Electron backscatter diffraction (EBSD) has been widely used in recent studies of eggshells for its convenience in collecting in situ crystallographic information. China has a wide variety of dinosaur eggshells, although nearly none have been studied with this technique. Elongatoolithid eggs include many oogenera, although the microstructural differences of some were not highly appreciated, leading to several parataxonomic problems. In this paper, we surveyed seven elongatoolithid oogenera in China using EBSD in order to acquire more information about their microstructural variation. It is shown in this paper that in some elongatoolithid eggshells, scaly calcite grains that form the squamatic ultrastructure are not the only form of calcite in the continuous layer. Large columnar grains separated by high-angled grain boundaries and slender subgrains separated by radially arranged low-angled grain boundaries could exist in certain areas of the eggshells such as Macroolithus and Macroelongatoolithus. This paper discusses the criteria for identifying squamatic ultrastructure and proposes type I (rich in rugged high-angled grain boundaries) and type II (rich in both rugged high- and low-angled grain boundaries) squamatic ultrastructures. A pathological layer is found in Undulatoolithus pengi. An external zone is identified in the eggshell of Heishanoolithus changii, which does not support its position within the oofamily Elongatoolithidae. We argue that Paraelongatoolithus no longer belongs to Elongatoolithidae based on a combination of reticulated ornamentation, columnar continuous layer, and acicular mammillae. The high structural variation in elongatoolithid eggshells also implies that it may be inappropriate to relate all previous elongatoolithid eggshells to oviraptorosaurs and assume they are non-monophyletic.

My 5 moments (M5M) was used less frequently among cleaning staff members, suggesting that a poor compliance score in this group may not indicate deficient handwashing. This quasi-experimental study compared hand hygiene compliance (HHC), hand hygiene (HH) moments, and HH time distribution in the control group (no HH intervention; n = 21), case group 1 (normal M5M intervention; n = 26), case group 2 (extensive novel six moments (NSM) training; n = 24), and case group 3 (refined NSM training; n = 18). The intervention’s effect was evaluated after 3 months. The HHC gap among the four groups gradually increased in the second intervention month (control group, 31.43%; case group 1, 38.74%; case group 2, 40.19%; case group 3, 52.21%; p < 0.05). After the intervention period, the HHC of case groups 2 and 3 improved significantly from the baseline (23.85% vs. 59.22%, 27.41% vs. 83.62%, respectively; p < 0.05). ‘After transferring medical waste from the site’ had the highest HHC in case group 3, 90.72% (95% confidence interval, 0.1926–0.3967). HH peak hours were from 6 AM to 9 AM and 2 PM to 3 PM. The study showed that the implementation of an NSM practice can serve as an HHC monitoring indicator and direct relevant training interventions to improve HH among hospital cleaning staff.

Energy homeostasis is essential for organisms to maintain fluctuation in energy accumulation, mobilization. Lipids as the main energy reserve in insects, their metabolism is under the control of many physiological program. This study aimed to determine whether the adipokinetic hormone receptor (AKHR) was involved in the lipid mobilization in the Spodoptera litura. A full-length cDNA encoding AKHR was isolated from S. litura. The SlAKHR protein has a conserved seven-transmembrane domain which is the character of a putative G protein receptor. Expression profile investigation revealed that SlAKHR mRNA was highly expressed in immatural stage and abundant in fat body in newly emerged female adults. Knockdown of SlAKHR expression was achieved through RNAi by injecting double-stranded RNA (dsRNA) into the 6th instar larvae. The content of triacylgycerol (TAG) in the fat body increased significantly after the SlAKHR gene was knockdown. And decrease of TAG releasing to hemolymph with increase of free fatty acid (FFA) in hemolymph were observed when the SlAKHR gene was knowned-down. In addition, lipid droplets increased in fat body was also found. These results suggested that SlAKHR is critical for insects to regulate lipids metabolism.

Across Eurasia, horse transport transformed ancient societies. Although evidence for chariotry is well dated, the origins of horse riding are less clear. Techniques to distinguish chariotry from riding in archaeological samples rely on elements not typically recovered from many steppe contexts. Here, the authors examine horse remains of Mongolia's Deer Stone-Khirigsuur (DSK) Complex, comparing them with ancient and modern East Asian horses used for both types of transport. DSK horses demonstrate unique dentition damage that could result from steppe chariotry, but may also indicate riding with a shallow rein angle at a fast gait. A key role for chariots in Late Bronze Age Mongolia helps explain the trajectory of horse use in early East Asia.

In this paper, an all-fiberized and narrow-linewidth 5 kW power-level fiber amplifier is presented. The laser is achieved based on the master oscillator power amplification configuration, in which the phase-modulated single-frequency laser is applied as the seed laser and a bidirectional pumping configuration is applied in the power amplifier. The stimulated Brillouin scattering, stimulated Raman scattering, and transverse mode instability effects are all effectively suppressed in the experiment. Consequently, the output power is scaled up to 4.92 kW with a slope efficiency of as high as approximately 80%. The 3-dB spectral width is about 0.59 nm, and the beam quality is measured to be M2∼1.22 at maximum output power. Furthermore, we have also conducted a detailed spectral analysis on the spectral width of the signal laser, which reveals that the spectral wing broadening phenomenon could lead to the obvious decrease of the spectral purity at certain output power. Overall, this work could provide a reference for obtaining and optimizing high-power narrow-linewidth fiber lasers.

The fiber laser based on an oscillating-amplifying integrated structure has the potential to benefit from the advantages of a fiber laser oscillator and amplifier with the characteristics of strong anti-back-reflected light ability and high efficiency. Here, we achieved a 3.5-kW near-single-mode (M2 ∼ 1.24) oscillating–amplifying integrated fiber laser with an active fiber length of 8 m in the oscillating section and 17.6 m in the amplifying section. While operating at the maximum power, the optical-to-optical conversion efficiency is 87.0%, and the intensity of stimulated Raman scattering is about 23.61 dB lower than that of the signal light. To the best of the authors’ knowledge, this is the highest output power of an oscillating–amplifying integrated fiber laser, accompanied with the best beam quality and the highest efficiency.

Power scaling based on traditional ytterbium-doped fibers (YDFs) is limited by optical nonlinear effects and transverse mode instability (TMI) in high-power fiber lasers. Here, we propose a novel long tapered fiber with a constant cladding and tapered core (CCTC) along its axis direction. The tapered-core region of the fiber is designed to enhance the stimulated Raman scattering (SRS) threshold and suppress higher-order mode resonance in the laser cavity. The CCTC YDF was fabricated successfully with a modified chemical vapor deposition (MCVD) method combined with solution doping technology, which has a cladding diameter of 400 μm and a varying core with a diameter of ~24 μm at both ends and ~31 μm in the middle. To test the performance of the CCTC fiber during high-power operation, an all-fiber laser oscillator based on a CCTC YDF was investigated experimentally. As a result, a maximum output power of 3.42 kW was achieved with an optical-to-optical efficiency of 55.2%, although the TMI effect was observed at an output power of ~3.12 kW. The measured beam quality (M2 factor) was ~1.7, and no sign of the Raman component was observed in the spectrum. We believe that CCTC YDF has great potential to simultaneously mitigate the SRS and TMI effects, and further power scaling is promising by optimizing the structure of the YDF.

In this paper, we use finite element analysis (FEA) to study the linear viscoelastic response of polyurea, a type of hard–soft block copolymer. A Niblack's algorithm-based technique employed on atomic force microscopy images provides geometry inputs for the FEA model, while the viscoelastic master curves of the soft matrix are obtained via a combination of dynamic mechanical analysis data and molecular dynamic (MD) estimations. In this microstructural image-based FEA framework, we introduce an interphase area of altered properties between the hard and soft domains. Both spatial and property distributions of this interphase area affect the viscoelastic response of the copolymer system. To quantitatively investigate the impact of structural and property features of the interphase on the energy storage and dissipation of a system during linear perturbation, we develop a statistical descriptor representation of the interphase region related to physical parameters. Utilizing decision-tree and random forest concepts from machine learning, we apply a ranking algorithm to identify the most significant features for four different mechanical response descriptors. Results show that the total interphase volume fraction and shifting factor distributions in the interphase area dominate the magnitude of the tan δ peak, whereas the magnitudes of the shifting factors primarily affect the tan δ peak location in frequency space. This method allows us to readily identify the dominant features impacting individual properties and paves the way for material design of hard–soft block copolymer systems.

In the process of composing a double-differenced positioning model, it is difficult to separate different frequency signals between code division multiple access (CDMA) systems, the single-difference ambiguity of the pivot satellite and phase differential inter-system biases (PDISBs). Hence it is difficult to calibrate in advance the bias between systems in order to build an inter-system model which only needs one pivot satellite. Based on analysis of the stability of PDISB parameters for non-overlapping frequency CDMA systems, this study adopts a particle filter to estimate the fractional part of the PDISBs (F-PDISBs) between the systems and proposes a particle filter-based inter-system positioning model. Results show that the F-PDISBs and code DISBs for the baselines with the same receiver types and some with different receiver types are rather stable over time and for these baselines it is feasible to use a particle filter to estimate the F-PDISB parameters in the initial stage. Having attained the F-PDISBs, the inter-system model can be constructed to improve positioning accuracy in complex operational environments.

The poultry red mite, Dermanyssus gallinae, is currently the most common ectoparasite affecting egg-laying hens. Since continuous culture of D. gallinae on birds is a biologically and economically costly endeavour, storage techniques for mites are urgently needed. Effects of temperature on adult and nymph survival were first studied to optimize storage conditions. Then, fecundity of D. gallinae was studied after mites were stored at optimal storage conditions. Results showed the survival rates of protonymphs (42.11%), deutonymphs (8.19%) and females (19.78%) at 5°C after 84 days were higher than those at 0, 25 and 30°C. Thereafter the fecundity and the capability of re-establishing colonies of D. gallinae were evaluated after they were stored for 40 and 80 days at 5°C. After storage, the mean number of eggs showed no statistical difference between treated (5°C for 40 or 80 days) and control groups (25°C for 7 days), while the hatching rates of eggs were in all cases above 97%. The dynamic changes of mite populations and egg numbers showed similar trends to the control group after the stored adult or nymph mites were fed on chicks. Dermanyssus gallinae can be successfully stored at 5°C for 80 days with no interference with the fecundity of mites, and the stored mites could re-establish colonies successfully. Adults and nymphs were two main stages with capability for low temperature storage. These results suggest that low temperature storage is a viable option for colony maintenance of D. gallinae under laboratory conditions.

Inter-system code double differencing is an effective method for improving the positioning accuracy of low-cost receivers in complex environments. Due to the adoption of Frequency Division Multiple Access (FDMA), Globalnaya Navigazionnaya Sputnikovaya Sistema (GLONASS) code observations are affected by the Inter-Frequency Code Biases (IFCBs), which makes it difficult to calculate the Differential Inter-System Code Biases (DISCBs) between GLONASS and the Code Division Multiple Access (CDMA) systems directly. In this contribution, the focus is on the performance of tightly combined Global Positioning System (GPS) and GLONASS code Double Difference (DD) positioning. After analysing the relationship between IFCBs and GLONASS channel numbers, an IFCB correction model and an inter-system code differencing model between GLONASS and GPS are proposed. Results show that even if there is no obvious relationship between IFCBs and channel numbers, the long-term stable IFCB values of each satellite can be obtained by using the proposed model. In addition, the GPS + GLONASS DISCB is also stable. Therefore, compared with the intra-system model, the inter-system model can benefit from prior IFCBs and DISCBs parameters and thus can significantly improve the positioning accuracy in obstructed environments.

High-power orbital angular momentum (OAM) beams have distinct advantages in improving capacity and data receiving for free-space optical communication systems at long distances. Utilizing the coherent combination of a beam array technique and helical phase approximation by a piston phase array, we have proposed a generating system for a novel high-power beam carrying OAM, which could overcome the power limitations of a common vortex phase modulator and a single beam. The characteristics of this generating method and the orthogonality of the generated OAM beams with different eigenstates have been theoretically analyzed and verified. Also a high-power OAM beam produced by coherent beam combination (CBC) of a six-element hexagonal fiber amplifier array has been experimentally implemented. Results show that the CBC technique utilized to control the piston phase differences among the array beams has a high efficiency of 96.3%. On the premise of CBC, we have obtained novel vortex beams carrying OAM of $\pm 1$ by applying an additional piston phase array modulation on the corresponding beam array. The experimental results agree approximately with the theoretical analysis. This work could be beneficial to areas that need high-power OAM beams, such as ultra-long distance free-space optical communications, biomedical treatments, and powerful trapping and manipulation under deep potential wells.

High-peak-power transform-limited narrow-linewidth nanosecond all-fiber lasers are desired in a range of applications. However, their linewidths will be broadened by self-phase modulation (SPM). We propose a novel concept that generates transform-limited laser pulses by temporally shaping the pulse seed. The impact of the pulse shape on SPM-induced spectral broadening was studied numerically and experimentally. It was found theoretically that the square-shape pulsed laser is immune to SPM-induced spectral broadening. Based on this principle, we built a high-peak-power, linearly polarized, square-shape nanosecond all-fiber laser in a master oscillator power amplifier (MOPA) configuration. Stimulated Brillouin scattering (SBS) limited peak powers of 4.02 kW, 5.06 kW, 6.52 kW and 9.30 kW were obtained at pulse widths of 8 ns, 7 ns, 6 ns and 5 ns. Thanks to the square-shape pulsed seed, the linewidths at maximum peak power remained at 129.5 MHz, 137.6 MHz, 156.2 MHz and 200.1 MHz, respectively, close to the transform-limited values of 110.8 MHz, 126.6 MHz, 147.7 MHz and 177.3 MHz.

Connected and Autonomous Vehicles (CAVs) have been researched extensively for solving traffic issues and for realising the concept of an intelligent transport system. A well-developed positioning system is critical for CAVs to achieve these aims. The system should provide high accuracy, mobility, continuity, flexibility and scalability. However, high-performance equipment is too expensive for the commercial use of CAVs; therefore, the use of a low-cost Global Navigation Satellite System (GNSS) receiver to achieve real-time, high-accuracy and ubiquitous positioning performance will be a future trend. This research used RTKLIB software to develop a low-cost GNSS receiver positioning system and assessed the developed positioning system according to the requirements of CAV applications. Kinematic tests were conducted to evaluate the positioning performance of the low-cost receiver in a CAV driving environment based on the accuracy requirements of CAVs. The results showed that the low-cost receiver satisfied the “Where in Lane” accuracy level (0·5 m) and achieved a similar positioning performance in rural, interurban, urban and motorway areas.

X-ray powder diffraction data for (S)-methyl-2-hexanamido-3-(4-hydroxyphenyl)propanoate, C16H23NO4, are reported [a = 17.795(4) Å, b = 15.101(1) Å, c = 12.746(3) Å, unit-cell volume V = 3425.51 Å3, Z = 8, and space group P212121]. All measured lines were indexed and are consistent with the P212121 space group. No detectable impurities were observed. The single crystallographic data of the compound are also reported [a = 12.5998(3) Å, b = 17.6856(5) Å, c = 14.6711(5) Å, unit-cell volume V = 3269.25(16) Å3, Z = 8, and space group P212121]. Because of the single-crystal diffraction data were measured at low temperature (110 K), the cell parameters, volume, and calculated density of single-crystal experiment have slight differences with powder diffraction results.

Stimulated Raman scattering (SRS) effect is considered to be one of the main obstacles for power scaling in general-type fiber lasers. Different from previous techniques that aim at suppressing SRS, nonlinear fiber amplifier (NFA), which manipulates and employs the SRS for power scaling in rare-earth-doped fiber, is under intensive research in recent years. In this paper, the authors will present an all-round study on this new kind of high-power fiber amplifier. A theoretical model is proposed based on the rate equation and amplified spontaneous emission (ASE), with random noise taken into account. By numerical solving of the theoretical model, the power scaling potential, heat analysis and advantages in suppressing the undesired backscattering light are quantificationally analyzed for the first time. Then two different types of high-power NFAs are demonstrated individually. Firstly, a laser diode pumped NFA has reached kilowatt output power, and the results agree well with theoretical predictions. Secondly, a tandem-pumped NFA is proposed for the first time and validated experimentally, in which 1.5 kW output power has been achieved. The authors also briefly discuss several new issues relating to the complex nonlinear dynamics that occur in high-power NFAs, which might be interesting topics for future endeavors.