Whether rubber plantations have the role of water pumps in tropical Southeast Asia is under active debate. Fifteen years (1994–2008) of paired catchments water observation data and one year paired ...eddy covariance water flux data in primary tropical rain forest and tropical rubber plantation was used to clarify how rubber plantation affects local water resources of Xishuangbanna, China. Both catchment water observations and direct eddy covariance estimates indicates that more water was evapotranspired from rubber plantation (1137 mm based on catchment water balance, 1125 mm based on eddy covariance) than from the rain forest (969 mm based on catchment water balance, 927 mm based on eddy covariance). Soil water storage during the rainy season is not sufficient to maintain such high evapotranspiration rates, resulting in zero flow and water shortages during the dry season in the rubber plantation. Therefore, this study supports the idea that rubber plantations act as water pumps as suggested by local inhabitants.
Key Points
Two independent methods give the same results
More water was evapotranspirated by rubber plantation than rain forest
Rubber plantation do act as water pumps
The use of mixed halide perovskites in the preparation of blue light-emitting diodes (LEDs) is considered to be the most effective and direct approach. However, the introduction of chlorine (Cl) ...element might raise stability issues in the system and lead to low efficiency, thereby impeding the development of deep blue light-emitting diodes with high efficiency and stability. Determining the alloy concentration and the atomic distribution of bromine-chlorine (Br-Cl) mixed systems is essential for further application of deep blue light-emitting diodes. In this work, we have systematically investigated the stability of bromine-chlorine (Br-Cl) mixed alloy systems in various substitution configurations using high-throughput theoretical calculations. Based on this, we have examined the relationship between configuration stability and three aspects: the type of octahedra, the orientation of the octahedra and the Pb-X-Pb distortion angle in the configuration.
Objective
This study aimed to investigate the value of high‐flow nasal cannula (HNFC) oxygen therapy in treating patients with severe novel coronavirus pneumonia (COVID‐19).
Methods
The clinical data ...of 22 patients with severe COVID‐19 were collected. The heart rate (HR), respiratory rate (RR) and oxygenation index (PO2/FiO2) at 0, 6, 24 and 72 hours after treatment were compared between the HFNC oxygen therapy group and the conventional oxygen therapy (COT) group. In addition, the white blood cell (WBC) count, lymphocyte (L) count, C‐reactive protein (CRP) and procalcitonin (PCT) were compared before and at 72 hours after oxygen therapy treatment.
Results
The differences at 0 hours between the two groups were not statistically significant. Compared with COT group,in the HFNC oxygen therapy group, HR, RR and PaO2/FiO2 were better at 6 hours after treatment, PaO2/FiO2 was better at 24 and 72 hours. After 72 hours, L and CRP had improved in the HFNC oxygen therapy group compared with the COT group, but the differences in WBC and PCT were not statistically significant. The length of stay in the intensive care unit (ICU) and the total length of hospitalization was shorter in the HFNC oxygen therapy group than in the COT group.
Conclusion
Compared with COT, early application of HFNC oxygen therapy in patients with severe COVID‐19 can improve oxygenation and RR, and HFNC oxygen therapy can improve the infection indexes of patients and reduce the length of stay in the ICU of patients. Therefore, it has high clinical application value.
(1) Background: Exercise is effective in promoting and maintaining bone mass. The aim of this study was to detect the exercise-induced metabolic changes in bone tissue of zebrafish. (2) Methods: ...Thirty-eight zebrafish (Danio rerio, six months old) were analyzed. The exercise group (
= 19) received 8 weeks of counter-current swimming training. The control group (
= 19) was not subjected to exercise. Mineralization was quantified, and alkaline phosphatase (Alp) and anti-tartrate acid phosphatase (Trap) activities were estimated (
= 12). The metabolomics (
= 12) and transcriptomics (
= 14) data of bone tissue were used for the integration analyses. (3) Results: The results showed that the exercise training improved the bone mineralization of zebrafish, e.g., the exercise group (5.74 × 10
± 7.63 × 10
) had a higher mean optical density than the control group (5.26 × 10
± 8.56 × 10
,
= 0.046) for the caudal vertebrae. The amount of mineralized matrix in scales of the exercised zebrafish was also higher (0.156 ± 0.012 vs. 0.102 ± 0.003,
= 0.005). Both histological staining and biochemical analysis revealed increased Alp activity (0.81 ± 0.26 vs. 0.76 ± 0.01,
= 0.002) and decreased Trap activity (1.34 ± 0.01 vs. 1.36 ± 0.01,
= 0.005) in the exercise group. A total of 103 different metabolites (DMs, VIP ≥ 1, fold change (FC) ≥ 1.20 or ≤0.83,
< 0.050) were identified. Alanine, aspartate and glutamate metabolism, β-alanine metabolism, pyrimidine metabolism, and pantothenate and CoA biosynthesis were the significantly enriched metabolic pathways (
< 0.050). A total of 35 genes (
≤ 0.050 (BH), |Log2FC| ≥ 0.5) were coenriched with the 103 DMs in the four identified pathways. Protein-protein interaction network analysis of the 35 genes showed that
,
, and
were the core genes. (4) Conclusions: The results of this study suggest that alanine, aspartate and glutamate metabolism, β-alanine metabolism, pyrimidine metabolism, and pantothenate and CoA biosynthesis contributed to exercise-induced improvements in bone mass.
•A volumetric accuracy enhancement method is proposed to identify and compensate geometric errors of rotary axes.•A new concept named equivalent rotary axis is established to depict the actual poses ...of rotary axes with six parameters.•The identification method respects the constraints of rotary axes, and avoids the normalization and iteration procedures.•The compensation method provides explicit and analytical equations to generate the compensated motion commands.•The influences of translational axes, setup errors of table ball and tool ball are comprehensively considered.
Display omitted
This paper proposes a volumetric accuracy enhancement method of rotary axes in five-axis machine tools through constructing equivalent rotary axis (ERA). The influences of translational axes, setup errors of table ball and tool ball are simultaneously considered. A new concept named ERA, originated from the definition of axis of rotation, is proposed to globally describe the instantaneous position and orientation of rotary axes. Based on this concept, only six parameters are needed to describe the influences of geometric errors rather than ten parameters required by the existing concept of PDGEs and PIGEs. At the same time, the coupled relationship between the compensated motion commands of rotary axes and geometric error components is eliminated, and the geometric error compensation is realized by formulating analytical expressions. The typical characteristics of the proposed method lie in the following three aspects. First, the axis twists in the identification method naturally follow the constraint of rotary axis, and thus the normalization and iteration procedure required by existing literatures are avoided. Second, compact form of geometric error compensation is established and explicit equations are given to generate the compensated motion commands. Specially, the inverse kinematic model of five-axis machine tools can be well integrated into the proposed method. Third, besides machine tools with non-orthogonal rotary axes, the proposed method can also be easily applied to five-axis machine tools with non-orthogonal rotary axes just by modifying the ERA parameters. Simulation results and blade machining tests verify the effectiveness of the proposed method, and more than 70% machining precision improvement is observed.
Polymeric g‐C3N4 with controllable photoluminescence emission wavelength in the whole visible light range (450–650 nm) is synthesized through the one‐step molecular doping during the thermal ...condensation process of g‐C3N4 conjugated framework, which opens up its application beyond the conventional catalysis scopes. By adjusting the doped content of hetero‐molecules, the modified g‐C3N4 with the optical properties controlled according to the demand of practical applications can be facilely and largely obtained. It overcomes the limitation of the narrow adjusting range of conventional g‐C3N4 on optical properties and makes it become more promising for applications in solid‐state displays. The corresponding multiple‐color g‐C3N4‐based LED devices and the white‐light LEDs with high quality can be obtained as supported by experiments and theoretical calculations. Moreover, the effect of doped molecule on the π‐conjugated system of g‐C3N4 is systematically studied here, and the tunable luminescence mechanism is proposed.
The full‐color photoluminescence emissions (457–650 nm) of g‐C3N4 are first achieved by simple one‐step molecular doping, especially the red‐light emission feature. The corresponding multiple‐color LED devices and the white LED with high color quality are experimentally fabricated with theoretical demonstration of their potential commercial value.
MnSb2Te4 has a similar structure to an emerging material, MnBi2Te4. According to earlier theoretical studies, the formation energy of Mn antisite defects in MnSb2Te4 is negative, suggesting its ...inherent instability. This is clearly in contrast to the successful synthesis of experimental samples of MnSb2Te4. Here, the growth environment of MnSb2Te4 and the intrinsic defects are correspondingly investigated. We find that the Mn antisite defect is the most stable defect in the system, and a Mn-rich growth environment favors its formation. The thermodynamic equilibrium concentrations of the Mn antisite defects could be as high as 15% under Mn-poor conditions and 31% under Mn-rich conditions. It is also found that Mn antisite defects prefer a uniform distribution. In addition, the Mn antisite defects can modulate the interlayer magnetic coupling in MnSb2Te4, leading to a transition from the ideal antiferromagnetic ground state to a ferromagnetic state. The ferromagnetic coupling effect can be further enhanced by controlling the defect concentration.
This article proposes a real-time method to control the contour error for industrial five-axis machine tools by combining the generalized predictive control (GPC) and the feedback correction (FBC) ...with dynamic contour error estimation (CEE). The CEE is developed by well considering the curve's curvature and torsion based on Taylor series expansion and Frenet frame theory. By utilizing the spherical linear interpolation, the tool orientation and the tool tip position are synchronized with respect to the curve length. A novel dynamic foot point searching procedure is established to weaken the influences of the tracking errors' magnitude on the CEE precision. To tackle the transmission effect, the GPC is adopted to predict the servo systems' outputs, and then, the induced tool pose deviations, which are subsequently utilized to counteract the contour errors, are predicted by constructing Jacobian matrixes. Especially, the FBC loops are constructed to suppress the influences of disturbances and further to reduce the magnitudes of contour errors. Simulations and experiments are conducted to verify the effectiveness of the proposed methods.
Quantum teleportation and quantum memory are two crucial elements for large-scale quantum networks. With the help of prior distributed entanglement as a “quantum channel,” quantum teleportation ...provides an intriguing means to faithfully transfer quantum states among distant locations without actual transmission of the physical carriers Bennett CH, et al. (1993) Phys Rev Lett 70(13):1895–1899. Quantum memory enables controlled storage and retrieval of fast-flying photonic quantum bits with stationary matter systems, which is essential to achieve the scalability required for large-scale quantum networks. Combining these two capabilities, here we realize quantum teleportation between two remote atomic-ensemble quantum memory nodes, each composed of ∼10 ⁸ rubidium atoms and connected by a 150-m optical fiber. The spin wave state of one atomic ensemble is mapped to a propagating photon and subjected to Bell state measurements with another single photon that is entangled with the spin wave state of the other ensemble. Two-photon detection events herald the success of teleportation with an average fidelity of 88(7)%. Besides its fundamental interest as a teleportation between two remote macroscopic objects, our technique may be useful for quantum information transfer between different nodes in quantum networks and distributed quantum computing.
Glucose sensors based blood glucose detection are of great significance for the diagnosis and treatment of diabetes because diabetes has aroused wide concern in the world. In this study, bovine serum ...albumin (BSA) was used to cross-link glucose oxidase (GOD) on a glassy carbon electrode (GCE) modified by a composite of hydroxy fullerene (HFs) and multi-walled carbon nanotubes (MWCNTs) and protected with a glutaraldehyde (GLA)/Nafion (NF) composite membrane to prepare a novel glucose biosensor. The modified materials were analyzed by UV-visible spectroscopy (UV-vis), transmission electron microscopy (TEM), and cyclic voltammetry (CV). The prepared MWCNTs-HFs composite has excellent conductivity, the addition of BSA regulates MWCNTs-HFs hydrophobicity and biocompatibility, and better immobilizes GOD on MWCNTs-HFs. MWCNTs-BSA-HFs plays a synergistic role in the electrochemical response to glucose. The biosensor shows high sensitivity (167 μA·mM
·cm
), wide calibration range (0.01-3.5 mM), and low detection limit (17 μM). The apparent Michaelis-Menten constant Kmapp is 119 μM. Additionally, the proposed biosensor has good selectivity and excellent storage stability (120 days). The practicability of the biosensor was evaluated in real plasma samples, and the recovery rate was satisfactory.
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