This article addresses the localization problem in robotic autonomous luggage trolley collection at airports and provides a systematic evaluation of different methods to solve it. The robotic autonomous luggage trolley collection is a complex system that involves object detection, localization, motion planning and control, manipulation, etc. Among these components, effective localization is essential for the robot to employ subsequent motion planning and end-effector manipulation because it can provide a correct goal position. This article explores four popular and representative localization methods for object localization in luggage trolley collection: radio frequency identification (RFID), Keypoints, ultrawideband (UWB), and Reflectors. A qualitative evaluation framework is constructed to assess performance, encompassing Localization Accuracy, Mobile Power Supplies, Coverage Area, Cost, and Scalability. Furthermore, a series of quantitative experiments concerning Localization Accuracy and Success Rate have been conducted on a real-world robotic autonomous luggage trolley collection system. The performance of various localization methods is further analyzed based on experimental results, indicating that the Keypoints method is optimally suited for indoor environments to facilitate luggage trolley collection. Significantly, these experiment results provide a valuable reference point, extending the application of indoor localization methods across diverse scenarios. A website about this work is available at https://sites.google.com/view/localization-evaluation/.

Currently, there is an increasing demand for parallel mechanisms with fewer inputs and more outputs in aerospace, antennas, and recreational facilities. Therefore, this paper proposes a new parallel mechanism (PM) with a separation of constraints and drives, facilitating centralized drive management. Based on screw theory, the type synthesis of new parallel mechanisms with 3T (T representing translation), 3R (R representing revolute), 2T1R, and 2R1T is proposed. Three-degree-of-freedom (3-DOF) parallel mechanisms with fewer inputs and multiple outputs are proposed. Taking the 3RPS-PPPS parallel mechanism as an example, the closed-loop vector method is employed to solve for the lengths of actuated branches. A complete Jacobi matrix is constructed. The motion/force transmission performance of the 3RRS/PPPS parallel mechanism is better than the 3RRS parallel mechanism. Centralized management of drive branches greatly reduces the number of drives, making maintenance and repair easier. It has many application scenarios in antennas, recreational facilities, and other occasions.

From 2020 to December 2022, China implemented strict measures to contain the spread of severe acute respiratory syndrome coronavirus 2. However, despite these efforts, sustained outbreaks of the Omicron variants occurred in 2022. We extracted COVID-19 case numbers from May 2021 to October 2022 to identify outbreaks of the Delta and Omicron variants in all provinces of mainland China. We found that omicron outbreaks were more frequent (4.3 vs. 1.6 outbreaks per month) and longer-lasting (mean duration: 13 vs. 4 weeks per outbreak) than Delta outbreaks, resulting in a total of 865,100 cases, of which 85% were asymptomatic. Despite the average Government Response Index being 12% higher (95% confidence interval (CI): 9%, 15%) in Omicron outbreaks, the average daily effective reproduction number (Rt) was 0.45 higher (95% CI: 0.38, 0.52, p < 0.001) than in Delta outbreaks. Omicron outbreaks were suppressed in 32 days on average (95% CI: 26, 39), which was substantially longer than Delta outbreaks (14 days; 95% CI: 11, 19; p = 0.004). We concluded that control measures effective against Delta could not contain Omicron outbreaks in China. This highlights the need for continuous evaluation of new variants’ epidemiology to inform COVID-19 response decisions.

Autonomous fabric manipulation is a challenging task due to complex dynamics and potential self-occlusion during fabric handling. An intuitive method of fabric-folding manipulation first involves obtaining a smooth and unfolded fabric configuration before the folding process begins. However, the combination of quasi-static actions like pick & place and dynamic action like fling proves inadequate in effectively unfolding long-sleeved T-shirts with sleeves mostly tucked inside the garment. To address this limitation, this paper introduces an enhanced quasi-static action called pick & drag, specifically designed to handle this type of fabric configuration. Additionally, an efficient dual-arm manipulation system is designed in this paper, which combines quasi-static (including pick & place and pick & drag) and dynamic fling actions to flexibly manipulate fabrics into unfolded and smooth configurations. Subsequently, once it is confirmed that the fabric is sufficiently unfolded and all fabric keypoints are detected, the keypoint-based heuristic folding algorithm is employed for the fabric-folding process. To address the scarcity of publicly available keypoint detection datasets for real fabric, we gathered images of various fabric configurations and types in real scenes to create a comprehensive keypoint dataset for fabric folding. This dataset aims to enhance the success rate of keypoint detection. Moreover, we evaluate the effectiveness of our proposed system in real-world settings, where it consistently and reliably unfolds and folds various types of fabrics, including challenging situations such as long-sleeved T-shirts with most parts of sleeves tucked inside the garment. Specifically, our method achieves a coverage rate of 0.822 and a success rate of 0.88 for long-sleeved T-shirts folding. Supplemental materials and dataset are available on our project webpage at https://sites.google.com/view/fabricfolding.

Plumbogaidonnayite, ideally PbZrSi3O9⋅2H2O, is a new gaidonnayite-group mineral discovered as a secondary product derived from the alteration of eudialyte from the Saima alkaline complex, China. It occurs as aggregates (up to 1 mm) composed of subhedral to anhedral or platy crystals (individually 5–50 μm), associated closely with microcline, natrolite, aegirine, gaidonnayite, georgechaoite, zircon, bobtraillite and britholite-(Ce) in eudialyte pseudomorphs. The crystals are transparent, colourless or light brown with a vitreous lustre. Plumbogaidonnayite is brittle with conchoidal fracture, and it has a Mohs hardness of ~5 and a calculated density of 3.264 g/cm3. It is optically biaxial (+) with α = 1.61(3), β = 1.63(3) and γ = 1.66(4). The calculated 2V is 80°, with the optical orientations X, Y and Z parallel to the crystallographic a, b and c axes, respectively. The empirical formula is (Pb0.70Ca0.17Ba0.01K0.11Na0.01Y0.01)Σ1.01(Zr1.00Hf0.01Ti0.01)Σ1.02Si3.01O9⋅2H2O calculated on the basis of nine oxygen atoms per formula unit and assuming the occurrence of two H2O groups. Plumbogaidonnayite is orthorhombic, P21nb, a = 11.7690(4) Å, b = 12.9867(3) Å, c = 6.66165(16) Å, V = 1018.17(5) Å3 and Z = 4. The nine strongest lines of its powder XRD pattern [d in Å (I, %) (hkl)] are: 6.489 (36) (020), 5.803 (100) (101), 4.661 (27) (021), 4.336 (29) (121), 3.640 (30) (221), 3.114 (79) (112), 2.947 (27) (400), 2.622 (27) (241) and 2.493 (27) (312). Plumbogaidonnayite has a similar spiral chain framework structure with gaidonnayite and georgechaoite, which is composed of SiO4 tetrahedra and ZrO6 octahedra, but with disordered extra-framework sites (cations and H2O groups) characterised by the substitution of 2Na+ (K+)→Pb2+ (Ca2+) + □ (vacancy). The discovery of plumbogaidonnayite adds a new perspective on the cation ordering and heterovalent substitution mechanism in gaidonnayite-group minerals.

A high-power all polarization-maintaining (PM) chirped pulse amplification (CPA) system operating in the 2.0 μm range is experimentally demonstrated. Large mode area (LMA) thulium-doped fiber (TDF) with a core/cladding diameter of 25/400 μm is employed to construct the main amplifier. Through dedicated coiling and cooling of the LMA-TDF to manage the loss of the higher order mode and thermal effect, a maximum average power of 314 W with a slope efficiency of 52% and polarization extinction ratio of 20 dB is realized. The pulse duration is compressed to 283 fs with a grating pair, corresponding to a calculated peak power of 10.8 MW, considering the compression efficiency of 88% and the estimated Strehl ratio of 89%. Moreover, through characterizing the noise properties of the laser, an integrated relative intensity noise of 0.11% at 100 Hz−1 MHz is obtained at the maximum output power, whereas the laser timing jitter is degraded by the final amplifier from 318 to 410 fs at an integration frequency of 5 kHz to 1 MHz, owing to the self-phase modulation effect-induced spectrum broadening. The root-mean-square of long-term power fluctuation is tested to be 0.6%, verifying the good stability of the laser operation. To the best of our knowledge, this is the highest average power of an ultrafast laser realized from an all-PM-fiber TDF-CPA system ever reported.

An all-fiber high-power linearly polarized chirped pulse amplification (CPA) system is experimentally demonstrated. Through stretching the pulse duration to a full width of approximately 2 ns with two cascaded chirped fiber Bragg gratings (CFBGs), a maximum average output power of 612 W is achieved from a high-gain Yb-doped fiber that has a core diameter of 20 μm with a slope efficiency of approximately 68% at the repetition rate of 80 MHz. At the maximum output power, the polarization degree is 92.5% and the M2 factor of the output beam quality is approximately 1.29; the slight performance degradations are attributed to the thermal effects in the main amplifier. By optimizing the B-integral of the amplifier and finely adjusting the higher-order dispersion of one of the CFBGs, the pulse width is compressed to 863 fs at the highest power with a compression efficiency of 72%, corresponding to a maximum compressed average power of 440.6 W, single pulse energy of 5.5 μJ and peak power of about 4.67 MW. To the best of our knowledge, this is the highest average power of a femtosecond laser directly generated from an all-fiber linearly polarized CPA system.

The new mineral, gysinite-(La), with the ideal formula PbLa(CO3)2(OH)⋅H2O, has been discovered in lujavrite from the Saima alkaline complex, Liaoning Province, China. It commonly occurs as subhedral to anhedral, granular and platy crystals of 5 to 50 μm in size, in interstices or enclosed in microcline, aegirine and nepheline. Associated minerals include nepheline, aegirine, microcline, natrolite, eudialyte, lamprophyllite, bastnäsite-(Ce), parasite-(Ce), ancylite-(La), ancylite-(Ce), bobtraillite, britholite-(Ce), thorite, calcite and galena. The crystallisation of gysinite-(La) may be related to the post-magmatic carbonation event. Gysinite-(La) crystals are generally transparent, colourless, or pale yellow, with a vitreous lustre and white streak. It is brittle with an uneven fracture, and the estimated Mohs hardness is 3½ to 4. The calculated density is 5.007 g/cm3. Optically, gysinite-(La) is biaxial (–), α= 1.832(2), β= 1.849(4), γ = 1.862(5) in white light and 2Vmeas = 81.6°. The empirical formula of gysinite-(La) is (La0.93Pb0.61Nd0.23Pr0.14Sr0.04Gd0.02Sm0.01Eu0.01Ca0.01)Σ2(CO3)2(OH)1.34⋅0.66H2O, which is calculated on the basis of general formula (REExM2+2–x)(CO3)2(OH)x⋅(2–x)H2O. The strongest eight lines of its powder X-ray diffraction pattern [d, Å (I, %) (hkl)] are: 5.596 (21) (011), 4.349 (100) (110), 3.732 (68) (111), 2.984 (61) (121), 2.667 (21) (031), 2.363 (48) (131), 2.090 (29) (221) and 2.028 (21) (212). Gysinite-(La) is orthorhombic, in the space group Pmcn, and unit-cell parameters refined from single-crystal X-ray diffraction data are: a = 5.0655(2) Å, b = 8.5990(3) Å, c = 7.3901(4) Å, V = 321.90(2) Å3 and Z = 2. It is a new member of the ancylite group and isostructural with gysinite-(Nd), but with La and Pb dominant in the metal cation sites in the structure.

Recently, deep learning methods have achieved considerable performance in gesture recognition using surface electromyography signals. However, improving the recognition accuracy in multi-subject gesture recognition remains a challenging problem. In this study, we aimed to improve recognition performance by adding subject-specific prior knowledge to provide guidance for multi-subject gesture recognition. We proposed a time–frequency feature transform suite (TFFT) that takes the maps generated by continuous wavelet transform (CWT) as input. The TFFT can be connected to a neural network to obtain an end-to-end architecture. Thus, we integrated the suite into traditional neural networks, such as convolutional neural networks and long short-term memory, to adjust the intermediate features. The results of comparative experiments showed that the deep learning models with the TFFT suite based on CWT improved the recognition performance of the original architectures without the TFFT suite in gesture recognition tasks. Our proposed TFFT suite has promising applications in multi-subject gesture recognition and prosthetic control.

Fluorsigaiite, ideally Ca2Sr3(PO4)3F, is a new Sr analogue of fluorphosphohedyphane and a new member of the apatite supergroup. It was discovered in lujavrite from the Saima alkaline complex, Liaoning Province, China. Fluorsigaiite commonly occurs as individual prismatic, columnar and platy crystals of 10 to 50 μm in size, associated with microcline, nepheline, aegirine, natrolite, eudialyte, fluorapatite, a fluorstrophite-like mineral, stronadelphite and calcite. Occasionally, crystals of fluorsigaiite form prismatic aggregates in the interstices of lujavrite. Fluorsigaiite is translucent to transparent, colourless to yellowish white with a vitreous lustre and without fluorescence. The estimated Mohs hardness is 5, and the tenacity is brittle with uneven fractures. The calculated density is 3.842 g/cm3. Optically, fluorsigaiite is uniaxial (–) with ω = 1.64(1) and ɛ = 1.63(1) in white light and without dispersion. The mean chemical composition (in wt.%) of fluorsigaiite is Na2O 0.75, CaO 15.17, SrO 44.44, La2O3 3.64, Ce2O3 2.22, Pr2O3 0.19, Nd2O3 0.13, Sm2O3 0.05, Gd2O3 0.23, P2O5 31.87, F 1.91, H2O 0.46, sum 100.26, giving the empirical formula (Sr2.82Ca1.79Na0.16La0.15Ce0.09Pr0.01Nd0.01Gd0.01)Σ5.04P2.97O12[F0.66(OH)0.34]Σ1, which is calculated on the basis of 13 total anions and F+(OH) = 1. The strongest eight lines of its powder X-ray diffraction pattern [d, Å (I, %) (hkl)] are: 3.563 (15) (002), 3.275 (15) (102), 3.144 (19) (120), 2.876 (100) (121), 2.861 (96) (112), 2.772 (27) (300), 1.991 (17) (222) and 1.895 (23) (213). Fluorsigaiite is hexagonal, in the space group P63/m and unit-cell parameters refined from single-crystal X-ray diffraction data are: a = 9.6101(2) Å, c = 7.1311(1) Å, V = 570.35(3) Å3 and Z = 2. It is isostructural with hedyphane-group minerals, and contains different prevailing (species-defining) Ca and Sr cations at the Ca1 and Ca2 sites, respectively. Fluorsigaiite was probably formed from Sr-rich fluids at late-magmatic or hydrothermal stage of the Saima lujavrite.

The objective of this study was to analyze differences in birth weight and overweight/obesity in a Shanghai twin cohort. We also wanted to study their association and explore possible risk factors for the discordance of overweight/obesity within twins. This was an internal case–control study designed for twins. The 2012 Shanghai Twin Registration System baseline survey data of a total of 3417 twin pairs were statistically analyzed using SPSS22 software. Results show that the body mass index (BMI) of the Shanghai twin population increased with age. Twins with a high birth weight had a higher BMI and a higher rate of overweight and obesity; 0- to 6-year-old twins, male twins and dizygotic (DZ) twins had higher rates of overweight/obesity than other groups. The greater the discordant birth weight rate of twins, the more obvious the difference in BMI (p < .05). There was a significant difference in overweight/obesity between twins with a relative difference of birth weight ≥15% in DZ twins (p < .05). DZ twins, male twins and 0- to 6-year-old twins were more likely to be discordant in overweight/obese than others. The discordant birth weight within twins was not a risk factor for discordant overweight/obesity. However, attention should be paid to childhood obesity, and appropriate interventions should be made at the appropriate time. Genetics may play an important role in the occurrence and development of overweight/obesity. In conclusion, discordant growth and development in the uterus early in life may not lead to discordant weight development in the future.

Laser pulses of 200 ps with extremely high intensities and high energies are sufficient to satisfy the demand of shock ignition, which is an alternative path to ignition in inertial confinement fusion (ICF). This paper reports a type of Brillouin scheme to obtain high-intensity 200-ps laser pulses, where the pulse durations are a challenge for conventional pulsed laser amplification systems. In the amplification process, excited Brillouin acoustic waves fulfill the nonlinear optical effect through which the high energy of a long pump pulse is entirely transferred to a 200-ps laser pulse. This method was introduced and achieved within the SG-III prototype system in China. Compared favorably with the intensity of $2~\text{GW}/\text{cm}^{2}$ in existing ICF laser drivers, a 6.96-$\text{GW}/\text{cm}^{2}$ pulse with a width of 170 ps was obtained in our experiment. The practical scalability of the results to larger ICF laser drivers is discussed.

This research communication describes the profile of gene expression related to the synthesis of yak milk as determined via quantitative reverse transcription polymerase chain reaction (RT-qPCR). Significant up-regulation during lactation were observed in genes related to fatty acid (FA) uptake from blood (LPL, CD36), intracellular FA transport (FABP3), intracellular FA activation of long- and short-chain FAs (ACSS1, ACSS2, ACSL1), de novo synthesis (ACACA), desaturation (SCD), triacyglycerol (TAG) synthesis (AGPAT6, GPAM, LPIN1), lipid droplet formation (PLIN2, BTN1A1, XDH), ketone body utilisation (BDH1, OXCT1), and transcription regulation (THRSP, PPARGC1A). In particular, intracellular de novo FA synthesis (ACSS2, ACACA, and FABP3) and TAG synthesis (GPAM, AGPAT6, and LPIN1), whose regulation might be orchestrated as part of the gene network under the control of SERBF1 in the milk fat synthesis process, were more activated compared to levels in dairy cows. However, the genes involved in lipid droplet formation (PLIN2, XDH, and BTN1A1) were expressed at lower levels compared to those in dairy cows, where these genes are mainly controlled by the PPARG regulator.

Using phytolith analysis from a well-dated and high-resolution sediment sequence in the apex of northern Yangtze Delta, we investigate environmental changes, the rise and decline of rice exploitation and possible impacts of environment on rice exploitation during the early mid-Holocene. The phytolith sequence documents a relatively warm and dry interval during ca.9000 to 8200 cal yr BP, followed by climatic amelioration before 7200 cal yr BP. Phytolith evidence indicates that rice exploitation at the apex of northern Yangtze Delta began at 8200 cal yr BP, flourished by 7700 cal yr BP and ceased after 7400 cal yr BP. The first emergence of marine diatom species approximately 7300 cal yr BP likely indicates an accelerated sea-level rise. The apparent correlation of the initiation of rice exploitation with climatic amelioration during the early mid-Holocene suggests that climatic changes may have played an important role in facilitating rice exploitation. Both the ideal climatic conditions and stable sea level enabled flourishing rice exploitation during 8200 to 7400 cal yr BP. Although the climate remained warm and wet after 7400 cal yr BP, local sea-level rise possibly led to the termination of earlier rice exploitation at this site of the northern Yangtze Delta.

A 100-J-level Nd:glass laser system in nanosecond-scale pulse width has been constructed to perform as a standard source of high-fluence-laser science experiments. The laser system, operating with typical pulse durations of 3–5 ns and beam diameter 60 mm, employs a sequence of successive rod amplifiers to achieve 100-J-level energy at 1053 nm at 3 ns. The frequency conversion can provide energy of 50-J level at 351 nm. In addition to the high stability of the energy output, the most valuable of the laser system is the high spatiotemporal beam quality of the output, which contains the uniform square pulse waveform, the uniform flat-top spatial fluence distribution and the uniform flat-top wavefront.

In this paper we make an empirical comparison of sales time series for online and offline channels. In particular, we analyse the sales dynamic and fluctuation level underlying the sales time series in different channels. The accumulative daily sales distributions of commodities are analysed statistically and the daily sales series are also studied from the perspective of complex networks. We find that most of the commodities' accumulative sales distributions can be fitted by power-law distributions. Visibility graphs are constructed for the daily sales series, and the accumulative degree distributions are also investigated – it is found that they also almost follow power-law distribution. The constant parameter α indicates that different specifications of the same goods have different sales characteristics, and different forms of packaging of commodities, either special offer or ordinary, also show distinctive sales fluctuation levels. The differences show that the direction of these relationships is opposite for online and offline channels.

We conducted an intensive survey of the Vulnerable eastern hoolock gibbon Hoolock leuconedys along the west bank of the Salween River in southern China, covering all known hoolock gibbon populations in China. We found 40–43 groups, with a mean group size of 3.9, and five solitary individuals. We estimated the total population to be < 200. In the nine groups for which we recorded composition, seven comprised one adult pair and 0–3 offspring and the other two groups both comprised one adult male and two adult females. The population is severely fragmented, in 17 locations, with the largest subpopulation containing only five family groups. Compared with the population in 1985 and 1994 five subpopulations have declined and gibbons have been extirpated from nine localities, although we discovered two previously unknown subpopulations. Commercial logging, illegal hunting, agricultural encroachment and population fragmentation pose serious threats to the future of H. leuconedys in China. An integrated conservation plan, including nature reserve establishment/expansion, enforcement of existing laws, conservation education, translocation and conservation-oriented research are needed to ensure the survival of H. leuconedys in China.