Search

Fast development in science and technology has driven the need for proper statistical tools to capture special data features such as abrupt changes or sharp contrast. Many applications in the data science seek spatiotemporal reconstruction from a sequence of time-dependent objects with discontinuity or singularity, e.g. dynamic computerized tomography (CT) images with edges. Traditional methods based on Gaussian processes (GP) may not provide satisfactory solutions since they tend to offer over-smooth prior candidates. Recently, Besov process (BP) defined by wavelet expansions with random coefficients has been proposed as a more appropriate prior for this type of Bayesian inverse problems. While BP outperforms GP in imaging analysis to produce edge-preserving reconstructions, it does not automatically incorporate temporal correlation inherited in the dynamically changing images. In this paper, we generalize BP to the spatiotemporal domain (STBP) by replacing the random coefficients in the series expansion with stochastic time functions following Q-exponential process which governs the temporal correlation strength. Mathematical and statistical properties about STBP are carefully studied. A white-noise representation of STBP is also proposed to facilitate the point estimation through maximum a posterior (MAP) and the uncertainty quantification (UQ) by posterior sampling. Two limited-angle CT reconstruction examples and a highly non-linear inverse problem involving Navier-Stokes equation are used to demonstrate the advantage of the proposed STBP in preserving spatial features while accounting for temporal changes compared with the classic STGP and a time-uncorrelated approach., 29 pages, 13 figures

Based on the cam-roller pair of an internal combustion engine, a mathematical model of transient thermal elastohydrodynamic lubrication under finite line-contact and the corresponding numerical solver have been established. Under an actual load spectrum and other working parameters from an industry partner, the detailed lubrication performance of the cam-roller pair has been obtained in a cam rotation cycle. Particularly, the influences of the roller convexity, the roller tilting and the skidding between cam and roller on the contact pair lubrication are presented. The lubrication performance of the cam-roller pair depends on the roller convexity markedly, and an optimal roller convexity can effectively reduce the probability of the lubrication film rupture and improve the uniformity of pressure distribution in the contact zone. The roller tilting can worsen the lubrication of the contact zone, and increase the possibility of lubrication failure. If the tilting is taken into consideration at the beginning of the roller convexity design, its negative effect can be effectively alleviated to a certain extent. The skidding results in noticeable increase in temperature and friction coefficient, which can deteriorate the contact zone lubrication. The results provide some theoretical data basis for the lubrication design of cam-roller pairs.

Under continuous light illumination, it is known that localized domains with segregated halide compositions form in semiconducting mixed-halide perovskites, thus severely limiting their optoelectronic applications due to the negative changes in bandgap energies and charge-carrier characteristics. Here we deposit mixed-halide perovskite CsPbBr1.2I1.8 nanocrystals onto an indium tin oxide substrate, whose temperature can be rapidly changed by ~10 degree in a few seconds by applying or removing an external voltage. Such a sudden temperature change induces a temporary transition of CsPbBr1.2I1.8 nanocrystals from the segregated phase to the mixed phase, the latter of which can be permanently maintained when the light illumination is coupled with periodic heating cycles. These findings mark the emergence of a practical solution to the detrimental phase-segregation problem, given that a small temperature modulation is readily available in various fundamental studies and practical devices using mixed-halide perovskites., 25 pages, 4 figures

We study the nature of the debated thermal Hall effect in the candidate Kitaev material $\alpha$-RuCl$_3$. Without assuming the existence of a gapped spin liquid, we show that a realistic minimal spin model in the canted zigzag phase suffices, at the level of linear spin-wave theory, to qualitatively explain the observed temperature and magnetic field dependence of the non-quantized thermal Hall conductivity $\kappa_{xy}$, with its origin lying in the Berry curvature of the magnon bands. The magnitude of the effect is however too small compared to the measurement by Czajka et al. [Nat. Mater. 22, 36-41 (2023)], even after scanning a broad range of model parameters so as to maximize $\kappa_{xy}/T$. Recent experiments suggest that phonons play an important role, which we show couple to the spins, endowing phonons with chirality. The resulting intrinsic contribution, from both magnons and phonons, is however still insufficient to explain the observed magnitude of the Hall signal. After careful analysis of the extrinsic phonon mechanisms, we use the recent experimental data on thermal transport in $\alpha$-RuCl$_3$ by Lefran\c{c}ois et al. [Phys. Rev. X 12, 021025 (2022)] to determine the phenomenological ratio of the extrinsic and intrinsic contributions $\eta\equiv \kappa_{xy}^{E}/\kappa_{xy}^{I}$. We find $\eta=1.2\pm 0.5$, which when combined with our computed intrinsic value, explains quantitavely both the magnitude and detailed temperature dependence of the experimental thermal Hall effect in $\alpha$-RuCl$_3$., Comment: 15 pages, 10 figures (including Supplementary Materials)

We study the nature of the debated thermal Hall effect in the candidate Kitaev material $α$-RuCl$_3$. Without assuming the existence of a gapped spin liquid, we show that a realistic minimal spin model in the canted zigzag phase suffices, at the level of linear spin-wave theory, to qualitatively explain the observed temperature and magnetic field dependence of the non-quantized thermal Hall conductivity $κ_{xy}$, with its origin lying in the Berry curvature of the magnon bands. The magnitude of the effect is however too small compared to the measurement by Czajka et al. [Nat. Mater. 22, 36-41 (2023)], even after scanning a broad range of model parameters so as to maximize $κ_{xy}/T$. Recent experiments suggest that phonons play an important role, which we show couple to the spins, endowing phonons with chirality. The resulting intrinsic contribution, from both magnons and phonons, is however still insufficient to explain the observed magnitude of the Hall signal. After careful analysis of the extrinsic phonon mechanisms, we use the recent experimental data on thermal transport in $α$-RuCl$_3$ by Lefrançois et al. [Phys. Rev. X 12, 021025 (2022)] to determine the phenomenological ratio of the extrinsic and intrinsic contributions $η\equiv κ_{xy}^{E}/κ_{xy}^{I}$. We find $η=1.2\pm 0.5$, which when combined with our computed intrinsic value, explains quantitavely both the magnitude and detailed temperature dependence of the experimental thermal Hall effect in $α$-RuCl$_3$., 15 pages, 10 figures (including Supplementary Materials)

Regularization is one of the most fundamental topics in optimization, statistics and machine learning. To get sparsity in estimating a parameter $u\in\mbR^d$, an $\ell_q$ penalty term, $\Vert u\Vert_q$, is usually added to the objective function. What is the probabilistic distribution corresponding to such $\ell_q$ penalty? What is the correct stochastic process corresponding to $\Vert u\Vert_q$ when we model functions $u\in L^q$? This is important for statistically modeling large dimensional objects, e.g. images, with penalty to preserve certainty properties, e.g. edges in the image. In this work, we generalize the $q$-exponential distribution (with density proportional to) $\exp{(- \half|u|^q)}$ to a stochastic process named \emph{$Q$-exponential (Q-EP) process} that corresponds to the $L_q$ regularization of functions. The key step is to specify consistent multivariate $q$-exponential distributions by choosing from a large family of elliptic contour distributions. The work is closely related to Besov process which is usually defined by the expanded series. Q-EP can be regarded as a definition of Besov process with explicit probabilistic formulation and direct control on the correlation length. From the Bayesian perspective, Q-EP provides a flexible prior on functions with sharper penalty ($q, 20 pages, 14 figures

The repair of large bone defects remains challenging due to the respective limitations of the clinically available bone grafts. Therefore, continuous efforts have been made to develop new bone and periosteum substitutes to enhance bone regeneration. HUCMSCs are promising stem cells for bone tissue engineering. However, a series of in-vitro studies have shown that the osteogenic efficacy of hUCMSCs is relatively lower than that of BMSCs. Therefore, in Chapter 2, we adopted a biomimetic strategy of co-culturing osteogenically- and angiogenically-committed hUCMSCs in various mixing ratios and culture media to promote the osteogenic efficacy of hUCMSCs. Compared with mono-cultured osteogenically-committed hUCMSCs in OM, a 3:1 ratio of osteogenically- and angiogenically-committed cells co-cultured in a 3:1 ratio of osteogenic medium and endothelial cell induction medium bore dramatically higher osteogenic properties, thus providing a novel strategy to fabricate hUCMSC-based biomimetic BTE constructs with enhanced osteogenic efficacy. It is established that ECM hydrogels bear a tissue-specific induction property. Therefore, in Chapter 3, decellularized periosteum-derived hydrogels (dPH) were fabricated and compared with the non-periosteum/bone-specific ECM hydrogel, Matrigel. Our study showed dPH exhibited a prominent effect on promoting the initial cellular spreading, migration, and proliferation. Moreover, the dPH group was associated with the enhanced osteogenesis-related genes expression and mineralized matrix formation of hUCMSCs than that of Matrigel. Our study indicated a promising application potential of biomimetic hUCMSCs/dPH constructs to repair bone defects. BioCaP coating has long been used to confer bone constructs an osteoconductive surface and enhanced scaffold-cell interactions. However, its biomedical application is limited by the low coating yield efficiency and protein-incorporation rate of the current coating procedure using 1× supersaturated CaP solution (SCPS). Therefore, in Chapter 4, we developed a highly concentrated 4.5× SCPS solution to harvest BioCaP coating. The thereby produced coating bore several advantages over the original coating, such as a higher coating yield efficiency and protein-incorporating rate. The new coating was identified as DCPD/apatite crystalline and showed a strong acid-resistant property. These properties conferred the new coating a promising potential in the functionalization of titanium implants for biomedical applications. Polydopamine (pDA) coating is a simple and effective method to modify scaffolds, thus covalently immobilizing growth factors and increasing surface bioactivity. Whether 3D printed TCP scaffolds functionalized by pDA-immobilized BMP2 were superior in prefabricating biomimetic bone grafts than the scaffolds functionalized by the superficially adsorbed one in latissimus dorsi muscle remained to be studied. Therefore, in Chapter 5, pDA-coated TCP (TCP/pDA) scaffolds were fabricated and characterized. Our study demonstrated that pDA coating was an efficacious method to improve the loading efficacy of BMP2 on the scaffolds, which also ensured a slow release profile of the loaded BMP2. Besides, pDA-immobilized BMP2 significantly promoted the osteogenic differentiation of C2C12 and the in-vivo bone formation. Our data suggested that the 3D printed TCP scaffolds functionalized with pDA-immobilized BMP2 were promising to prefabricate biomimetic bone grafts for repairing large bone defects. The development of tissue-engineered periosteum (TEP) is a promising strategy to accelerate the repair of bone defects. However, the previously developed TEPs lack periosteum-specific niches to regulate cellular activities and are hard to realize genuine biomimetic periosteum in composition. Therefore, in Chapter 6, we adopted the co-axial electrospinning technique to fabricate a novel biomimetic TEP with PCL-core/dECM-shell-structured microfibers. The novel PEC resembled the mechanical strength of the PCL membrane and bore dECM-like hydrophilicity and bioactivity to promote cell spreading, proliferation, and osteogenic activities. Moreover, PEC bore a comparable healing efficacy in repairing bone defects to the pure ECM, which was significantly higher than that in the pure PCL membrane. These findings indicated a promising application potential of the novel PEC-TEP in repairing bone defects.

The purpose of this study is to analyze the relationship between psychology and modern art design education in colleges, and to provide the basis for improving the quality of art education in colleges. Based on the relevant theory, the characteristics of educational psychology and art psychology and the correlation between them were analyzed from the angle of art education. According to the characteristics of college students' psychological development, the significance of art psychology-related courses was analyzed. Through the form of questionnaire, a total of 200 students (400 students in total) were randomly selected from Xi'an Academy of Fine Arts (professional art college) and Xi'an University of Science and Technology (comprehensive university), respectively. A total of 400 questionnaires were issued, and 382 valid questionnaires were recovered. The results show that almost all students in two colleges think pedagogy and educational psychology are the theoretical basis for art teachers, while less than one-third of students in Xi'an University of Science and Technology think that art psychology is the theoretical basis for art teachers. The difference between the students' aesthetic and life values in the two colleges is significant (p < 0.01). In the 15 directions of life values, there are significant differences in five directions: spirit—material (p < 0.05), enrichment—emptiness (p < 0.05), enthusiasm—apathy (p < 0.05), hope—despair (p < 0.01), and dedication—acceptance (p < 0.01). It shows that the psychological and values of college students are changeable, and the educators should pay attention to the education in the related fields of psychology. This exploration was conducted based on educational psychology, which is of great significance for improving the educational level of art psychology in colleges and enable students to form correct aesthetic standards and life values.

Frustrated spin-systems have traditionally proven challenging to understand, owing to a scarcity of controlled methods for their analyses. By contrast, under strong magnetic fields, certain aspects of spin systems admit simpler and universal description in terms of hardcore bosons. The bosonic formalism is anchored by the phenomenon of Bose-Einstein condensation (BEC), which has helped explain the behaviors of a wide range of magnetic compounds under applied magnetic fields. Here, we focus on the interplay between frustration and externally applied magnetic field to identify instances where the BEC paradigm is no longer applicable. As a representative example, we consider the antiferromagnetic $J_1 - J_2 - J_3$ model on the square lattice in the presence of a uniform external magnetic field, and demonstrate that the frustration-driven suppression of the N\'{e}el order leads to a Lifshitz transition for the hardcore bosons. In the vicinity of the Lifshitz point, the physics becomes unmoored from the BEC paradigm, and the behavior of the system, both at and below the saturation field, is controlled by a Lifshitz multicritical point. We obtain the resultant universal scaling behaviors, and provide strong evidence for the existence of a frustration and magnetic-field driven correlated bosonic liquid state along the entire phase boundary separating the N\'{e}el phase from other magnetically ordered states., Comment: 6 pages; 5 figures; v2) updated references, typos fixed, supplemental information added as ancillary file

Inverse problems with spatiotemporal observations are ubiquitous in scientific studies and engineering applications. In these spatiotemporal inverse problems, observed multivariate time series are used to infer parameters of physical or biological interests. Traditional solutions for these problems often ignore the spatial or temporal correlations in the data (static model), or simply model the data summarized over time (time-averaged model). In either case, the data information that contains the spatiotemporal interactions is not fully utilized for parameter learning, which leads to insufficient modeling in these problems. In this paper, we apply Bayesian models based on spatiotemporal Gaussian processes (STGP) to the inverse problems with spatiotemporal data and show that the spatial and temporal information provides more effective parameter estimation and uncertainty quantification (UQ). We demonstrate the merit of Bayesian spatiotemporal modeling for inverse problems compared with traditional static and time-averaged approaches using a time-dependent advection-diffusion partial different equation (PDE) and three chaotic ordinary differential equations (ODE). We also provide theoretic justification for the superiority of spatiotemporal modeling to fit the trajectories even it appears cumbersome (e.g. for chaotic dynamics)., Comment: 38 pages, 23 figures

Additional file 1: Table S1. Agents used in the FCM. Figure S1. FACS gating of DCs and correlative subsets. The FACS gating strategy was listed as following: first, DCs were gated as Gate 1; then, CD80+/CD86+ cells were gated as Gate 2, which was gathered in the lower-right quadrant. The correlative subsets were gated with the similar strategy. DCs were gated as Gate 1; then, CD11c+ cells were gated as Gate 2, CD8a+ cells were gated as Gate 3, and CD11b+ cells were gated as Gate4. Figure S2. CD40 Ab and OK-432 synergistically activate the expression of CD80. A, B. Identification of dendritic cells (DCs). DC-associated markers (CD8α, CD80, CD86, CD11c, and CD11b) were employed to identify the subset of DCs, which was achieved by FCM. DCs marked by the co-stimulatory signals (CD80, CD86) are more than 85%. 36.7% were marked by DCs defining marker CD11c, among of which 12.9% were CD11b-marked cells. And these markers defined the DC subset that is committed to play critical role in T cell activation. C, D. CD40 Ab and OK-432 synergistically activate the expression of CD80. The experiment was performed in six groups, including three control groups: Neg-Ctrl (without any agent), Ag-Ctrl (with anergic antigen), and TNF-α (positive control), and three test groups: CD40 Ab, OK-432, and 40432 group (combinational group, CD40 Ab and OK-432). Compared to the control groups (Neg-Ctrl, Ag-Ctrl, and TNF-α), expression of CD80 can be separately improved by CD40 Ab, and OK-432, and the synergistic group 40432 was most significantly improved. Figure S3. FACS gating of T cells and correlative subsets. The FACS gating strategy was listed as following: first, T cells were gated as Gate 1; then, CD8+ cells were gated as Gate 2. CD4+ cells were gated as Gate 2, Foxp3+ cells were gated as Gate 3.

In children’s learning subjects, English courses has its relative particularity compared with Chinese courses and the mathematics. Children’s English teaching is often inefficient because of the lack of students’ timely consolidation after class. Given this, the present work starts with the analysis of the current situation of children’s learning, and introduces the film-assisted English teaching. In the specific teaching links, English teaching is carried out in a three-dimensional teaching mode. Before that, topics of the films are selected for the English teaching, and the films are edited and processed. Initially, the present work expounds the English children’s films and their educational functions. Then, children can obtain teaching effect from the films. An English questionnaire is designed to analyze the application effect of English films in children’s English teaching. The results show that the film teaching mode improves children’s learning interest and motivation, and English film teaching can stimulate students’ learning interest. Students are also more active to participate in teaching activities, thus improving their language skills. Under the teaching in the scenes of films, students can perceive the functions of language in certain contexts. Comprehensible language input promotes students’ English listening ability and oral expression ability. The films can intuitively show the humanistic style, historical geography, cultures, and customs of English countries, and then cultivate students’ western cultural literacy. Practice has proved that the method proposed here can achieve good teaching effect, and it provides certain references for children’s English education.

ObjectivesThe study aimed to explore the relationship of thyroid function and resistance indices with subsequent risk of gestational diabetes (GDM).DesignThis was a longitudinal study embedded in the Huizhou Birth Cohort.MethodsA total of 2,927 women of singleton pregnancy were recruited from January to October of 2019. Thyroid central resistance indices were evaluated by Thyroid Feedback Quartile-Based index (TFQI), Thyrotrophy T4 Resistance Index (TT4RI), and TSH Index (TSHI) based on plasma-free thyroxine (FT4) and thyroid-stimulating hormone (TSH) levels during the first half of pregnancy. Thyroid peripheral sensitivity was assessed by free triiodothyronine (FT3) to FT4 ratio (FT3/FT4), a proxy of deiodinase activity. GDM was diagnosed between 24 and 28 weeks of gestation by a standardized 75 g oral glucose tolerance test. Multivariable linear and logistic regression was applied to examine the associations of thyroid markers with GDM risk.ResultsFT3 and FT3/FT4 were positively associated with both fasting and post-load glucose levels, while TSH, TSHI, TT4RI, and TFQI were negatively associated with 1 and 2 h post-load glucose levels. Compared with the lowest quartile, GDM risk in the highest quartile increased by 44% [odds ratio (OR) = 1.44; 95%CI, 1.08–1.92; ptrend = 0.027] for FT3 and 81% (OR = 1.81; 95%CI, 1.33–2.46; ptrend < 0.001) for FT3/FT4, while it lowered by 37% (OR = 0.63; 95%CI, 0.47–0.86; ptrend = 0.002] for TSHI, 28% for TT4RI (OR = 0.72; 95%CI, 0.54–0.97; ptrend = 0.06), and 37% for TFQI (OR = 0.63; 95%CI, 0.46–0.85; ptrend < 0.001).ConclusionsThis longitudinal study indicated that higher FT3 and FT3/FT4 and lower central thyroid resistance indices were associated with increased risk of GDM.

The fabrication of aptamers on DNA nanostructures through the DNA origami method has shown great potential for in vitro and in vivo tumor targeting delivery. Herein, tetrahedral multivalent DNA (Td) nanocages modified with different numbers of MUC1-aptamers (nApt-Td) were obtained via the self-assembly of nucleic acid backbones containing the aptamer DNA fragment without complicated chemical modification steps. Then, doxorubicin (DOX) was encapsulated in the modified nApt-Td nanocages via non-covalent interactions. Due to the specific identification of the aptamers, the intracellular uptake studies demonstrated that the multivalent modified aptamers on the vertex of Td significantly enhanced the intracellular uptake efficiency in MCF-7 tumor cells, but reduce that of normal cells. The number of aptamers had a significant influence on the intracellular uptake efficiency of Td nApt-Td. Furthermore, improved in vivo systemic safety and decreased systemic toxicity accompanied with effective tumor inhibition were also demonstrated compared with the anti-tumor efficiency of free DOX.

Apoferritin caged a huge amount of photocatalysts and enhanced H2 generation capability under homogeneous acidic conditions., We took advantage of the iron binding affinity of apoferritin to immobilize iron–sulfur clusters into apoferritin up to 312 moieties per protein, with a loading rate as high as 25 wt%. The photocatalytic hydrogen generation activity in acidic aqueous solutions was achieved with TONs up to 31 (based on a single catalyst moiety) or 8.3 × 103 (based on a single protein) upon 3 h of visible light irradiation. The present study provides a versatile strategy to construct uniform protein/photocatalyst supramolecular systems with FeFe-H2ase activity.

Revised Supplemental Materials: Serum TMAO and incident type 2 diabetes

Hui Yang,1 Wei Sun,2 Pei Ma,1 Chunsuo Yao,1 Yannan Fan,1 Shuyi Li,1 Jiqiao Yuan,1 Ziqian Zhang,1 Xuyu Li,1 Mingbao Lin,1 Qi Hou1 1State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, People’s Republic of China; 2Beijing Friendship Hospital, Capital Medical University, Beijing, People’s Republic of ChinaCorrespondence: Mingbao Lin; Qi Hou Tel +86-10-63165192; +86-10-63165191Email mingbaolin@imm.cams.cn; houq@imm.ac.cnBackground: Perilla frutescens (L.) Britt., a classic medicinal plant, has been demonstrated to have anti-inflammatory and anti-allergic effects in asthma. Perilla leaves extract (PLE) exerted significant therapeutic effect against allergic asthma inflammation through Syk inhibition. But the active chemical ingredients from PLE are complex and unclear, it is difficult to fully elucidate its pharmacological mechanisms.Methods: A method was established for rapid screening and characterization of active ingredients from PLE that targeted Syk, with which three potential active ingredients were identified. By using OVA-induced allergic asthma mouse model in vivo, OVA-induced human PBMCs inflammation model and DNP-IgE/BSA-induced RBL-2H3 cells model in vitro, the effects and mechanisms of PLE and its active components were evaluated.Results: Using Syk-affinity screening method, roseoside (RosS), vicenin-2 (Vic-2) and rosmarinic acid (RosA) were identified from PLE. In vitro, PLE and its ingredients showed significant inhibitory activities against Syk, with their mixture (Mix, prepared by RosS, Vic-2 and RosA in accordance with their ratio in Syk-conjugated beads bound fraction) showing a stronger inhibitory activity. RosS, Vic-2 and RosA also showed significant effects on allergic asthma, and a synergistic effect of Mix was observed. Moreover, treatment with PLE, RosS, Vic-2, RosA, and Mix significantly inhibited the expression and phosphorylation of Syk, PKC, NF-κB p65, and cPLA2 in allergic mice lung tissue and in RBL-2H3 cells.Conclusion: PLE may alleviate allergic airway inflammation partly through the multiple components synergistic targeting on Syk and its downstream inflammatory pathway.Keywords: allergic airway inflammation, multi-component, PLE, Syk, synergistic effect

Co-located multiple input multiple output (MIMO) radar is one kind of new style radar, whose transmitting waveforms of each sub-array are orthogonal to each other. Compared with phased array radar, its beam width is wider. Therefore, different targets may be illuminated simultaneously with one beam in co-located MIMO radar. An adaptive resource management in tracking for co-located MIMO radar is proposed, where the sub-array number, the illuminated targets set and the transmitting waveform of the system can be controlled. The optimal parameters are chosen according to a cost function that takes both the desired tracking precision and consumed energy into consideration. Simulation results demonstrate the effectiveness of the algorithm. Using the algorithm, co-located MIMO radar can achieve the desired tracking precision with less cost compared with phased array radar.

People are increasingly becoming accustomed to taking photos of everyday life in modern cities and uploading them on major photo-sharing social media sites. These sites contain numerous pictures, but many have incomplete or blurred location information. The geo-localization of crowd-sourced pictures enriches the information contained therein, and is applicable to activities such as urban construction, urban landscape analysis, and crime tracking. However, geo-localization faces huge technical challenges. This paper proposes a method for large-scale geo-localization of crowd-sourced pictures. Our approach uses structured, organized Street View images as a reference dataset and employs a three-step strategy of coarse geo-localization by image retrieval, selecting reliable matches by image registration, and fine geo-localization by 3D reconstruction to attach geographic tags to pictures from unidentified sources. 3D reconstruction based on close-range photogrammetry is used to restore the 3D geographical information of the crowd-sourced pictures, resulting in the proposed method improving the median error from 256.7 m to 69.0 m, and the percentage of the geo-localized query pictures under a 50 m error requirement from 17.2% to 43.2% compared with the previous method. Another discovery of the proposed method is that, regarding the causes of reconstruction error, closer distances from the query cameras to the main objects in query pictures tend to produce smaller errors. The proposed method is not limited to small areas, and could be expanded to cities and larger areas owing to its flexible parameters.

Based on the pursuit of different goals in the operation of the microgrid, it is not possible to meet the lowest cost and the least pollution at the same time. From the perspective of economy and environmental protection, a microgrid model including photovoltaic power generation, wind power generation, micro gas turbine, fuel cell and energy storage device is proposed. This paper establishes a comprehensive benefit objective function that considers both microgrid fuel cost, maintenance management cost, depreciation cost, interaction cost with public grid and pollutant treatment cost. In order to avoid the defect that the traditional particle swarm optimization algorithm is easy to fall into the local optimal solution, this paper uses the combination of simulated annealing algorithm and particle swarm optimization algorithm to compare with the traditional particle swarm optimization algorithm to obtain a more suitable method for microgrid operation. Finally, a typical microgrid in China is taken as an example to verify the feasibility of the algorithm.

The performance of different forcing datasets for trajectory prediction in the South China Sea and the sensitivity of prediction accuracy from selected datasets and model-based methods have been studied using Lagrangian models. Seven global ocean forecast or reanalysis forcing datasets including three current forcing datasets (CMEMS, CMEMS-R, and GlobCurrent), three wind forcing datasets (NCEP, ERA5, and IFREMER) and one waves forcing dataset (MFWAM) were selected to advect the virtual drifters for modeling the drift trajectories of dummies and SVP drifters in four experimental regions. We use an integrated analysis framework to conduct several holistic prediction experiments, evaluate quantitatively the accuracy of trajectory prediction using statistical indicators and FSLE analysis, and to further estimate the uncertainty factors from data and model levels. The experimental results show that the CMEMS-R can meet the needs of trajectory prediction of dummies within 48 hours in Region 1, but neither CMEMS nor CMEMS-R can better follow the complex ocean current pattern in Region 2, which leads to the poor results of the 24-hour trajectory prediction driven by CMEMS or CMEMS-R. In the deep water regions (Region 3-4), the performance of the GlobCurrent derived from satellite-observations for modeling the trajectories of SVP drifters is comparable with the CMEMS in general, and shows obvious advantages in Region 3, even though CMEMS has a finer spatial and temporal resolution. The two wind forcing datasets, ERA5 and IFREMER, show roughly similar performance in the trajectory prediction in Region 1. Compared with the significant difference between current forcing datasets, the three wind forcing datasets have relatively consistent temporal and spatial variations in the other three experimental regions. In four experimental regions, the separation distance between the simulated and actual trajectories increases in a uniform linear mode with mean separation velocity. In general, the selection of current forcing fields has more influence on the trajectory prediction of the three types of floating objects than other factors. The ocean current pattern represented by related current forcing datasets is the key to this essential influence.

Supplement 1 for the article

Supplement 1 for the article

Purpose A meta-analysis to compare iris-claw intraocular lens (IC-IOL) and scleral-fixated posterior chamber intraocular lens (SF-PCIOL) implantations in correcting aphakia without sufficient capsular support. Methods Eligible studies were collected through PubMed, Web of Science, Embase, and the Cochrane library. The pooled relative risks (RR), pooled standardized mean difference (SMD), and their 95% confidence interval of the eligible studies were then calculated. Seven studies met our inclusion criteria, involving 232 and 158 eyes in IC-IOL and SF-PCIOL groups, respectively. Results The pooled SMD of the mean postoperative corrected distance visual acuity (CDVA) (logMAR) was -0.25. The pooled RR of the eyes achieving 20/40 or better postoperatively was 1.16. The pooled SMD of the surgical time was -2.97. The pooled RR of the surgical complications was 0.86. The pooled RR of IOL dislocation, retinal detachment (RD), and cystoid macular edema (CME) between the two groups were 0.22, 0.63, and 0.64. Conclusions Implantation of IC-IOL has a more simple procedure and shorter learning curve than SF-PCIOL implantation in correcting aphakia without sufficient capsular support.

Problems with water resources security (WRS) resulting from water scarcity are occurring worldwide, and the most feasible solution to such problems is to increase the productivity of limited water resources through rational water use allocation within the affected region. In this study, an optimal water allocation model (OWAM) based on WRS assessment was developed and applied to improve the water use benefits in Zhangjiakou Region of northern China in 2020. The OWAM was an optimal linear programming model that comprehensively considered eco-environmental and socio-economic benefits. Some WRS assessment indicators that can be easily adjusted, including the ratio of ecological water to total water demand, surface water pollution index, exploitation ratio of water resources, water supply per capita, industrial water scarcity, and agricultural water scarcity, were incorporated into the OWAM as constraining conditions. The model had different solutions corresponding to four WRS statuses (quite safe, basically safe, unsafe, and extremely unsafe). The results indicated that optimal water allocation determined using this model met the domestic and environmental water demand, and led to increased water use benefits within the region when compared with before allocation. The benefits of basically safe status were bigger than those of unsafe status. In contrast to the conventional OWAM, the developed model could help to assure sustainable water use at the regional scale when used in combination with WRS assessment.

We investigate relations among tree-level off-shell currents in nonlinear sigma model. Under Cayley parametrization, we propose and prove a general revised BCJ relation for even-point currents. Unlike the on-shell BCJ relation, the off-shell one behaves quite differently from Yang-Mills theory although the algebraic structure is the same. After performing the permutation summation in the revised BCJ relation, the sum is non-vanishing, instead, it equals to the sum of sub-current products with the BCJ coefficients under a specific ordering, which is presented by an explicit formula. Taking on-shell limit, this identity is reduced to the on-shell BCJ relation, and thus provides the full off-shell correspondence of tree-level BCJ relation in nonlinear sigma model., 40 pages, 14 figures

In this study, we investigate the influence of absorber thickness on Cu2ZnSnS4 (CZTS) solar cells, ranging from 500 to 2000 nm, with nearly constant metallic composition. Despite the observed ZnS and SnS phases on the surface and backside of all absorber films, scanning electron microscopy, Raman scattering, and X-ray diffraction show no large variations in material quality for the different thicknesses. The open-circuit voltage (V-oc), short-circuit current and overall power conversion efficiency of the fabricated devices show an initial improvement as the absorber thickness increases but saturate when the thickness exceeds 750 nm. External quantum efficiency (EQE) measurements suggest that the current is mainly limited by collection losses. This can result from non-optimal bulk quality of the CZTS absorber (including the presence of secondary phases), which is apparently further reduced for the thinnest devices. The observed saturation of V-oc agrees with the expected influence from strong interface recombination. Finally, an effective collection depth of 750-1000 nm for the minority carriers generated in the absorber can be estimated from EQE, indicating that the proper absorber thickness for our device process is approximately 1000 nm. Performance could be improved for thicker films, if the collection depth can be increased.

VO2-based films are thermochromic and exhibit high or low infrared transmittance when the temperature is below or above a critical temperature. The thermochromic switching is passive and reversible, and therefore VO2 based films are promising for energy-efficient window appli­cations. However the practicaluse of VO2 for energy-efficient windows has long been hampered by low luminous transmittance and low solar energy transmittance modulation. The main goal of this dissertation work is to address these issues. The first half of the work proposes the concept of nanothermochromics for simultaneous improvement of luminous transmittance and modulation of solar energy throughput. nanoth­ermochromics considers VO2 nanoparticle composite layers, whose optical properties were modeled by effective medium theories. Calculations on VO2 spheroids have shown that VO2 nanoparticles, especially nanospheres, can offer dramatically improved luminous transmittance and solar transmittance modulation that are not possible for films. Calculations done on coreshell nanoparticles showed comparable improvements and offer an opportunity to reduce the material costs. It was also found that the composite of In2O3:Sn (ITO) and VO2 can yield moderately high luminous transmittance, solar transmittance modulation and low-emittance properties. In the second half of the dissertation work, Mg-doped VO2 films were sputter deposited. Their band gaps and Mg-content were investigated by means of optical absorption measurement and Rutherford backscattering spectrometry, respectively. The band gaps of VO2 were found to increase by ∼3.9±0.5 eV per unit of atom ratio Mg/(Mg+V) for 0

The Remund-Long (RL) Multi-Sensor Sea Ice Classification algorithm� combines both radiometer and scatterometer data using Principle Component Analysis and reduces the dimensionality and noise level of the data. The algorithm uses an iterative Maximum a Posteriori (MAP) method based on a multi-variant Gaussian model with a temporal prior. As a result, the algorithm successfully classifies Winter Antarctic region into five different ice types. However, due to the nature of this pixel wise classification algorithm, the final classification is more likely to be corrupted by slat-pepper-shaped artifacts. Such artifacts are introduced by the Scatterometer Image Reconstruction (SIR) algorithm which utilizes multi-swath raw scatterometer data to generate high resolution images. In order to resolve such problem in RL algorithm, posterior distribution function with spatial prior is embedded into the classification process. A Markov Chain Monte Carlo (MCMC) sampling method is one way to sample such posterior distribution of the state space in which each element of the space has the size of an entire image. This report gives a brief introduction to the concept of Metropolis-Hastings Markov Chain Monte Carlo (MH MCMC) algorithm, discusses its implementation on polar sea ice classification, and compares the result with the RL algorithm.