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This paper explores the effects of cone tip roughness factor, soil in situ stress ratio and strength non-homogeneity on cone tip resistance in three-layer clay deposits, aiming at presenting a general CPT data interpretation framework to extract soil layered profiles and strengths. Large deformation finite element (LDFE) analysis has been carried out, simulating continuous penetration of the standard cone penetrometer from the seabed surface, with the consideration of cone tip roughness factor, in situ stress ratio and soil strength non-homogeneity within a practical range. In the LDFE analyses, a thin relatively stiff or soft clay layer was interbedded in a uniform or NC clay deposit, with various strength ratios between two successive layers and thickness ratios of the thin layer to the cone diameter explored. The results have shown that the noted factors have significant influence on net cone penetration resistance in stratified deposits. These influences in the layered deposits were found to be similar in magnitude to those on the cone limiting resistance in a single clay layer, leading to the resultant influence on a thin layer correction factor for cone penetration resistance minimal. This was confirmed by the evidence of the evolving soil flow mechanisms around the cone tip. Therefore, the design charts and formulas developed for a smooth cone in uniform three-layer soils are applicable for delineating layer boundaries and interpreting the undrained shear strength of each identified layer for a partially rough cone in three-layer non-homogeneous clay deposits. However, the cone tip roughness factor was shown to have an influence in the layer boundary identification, especially for the cone penetration from a stiff layer to a soft layer. [ABSTRACT FROM AUTHOR]

This paper addresses an open-time Lambert problem under first-order gravitational perturbations with unfixed parking time and transfer time. The perturbations are compensated by introducing its analytical solutions derived from Lagrange's planetary equations into Lambert problem. A drift vector of aim position correction is defined to reduce the aim position bias caused by the perturbations. The first purpose of optimization is to find sufficiently small intervals involving the global optimal parking time, transfer time, drift vector and velocity increment. The second is to determine the global solution or the solution close to it in these intervals. Interval analysis and a double-deck gradient-based method with GA estimating the initial range of drift vector are utilized to obtain the sufficiently small intervals including the global minimum velocity increment and the global minimum solution or one sufficiently close to it in these intervals. [ABSTRACT FROM AUTHOR]

[Display omitted] • Tannic acid-modified MXene (MT) improved the oxidation resistance and toughness. • MT exhibits a more stable structure and a regular laminar alignment. • BC bonded with MT via H-bonds and improves the toughness and hydrophilicity. As an emerging two-dimensional nanomaterial, Ti 3 C 2 T X MXene exhibits promising applications in the fields of energy, electromagnetic shielding, sensors and actuators. However, the structural instability and vulnerability to oxidation of MXene limit its application in moisture self-driven actuator. In this work, a composite film of moisture actuator with a lamellar structure inspired by pearl was reported. The composite film consists of tannic acid-modified Mxene and bacterial cellulose (BC). The synergistic interaction between TA and MXene imparts MXene with toughness and oxidation resistance, whereas the introduction of high wet/dry strength BC imparts the composite film with high tensile strength (243.5 MPa for dry strength and 173.4 MPa for wet strength) and high fracture strain (7.4 %). In addition, the actuator is highly moisture sensitive with fast response (2.48 s) and high cycling stability (more than 100 cycles). The results provide a strategy for the development of moisture-driven soft actuators, and reveal the great promise of this moisture actuator for applications in soft bionic robots and flexible arms, solving the current shortcomings of poor durability and low strength of MXene-based actuators, establishing the foundation for a wider application of moisture actuator devices. [ABSTRACT FROM AUTHOR]

By defining two open-time impulse points, the optimization of a two-impulse, open-time terminal rendezvous and docking with target spacecraft on large-eccentricity elliptical orbit is proposed in this paper. The purpose of optimization is to minimize the velocity increment for a terminal elliptic-reference-orbit rendezvous and docking. Current methods for solving this type of optimization problem include for example genetic algorithms and gradient based optimization. Unlike these methods, interval methods can guarantee that the globally best solution is found for a given parameterization of the input. The non-linear Tschauner- Hempel(TH) equations of the state transitions for a terminal elliptic target orbit are transformed form time domain to target orbital true anomaly domain. Their homogenous solutions and approximate state transition matrix for the control with a short true anomaly interval can be used to avoid interval integration. The interval branch and bound optimization algorithm is introduced for solving the presented rendezvous and docking optimization problem and optimizing two open-time impulse points and thruster pulse amplitudes, which systematically eliminates parts of the control and open-time input spaces that do not satisfy the path and final time state constraints. Several numerical examples are undertaken to validate the interval optimization algorithm. The results indicate that the sufficiently narrow spaces containing the global optimization solution for the open-time two-impulse terminal rendezvous and docking with target spacecraft on large-eccentricity elliptical orbit can be obtained by the interval algorithm (IA). Combining the gradient-based method, the global optimization solution for the discontinuous nonconvex optimization problem in the specifically remained search space can be found. Interval analysis is shown to be a useful tool and preponderant in the discontinuous nonconvex optimization problem of the terminal rendezvous and docking than GA. [ABSTRACT FROM AUTHOR]

We have measured high-resolution absorption spectra of methane broadened by N 2 and air at sample temperatures between 173.0 K and room temperature. The measurements were performed based on direct laser absorption spectroscopy using a tunable diode laser combined with a temperature controlled cryogenically cooled absorption cell. These spectra have been analyzed to determine the pressure-broadened half-width coefficients as well as their temperature dependences for six singlet lines belonging to the ν 3 band of methane near 3.38 μm. To our knowledge, the temperature dependence exponents for the pressure-broadened half-width coefficients are reported experimentally for the first time for six transitions of 12 CH 4 with intensities stronger than 4×10 −20 cm −1 /(molecule cm −2 ). The measured half-width coefficients and the temperature dependence exponents of these transitions are compared with the available values reported in the literature and the HITRAN2012 database. Agreements and discrepancies are discussed. [ABSTRACT FROM AUTHOR]

Phosphorus (P) has been proposed as an important factor determining photosynthesis through improvements in leaf anatomical traits and carboxylation efficiency. However, little is known about the combined effects of straw mulch and P fertilizer on the relationship between flag leaf P content and photosynthesis. This study was conducted to determine the combined effects of straw mulch combined with P fertilizer on wheat flag leaf photosynthetic capacity and grain yield. We performed field experiments during 2020–2022 to investigate the combined effects of straw mulch (0 and 8000 kg ha−1) with P fertilizer (0, 75, and 120 kg P2O5 ha−1) in Southwest China. Straw mulch with 75 kg P2O5 ha−1 gave an 18.3% yield advantage over no mulch with 120 kg P2O5 ha−1. Straw mulching with P fertilizer increased flag leaf P content and increased stomatal density. These changes increased stomatal conductance, mesophyll conductance, and net photosynthetic rate (Pn) by 17.4%, 16.3%, and 20.8%, respectively, compared with no‐mulch plots. The increased Pn was found associated with decreased stomatal and mesophyll limitation. Straw mulching with P fertilizer increased the activities of ribulose‐1,5‐bisphosphate carboxylase‐oxygenase and sucrose synthesis enzymes, thus promoting sucrose synthesis in flag leaves, which is beneficial for increasing grain number per meter square and grain yield. Straw mulching combined with 75 kg P2O5 ha−1 increased flag leaves P content and stomatal density, and increased stomatal and mesophyll conductance, resulting in improved leaf photosynthesis and grain yield. Core Ideas: Straw mulching with phosphorus (P) fertilizer leads to thicker leaves and increased P accumulation, increasing stomatal and mesophyll conductance for high net photosynthetic rate (Pn).Straw mulching with P fertilizer increased carboxylation capacity and ribulose‐1,5‐bisphosphate carboxylase‐oxygenase enzyme activity in leaves, but biochemical limitation is the main limiting factor for Pn enhancement.Straw mulching with P fertilizer increased sucrose export and grain yield by improving photosynthetic capacity and sucrose synthesis. [ABSTRACT FROM AUTHOR]

Recently, large efforts have been made to develop surface soil moisture (SSM) products based on observations from passive microwave L-band satellites at the global scale. Despite vast previous efforts to assess satellite SSM products based on in situ data, the performance of L-band SSM products remains still little known over the tropical areas including the rainforests. To close this knowledge gap, a comprehensive evaluation of five L-band SSM products from the Soil Moisture and Ocean Salinity (SMOS) and Soil Moisture Active Passive (SMAP) satellites, including SMOS-IC, SMAP SCA-V, DCA, and MTDCA, as well as the recently developed SMAP INRAE-BORDEAUX (SMAP-IB) was conducted in tropical areas from 2015 to 2020. The investigation was implemented by using in situ observations, and expanded by the Triple Collocation Analysis (TCA) and double instrumental variable (IVd) methods. The results revealed that all the five L-band SSM products show a good capacity to estimate SSM in most moderately vegetated areas of the tropical areas while they exhibit some uncertainties in dense vegetation (e.g., rainforests). The SSM climatology of the five L-band products in rainforests agreed generally well with that of in situ measurements especially for SMOS-IC (R = 0.75), followed by SMAP-IB (R = 0.72). Notably, the newly developed SMAP-IB shows satisfactory performance in the tropics with the highest R of 0.73 and the smallest unbiased root mean square difference (ubRMSD) of 0.041 m3/m3 from the study based on in situ SM data, and R of >0.81 from the combined TCA/IVd method in most vegetation conditions. SMAP-DCA SSM demonstrates comparable performance to SMAP-SCA-V (R = 0.66) from the in situ based analysis. This study is expected to deepen our understanding on the skill of L-band SSM products in tropical areas and further promote possible upgrades in algorithms and applications in these regions. • Five L-band SSM products were evaluated over the tropics. • The newly developed SMAP-IB showed satisfying performances. • The combined TCA/IVd and in situ analyses led to consistent results. • L-band SSM shows acceptable climatology results in rainforests. [ABSTRACT FROM AUTHOR]