Soil salinization represents an increasingly serious threat to agronomic productivity throughout the world, as rising ion concentrations can interfere with the growth and development of plants, ...ultimately reducing crop yields and quality. A combination of factors is driving this progressive soil salinization, including natural causes, global climate change, and irrigation practices that are increasing the global saline-alkali land footprint. Salt stress damages plants both by imposing osmotic stress that reduces water availability while also inducing direct sodium- and chlorine-mediated toxicity that harms plant cells.
L. exhibits relatively high levels of resistance to soil salinization. However, as with other crops, grapevine growth, development, fruit yields, and fruit quality can all be adversely affected by salt stress. Many salt-tolerant grape germplasm resources have been screened in recent years, leading to the identification of many genes associated to salt stress and the characterization of the mechanistic basis for grapevine salt tolerance. These results have also been leveraged to improve grape yields through the growth of more tolerant cultivars and other appropriate cultivation measures. The present review was formulated to provide an overview of recent achievements in the field of research focused on grapevine salt tolerance from the perspectives of germplasm resource identification, the mining of functional genes, the cultivation of salt-tolerant grape varieties, and the selection of appropriate cultivation measures. Together, we hope that this systematic review will offer insight into promising approaches to enhancing grape salt tolerance in the future.
The shape-selective catalysis enabled by zeolite micropore's molecular-sized sieving is an efficient way to reduce the cost of chemical separation in the chemical industry. Although well studied ...since its discovery, HZSM-5's shape-selective capability has never been fully exploited due to the co-existence of its different-sized straight channels and sinusoidal channels, which makes the shape-selective p-xylene production from toluene alkylation with the least m-xylene and o-xylene continue to be one of the few industrial challenges in the chemical industry. Rather than modifications which promote zeolite shape-selectivity at the cost of stability and reactivity loss, here inverse Al zoned HZSM-5 with sinusoidal channels predominantly opened to their external surfaces is constructed to maximize the shape-selectivity of HZSM-5 sinusoidal channels and reach > 99 % p-xylene selectivity, while keeping a very high activity and good stability ( > 220 h) in toluene methylation reactions. The strategy shows good prospects for shape-selective control of molecules with tiny differences in size.
The zeolite-catalyzed conversion of DME into chemicals is considered environmentally friendly in industry. The periodic density functional theory, statistical thermodynamics, and the transition state ...theory are used to study some possible parallel reactions about the hydrogen-bonded DME over zeolite ferrierite. The following are the key findings: (1) the charge separation probably leads to the conversion of a hydrogen-bonded DME into a dimethyl oxonium ion (i.e., DMO
or (CH
)
OH
) with a positive charge of about 0.804 e; (2) the methylation of DME, CH
OH, H
O, and CO by DMO
at the T2O6 site of zeolite ferrierite shows the different activated internal energy (∆E
) ranging from 18.47 to 30.06 kcal/mol, implying the strong methylation ability of DMO
; (3) H-abstraction by DMO
is about 3.94-15.53 or 6.57-18.16 kcal/mol higher than DMO
methylation in the activation internal energy; (4) six DMO
-mediated reactions are more likely to occur due to the lower barriers, compared to the experimental barrier (i.e., 39.87 kcal/mol) for methyl acetate synthesis; (5) active intermediates, such as (CH
)
O
, (CH
)
OH
, CH
CO
, CH
OH
, and CH
=OH
, are expected to appear; (6) DMO
is slightly weaker than the well-known surface methoxy species (ZO-CH
) in methylation; and (7) the methylated activity declines in the order of DME, CH
OH, H
O, and CO, with corresponding rate constants at 463.15 K of about 3.4 × 10
, 1.1 × 10
, 0.18, and 8.2 × 10
s
, respectively.
•Build a multi-sector dynamic general equilibrium model to characterize the impact of sectoral heterogeneity on the industrial structure transformation and labor income shares, and then perform it ...with numerical simulations result.•Find that the changing direction of total labor income share is same as the labor share of labor-intensive industries.•Explain the “U-shape” trend of China's total labor income share changes.•Help to further understand the economic connotation of the time-varying elasticity production function model and the ongoing structural transformation of China's economy.
In recent years, China's labor income share has undergone substantial changes and the evolution of income distribution is inseparable from the process of industrial structural transformation. From the perspective of sectoral heterogeneity, this study develops Ngai and Pissarides’ (2007) model, constructing a multisector dynamic general equilibrium model. We propose that technological progress or capital deepening will promote the flow of production factors among sectors, with the direction dependent on the substitution elasticity between products, sectoral differences in the rate of technological progress, factor output elasticity, and elasticity of factor substitution. This process of factor flow also causes changes in total labor income share, and the direction parallels the labor share of labor-intensive industries. Combining the development data of China's three major industries during different periods, the results demonstrate that in the industrial period, labor flows from the agricultural sector to the industrial sector and the total labor income share decreases; in the postindustrial period, labor flows from the industrial sector to the service sector and the total labor income share increases. The contribution of this study is in presenting a comprehensive and systematic examination of the impact of sectoral heterogeneity on industrial structure transformation and labor income share, which explains the U-shaped trend of China's overall total labor income share and also helps to further understand the structural transformation of the Chinese economy.
The exposure risk of droplets and aerosols emitted from the oral cavity to the dental professionals and patients has received more attention especially the ongoing outbreak of COVID-19. The aim of ...this study is to address the question about how the use of the high-volume evacuation (HVE) alters the risk profiles compared with the situation only personal protective equipment (PPE). The risk profiles of the different situations were analyzed in terms of droplet velocity, flow field characteristics, and particle removal efficiency. The ultrasonic scaling with suction was performed in the mock-up experimental dental clinic, and the instantaneous moment when the HVE acted on the droplets was visualized using a laser light scattering technique. From the results of the velocity profiles, the hypothesis about the moderate effect of the HVE on high-velocity small droplets near the mannequin's mouth had been firstly proven in this study. The suction can be characterized as low-threshold equipment to bring substantial benefits to reduce the area of the contaminated region. Once the cooperation of suction, the pair of vortexes that were in the face shield area of the dental professional would be eliminated, removing the high-level contaminated region near the breathing area of dental professionals. Compared with the low and medium volume evacuation, the particle removal efficiency of the HVE was more stable at 60%. The research will provide references to the HVE recommendation in the dentistry clinical practice guidelines.
•Proving the hypothesis about the moderate effect of HVE on high-velocity droplets.•Suction can be characterized as low-threshold equipment to bring substantial benefits.•Altering the risk profiles by eliminating the pair of vortexes in the face shield area.•The particle removal efficiency of the HVE was more stable at 60%.•The research would provide references to the dentistry clinical practice guidelines.
In grapevines, the MYB transcription factors play an important regulatory role in the phenylpropanoid pathway including proanthocyanidin, anthocyanin, and flavonoid biosynthesis. However, the role of ...MYB in abiotic stresses is not clear. In this study, an R2R3-MYB transcription factor,
VyMYB24
, was isolated from a high drought-tolerant Chinese wild
Vitis
species
V. yanshanesis
. Our findings demonstrated that it was involved in plant development and drought tolerance.
VyMYB24
is a nuclear protein and is significantly induced by drought stress. When over-expressed in tobacco,
VyMYB24
caused plant dwarfing including plant height, leaf area, flower size, and seed weight. The GA1+3 content in transgenic plants was reduced significantly, and spraying exogenous gibberellin could recover the dwarf phenotype of
VyMYB24
transgenic plants, suggesting that
VyMYB24
might inhibit plant development by the regulation of gibberellin (GA) metabolism. Under drought stress, the
VyMYB24
transgenic plants improved their tolerance to drought with a lower wilting rate, lower relative electrical conductivity, and stronger roots. Compared to wild-type tobacco plants,
VyMYB24
transgenic plants accumulated less reactive oxygen, accompanied by increased antioxidant enzyme activity and upregulated gene expression levels of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) genes. In addition, transgenic plants accumulated more proline, and their related synthetic genes
NtP5CR
and
NtP5CS
genes were significantly upregulated when exposed to drought. Besides, abiotic stress-responsive genes,
NtDREB, NtERD10C, NtERD10D
, and
NtLEA5
, were upregulated significantly in
VyMYB24
transgenic plants. These results indicate that
VyMYB24
plays a positive regulatory role in response to drought stress and also regulates plant development, which provides new evidence to further explore the molecular mechanism of drought stress of the MYB gene family.
Nano-ferrierite zeolite aggregates with hierarchical porosity were successfully prepared by using pyrrolidine as sole organic structure-directing agent. SEM and TEM images revealed that nano-sized ...crystals (40–60 nm) stacked together loosely to form irregular clusters. Influence of crystallization temperature and initial gel compositions (pyrrolidine content, alkalinity, water content) on the synthesis of ferrierite zeolite were investigated in detail. Low crystallization temperature and high alkalinity were beneficial to form nano-ferrierite zeolite aggregates with high hierarchical porosity (total pore volume: 0.461 cm3/g). Compared with commercialized ferrierite zeolite, hierarchical nano-ferrierite aggregates showed better catalytic stability and product selectivity in the 1-butene skeletal isomerization reaction.
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•Hierarchical nano-ferrierite aggregates were synthesized using pyrrolidine as the sole OSDA.•Hierarchical nano-ferrierite aggregates consisted of mainly intercrystalline mesopore due to the stacking and assembly of nano-particles.•The size of nano-ferrierite was in the range of 40–180 nm depending on the crystallization temperature and initial gel compositions.•Excellent catalytic stability and product selectivity in 1-butene skeletal isomerization reaction were observed.
This research reports the preparation and characterization of amorphous microporous carbon nitride using HZSM-5 zeolite as template, and ethidene diamine and carbon tetrachloride as chemical ...precursors. Microporous amorphous carbon nitride is generated by removal of HZSM-5 zeolite in the obtained zeolite/carbon nitride composite using hydrofluoric acid after carbonization the precursor inside the channels of zeolite. The microporous carbon nitride was characterized by nitrogen sorption techniques, scanning electron microscopy, elemental analysis, X-ray diffraction, X-ray photoelectron spectroscopy, IR spectroscopy, Ultraviolet–visible spectroscopy, Raman spectroscopy, and thermo-gravimetric analysis. Amorphous microporous carbon nitride with high surface area and narrow pore size distribution is thermal stable under atmosphere conditions up to 700
K.
•Addition of methanol inhibits dry gas production and promotes LPG production.•Water may occupy catalytic active sites and thus suppress the aromatics production.•The formation of olefins is also ...influenced by water, but to a less extent.•Under the suitable cofeeding ratio, good aromatics selectivity can be maintained.
The aromatization performance of cofeeding n-butane with methanol was investigated in a fixed bed reactor over a Zn loaded ZSM-5/ZSM-11 zeolite. Coke deposited on the catalyst was characterized by TG, TPO, FTIR and Raman technique. During the 48h life-test under the conditions of 510°C, 0.4MPa, WHSV (CH2)=2h−1, pure n-butane reaction performance of the catalyst changes little, but high LPG and low aromatics yields are obtained. Only under the suitable n-butane/methanol ratio, the relatively good aromatics selectivity can be obtained and maintained during the reaction process. Compared with methanol aromatization, the integrated process exhibits a much slower rate of deactivation. Addition of methanol in n-butane inhibits the dry gas production while promotes the LPG production. Water generated from methanol dehydration may occupy the catalytic active sites for olefins aromatization over the catalyst and thus suppress the production of total aromatics. In fact, water mainly suppresses benzene formation and this inhibiting effect increases with n-butane content in the feed, in contrast to its promoting effect on formation of C8 and C9 aromatics. Increasing methanol content in the feed, a simultaneous increase in coke content of the spent catalyst and preference for coke deposition in micropore is observed. Furthermore, the fraction of aliphatics in coke decreases, while those of less-condensed aromatics and polyaromatics incease, which is associated with the increased deactivation of catalyst.
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•The adsorption isotherm of DME and CO in FER zeolite with different Si/Al ratios and Al positions at the reaction condition was simulated and compared.•Distribution density for CO ...and DME in FER zeolite with different Si/Al ratios and Al positions was investigated.•This study sets the stage for further study on the reaction mechanism of DME carbonylation.
The adsorption behavior of dimethyl ether (DME) and carbon dioxide (CO) on FER zeolite with different Si/Al ratios and Al positions was calculated. For pure CO or DME gas, the CO adsorption quantity rises near linearly with pressure, while the DME adsorption quantity firstly rises rapidly but then rises much moderately at higher pressure. For the CO-DME gas mixture, both CO and DME adsorption quantity rises rapidly but then rises much moderately at higher pressure. Further investigation reveals that CO and DME molecules are preferentially located in the 6-MR zone of the 8-MR channel.
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