This paper reports the fabrication of a composite structure (AgNP@PS/WE-Ag) by constructing wedge-shaped Ag shells on a monolayer array of polystyrene (PS) microspheres via oblique-angle rotating thermal evaporation, followed by the secondary growth of Ag nanoparticles on the inverted structure. This structure forms multi-level spatial nanogaps between the Ag nanoparticles as well as between the nanoparticles and the wedge-shaped edges. The results indicate that the surface-enhanced Raman scattering (SERS) performance of the substrate is highly dependent on the thickness of the secondary Ag layer. The optimal SERS enhancement was achieved at a Ag layer thickness of 20 nm, with a detection limit for crystal violet (CV) as low as 10-11 M, a relative standard deviation (RSD) of 7.42%. Furthermore, the successful detection of malachite green (MG) down to 10- 9 M demonstrates that this novel SERS hotspot engineering strategy holds promising application prospects in trace molecular detection.

The pillar-layered Metal-Organic Framework (MOF) material NTUniv-75, featuring embedded arrays of melamine-based molecular clamps as pillars, enhances the spatial utilization of the framework and selectively targets ethane (C2H6) and propane (C3H8), thereby achieving record-breaking methane (CH4) purification (>99.99% purity, 14.5 mmol g-1) from CH4/C2H6/C3H8 gas mixtures at 298 K.

The strategy of flow channel with wrinkles and calcium sites for single-step C2H4 purification from C2 gases and methanol-to-olefins (MTO) products separation was realized in FJI-Y9. The adsorption amounts showed a total reversal order of C3H6 > C2H6 > C2H2 > C2H4 at 298 K. Modeling indicated that the wrinkles and Ca2+ facilitated the full contact of C3H6 and C2H6. Breakthrough experiments illustrated that FJI-Y9 could yield pure C2H4 in a single step with a productivity of 0.78 mmol g(-1). In a lone adsorption/desorption cycle for MTO product separation, the productivities of C3H6 and C2H4 were 1.96 and 1.29 mol g(-1), standing as the highest recorded values.

In recent years, organic–inorganic hybrid perovskite materials have garnered extensive attention from scholars. Given its high absorption coefficient, carrier mobility, and diffusion length, it is widely studied for applications in various optoelectronic devices, such as solar cells, photodetectors, field-effect transistors, and light emitting diodes. Among them, the interfacial charge transfer process is a key factor influencing the performance of devices using perovskite materials. The charge transfer (CT) at the interface is typically detected via Raman spectroscopy. There are three types of related CT processes, namely, the interfacial ground state charge transfer, the photoinduced charge transfer resonance, and the electronic excitation resonance within the molecule itself. Among these factors, electronic excitation resonance manifests as an exciton resonance within the perovskite structure, providing energy for nearby charge transfer, thereby promoting charge transfer and enhancing Raman signals. Therefore, enhancing exciton resonance within the perovskite structure plays a crucial role in optoelectronic devices. This paper aimed to study the mechanism of oxygen plasma passivation of interstitial iodine defects and its enhancement effect on the Raman of perovskite substrates. Typically, interstitial iodine defects induce electron–hole recombination. In the process of oxygen plasma treatment, interstitial iodine is converted into pentavalent iodine, which can effectively fill related defects, inhibit electron–hole recombination, and prolong exciton lifetime, thereby promoting charge transfer and enhancing Raman intensity.

The single-step purification of ethylene (C2H4) from a mixture of carbon dioxide (CO2), acetylene (C2H2), ethylene (C2H4), and ethane (C2H6) was achieved through MOF Compound-1, where the aromatic pore surface and carboxylates selectively recognized C2H6 and CO2, respectively, resulting in a reversal of the adsorption orders for both gases (C2H6 > C2H4 and CO2 > C2H4). Breakthrough testing verified that the C2H4 purification ability could be enhanced 2.6 times after adding impure CO2. Grand Canonical Monte Carlo (GCMC) simulations demonstrate that there are interactions between CO2 and C2H6 molecules as well as between CO2 molecules themselves. These interactions contribute to the enhancement of the C2H4 purification ability upon the addition of CO2 and the increased adsorption of CO2.

Single-step ethylene (C2H4) production from acetylene (C2H2), ethylene (C2H4), and ethane (C2H6) mixtures was realized via the strategy of a flow channel with recognition corners in MOF NTUniv-64. Both the uptake amounts and the enthalpy of adsorption (Q(st)) showed the same order of C2H2 > C2H6 > C2H4. Breakthrough testing also verified the above data and the C2H4 purification ability. Grand Canonical Monte Carlo (GCMC) simulations indicated that uneven corners could precisely detain C2H2 and C2H6, in which the C-Hpi interaction distance between C2H2 (2.84 & Aring;) and C2H6 (3.03 & Aring;) and the framework was shorter than that of C2H4 (3.85 & Aring;).

The concept of an expanding MOF with unexpanded channel size was realized in MOF NTUniv-61 by the utilization of a ketone-functional-group-decorated semirigid ligand and pillar-layer platform. After this unusual expansion, the preferential C2H6 adsorption was preserved via the unchanged pore size, and the functional group was inserted into the MOF. Interestingly, the C2H2 uptake ability, C2H4 selective adsorption ability, and structural stability were obviously enhanced due to the incorporation of the ketone functional group, which were further verified by isosteric heats of adsorption (Qst), GCMC modeling, and breakthrough experiments.

Due to the similar kinetic diameters of C2H2, C2H4, and C2H6, one-step purification of C2H4 from a ternary C2H2/C2H4/C2H6 mixture by adsorption separation is still a challenge. Based on a C2H6-trapping platform and crystal engineering strategy, the N atom and amino group were introduced into NTUniv-58 and NTUniv-59, respectively. Gas adsorption testing of NTUniv-58 showed that both the C2H2 and C2H4 uptake capacities and the C2H2/C2H4 separation ability were boosted compared with the original platform. However, the C2H4 uptake value exceeds the C2H6 adsorption data. For NTUniv-59, the C2H2 uptake at low pressure increased and the C2H4 uptake decreased; thus, the C2H2/C2H4 selectivity was enhanced and the one-step purification of C2H4 from a ternary C2H2/C2H4/C2H6 mixture was realized, which was supported by the enthalpy of adsorption (Qst) and breakthrough testing. Grand canonical monte carlo (GCMC) simulation indicated that the preference for C2H2 over C2H4 originates from multiple hydrogen-bonding interactions between amino groups and C2H2 molecules.

One-step C2H4 purification from a mixture of C2H2/C2H4/C2H6 by physical adsorption separation was realized via creating an ethane trap in MOF NTUniv-63 by the utilization of a ketone-decorated semirigid ligand, which has further been verified by the breakthrough experiment, isosteric heats of adsorption (Qst), and Grand Canonical Monte Carlo (GCMC) modeling.

One-step C2H4 purification from a mixture of C2H2/C2H4/C2H6 could be achieved by metal-organic framework (MOF) NTUniv-70 with an F-functional group. The selectivities of C2H4/C2H6 and C2H4/C2H2 of NTUnvi-70 based on ideal adsorbed solution theory were at least twice that of the original MOF platform, which was in line with the enthalpy of adsorption (Q(st)) and breakthrough testing. Grand canonical Monte Carlo simulations indicated that the C-HF interactions played an important role in enhanced C2H4/C2H6 and C2H4/C2H2 adsorption selectivities.

A polar flow channel with embedded gas recognition pockets was made in a 10-connected hexanuclear yttrium-based metal-organic frameworks (MOF) NTUniv-57 (NTUniv = Nantong University) by lowering the symmetry of the ligand, which showed high chemical stability and obviously enhanced gas adsorption selectivities.

A small rhombohedral supramolecular building block (SBB) with a narrowed window was linked with amide-functionalized helical ligand 5,5'-(((1,1'-biphenyl)-2,2'-dicarbonyl)bis(azanediyl))diisophthalic acid (H4L) for the first time, and a microporous metal-organic framework (MOF) [Cu-2(L)(H2O)(2)]center dot DMF center dot 6H(2)O(NTUniv-53) with pcu topology was formed. The synthesized NTUniv-53 showed a noticeable CO 2 selective adsorption at room temperature, which was insensitive to temperature change due to the narrowed windows and amide groups.

By shortening the previous shortest tetracarboxylate ligand, the first ligand-to-ligand and axial-to-axial pillaring method was realized in the prototype MOF NTUniv-56 (NTUniv = Nantong University), which exhibit a rare (2,4,6)-connected net with a new topology and interesting gas adsorption performance.

A gradual amide truncation strategy was presented to tune the pore chemistry and CO2 capture performance of a series of tetracarboxylate-based Cu-MOFs. These MOFs exhibited a high density of Lewis basic sites (LBSs) and open metal sites and were prepared with the goal to enhance CO2 selective adsorption capacity. [Cu2(L1)(H2O)2]n (NJU-Bai42: NJU-Bai for Nanjing University Bai's group), [Cu2(L2) (H2O)2]n (NJU-Bai17), and [Cu2(L3)(H2O)2]n (NTUniv-60: NTUniv for Nantong University) were synthesized, and we observed that the CO2 adsorption capacities and MOF structures were impacted by subtle changes in ligands. Interestingly, although the NTUniv-60 was decorated with the least LBSs in these three MOFs, its CO2 adsorption capacity reached 270 (53.0 wt %) and 164 (32.2 wt %) cm3 g-1 at 273 and 296 K under 1 bar, respectively, which is the highest data reported for MOFs under similar conditions. From the grand canonical Monte Carlo (GCMC) simulation, the cooperative interactions between the CO2 molecules within the shuttle-shaped cages of NTUniv-60 could potentially explain why the CO2 uptake is high in this material.

The metal-organic framework (MOF) NTUniv-54 (NTUniv = Nantong University) was assembled via utilizing click chemistry with densely decorated trizole units and exposed metal sites, which exhibited the best methane working ability (197 cm3·cm-3 from 100 to 5 bar and 177 cm3·cm-3 from 65 to 5 bar at 298 K), and the lowest CO2 Qst of 22.8 kJ·mol-1 in all triazole-MOFs at room temperature.

In this paper, a visual-inertial localization system that reuses a prior map built by Lidar is proposed. Relying exclusively on a monocular camera and an IMU, the point and line features detected in the images are reconstructed and utilized for geometrically estimating the relative pose of the robot with respect to the prior 3D point cloud map. To leverage the alignment between the body frame and the map frame, a modified normal distribution transformation(NDT) algorithm is tightly coupled into the bundle adjustment(BA). We extract dual layered grid cell map from the raw Lidar-built map for both the point-to-distribution and line-to-distribution registration. By utilizing line features, the proposed method can achieve competitive performance in low textured environments. Evaluations on different real-world environments, including tests on both the benchmark dataset and the self-collected one are presented.

Three-dimensional (3D) highly dynamic unmanned aerial vehicle networks (UAVNets) could serve as a pivotal intermediate architecture in air and space integration networks. For UAVNets, efficient routing protocols for data packet delivery are crucial to its wide use. However, communication in UAVs has been a challenging project because of frequent failures at forwarding nodes. In this paper, we propose a localized heuristic solution, called the reliability-aware adaptive greedy-multicast routing (RAGM-3D), to reduce the negative impact of failure on route forwarding. RAGM-3D dynamically adjusts the next-hop forwarding node set which, initially selected by a new multi-factor hybrid greedy strategy, are based on the reliability evaluation to route packets to the destination efficiently. Simulation results show that comprehensive performance of RAGM-3D in terms of packet delivery ratio, delay, and routing overhead outperforms other compared protocols.

The challenges of driving on snow and ice roads bring out a demand for object detection and drivable area segmentation in snowy environments. Semantic segmentation techniques have been able to achieve good results provided that the models are well-trained based on the appropriate dataset. However, no current driving dataset exists that contains adequate images in snowy environments. To address this issue, we introduce our snowy driving dataset to train and test models for pixel-wise semantic labeling. This snowy driving dataset consists of both real and synthetic samples with 11 classes. We conduct comparative experiments based on a series of the proposed dataset, as well as provide statistics and visual results to show improvement.

As an important part of large-scale intelligent warehouse system, path planning by considering the cooperation among automated guided vehicles (AGVs) becomes an important factor to enhance the efficiency of the system. To this end, we propose a novel path planning scheme based on space-time map with the target of improving the path planning efficiency. Specifically, we first model the time dimension and construct a space-time map to obtain the planned path information of the intelligent warehouse system. Then, by taking the size of AGV and turning cost into consideration, we design a node extension algorithm to limit the search direction of AGVs. To decrease the complexity of the proposed algorithm and improve the efficiency of head-on conflict avoidance, a time window based piecewise path planning method and a mechanism of protected zone are developed, respectively. Simulation results show that the proposed space-time map based path planning scheme has a better performance than the conventional method in terms of the number of turns, the system running time and the moving distance of AGVs.

Highly dynamic network has a growing demand with the popularization and application of high-speed mobile equipments, such as aircraft, unmanned boat and etc. There are many new features for highly dynamic networks over mobile networks, which include high link failure rate, high frequency enter-and-exit the network and frequent changes of the topology. Therefore, the design of access protocols is more stringent. Particularly, the packets would be invalid when waiting to be sent to the next hop node due to the link breaking with highspeed motion of the nodes in highly dynamic network. In order to better adapt to highly dynamic network scenarios, we propose a novel access protocol based on link validity prediction. Firstly, the protocol obtains the valid time of the packet in the buffer by considering the validity of the next hop link. Further, we designed a backoff mechanism based on packet valid time differentiation. We derive the mathematical expressions for the performance metrics. The performance evaluation exhibits our protocol by providing a lower latency and higher success transmission rate.