabilitation and 3 weeks after rehabilitation. All the patients were trained with finger movements, the distracting thoughts should be eliminated as much as possible especially during the movement phase, the patients should highly concentrate on the hand movements. The range for the finger movements should be as large as possible with moderate frequency. The hand movements should be 10 s with an interval of 30 s. Te AVANTO 1.5T MRI machine （Siemens Company, Germany） was used for scanning, the 30 s before fMRI BOLD scanning was the adaptation phase for the patients, and the finger movements were alternated for 6-10 times till the end of the scanning. MAIN OUTCOME MEASURES ： Differences after rehabilitation evaluated by the activations of different sensorimotor cortex in the hemiplegic patients with acute stroke. RESULTS： ① In passive and active movements of the affected hand, 5 cases of Brunnstrom grade Ⅰ or Ⅱ were manifested by the activation of unilateral sensorimotor cortex （SMC） of the hemiplegic side, and they were Brunnstrom grade Ⅱ after 3-week rehabilitation, and 1 case with activations of bilateral SMC recovered to Brunnstrom grade Ⅲ. ② Among the patients of Brunnstrom grade Ⅲ or Ⅳ, 5 cases were unilaterally activated, and had no changes after 3-week rehabilitation; Whereas of the 9 cases of bilateral activations, 3 recovered to grade Ⅵ and 6 recovered to grade Ⅴ after 3-week rehabilitation. ③ In the passive and active movements of the affected hand, all the cases of Brunnstrom grades Ⅴ and Ⅵ were manifested by the activations of bilateral SMC. After 3-week rehabilitation, 2 of the 4 cases of grade Ⅴ recovered to grade Ⅵ, and the other 2 recovered to normal; Whereas 5 of the 6 cases of grade Ⅵ recovered to normal, and the other 1 was still grade Ⅵ. CONCLUSION ： BOLD fMRI showed that the outcomes of short-term rehabilitation in the patients with bilateral activations were obvious, whereas the outcomes were bad in the patients whose ipsilateral cortexes were activated. The activated signal in ipsilateral or bilateral SMC and the activation of supplementary motor area in active movements were greater than those in the passive ones.展开更多
This study proposes a method of constructing type Ⅱ generalized angulated elements(GAEs Ⅱ)Hoberman sphere mechanisms on the basis of deployment axes that intersect at one point.First,the constraint conditions for in...This study proposes a method of constructing type Ⅱ generalized angulated elements(GAEs Ⅱ)Hoberman sphere mechanisms on the basis of deployment axes that intersect at one point.First,the constraint conditions for inserting n GAEs II into n deployment axes to form a loop are given.The angle constraint conditions of the deployment axes are obtained through a series of linear equations.Second,the connection conditions of two GAEs Ⅱ loops that share a common deployable center are discussed.Third,a flowchart of constructing the generalized Hoberman sphere mechanism on the basis of deployment axes is provided.Finally,four generalized Hoberman sphere mechanisms based on a fully enclosed regular hexahedron,arithmetic sequence axes,orthonormal arithmetic sequence axes,and spiral-like axes are constructed in accordance with the given arrangement of deployment axes that satisfy the constraint conditions to verify the feasibility of the proposed method.展开更多
With recent relevant publications on stochastic motion robots in Nature, Science, and other journals, research on such robots has gained increasing attention. However, theoretical and applied research on stochastic mo...With recent relevant publications on stochastic motion robots in Nature, Science, and other journals, research on such robots has gained increasing attention. However, theoretical and applied research on stochastic motion in the field of robotics and mechanisms face many challenges due to the uncertainty of stochastic motion. Currently, a large gap remains in the research of stochastic motion mechanism. In this study, a novel mechanism that can conduct probabilistic rolling is proposed to reach a designated position and achieve overlying movement over a particular area. The mechanism consists of a regular tetrahedron frame, a central node, and four connecting linear actuators. According to mobility and kinematic analyses, the mechanism can implement probabilistic rolling. Each rolling gait has three probable rolling directions, and the mechanism rolls in one of the three directions in probability. A kinematic simulation is conducted, and a control method is proposed on the basis of the moving path analysis. Furthermore, the mathematical principle of probabilistic rolling is revealed in terms of probability theory and statistics. Lastly, a prototype is fabricated. To achieve the rolling function, the design of the linear actuators is improved, and the extension ratio is increased from 0.58 to 1.13. Then, tests are conducted. In a 4 m2 test site, the mechanism makes 11 moves to reach the target position and covers 29.25% of the site.展开更多
This paper focuses on the visual analytics support for extracting domain-specific entities from extensive scientific literature,a task with inherent limitations using traditional named entity resolution methods.With t...This paper focuses on the visual analytics support for extracting domain-specific entities from extensive scientific literature,a task with inherent limitations using traditional named entity resolution methods.With the advent of large language models(LLMs)such as GPT-4,significant improvements over conventional machine learning approaches have been achieved due to LLM’s capability on entity resolution integrate abilities such as understanding multiple types of text.This research introduces a new visual analysis pipeline that integrates these advanced LLMs with versatile visualization and interaction designs to support batch entity resolution.Specifically,we focus on a specific material science field of Metal-Organic Frameworks(MOFs)and a large data collection namely CSD-MOFs.Through collaboration with domain experts in material science,we obtain well-labeled synthesis paragraphs.We propose human-in-the-loop refinement over the entity resolution process using visual analytics techniques,which allows domain experts to interactively integrate insights into LLM intelligence,including error analysis and interpretation of the retrieval-augmented generation(RAG)algorithm.Our evaluation through the case study of example selection for RAG demonstrates that this visual analysis approach effectively improves the accuracy of single-document entity resolution.展开更多
Liquid-phase chemically deposited lead sulfide as a narrow-bandgap semiconductor holds great potential for extended short-wavelength infrared sensing.However,lead sulfide thin films typically contain massive sulfur va...Liquid-phase chemically deposited lead sulfide as a narrow-bandgap semiconductor holds great potential for extended short-wavelength infrared sensing.However,lead sulfide thin films typically contain massive sulfur vacancies and oxygen impurities,which form during chemical deposition,leading to inferior device performance.Here,for the first time,we report on the in-situ passivation of lead sulfide polycrystalline film with chloride ions as an additive during liquid-phase chemical deposition.Due to the similar ionic radius of chloride ions to sulfur ions and their ability to coordinate with lead ions,the addition of chloride ions effectively reduces sulfur vacancy and oxygen-in-sulfur defect densities.The reduction of bulk defect densities lowered the dark current density of homojunction photodiodes made from the passivated film by more than threefold.The photodiode exhibited a high responsivity of 0.79 A/W at 2.5μm and a fast response speed of 19.6μs.At room temperature,the 1 mm^(2)photodiodes exhibited a resistance-area product of 8.78Ωcm^(2)and a specific detectivity of 8.79×10^(9)Jones at 2.5μm,among the best-reported performance of lead sulfide bulk thin film photodiode.At 80 K,the resistance-area product was 6.16 kΩcm^(2).This research paves a new path for high-performance extended short-wavelength infrared photodetector.展开更多
In this study, a novel duoprism mechanism that demonstrates a fascinating eversion motion is developed. The mechanism comprises three scalable platforms and nine retractable limbs and is constructed by inserting prism...In this study, a novel duoprism mechanism that demonstrates a fascinating eversion motion is developed. The mechanism comprises three scalable platforms and nine retractable limbs and is constructed by inserting prismatic and revolute joints into the： edges and vertices of the duoprism, respectively. According to mobility and kinematic analyses, the mechanism has five degrees of freedom. Six inputs, including a redundant one, are required to overcome singularity and achieve an eversion motion. In the eversion motion, three platforms expand/ contract synchronously, and the mechanism continuously turns inside out. The detailed gait：~ of eversion motion along an ellipse and a circle after a cycle are illustrated with two examples. A kinematic simulation is conducted, and a manual prototype is fabricated to verify the feasibility of the eversible duoprism mechanism.展开更多
Transfer printing of small-molecular organic semiconductors often faces challenges due to surface adhesion mismatch.Here,we developed a sacrificing-layer-assisted transfer printing technique for the deposition of smal...Transfer printing of small-molecular organic semiconductors often faces challenges due to surface adhesion mismatch.Here,we developed a sacrificing-layer-assisted transfer printing technique for the deposition of smallmolecular thin films.High-boiling-point ethylene glycol(EG)was doped in aqueous solution poly(3,4-ethylenedioxythiophene)polystyrene sulfonate(PEDOT:PSS)as the sacrificing layer to manipulate residual water in film,which allowed chlorobenzene solution to spontaneously spread and form uniform film.展开更多
基金support from the National Key R&D Program of China(2019YFE0120300)the National Natural Science Foundation of China(NSFC,11904266,62204174 and 91850207)the Fundamental Research Funds for the Central Universities(2042021kf0202 and 2042021kf0069)。
文摘Antimony trisulfide(Sb_(2)S_(3)) solar cells suffer from large open circuit voltage deficits due to their intrinsic defects which limit the power conversion efficiency.Thus,it is important to elucidate these defects’ origin and defects at the interface.Here,we discover that sulfide radical defects have a significant impact on the performance of Sb_(2)S_(3)solar cells.Moreover,it has been illustrated that these defects at the CdS/Sb_(2)S_(3)interface can be reduced by optimizing the deposition process.A trap distribution model is used to quantify the defect density at the CdS/Sb_(2)S_(3)interface.It shows that the interface defects can be reduced by24% by improving the deposition process.This work reveals the importance of interface defects and guides the future optimization of Sb_(2)S_(3)solar cells.
文摘BACKGROUND： Previous studies about blood oxygenation-level dependent （BOLD） functional MRI （fMRI） have indicated that the poststroke recovery of motor function is accompanied by the selective activation of motor cortexes with high correlation. OBJECTIVE： To evaluate the short-term outcomes after rehabilitative interventions with BOLD fMRI in hemiplegic patients with acute stroke, and analyze the correlation of the excitement of brain function in the passive and active movements of the affected limb with the recovery of motor function. DESIGN ： A case observation.SETTING： Department of Neurology, Baotou Central Hospital.PARTICIPANTS： Thirty hemiplegic inpatients with ischemic stroke were selected from the Department of Neurology, Baotou Central Hospital from January to December in 2005, including 16 males and 14 females, aging 44-71 years with an average age of （56±5） years, and the disease course ranged from 12 to 72 hours. Inclusive criteria： In accordance with the diagnostic standard of ischemic stroke revised by the Fourth National Academic Meeting for Cerebrovascular Disease; Confirmed by cranial CT or MRI. They were all informed agreed with the detected items. METHODS ： ① The Bobath technique was adopted in the rehabilitative interventions of the 30 patients, 30 minutes for each time, twice a day for three weeks continuously. ② The hand motor recovery of the stroke patients was graded by the Brunnstrom stages （ Ⅰ -Ⅵ）, and be able to grasp various objects and extend for the whole range was taken as grade Ⅵ. ③ The patients were examined with fMRI BOLD before rehabilitation and 3 weeks after rehabilitation. All the patients were trained with finger movements, the distracting thoughts should be eliminated as much as possible especially during the movement phase, the patients should highly concentrate on the hand movements. The range for the finger movements should be as large as possible with moderate frequency. The hand movements should be 10 s with an interval of 30 s. Te AVANTO 1.5T MRI machine （Siemens Company, Germany） was used for scanning, the 30 s before fMRI BOLD scanning was the adaptation phase for the patients, and the finger movements were alternated for 6-10 times till the end of the scanning. MAIN OUTCOME MEASURES ： Differences after rehabilitation evaluated by the activations of different sensorimotor cortex in the hemiplegic patients with acute stroke. RESULTS： ① In passive and active movements of the affected hand, 5 cases of Brunnstrom grade Ⅰ or Ⅱ were manifested by the activation of unilateral sensorimotor cortex （SMC） of the hemiplegic side, and they were Brunnstrom grade Ⅱ after 3-week rehabilitation, and 1 case with activations of bilateral SMC recovered to Brunnstrom grade Ⅲ. ② Among the patients of Brunnstrom grade Ⅲ or Ⅳ, 5 cases were unilaterally activated, and had no changes after 3-week rehabilitation; Whereas of the 9 cases of bilateral activations, 3 recovered to grade Ⅵ and 6 recovered to grade Ⅴ after 3-week rehabilitation. ③ In the passive and active movements of the affected hand, all the cases of Brunnstrom grades Ⅴ and Ⅵ were manifested by the activations of bilateral SMC. After 3-week rehabilitation, 2 of the 4 cases of grade Ⅴ recovered to grade Ⅵ, and the other 2 recovered to normal; Whereas 5 of the 6 cases of grade Ⅵ recovered to normal, and the other 1 was still grade Ⅵ. CONCLUSION ： BOLD fMRI showed that the outcomes of short-term rehabilitation in the patients with bilateral activations were obvious, whereas the outcomes were bad in the patients whose ipsilateral cortexes were activated. The activated signal in ipsilateral or bilateral SMC and the activation of supplementary motor area in active movements were greater than those in the passive ones.
基金This work was supported by the National Natural Science Foundation of China(Grant No.51905015)China Postdoctoral Science Foundation(Grant No.2018M631300).
文摘This study proposes a method of constructing type Ⅱ generalized angulated elements(GAEs Ⅱ)Hoberman sphere mechanisms on the basis of deployment axes that intersect at one point.First,the constraint conditions for inserting n GAEs II into n deployment axes to form a loop are given.The angle constraint conditions of the deployment axes are obtained through a series of linear equations.Second,the connection conditions of two GAEs Ⅱ loops that share a common deployable center are discussed.Third,a flowchart of constructing the generalized Hoberman sphere mechanism on the basis of deployment axes is provided.Finally,four generalized Hoberman sphere mechanisms based on a fully enclosed regular hexahedron,arithmetic sequence axes,orthonormal arithmetic sequence axes,and spiral-like axes are constructed in accordance with the given arrangement of deployment axes that satisfy the constraint conditions to verify the feasibility of the proposed method.
基金supported by the Fundamental Research Funds for the Central Universities,China(Grant No.2019JBM046).
文摘With recent relevant publications on stochastic motion robots in Nature, Science, and other journals, research on such robots has gained increasing attention. However, theoretical and applied research on stochastic motion in the field of robotics and mechanisms face many challenges due to the uncertainty of stochastic motion. Currently, a large gap remains in the research of stochastic motion mechanism. In this study, a novel mechanism that can conduct probabilistic rolling is proposed to reach a designated position and achieve overlying movement over a particular area. The mechanism consists of a regular tetrahedron frame, a central node, and four connecting linear actuators. According to mobility and kinematic analyses, the mechanism can implement probabilistic rolling. Each rolling gait has three probable rolling directions, and the mechanism rolls in one of the three directions in probability. A kinematic simulation is conducted, and a control method is proposed on the basis of the moving path analysis. Furthermore, the mathematical principle of probabilistic rolling is revealed in terms of probability theory and statistics. Lastly, a prototype is fabricated. To achieve the rolling function, the design of the linear actuators is improved, and the extension ratio is increased from 0.58 to 1.13. Then, tests are conducted. In a 4 m2 test site, the mechanism makes 11 moves to reach the target position and covers 29.25% of the site.
基金supported by the National Key R&D Program of China(2021YFB3500700)the National Natural Science Foun-dation of China Grant 62172026&Grant 62202033+1 种基金the National Social Science Fund of China(22&ZD153)the Fundamental Re-search Funds for the Central Universities,and the State Key Lab-oratory of Complex&Critical Software Environment(SKLCCSE).
文摘This paper focuses on the visual analytics support for extracting domain-specific entities from extensive scientific literature,a task with inherent limitations using traditional named entity resolution methods.With the advent of large language models(LLMs)such as GPT-4,significant improvements over conventional machine learning approaches have been achieved due to LLM’s capability on entity resolution integrate abilities such as understanding multiple types of text.This research introduces a new visual analysis pipeline that integrates these advanced LLMs with versatile visualization and interaction designs to support batch entity resolution.Specifically,we focus on a specific material science field of Metal-Organic Frameworks(MOFs)and a large data collection namely CSD-MOFs.Through collaboration with domain experts in material science,we obtain well-labeled synthesis paragraphs.We propose human-in-the-loop refinement over the entity resolution process using visual analytics techniques,which allows domain experts to interactively integrate insights into LLM intelligence,including error analysis and interpretation of the retrieval-augmented generation(RAG)algorithm.Our evaluation through the case study of example selection for RAG demonstrates that this visual analysis approach effectively improves the accuracy of single-document entity resolution.
基金supported by the National Key Research and Development Program of China(2024YFA1209503,2021YFB3501800)the National Natural Science Foundation of China(62322505,62374069)the Innovation Project of Optics Valley Laboratory(OVL2023ZD002)。
文摘Liquid-phase chemically deposited lead sulfide as a narrow-bandgap semiconductor holds great potential for extended short-wavelength infrared sensing.However,lead sulfide thin films typically contain massive sulfur vacancies and oxygen impurities,which form during chemical deposition,leading to inferior device performance.Here,for the first time,we report on the in-situ passivation of lead sulfide polycrystalline film with chloride ions as an additive during liquid-phase chemical deposition.Due to the similar ionic radius of chloride ions to sulfur ions and their ability to coordinate with lead ions,the addition of chloride ions effectively reduces sulfur vacancy and oxygen-in-sulfur defect densities.The reduction of bulk defect densities lowered the dark current density of homojunction photodiodes made from the passivated film by more than threefold.The photodiode exhibited a high responsivity of 0.79 A/W at 2.5μm and a fast response speed of 19.6μs.At room temperature,the 1 mm^(2)photodiodes exhibited a resistance-area product of 8.78Ωcm^(2)and a specific detectivity of 8.79×10^(9)Jones at 2.5μm,among the best-reported performance of lead sulfide bulk thin film photodiode.At 80 K,the resistance-area product was 6.16 kΩcm^(2).This research paves a new path for high-performance extended short-wavelength infrared photodetector.
基金financially supported by the National Natural Science Foundation of China(61875154 and 52022071)the Natural Science Foundation of Jiangsu Province,China(BK20190214)+1 种基金the National Key R&D Program of China(2020YFB2008800)China Postdoctoral Science Foundation(2021M702513)。
文摘In this study, a novel duoprism mechanism that demonstrates a fascinating eversion motion is developed. The mechanism comprises three scalable platforms and nine retractable limbs and is constructed by inserting prismatic and revolute joints into the： edges and vertices of the duoprism, respectively. According to mobility and kinematic analyses, the mechanism has five degrees of freedom. Six inputs, including a redundant one, are required to overcome singularity and achieve an eversion motion. In the eversion motion, three platforms expand/ contract synchronously, and the mechanism continuously turns inside out. The detailed gait：~ of eversion motion along an ellipse and a circle after a cycle are illustrated with two examples. A kinematic simulation is conducted, and a manual prototype is fabricated to verify the feasibility of the eversible duoprism mechanism.
基金financially supported by the National Natural Science Foundation of China(No.62175189)the Shenzhen Science and Technology Program(KQTD20170330110107046)+1 种基金funding support from the Program for Promoting Academic Collaboration and Senior Talent Fostering between China and Canada,Australia,NewZealand,and Latin America(2021-109)the Joint China-SwedenMobility Programme(No.52211530052).
文摘Transfer printing of small-molecular organic semiconductors often faces challenges due to surface adhesion mismatch.Here,we developed a sacrificing-layer-assisted transfer printing technique for the deposition of smallmolecular thin films.High-boiling-point ethylene glycol(EG)was doped in aqueous solution poly(3,4-ethylenedioxythiophene)polystyrene sulfonate(PEDOT:PSS)as the sacrificing layer to manipulate residual water in film,which allowed chlorobenzene solution to spontaneously spread and form uniform film.
