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Purpose: Reliable measurement of lymph nodes (LNs) in multi-parametric MRI (mpMRI) studies of the body plays a major role in the assessment of lymphadenopathy and staging of metastatic disease. Previous approaches do not adequately exploit the complementary sequences in mpMRI to universally detect and segment lymph nodes, and they have shown fairly limited performance. Methods: We propose a computer-aided detection and segmentation pipeline to leverage the T2 fat-suppressed (T2FS) and diffusion-weighted imaging (DWI) series from a mpMRI study. The T2FS and DWI series in 38 studies (38 patients) were co-registered and blended together using a selective data augmentation technique, such that traits of both series were visible in the same volume. A mask RCNN model was subsequently trained for universal detection and segmentation of 3D LNs. Results: Experiments on 18 test mpMRI studies revealed that the proposed pipeline achieved a precision of $\sim 58$\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\sim 58$$\end{document}%, sensitivity of $\sim 78$\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\sim 78$$\end{document}% at 4 false positives (FP) per volume, and dice score of $\sim 81$\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\sim 81$$\end{document}%. This represented an improvement of $\ge 12$\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\ge 12$$\end{document}% in precision, $\ge 15$\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\ge 15$$\end{document}% in sensitivity at 4 FP/volume, and $\ge 14$\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\ge 14$$\end{document}% in dice score, respectively, over current approaches evaluated on the same dataset. Conclusion: Our pipeline universally detected and segmented both metastatic and non-metastatic nodes in mpMRI studies. At test time, the input data used by the trained model could either be the T2FS series alone or a blend of co-registered T2FS and DWI series. Contrary to prior work, this eliminated the reliance on both the T2FS and DWI series in a mpMRI study.

After decades of research in the conservation of cultural heritage, nanolime (NL) has emerged as a potential alternative inorganic material to the frequently used organic materials. However, its poor kinetic stability in water has been a major challenge that restricted its penetration depth through cultural relics and resulted in unsatisfactory conservation outcomes. Here, for the first time, we realize NL water dispersion by modification of ionic liquid (1-butyl-3-methylimidazolium tetrafluoroborate) via a sample aqueous solution deposit method. Our findings indicate that the cation of the ionic liquid (IL) binds strongly to the surface of NL particles (IL-NL) by forming hydrogen bonds with Ca(OH)2facets. The absorption of IL causes an unexpected significant alteration in the morphology of NL particles and results in a drastic reduction in NL’s size. More importantly, this absorption endows NL excellent kinetic stability dispersed into water and implements NL water dispersion, which makes a breakthrough in terms of extreme poor kinetic stability of as-synthesized NL and commercial NL in water. The mechanism driving IL-NL water dispersion is explained by Stern theory. In the context of consolidating weathered stone, the presence of IL may delay carbonation of NL but the penetration depth of IL-NL through stone samples is three times deeper than that of as-synthesized and commercial NLs. Additionally, the consolidation strength of IL-NL is similar to that of as-synthesized NL and commercial NL. Moreover, IL-NL has no significant impact on the permeability, pore size, and microstructure of consolidated stone relics. Our research contributes to the field of NL-related materials and will enhance the dissemination and utilization of NL-based materials in the preservation of water-insensitive cultural heritage.

Energy-efficient separation of propylene (C3H6)/propane (C3H8) is in high demand for the chemical industry. However, this process is challenging due to the imperceptible difference in molecular sizes of these gases. Here, we report a continuous water nanotube dedicatedly confined in a Cu10O13-based metal–organic framework (MOF) that can exclusively adsorb C3H6over C3H8with a record-high selectivity of 1570 (at 1 bar and 298 K) among all the porous materials. Such a high selectivity originates from a new mechanism of initial expansion and subsequent contraction of confined water nanotubes (∼4.5 Å) caused by C3H6adsorption rather than C3H8. Such unique response was further confirmed by breakthrough measurements, in which one adsorption/desorption cycle yields each component of the binary mixture high purity (C3H6: 98.8%; C3H8: >99.5%) and good C3H6productivity (1.6 mL mL–1). Additionally, benefiting from the high robustness of the framework, the water nanotubes can be facilely recovered by soaking the MOF in water, ensuring long-term use. The molecular insight here demonstrates that the confining strategy opens a new route for expanding the function of MOFs, particularly for the sole recognition from challenging mixtures.

Purpose: Identification of lymph nodes (LNs) that are suspicious for metastasis in T2 Magnetic Resonance Imaging (MRI) is critical for assessment of lymphadenopathy. Prior work on LN detection has been limited to specific anatomical regions of the body (pelvis, rectum). Therefore, an approach to universally detect both benign and metastatic nodes in T2 MRI studies of the body is highly desirable. Methods: We developed a Computer Aided Detection (CAD) pipeline to universally identify LN in T2 MRI. First, we trained various neural networks for detecting LN: Faster RCNN with and without Hard Negative Example Mining (HNEM), FCOS, FoveaBox, VFNet, and Detection Transformer (DETR). Next, we show that VFNet with Adaptive Training Sample Selection (ATSS) outperformed Faster RCNN with HNEM. Finally, we ensembled models that surpassed a 45% mAP threshold. Results: Experiments on 122 test studies revealed that VFNet achieved a 51.1% mAP and 78.7% recall at 4 false positives (FP) per volume, while the one-stage model ensemble achieved a mAP of 52.3% and sensitivity of 78.7% at 4FP. We found that VFNet and the one-stage model ensemble can be interchangeably used in the CAD pipeline. Conclusion: Our CAD pipeline universally detected both benign and metastatic nodes in T2 MRI studies, resulting in a sensitivity improvement of $\sim$\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\sim $$\end{document}14% over the current LN detection approaches (sensitivity of 78.7% at 4 FP vs. 64.6% at 5 FP per volume).

Chemically functionalized series of metal–organic frameworks (MOFs), with subtle differences in local structure but divergent properties, provide a valuable opportunity to explore how local chemistry can be coupled to long-range structure and functionality. Using in situsynchrotron X-ray total scattering, with powder diffraction and pair distribution function (PDF) analysis, we investigate the temperature dependence of the local- and long-range structure of MOFs based on NU-1000, in which Zr6O8nodes are coordinated by different capping ligands (H2O/OH, Cl–ions, formate, acetylacetonate, and hexafluoroacetylacetonate). We show that the local distortion of the Zr6nodes depends on the lability of the ligand and contributes to a negative thermal expansion (NTE) of the extended framework. Using multivariate data analyses, involving non-negative matrix factorization (NMF), we demonstrate a new mechanism for NTE: progressive increase in the population of a smaller, distorted node state with increasing temperature leads to global contraction of the framework. The transformation between discrete node states is noncooperative and not ordered within the lattice, i.e., a solid solution of regular and distorted nodes. Density functional theory calculations show that removal of ligands from the node can lead to distortions consistent with the Zr···Zr distances observed in the experiment PDF data. Control of the node distortion imparted by the nonlinker ligand in turn controls the NTE behavior. These results reveal a mechanism to control the dynamic structure of MOFs based on local chemistry.

Many tomb murals have punctate losses, cracks, and craquelure due to underground subsidence and changes in their physical support. Visual non-destructive detection techniques enable rapid assessment of how much tomb murals are affected by cracking, providing suggestions for their conservation. However, tomb murals are typically created by sketching outlines and then colored. Detailed sketches can easily interfere with crack detection work, requiring the use of deep learning network to better learn crack features and improve detection accuracy. At the same time the limited data of tomb mural presents a challenge to build a deep learning network. To address these issues, this paper introduces a novel dual-attention detection network (DADNet) for crack segmentation of tomb murals. In this work, a customized dataset is first constructed by collecting mural images from the Tang Dynasty tombs. Then the ConvNeXt framework serves as the basis for feature extraction, enhancing the process. Lastly, a dual-attention module utilizing neighborhood attention and biaxial attention is employed to accurately identify the crack regions. Neighborhood attention performs a local self-attention operation around the pixel point, addressing the limitations of self-attention. This approach significantly reduces computational demands as the image size increases. Biaxial attention performs attention calculations in the horizontal and vertical directions. This compensates for the limitation of neighborhood attention in capturing global dependencies. Our DADNet outperformed the competing methods, achieving the highest recorded scores of 78.95% for MIoU and 61.05% for the Jaccard index.

Removing unwanted materials, such as organic coatings and soil, from the cultural relic surface is a complex and significant task in the field of cultural heritage conservation. Microemulsion-loaded gel can effectively and safely remove those organic coatings and soil. Here, we employed a simple solvent exchange strategy to prepare a microemulsion-loaded polyvinyl alcohol/polyethyleneimine (PVA/PEI) hydrogel. First, PVA and PEI were dissolved into DMSO to form a gel. Then, the gel was immersed into a microemulsion composed of water, ethyl acetate, propylene carbonate, sodium dodecyl sulfate, and 1-pentanol to exchange DMSO. Microemulsion-loaded PVA/PEI hydrogel can be synthesized by completely substituting DMSO. To investigate the microstructure, rheological properties, and mechanical properties of the gel, scanning electron microscopy, a rheometer, and a universal testing machine were used, respectively. Fourier transform infrared (FT-IR) analysis was conducted to explore the synthesis mechanism and confirm the successful loading of microemulsion within the microemulsion-loaded PVA/PEI hydrogel. Furthermore, FT-IR, a depth-of-field microscope, and a glossmeter were utilized to evaluate the cleaning efficiency of the microemulsion-loaded PVA/PEI hydrogel for removing animal glue and soil from the surfaces of cultural relics. Moreover, an X-ray fluorescence spectrometer was used to analyze the element component of the ancient coin. The application results showed that the microemulsion-loaded PVA/PEI hydrogel can effectively remove animal glue from an ancient wall painting surface. Moreover, it is capable of removing soil from an ancient coin surface as well, which helped to confirm the age of the coin. This offers a novel method to prepare microemulsion-loaded hydrogel and demonstrates great potential in the cleaning for cultural heritage.

AbstractIn plants, β-glucosidases (BGLUs) are important glycoside hydrolases involved in several biological phenomena, including the response to stresses viathe activation of phytohormones and the release of alpha-hydroxy nitriles to protect against stresses. Due to the importance of BGLUs in plant growth and stress response, genome-wide analyses have been conducted in Arabidopsisand rice, while not in tomato (Solanum lycopersicum). In this study, we identified 20 BGLU genes in the tomato that were unevenly distributed on nine chromosomes and divided into five subgroups. There were a variety of plant hormones and stress response cis-elements in the promoter region of the SlBGLU gene, indicating that the BGLU gene may be involved in several aspects of the tomato stress response. SlBGLU gene expression analysis showed that the BGLU gene of tomato was expressed in many tissues, especially in the roots and leaves. Transcriptome data and results of real-time quantitative reverse transcription-polymerase chain reaction showed that most SlBGLU genes could be induced by abscisic acid, chlorothalonil, NaCl and cold (4 °C), especially SlBGLU13 and SlBGLU19, which may be key BGLU genes in response to stress and hormonal stimulation in the tomato. In addition, we constructed a competing endogenous RNA (ceRNA) network, which confers a new direction for studies on the function of SlBGLU genes. These findings not only further clarify the potential function of the BGLU gene family in mediating abiotic stresses in the tomato, but also provide valuable information for the study of functional genomics of the tomato in the future.

The purpose of this paper is to combine machine learning to locate the 3D sensor network space. Real life is mostly a three-dimensional environment. Whether it is a factory in manufacturing or a vegetation base in agriculture, it needs to be monitored and positioned. In this paper, the localization algorithm is discussed to a certain extent. This paper firstly introduces the relevant background and organizes related work. It also wrote related algorithms, such as ranging-based positioning algorithms in the free space of wireless sensors. It shows the positioning link by introducing the wireless sensor network structure system and node structure. And this paper summarizes the Bounding-box Method positioning principle, TDOA algorithm principle, and TDOA positioning principle. It then describes the gradient boosting tree classification algorithm based on machine learning, and focuses on the admiral boosting tree classification algorithm related to the experiment. This paper also describes the ranging technology combining RSSI algorithm and DV-Hop algorithm in three-dimensional space, and mentions two algorithms of RSSI and DV-Hop. In the fourth part, the machine learning coordinate prediction accuracy improvement experiment and the three-dimensional space positioning algorithm optimization experiment and result analysis are carried out. It is proved by experiments that the model evaluation effect of the gradient boosting tree classification algorithm in machine learning is the best. It can be applied to the calculation of relative position coordinates of label nodes. It then carried out the three-dimensional positioning effect test experiment of IDV-Hop algorithm. This shows that when the network density in the experimental environment reaches more than 12, the localization coverage of IDV-Hop algorithm and DV-Hop algorithm are both higher than 91%. Finally, the hybrid algorithm of RSSI and DV-Hop algorithm is used to compare the positioning accuracy, positioning coverage and bad node rate with these two algorithms. It draws the stability of the hybrid algorithm and its effects, and finally discusses and summarizes the experiments.

To conquer the trade-off dilemma of the nanofiltration membranes for both high permeability for water and high rejection for pollutants has long been highly concerned. In this work, TiO2and Bi2S3nanoparticles were evenly dispersed successively into the interlayers of Ti3C2Txnanosheets, and then filtered onto cellulose acetate support membranes. The as-obtained composite membranes exhibited a maximum water flux of 374.4 L m−2 h−1bar−1, and a high rejection ratio for RhB, GR, MB and BSA at 97.8–100%, apparently higher than those of the Ti3C2Txand the related membranes in literature. Such a high separation capacity was found quite stable for various dye-containing aqueous solutions, even in a high salinity environment of 5 wt% NaCl. Interestingly, 25% NaCl salt was also rejected accompanying the almost complete rejection of dye pollutants. After the filtering process, the membrane fouling of fouled Ti3C2Tx/TiO2/Bi2S3membranes was verified quite lower than that of fouled Ti3C2Tx/TiO2and Ti3C2Txmembranes. Furthermore, the flux recovery rate of the fouled composite membrane could reach 92.1% after washing under visible light, which could be ascribed to the composition of heterojunction causing the red shift of diffuse reflectance UV–vis spectra and the narrowing of the band gap. This study provides a new idea for the preparation of highly permeable and rejective nanofiltration membranes, and lays a foundation for its high-capacity dye removal applications.

Keeping up with the latest variant-related research is vital for genomic medicine. Here we present LitVar 2.0, a significantly improved web-based system to accurately search for genetic variants in the unstructured literature. LitVar 2.0 provides a unified search of full text and supplementary data, and improved variant recognition accuracy.

The development of multifunctional films with a high permeability has been of great concern for effective separation of complex aqueous contaminants, especially in the face of zero or near-zero release regulations. Inspired by the natural structure of sandy soils, polydopamine-wrapped/connected polypyrrole sub-micron spheres (PPSM) were closely packed onto a polypyrrole-coated bacterial cellulose (PBC) support, by which a new two-layered PBC/PPSM composite film formed with graded nanofluidic channels. Interestingly, after being soaked in complex water environments of ethanol, acids, bases, heat, cold and high salinity, or else bended/folded for more than 10 times, the structure and performance of this film still stayed the same, validating its high structural stability and flexibility. Even in a high salinity environment over seawater, this PBC/PPSM film exhibits a dye-separation capacity of almost 100% with a surprisingly superhigh water permeance over one thousand L h−1m−2bar−1, one or two magnitudes higher than that of the related films reported in the literature. Meanwhile, the ability for effective oil–water-separation was also validated. Besides the superhydrophilicity and underwater superoleophobicity, the synapse-like-structure-induced graded nanofluidic channels are also proposed to play a key role for rendering such an outstandingly comprehensive performance of the film by greatly overcoming fluid resistance and reducing permeation viscosity.

Photoinduced charge transfer (PCT) is a key step in the light-harvesting (LH) process producing the redox equivalents for energy conversion. However, like traditional macromolecular donor–acceptor assemblies, most MOF-derived LH systems are designed with a large ΔG0to drive PCT. To emulate the functionality of the reaction center of the natural LH complex that drives PCT within a pair of identical chromophores producing charge carriers with maximum potentials, we prepared two electronically diverse carboxy-terminated zinc porphyrins, BFBP(Zn)-COOH and TFP(Zn)-COOH, and installed them into the hexagonal pores of NU-1000 via solvent-assisted ligand incorporation (SALI), resulting in BFBP(Zn)@NU-1000 and TFP(Zn)@NU-1000 compositions. Varying the number of trifluoromethyl groups at the porphyrin core, we tuned the ground-state redox potentials of the porphyrins within ca. 0.1 V relative to that of NU-1000, defining a small ΔG0for PCT. For BFBP(Zn)@NU-1000, the relative ground- and excited-state redox potentials of the components facilitate an energy transfer (EnT) from NU-1000* to BFBP(Zn), forming BFBP(Zn)S1* which entails a long-lived charge-separated complex formed through an exciplex-like [BFBP(Zn)S1*–TBAPy] intermediate. Various time-resolved spectroscopic data suggest that EnT from NU-1000* may not involve a fast Förster-like resonance energy transfer (FRET) but rather through a slow [NU-1000*–BFBP(Zn)] intermediate formation. In contrast, TFP(Zn)@NU-1000 displays an efficient EnT from NU-1000* to [TFP(Zn)–TBAPy], a complex that formed at the ground state through electronic interaction, and thereon showed the excited-state feature of [TFP(Zn)–TBAPy]*. The results will help to develop synthetic LHC systems that can produce long-lived photogenerated charge carriers with high potentials, i.e., high open-circuit voltage in photoelectrochemical setups.

Ammonia uptake by high-capacity and high-porosity sorbents is a promising approach to its storage and release, capture and mitigation, and chemical separation. Here, we examined the ammonia sorption behavior of several versions of an archetypal zirconium-based metal–organic framework (MOF) material, NU-1000—a meso- and microporous crystalline compound having the empirical formula (1,3,6,8-tetrakis(p-benzoate)pyrene)2Zr6(μ3-O)4(μ3-OH)4(H2O)4(OH)4with linkers and nodes arranged to satisfy a csqtopology. Depending on the thermal treatment protocol used prior to sorption measurements, ammonia can physisorb to NU-1000 via hydrogen-bonding and London-dispersion interactions and chemisorb via Brønsted acid–base reactions with node-integrated proton donors (μ3-hydroxos) and node-ligated proton donors (terminal hydroxos), via simple coordination at open Zr(IV) sites, or via dissociative coordination to Zr(IV) as NH2–and protonation of a node-based μ3-oxo. Ammonia adsorption occurs via both reversible and irreversible processes. The latter are of particular interest for protection and mitigation. Notably, the unexpected dissociative adsorption occurs only with nodes that have been fully dehydrated and irreversibly structurally distorted via thermal pre-treatment—a finding that is supported by density functional theory calculations. Differentiating and ranking the relative importance of the many modes of adsorption was facilitated, in part, by the availability of variants of NU-1000 that replace the majority of terminal aqua and hydroxo ligands with nonstructural formate ligands, auxiliary ditopic linkers, or both. The study provides insights into the chemical basis for both reversible and irreversible uptake of ammonia by Zr-MOFs and related compounds. The unexpectedly rich variety of sorption motifs suggest the criteria for designing or choosing MOFs that are optimal for specific ammonia-centric applications.

High-stability, zirconium-based metal–organic frameworks are attractive as heterogeneous catalysts and as model supports for uniform arrays of subsequently constructed heterogeneous catalysts—for example, MOF-node-grafted metal–oxy and metal–sulfur clusters. For hexa-Zr(IV)-MOFs characterized by nodes that are less than 12-connected, sites not used for linkers are ideally occupied by reactive and displaceable OH/H2O pairs. The desired pairs are ideal for grafting the aforementioned catalytic clusters, while aqua-ligand lability renders them effective for exposing highly Lewis-acidic Zr(IV) sites (catalytic sites) to candidate reactants. New single-crystal X-ray studies of an eight-connected Zr-MOF, NU-1000, reveal that conventional activation fully removes modulator ligands, but replaces them with three node-blocking formate ligands (from solvent decomposition) and only one OH/H2O pair, not four—a largely overlooked complication that now appears to be general for Zr-MOFs. Here we describe an alternative activation protocol that effectively removes modulators, avoids formate, and installs the full complement of terminal OH/H2O pairs. It does so via an unusual isolatable intermediate featuring eight aqua ligands and four non-ligated chlorides—again as supported by single-crystal X-ray data. We find that complete replacement of node-blocking modulators/formate with the originally envisioned OH/OH2pairs has striking consequences; here we touch upon just three. First, elimination of unrecognized formate renders aqua ligands much more thermally labile, enabling open Zr(IV) sites to be obtained at lower temperature. Second, in the absence of formate, which otherwise links and locks pairs of node Zr(IV) ions, reversible removal of aqua ligands engenders reversible contraction of MOF meso- and micropores, as evidenced by X-ray diffraction. Third, formate replacement with OH/OH2pairs renders NU-1000ca.10× more active for catalytic hydrolytic degradation of a representative simulant of G-type chemical warfare agents.

A desirable feature of metal–organic frameworks (MOFs) is their well-defined structural periodicity and the presence of well-defined catalyst grafting sites (e.g., reactive −OH and −OH2groups) that can support single-site heterogeneous catalysts. However, one should not overlook the potential role of residual organic moieties, specifically formate ions that can occupy the catalyst anchoring sites during MOF synthesis. Here we show how these residual formate species in a Zr-based MOF, NU-1000, critically alter the structure, redox capability, and catalytic activity of postsynthetically incorporated Cu(II) ions. Single-crystal X-ray diffraction measurements established that there are two structurally distinct types of Cu(II) ions in NU-1000: one type with residual formate and one without. In NU-1000 with formate, Cu(II) solely binds to the node via the formate-unoccupied, bridging μ3–OH, whereas in the formate-free case, it displaces protons from two node hydroxo ligands and resides close to the terminal −OH2. Under an inert atmosphere, node-bound formate facilitates the unanticipated reduction of isolated Cu(II) to nanoparticulate Cu(0)—a behavior which is essentially absent in the formate-free analogue because no other sacrificial reductant is present. When the two MOFs were tested as benzyl alcohol oxidation catalysts, we observed that residual formate boosts the catalytic turnover frequency. Density functional calculations showed that node-bound formate acts as a sacrificial two-electron donor and assists in reducing Cu(II) to Cu(0) by a nonradical pathway. The negative Gibbs free energy of reaction (ΔG) and enthalpy of reaction (ΔH) indicate that the reduction is thermodynamically favorable. The work presented here highlights how the often-neglected residual formate prevalent in nearly all zirconium-based MOFs can significantly modulate the properties of supported catalysts.

We propose a laser nutation tracking sensor for beaconless laser communication, which uses a micro-electro-mechanical system (MEMS) mirror to achieve high-efficiency and large-amplitude nutation at its resonant frequency. We derive a new formula for the case of incompletely detectable optical power in the nutation cycle. In the experiment, we measure the performance of the sensor in calculating boresight error under three different nutation radii. Combining with the proposed algorithm for the new scene, we complete the accurate boresight calculation in the range of ±200µrad, at the nutation radius of 4.9 µm. We trust that the receiving field of view (FOV) of this tracking sensor can be further expanded by increasing the nutation radius. The sensor, as proposed in this paper, will be of constructive help to simplify tracking systems in the future.

A coherent laser range finder based on optical phase modulation and phase shift measurement is presented. In the proposed laser range finder, the emitted laser is modulated by an electro-optic phase modulator using a 20 MHz sine signal, and the received laser is mixed with a local oscillator using a 90° optical hybrid. Compared with traditional laser phase shift range finders, the proposed laser range finder can measure the velocity and range at high precision simultaneously. An algorithm to calculate the range and velocity is deduced. Our preliminary experiments on moving targets indicate that when the measurement rate is 100 kHz, the root mean square errors of range and velocity, respectively, are 9.35×10^−4m and 4.74×10^−4m/s.

Single-site catalysts (SSCs) achieve a high catalytic performance through atomically dispersed active sites. A challenge facing the development of SSCs is aggregation of active catalytic species. Reducing the loading of these sites to very low levels is a common strategy to mitigate aggregation and sintering; however, this limits the tools that can be used to characterize the SSCs. Here we report a sintering-resistant SSC with high loading that is achieved by incorporating Anderson–Evans polyoxometalate clusters (POMs, MMo6O24, M = Rh/Pt) within NU-1000, a Zr-based metal–organic framework (MOF). The dual confinement provided by isolating the active site within the POM, then isolating the POMs within the MOF, facilitates the formation of isolated noble metal sites with low coordination numbers via exsolution from the POM during activation. The high loading (up to 3.2 wt %) that can be achieved without sintering allowed the local structure transformation in the POM cluster and the surrounding MOF to be evaluated using in situX-ray scattering with pair distribution function (PDF) analysis. Notably, the Rh/Pt···Mo distance in the active catalyst is shorter than the M···M bond lengths in the respective bulk metals. Models of the active cluster structure were identified based on the PDF data with complementary computation and X-ray absorption spectroscopy analysis.

Zr-based metal–organic frameworks (Zr-MOFs) with exceptional chemical stability have shown promising applications in water adsorption-based humidity control. However, due to the strong surface tension during the desorption of water, MOFs with both high water uptake capacity and high mechanical cycle stability are still rare. Through a hierarchical Zr-MOF (NU-601) with both micro- and mesopores showing high stability in water but fragility against the evacuation of solvent molecules as an illustration, we presented a stepwise strategy of locking Zr6nodes by auxiliary ligands from monodentate to bidentate, from monotopic to ditopic, and from nonstructural saturation to structural saturation, eventually realizing structural coordination saturation. The obtained new Zr-MOF (NJTech-4) with saturated (12-connected) Zr6nodes shows high water vapor uptake (995 cm3g–1) and excellent cycle stability, making it one of the suitable candidates for water-adsorption-based applications. Our experiments suggest that bidentate chelation of auxiliary ligands on Zr6clusters is a solution for stabilizing the nodes, which contributes to better cycle and thermal stability. Introducing supportive structural coordination could further strengthen the structure robustness against capillary forces, retaining a high water uptake capacity during the continuous removal of water from the pore.