Biomass Accumulation and Carbon Sequestration in Four Different Aged Casuarina equisetifolia Coastal Shelterbelt Plantations in South China

Thousands of kilometers of shelterbelt plantations of Casuarina equisetifolia have been planted to protect the southeast coastline of China. These plantations also play an important role in the regional carbon (C) cycling. In this study, we examined plant biomass increment and C accumulation in four different aged C. equisetifolia plantations in sandy beaches in South China. The C accumulated in the C. equisetifolia plant biomass increased markedly with stand age. The annual rate of C accumulation in the C. equisetifolia plant biomass during 0-3, 3-6, 6-13 and 13-18 years stage was 2.9, 8.2, 4.2 and 1.0 Mg C ha(-1) yr(-1), respectively. Soil organic C (SOC) at the top 1 m soil layer in these plantations was 17.74, 5.14, 6.93, and 11.87 Mg C ha(-1), respectively, with SOC density decreasing with increasing soil depth. Total C storage in the plantation ecosystem averaged 26.57, 38.50, 69.78, and 79.79 Mg C ha(-1) in the 3, 6, 13 and 18-yrs plantation, with most of the C accumulated in the aboveground biomass rather than in the belowground root biomass and soil organic C. Though our results suggest that C. equisetifolia plantations have the characteristics of fast growth, high biomass accumulation, and the potential of high C sequestration despite planting in poor soil conditions, the interactive effects of soil condition, natural disturbance, and human policies on the ecosystem health of the plantation need to be further studied to fully realize the ecological and social benefits of the C equisetifolia shelterbelt forests in South China

Rationally Designed Sodium Chromium Vanadium Phosphate Cathodes with Multi-Electron Reaction for Fast-Charging Sodium-Ion Batteries

Sodium super-ionic conductor (NASICON)-structured phosphates are emerging as rising stars as cathodes for sodium-ion batteries. However, they usually suffer from a relatively low capacity due to the limited activated redox couples and low intrinsic electronic conductivity. Herein, a reduced graphene oxide supported NASICON Na3Cr0.5V1.5(PO4)3 cathode (VC/C-G) is designed, which displays ultrafast (up to 50 C) and ultrastable (1 000 cycles at 20 C) Na+ storage properties. The VC/C-G can reach a high energy density of ≈470 W h kg−1 at 0.2 C with a specific capacity of 176 mAh g−1 (equivalent to the theoretical value); this corresponds to a three-electron transfer reaction based on fully activated V5+/V4+, V4+/V3+, V3+/V2+ couples. In situ X-ray diffraction (XRD) results disclose a combination of solid-solution reaction and biphasic reaction mechanisms upon cycling. Density functional theory calculations reveal a narrow forbidden-band gap of 1.41 eV and a low Na+ diffusion energy barrier of 0.194 eV. Furthermore, VC/C-G shows excellent fast-charging performance by only taking ≈11 min to reach 80% state of charge. The work provides a widely applicable strategy for realizing multi-electron cathode design for high-performance SIBs

Infrared Imaging of Magnetic Octupole Domains in Non-collinear Antiferromagnets

Magnetic structure plays a pivotal role in the functionality of antiferromagnets (AFMs), which not only can be employed to encode digital data but also yields novel phenomena. Despite its growing significance, visualizing the antiferromagnetic domain structure remains a challenge, particularly for non-collinear AFMs. Currently, the observation of magnetic domains in non-collinear antiferromagnetic materials is feasible only in Mn$_{3}$Sn, underscoring the limitations of existing techniques that necessitate distinct methods for in-plane and out-of-plane magnetic domain imaging. In this study, we present a versatile method for imaging the antiferromagnetic domain structure in a series of non-collinear antiferromagnetic materials by utilizing the anomalous Ettingshausen effect (AEE), which resolves both the magnetic octupole moments parallel and perpendicular to the sample surface. Temperature modulation due to the AEE originating from different magnetic domains is measured by the lock-in thermography, revealing distinct behaviors of octupole domains in different antiferromagnets. This work delivers an efficient technique for the visualization of magnetic domains in non-collinear AFMs, which enables comprehensive study of the magnetization process at the microscopic level and paves the way for potential advancements in applications.Comment: National Science Review in pres

“Mn-locking” effect by anionic coordination manipulation stabilizing Mn-rich phosphate cathodes

High-voltage cathodes with high power and stable cyclability are needed for high-performance sodium-ion batteries. However, the low kinetics and inferior capacity retention from structural instability impede the development of Mn-rich phosphate cathodes. Here, we propose light-weight fluorine (F) doping strategy to decrease the energy gap to 0.22 eV from 1.52 eV and trigger a “Mn-locking” effect—to strengthen the adjacent chemical bonding around Mn as confirmed by density functional theory calculations, which ensure the optimized Mn ligand framework, suppressed Mn dissolution, improved structural stability and enhanced electronic conductivity. The combination of in situ and ex situ techniques determine that the F dopant has no influence on the Na+ storage mechanisms. As a result, an outstanding rate performance up to 40C and an improved cycling stability (1000 cycles at 20C) are achieved. This work presents an effective and widely available light-weight anion doping strategy for high-performance polyanionic cathodes

System identification and modeling of primary electrosensory afferent response dynamics in the weakly electric fish Apteronotus leptorhynchus

The first stage of information processing in the electrosensory system of weakly electric fish involves the encoding of changes in transdermal potential into trains of action potentials in primary afferent nerve fibers. Using amplitude modulations (AMs) of the electric organ discharge (EOD), we systematically studied the stimulus coding properties of probability coding (P-type) electrosensory afferents in the weakly electric fish Apteronotus leptorhynchus (brown ghost knife fish). In response to brief (1 sec) AM step stimuli, we find that the time course of firing rate adaptation in P-type afferents can be approximated by one or two exponentially decaying components plus a tonic component. If the duration of the step stimulus is prolonged, however, the apparent tonic component of the response continues to fall slowly with time. By recording responses to prolonged step stimuli of 10-20 minutes in duration, we show that the overall time course is better described by a logarithmic function of the form A/(log(t) + B). For most units this form successfully fits the entire time course of the response over 5 log units in time, front milliseconds to hundreds of seconds, using just two free parameters. Based on experimental data using both step and sinusoidal AM stimuli, we have constructed a linear-nonlinear cascade model to describe the response properties of P-type afferents. We use parametric system identification technique to quantitatively characterize the response dynamics of the system. Comparisons of experimental data and model predictions to filtered white noise AM stimuli show that our linear-nonlinear cascade model can accurately predict responses to arbitrary AM stimuli. Finally a preliminary biophysical model of P-type afferent response dynamics has been developed to help identify cellular mechanisms that influence the encoding properties of primary afferent nerve fibers.U of I OnlyETDs are only available to UIUC Users without author permissio

Virtual analysis of influence of a filter on mould filling

Ceramic filters are used to avoid slag and impurities in foundry applications. When not properly applied, the presence of these filters may have a significant influence on mould filling. 3-D casting simulation has been applied to study the effects of the use of a ceramic filter on the metal flow in a gating system. Instead of using a pressure drop model to represent the behaviour of a fluid metal flow passing through a filter, a real exact filter geometry, which is created by a high resolution CT-scan and a non-destructive imaging technique, in the gating system is applied in the simulation. In this research, nodular cast iron is poured into a block casting. A depressurized gating system is used. After a choke, a filter with different orientations is placed in the system. Mould filling coupled with temperature is simulated. Geometries using different orientations of the filter, and without the filter have been researched. The simulated results show that the filter has no influence on the pouring time of the casting if the choke section is small enough compared to the effective section of the filter. Although the filter has no significant influence on the flow patterns in the block casting itself, the flow patterns in the filter zone are different. When the liquid metal passes a horizontal filter, it will be broken into many small streams and show a shower effect. After the part under the filter is full, the shower effect disappears. When the filter is located at the vertical position, due to the gravity, the shower effect is less. If no filter presents on the system, the liquid metal passes through the filter zone with a high speed and causes surface turbulence

Identification of a Novel Intron and 4 Polymorphisms in the Gene Encoding the y Subunit of the Epithelial Sodium Channel

The amiloride-sensitive epithelial sodium channel is a highly selective sodium channel that constitutes the rate-limiting step of sodium reabsorption in distal nephrons. It consists of at least 3 subunits (a, /?, and y) of similar structure and plays an important role in sodium and fluid homeostasis. Defects of this channel have been critically implicated in Liddle syndrome (pseudoaldosteronism) and pseudohypoaldosteronism type 1. A sample of 48 individuals from 23 nuclear families was selected from Anhui, China. We sequenced 12 exons and flanking intronic sequences and discovered a new 207-bp intron located in the previously described exon X of Thomas et al. (1996). In addition, 4 novel single nucleotide polymorphisms were identified; 3 were in exon 3 and 1 was in exon 13. Furthermore, 2 base substitutions in exon 13 were present in all the Chinese subjects compared with the published European SCNN1G DNA sequence

Study on the Motion Characteristics of Solid Particles in Fine Flow Channels by Ultrasonic Cavitation

Microjets caused by the cavitation effect in microchannels can affect the motion trajectory of solid particles in microchannels under ultrasonic conditions. The optimal parameters for an observation experiment were obtained through simulations, and an experiment was designed to verify these parameters. When the cavitation bubbles collapse in the near-wall area, the solid particles in the microchannel can be displaced along the expected motion trajectory. Using fluent software to simulate the bubble collapse process, it can be seen that, when an ultrasonic sound pressure acts on a bubble near the wall, the pressure causes the top of the bubble wall to sink inward and eventually penetrate the bottom of the bubble wall, forming a high-speed microjet. The maximum speed of the jet can reach nearly 28 m/s, and the liquid near the top of the bubble also moves at a high speed, driving the particles in the liquid towards the wall. A high-speed camera was used to observe the ultrasonic cavitation process of bubbles in the water to verify the simulation results. A comparison of particle motion with and without ultrasonic waves proved the feasibility of using the ultrasonic cavitation effect to guide small particles towards the wall. This method provides a novel experimental basis for changing the fluid layer state in the microchannel and improving precision machining