Effect of Initial Planting Density on the Moisture Content and Chemical Composition of the Triploid Chinese White Poplar (Populus× tomentosa Carrière) Plantation

The triploid Chinese white poplar (Populus × tomentosa Carrière) features desirable growth traits and wood properties, making it the preferred species in the pulp and paper industries and the sawn timber industry. In this study, we characterized the effects of initial planting densities on the moisture content (MC) and four chemical components (benzene-alcohol (BA), holocellulose (HC), alpha-cellulose (AC), and klason lignin (KL)) of the triploid Chinese white poplar. In this study, 11-year-old Chinese white poplars with three triploid clones (S86, B331, and B301) and one diploid clone (1316) that were planted using seven levels of planting densities (2490, 1665, 1110, 832, 624, 499 and 416 trees/hm2) were examined in the Huabei Great Plain in China. The MC was observed to initially decrease and then subsequently increase with decreasing planting density, and exhibited significant differences under different initial planting densities (0.001 < p < 0.01). In terms of the chemical composition, the BA content of the triploid hybrid clones presented with much higher phenotypic variation (CVp = 17.11%–32.45%) at each planting density compared to either the MC (CVp = 3.73%–11.21%) or the other three chemical composition variations (CVp = 1.16%–11.46%). Substantial differences were observed in the chemical composition of the triploid hybrid clones (p < 0.05), while no differences were found in the chemical composition within the initial planting density categories. The correlation between the chemical composition of wood (BA, HC, AC, and KL) and growth traits was generally weak. These results demonstrate that compared with the MC, the chemical composition of the triploid Chinese white poplar was primarily controlled by its own genetic background and was almost unaffected by the initial planting density. Thus, it is important to select a suitable clone and initial planting density to ensure the full growth of these trees and to improve the quality of pulping in the construction of pulp timber forests

Effect of Initial Planting Density on Growth Traits and Wood Properties of Triploid Chinese White Poplar (Populus tometosa) Plantation

Planting density primarily affects the yield and wood quality of plantations. There are multiple reports on the effects of planting density on growth traits and wood properties in young triploid Chinese white poplar (Populus tomentosa) plantations. Nevertheless, assessment of the effects of initial planting density is lacking for plantations older than ten years. Here, an 11-year-old plant density trial (2490, 1665, 1110, 832, 624, 499, and 416 trees/hm2) established with four hybrid clones (S86, B301, B331 and 1316) in northern China was used to determine the effect of initial planting density on growth traits (diameter at breast height (DBH), tree height (H), stem volume (SV) and stand wood volume (SWV)), basic wood density (BWD), and fiber properties (fiber length (FL), fiber width (FW), and the ratio of fiber length to width (FL/FW)). A total of 84 trees from four clones were sampled. In this study, the initial planting density had a highly significant effect on growth traits (p < 0.001) and had a moderate effect on FL. Overall, the reduction in initial planting density led to the increase in DBH, H, SV, and FL/FW. Triploid hybrid clones planted at 416 trees/hm2 had the largest DBH, H, SV, FL/FW and the smallest SWV and FW. Clonal effects were also significant (p < 0.05) for all studied traits except for FL. Clone S86 had a higher growth rate and the largest BWD and FW. Clones–initial planting densities interaction was insignificant for all growth traits and wood properties. A weak and positive estimated correlation between BWD and growth traits (H, SV, SWV) within each planting density was seen. Our results demonstrate that an appropriate reduction in initial density in triploid Chinese white poplar plantations with long rotation is a suitable strategy to promote tree growth and retain excellent wood processing characteristics

Effect of Initial Planting Density on Growth Traits and Wood Properties of Triploid Chinese White Poplar (<i>Populus tometosa</i>) Plantation

Planting density primarily affects the yield and wood quality of plantations. There are multiple reports on the effects of planting density on growth traits and wood properties in young triploid Chinese white poplar (Populus tomentosa) plantations. Nevertheless, assessment of the effects of initial planting density is lacking for plantations older than ten years. Here, an 11-year-old plant density trial (2490, 1665, 1110, 832, 624, 499, and 416 trees/hm2) established with four hybrid clones (S86, B301, B331 and 1316) in northern China was used to determine the effect of initial planting density on growth traits (diameter at breast height (DBH), tree height (H), stem volume (SV) and stand wood volume (SWV)), basic wood density (BWD), and fiber properties (fiber length (FL), fiber width (FW), and the ratio of fiber length to width (FL/FW)). A total of 84 trees from four clones were sampled. In this study, the initial planting density had a highly significant effect on growth traits (p 2 had the largest DBH, H, SV, FL/FW and the smallest SWV and FW. Clonal effects were also significant (p < 0.05) for all studied traits except for FL. Clone S86 had a higher growth rate and the largest BWD and FW. Clones–initial planting densities interaction was insignificant for all growth traits and wood properties. A weak and positive estimated correlation between BWD and growth traits (H, SV, SWV) within each planting density was seen. Our results demonstrate that an appropriate reduction in initial density in triploid Chinese white poplar plantations with long rotation is a suitable strategy to promote tree growth and retain excellent wood processing characteristics

Design of High-Q-Gradient Dielectric Nanoparticle Chain Surface Plasmonic Cavities

Surface plasmonic cavities consisting of dielectric nanoparticle chains directly placed on a metal substrate are designed and studied, including a periodic nanoparticle chain (PNC) cavity and several different surface plasmon trap (SPT) cavities. The SPT cavities are designed by adjusting the nanoparticle sizes and the spacing between nanoparticles. Among them, the nanoparticle sizes range from 10 nm to 140 nm, and the spacings between the nanoparticles range from 200 nm to 280 nm. Compared to the PNC cavity, the SPT cavities support a single mode operation with higher Q factors within a relatively wide bandwidth. In particular, when the particle size and the spacing between the particles of the chain are set to vary in a parabolic gradient profile, the Q factor of the SPT cavity can be improved up to 85% compared to the PNC cavity. Our designs can be applied in the development of high-Q-factor plasmonic nanolasers

Effects of Planting and Nitrogen Application Patterns on Alfalfa Yield, Quality, Water–Nitrogen Use Efficiency, and Economic Benefits in the Yellow River Irrigation Region of Gansu Province, China

Appropriate planting and nitrogen application patterns to support high-quality production of cultivated forage in light of issues of water scarcity, extensive field husbandry, and low productivity in cultivated grassland planting areas were investigated in this study. Using Medicago sativa L. (alfalfa) as the research object, this study analyzed the effects of planting patterns (conventional flat planting (FP) and ridge culture with film mulching (RM)) and nitrogen level (N0: 0 kg·ha−1, N1: 80 kg·ha−1, N2: 160 kg·ha−1, N3: 240 kg·ha−1) on the growth, yield, quality (crude protein content (CP), acid detergent fiber content (ADF), neutral detergent fiber content (NDF), and relative feeding value (RFV)), the water–nitrogen use efficiency, and economic benefits (EB) of alfalfa in the year of establishment. Results demonstrated that (1) RM might greatly increase the growth of alfalfa when compared to FP. The plant height, stem diameter, and leaf:stem ratio of alfalfa all increased under the same planting patterns before decreasing as the nitrogen application rate (NAR) increased. (2) Appropriate NAR combined with RM could improve the yield and quality of alfalfa. Compared with other treatments, the yield, CP, and RFV under RMN2 treatment increased by 5.9~84.9%, 4.9~28.6%, and 19.6~49.3%, respectively, and the ADF and NDF decreased by 14.0~27.6% and 13.0~26.1%, respectively. (3) Under the same nitrogen level, RM showed better performance than FP in terms of water use efficiency (WUE), irrigation water use efficiency (IWUE), precipitation use efficiency (PUE), partial factor productivity of nitrogen (PFPN), agronomic nitrogen use efficiency (ANUE), and EB of alfalfa. Under the same planting pattern, PFPN decreased as the NAR increased, while WUE, IWUE, PUE, ANUE, and EB first increased and then decreased as the NAR increased and reached a maximum value under the N2 condition. In conclusion, the RM planting pattern combined with a nitrogen level of 160 kg·ha−1 can significantly promote alfalfa growth as well as the yield, quality, water–nitrogen use efficiency, and EB of alfalfa, making it a suitable planting management mode for alfalfa production in the Yellow River irrigation region in Gansu Province, China and areas with similar climate

Interdependence between nanoclusters AuAg24 and Au2Ag41

Despite recent progress in individual nanocluster synthesis, understanding the competing or coexisting effects between particles in solution remains challenging. Here, the authors present the synthesis of a bi-nanocluster system comprising two atomically precise nanoclusters, and map out the interdependent relationship between them

Curving effects of concave dodecahedral nanocarbons enable enhanced Li-ion storage

Dodecahedral nanocarbons with highly curving concave faces are synthesized via a one-step direct pyrolysis strategy. When tested as anodes in lithium-ion batteries (LIBs), the concave dodecahedral carbons (CDCs) show much enhanced capacity (∼2 times) and improved rate capability (603 mA h g-1at 2000 mA g-1), when compared with the perfect ones without curved planes (PDCs, 280 mA h g-1). The curving effects of CDCs on Li ion storage are further investigated by constructing a CDC particle-based nanobattery device in an in situ transmission electron microscope (TEM). During the lithiation process of CDCs, the spacing in the curved parts expands much more than the perfect ones (from 0.5 nm to 0.7 nm), providing increasing active sites for Li ion storage. And the stable solid electrolyte interphase (SEI) layer and structural integrity for CDCs are also visualized during the discharge process, in good agreement with their ultralong cycle life. This design concept, enhancing curved parts in the structures, provides guidance in the development of next-generation advanced electrode materials

Stepwise on-surface dissymmetric reaction to construct binodal organometallic network

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