Expansion Stage Research Articles

Transcriptomic-metabolomic analysis of magnesium-stimulated in peel coloration of Satsuma mandarin

Magnesium (Mg) has been found to promote the color change citrus peel, but the underlying mechanism remains unclear. In this study, Mg application treatment significantly increased the Mg content in the peel of Satsuma mandarin fruit during the expansion stage (90–150 days after flowering). Mg fertilizer treatment was also found to significantly reduce chlorophyll (Chl) a content and increase β, β-xanthophyll (β-cryptoxanthin, zeaxanthin, neoxanthin), and abscisic acid (ABA) content in the flavedo during the key period of color change in Satsuma mandarin (165–195 days after flowering). Under Mg fertilizer treatment, Chl biosynthesis genes (CitGGDR, CitCHLH, CitCHLM, CitCHL27, and CitPORA) was down-regulated and that of Chl degradation genes (CitNYC, CitPPH, CitPAO, and CitRCCR) was up-regulated, which resulted in a lower Chl content in the flavedo than the control. Moreover, Mg fertilizer treatment up-regulated carotenoid biosynthesis genes (CitPSY, CitPDS, CitZDS, CitLCYb1, CitLCYb2, CitZEP, CitNCED2, and CitNCED3), leading to the accumulation of β, β-xanthophyll and ABA in the flavedo. Mg fertilizer treatment also promoted sugar (mainly fructose, glucose, and sucrose) accumulation in fruit flavedo, which showed significant negative correlations with Chl, α-carotene, lutein, and β-carotene, but positive correlations with β, β-xanthophyll compositions, and ABA in the flavedo. An analysis integrating transcriptome and metabolome data revealed that Mg may promote the color change of Satsuma mandarin fruit flavedo by regulating various metabolic pathways related to peel coloration, such as sugar accumulation, Chl degradation, carotenoid and ABA biosynthesis, and carbon fixation. The results can explain the regulatory pathways and networks of Mg-induced citrus peel coloration.

Combined metabolomic and transcriptomic analysis reveals variation in phenolic acids and regulatory networks in the peel of sweet orange 'Newhall' (C. sinensis) after grafting onto two different rootstocks

Grafting plays a significant role in the biosynthesis of secondary metabolites in plants. In our study, we examined the impact of grafting on the phenolic acid biosynthesis in sweet orange 'Newhall' peel. Through transcriptome-metabolome analysis, we observed notable differences in total phenolic acid content between the two rootstocks [Poncirus trifoliata (ct) and C. junos Siebold ex Tanaka (cj)]. Total phenolic acid content reached its highest level during the later fruit expansion stage (347.27 µg · g−1 FW) in ct. The metabolome analysis identified 270 phenolic acids, out of which 24 were found to be influenced by rootstock grafting. The transcriptome analysis identified 8,562 differentially expressed genes (DEGs). Further analysis using KEGG and GO enrichment revealed that 36 structural genes enriched in the phenolic acid biosynthesis pathway and showed differential expression in ct and cj. Co-expression analysis indicated that the AP2/ERF-ERF and MYB family members exhibited the highest number of differences in ct and cj, suggesting their potential involvement in phenolic acid biosynthesis. Our findings provide insights into the differential accumulation mechanism of phenolic acids in sweet orange 'Newhall' peel after grafting with different rootstocks. These results enhance our understanding of the regulatory mechanisms underlying phenolic acid biosynthesis and offer valuable information for the effective utilization of citrus peel.

Extracellular vesicles derived from M1 macrophages enhance rat midpalatal suture expansion by promoting initial bone turnover and inflammation

BackgroundMidpalatal suture (MPS) expansion can be affected by many factors, and researchers have attempted to regulate the initial inflammatory stage of expansion to optimize clinical outcomes and their underlying mechanisms. This study aimed to investigate the potential effects and mechanisms of M1 macrophage small extracellular vesicles during rat MPS expansion.Materials and methodsRAW264.7 cells were induced to M1 or M2 polarization and, small extracellular vesicles were isolated from the polarized macrophages. Male Sprague–Dawley rats (6–7 weeks) were administered 70 ± 5 g expansion force devices for 7 days. Rats with expanders without force served as controls. M1/M2 small extracellular vesicles were injected into the MPS region (50 µg/day) in the M1 and M2 small extracellular vesicle-assisted groups, while 0.9% saline was injected into the expansion-only group. Suture width, bone mass, and morphological changes in the region of interest (ROI) were examined.ResultsThe M1 small extracellular vesicle-assisted group showed a significantly increased MPS suture width in vivo (P < 0.001), and less bone mass was observed in the ROI (P < 0.05). Histological examination showed that the M1 small extracellular vesicle-assisted group exhibited a wider palatal area and obvious fibrous tissue rearrangement. The expression of RANKL and the number of osteoclasts were increased (P < 0.01) in the bony edges, and the p65 protein expression was significantly higher (P < 0.001).ConclusionsM1 macrophage-derived small extracellular vesicles have a positive effect in MPS expansion and increase p65 protein content and RANKL expression, thus promoting bone turnover. This study may contribute to the clinical application of small extracellular vesicles in the expansion of the palatal suture.

Mechanical and seepage characteristics of polyvinyl alcohol fiber concrete under stress-seepage coupling

This study presents an experimental investigation of the coupled stress and seepage water pressure loading test conducted on polyvinyl alcohol (PVA) fiber concrete, which had undergone salt attack freeze-thaw (F-T) cycles. This study delves into the influence of the number of salt attack F-T cycles, as well as the magnitude of seepage water pressure, on the triaxial compression seepage mechanical properties and permeability evolution of the specimens. Additionally, the nuclear magnetic resonance (NMR), scanning electron microscope (SEM) and X-ray diffraction (XRD) test results were analyzed, revealing that sodium sulfate solution penetrates the interior of PVA fiber concrete and reacts with cement stone to form ettringite and gypsum, which initially fills and compacts the pore structure. The increased production of such compounds causes pore structure to expand, with the maximum number of mesopores and macropores increasing by 115.5%. Macroscopically, it was observed that the mass and peak strength of the specimens increased at the beginning of the cycle, and the initial permeability decreased. However, the opposite phenomenon occurred after 15 cycles. When seepage water pressure was increased from 1 MPa to 3 MPa, the crack initiation stress, crack damage stress, and peak stress of the specimens decreased by 13.1%, 16.9%, and 15.6% on average, respectively, and the initial permeability increased by 69.3% on average. The deformation process of PVA fiber concrete under stress-seepage coupling loading was divided into five stages, including the initial compaction stage, elastic deformation stage, crack initiation and stable propagation stage, crack unstable propagation stage, and post-peak deformation stage. Correspondingly, the permeability exhibited a rapid decline, followed by a relatively stable phase, a slow rise, a rapid rise, and a continuous increase. Besides, the relationship between permeability and volume strain in compression and expansion stages was clarified.

Spam Spoiler for Public and Private E-Mail Services

Abstract: In recent years, cyber security incidents have occurred frequently. In most of these incidents, attackers have used different types of spam email as a knock-on to successfully invade government systems, well-known companies, and websites of politicians and social organizations in many countries. The detection of spam mail from big email data has been paid public attention. However, the camouflage technology of spam mail is becoming more and more complex, and the existing detection methods are unable to confront the increasingly complex deception methods and the growing number of emails. In this project, we proposed to design a novel efficient approach named Spam Spoiler for big email data classification into four different classes: Normal, Fraudulent, Harassment, and Suspicious E-mails by using LSTM-based GRU. The new method includes two important stages, the sample expansion stage and the testing stage under sufficient samples. This project the LSTM-based GRU efficiently captures meaningful information from E-mails that can be used for forensic analysis as evidence. Experimental results revealed that Spam Spoiler performed better than existing ML algorithms and achieved a classification accuracy of 98% using the novel technique of LSTM with recurrent gradient units. As different types of topics are discussed in E-mail content analysis. Spam Spoiler effectively outperforms existing methods while keeping the classification process robust and reliable.

Effects of water and fertilizer deficit regulation with drip irrigation at different growth stages on fruit quality improvement of kiwifruit in seasonal arid areas of Southwest China

For a long time, seasonal drought occurs frequently in Southwest China, and the management of water and fertilizer in kiwifruit orchards has no quantitative standards, which seriously affects the yield and quality of kiwifruit. Therefore, the effects of water and fertilizer deficit regulation with drip irrigation (WFDRDI) on the quality of kiwifruit at different growth stages were explored to achieve water and fertilizer saving, and green and efficient production of kiwifruit. We select ‘Jin Yan’ kiwifruit and set two water deficit levels (WD20% and WD40%) and three fertilizer deficit levels (FD15%, FD30% and FD45%) at bud burst to leafing stage (stage I), flowering to fruit set stage (stage II), fruit expansion stage (stage III) and fruit maturation stage (stage IV), respectively, with a full irrigation and fertilization as the control treatment (CK) in 2017 and 2018. Results showed that the WFDRDI at stage II and III had significant effect on fruit physical quality of kiwifruit, specifically, the III-WD40%FD30% and III-WD20%FD45% treatments significantly increased fruit firmness by 13.62 and 15.59% (P<0.05), respectively; the II-WD40%FD15% and III-WD40%FD15% treatments significantly increased dry matter by 8.19 and 6.47% (P<0.05), respectively; the III-WD20%FD15% treatment significantly increased single fruit weight and fruit volume by 9.33 and 12.65% (P<0.05), respectively; the II-WD20%FD15% treatment significantly increased fruit water content by 1.99% (P<0.05). The WFDRDI had an obvious effect on fruit chemical quality of kiwifruit. The III-WD20%FD45%, IV-WD40%FD15% and IV-WD20%FD30% treatments significantly increased vitamin C (Vc) content by 69.96, 36.96 and 34.31% (P<0.05), respectively; the III-WD40%FD15% and IV-WD40%FD15% treatments significantly increased total soluble solid (TSS) content by 3.79 and 17.05% (P<0.05), respectively, and significantly increased soluble sugar content by 28.61 and 34.79% (P<0.05), respectively; the contents of fructose, glucose and sucrose also had a significantly increasing trend, which was increased significantly by 5.58–19.63%, 40.55–60.36% and 54.03–54.92% in the III-WD40%FD15% and IV-WD40%FD15% treatments (P<0.05), respectively; sugar–acid ratio was increased significantly in the IV-WD40%FD15% treatment by 64.65% (P<0.05). The degree and duration of water and fertilizer deficit had a comprehensive effect on fruit quality of kiwifruit. The WFDRDI at stage II and III contribute to improving fruit physical quality, and the threshold of water and fertilizer deficit were 20 and 15%, respectively; stage III and IV are the critical periods for improving fruit chemical quality by water and fertilizer coupling effect, and the threshold of water and fertilizer deficit were 40 and 15%, respectively. Therefore, aiming at precise water and fertilizer saving, the I-WD20%FD30%, II-WD40%FD15%, III-WD40%FD15% and IV-WD40%FD15% treatments under WFDRDI during the whole growth period of kiwifruit were the best mode to improve quality and production of kiwifruit.

Thermodynamic and Economic Analysis of a Liquid Air Energy Storage System with Carbon Capture and Storage for Gas Power Plants

Liquid air energy storage (LAES) technology is helpful for large-scale electrical energy storage (EES), but faces the challenge of insufficient peak power output. To address this issue, this study proposed an efficient and green system integrating LAES, a natural gas power plant (NGPP), and carbon capture. The research explores whether the integration design is theoretically feasible for future adoption in operating the LAES system and NGPP. The effect of the charging pressure, the number of air expansion stages, and electricity prices on the overall thermodynamic and economic characteristics are investigated. The round-trip efficiency and the exergy round-trip efficiency of the proposed system are 47.72% and 69.74%, respectively. The calculations show that the minimum dynamic payback period for such a project is 3.72 years, and the lowest levelized cost of electricity is 0.0802 USD·kWh−1. This work provides a reference for peak-shaving power stations with energy storage and carbon capture.

Zanzalintinib in combination with immune checkpoint inhibitors: Design of the renal cell carcinoma expansion stage cohorts in STELLAR-002

Abstract Background: Zanzalintinib (XL092) is a novel, potent, orally bioavailable small molecule inhibitor of several receptor tyrosine kinases, including VEGFR2, MET, and the TAM kinases AXL, and MER. These receptor tyrosine kinases are implicated in several oncogenic processes, including tumor angiogenesis, proliferation, invasion, and metastasis. MET and AXL are known to play important roles in the development of resistance to antiangiogenic therapies. In addition, drugs targeting the TAM kinases are thought to promote an immune-permissive environment, potentially enhancing responses to immune checkpoint inhibitors (ICIs). This hypothesis has been confirmed in preclinical murine tumor models in which zanzalintinib in combination with an anti–PD-1 agent showed significantly greater antitumor and immunomodulatory activity, as well as a greater survival benefit, when compared with either agent alone (Hsu J, et al. Mol Cancer Ther 2023). In a phase 1 first-in-human study, zanzalintinib alone or in combination with atezolizumab showed a manageable safety profile and a half-life of 16–22 hours for zanzalintinib supporting once-daily dosing. The combination also showed promising clinical activity in patients with advanced or metastatic solid tumors, including renal cell carcinoma (RCC; Sharma MR, et al. ESMO 2022:Abs 481P). The encouraging preclinical and clinical activity support the evaluation of zanzalintinib in combination with ICIs in clinical studies, including STELLAR-304 (NCT05678673), a randomized study that is exploring the efficacy and safety of zanzalintinib in combination with nivolumab in patients with non-clear cell RCC (nccRCC). STELLAR-002 (NCT05176483) is another ongoing study assessing the safety and preliminary efficacy of zanzalintinib in multiple ICI combinations in patients with advanced solid tumors. Presented here is the study design of the cohort-expansion stage for patients with RCC in STELLAR-002. Methods: STELLAR-002 is a multicenter, open-label, phase 1b trial consisting of a dose-escalation stage and a tumor-specific cohort-expansion stage. The study is enrolling adults who have a cytologically or histologically confirmed solid tumor that is unresectable, locally advanced, or metastatic. In addition, patients with RCC enrolled in the expansion phase must have measurable disease per RECIST v1.1 as assessed by the investigator. The recommended doses of zanzalintinib plus nivolumab, zanzalintinib plus nivolumab and ipilimumab, and zanzalintinib plus nivolumab and relatlimab are being established in the dose-escalation stage of the study. The study includes three dose-expansion cohorts for patients with RCC: first-line clear cell RCC (ccRCC; Cohort 1), second-line ccRCC after 1 prior ICI-based combination therapy (Cohort 2), and first-line nccRCC (Cohort 6). The following regimens are available options for randomization at the recommended dose depending on the cohort: single-agent zanzalintinib (Regimen A), zanzalintinib plus nivolumab (Regimen B), zanzalintinib plus nivolumab and ipilimumab (Regimen C), or zanzalintinib plus nivolumab and relatlimab (Regimen D). Patients in Cohort 1 may be randomized to Regimens B, C, or D, patients in Cohort 2 to Regimens A, B, or D, and patients in Cohort 6 to Regimens A or B. The primary objectives of the cohort-expansion stage are objective response rate per RECIST v1.1 (as assessed by the investigator) and incidence and severity of adverse events, including serious and immune-mediated events. The trial is ongoing and enrolling patients from 13 countries in North America, Europe, and the Asia-Pacific region.

Second Chance Pell sets the stage for rapid expansion of prison college programs

Second Chance Pell sets the stage for rapid expansion of prison college programs

Second Chance Pell sets the stage for rapid expansion of prison college programs

WASHINGTON, D.C. — Higher education is in need of some good news. The Supreme Court has struck down affirmative action in college admissions and nixed President Biden's expansive idea to cancel $400 billion of student debt. Polls constantly show the public's faith in the importance of higher education is sliding, and to top it off, an enrollment cliff is imminent.

Study on characteristics of photovoltaic and photothermal coupling compressed air energy storage system

This paper studies the energy storage and generation characteristics of the photovoltaic power generation coupling compressed air energy storage system for the 5 kW base station, and analyzes the photovoltaic power generation characteristics within 24 h and its influence on the flow characteristics of the compressed air energy storage system. The results show that, affected by precipitation and sunlight, the compressed air energy storage power reaches highest value in May and August, and the compressed air flow and cooling water flow in a single day increase with the increase of light intensity. The power generation time reaches longest value in June, shortest in December, the energy storage time reaches longest in June and shortest in January. Considering the combined demand of cold energy, thermal energy and electric energy in actual production and life, the setting scheme of the compressed air energy storage system for combined cold heat power supply is obtained, and the parameter values such as compression/expansion stage, compression/expansion pressure ratio, temperature and pressure at the inlet and outlet of the compressor/expander/heat exchanger are defined. Adding solar thermal energy storage to the photovoltaic power generation compressed air energy storage system, it is found that it can effectively increase the air temperature and thus reduce the expansion stages required at a specific time.

Effects of Microbial Fertilizer on Physicochemical Properties and Bacterial Communities of Saline Soil Under Brackish Water Irrigation

The improvement of saline soil with microbial fertilizer has numerous advantages including high efficiency, green environmental protection, etc. At the same time, applying microbial fertilizer is an effective way to safely use brackish water. Based on the moderately saline soil in the Hetao irrigation area, four treatments of F1 (4500 kg·km-2), F2 (7500 kg·km-2), F3 (10500 kg·km-2), and CK without microbial fertilizer were applied under brackish water irrigation using Lycium barbarum as the indicator plants. The aim was to study the effects of different microbial fertilizer application rates on soil ions, soil moisture content, pH value, nutrients, and bacterial community in four key growth stages of L. barbarum (flowering stage, fruit expansion stage, full fruit stage, and deciduous stage). The results showed that, compared with that in CK, F1 only significantly decreased Na+ content in the first two growth stages (P<0.05), whereas F2 and F3 significantly decreased Na+ content in the whole growth period (P<0.05), with an average reduction of 33.66% and 57.98%, respectively, and F3 significantly increased soil moisture content (MC), organic matter (OM), alkaline hydrolysis nitrogen (AN), and available phosphorus (AP) contents (P<0.05) during the whole growth period. In the flourishing period of L. barbarum, the Shannon index of F3 increased by 4.41% compared with that of CK. The dominant bacterial phyla in the soil were Proteobacteria, Bacteroidetes, and Actinobacteria, and the dominant bacterial genera were Sphingomonas and Pseudomonas. The most abundant functions of bacterial communities in the study area were chemoheterotrophy and aerobic chemoheterotrophy, with an average relative abundance of 15.07% and 13.16%, respectively. The application of microbial fertilizer increased the chitinolysis function and chloroplast functions of soil bacteria, which F2 increased to the highest degree. Canonical correlation analysis (CCA) showed that MC, Na+, and OM were important factors affecting the composition of the bacterial community. The correlation heat map showed that MC was positively correlated with Planctomycetes (P<0.01), and Gp6 was positively correlated with AN (P<0.01). Compared with that in CK, the F3 treatment increased the relative abundance of Gp6 and optimized the community structure during the growth period. In conclusion, the application of 10500 kg·km-2 microbial fertilizer (F3 treatment) under brackish water irrigation could significantly reduce soil salinity, increase nutrients, and improve the diversity of the soil bacterial community structure, which is conducive to the safe utilization of brackish water and the maintenance of soil ecological health.

Experimental Study on Gaseous Moisture Absorption and Swelling of Red-Bed Mudstone in Central Sichuan, China under Different Relative Humidity Environments

Aiming to resolve the engineering hazards caused by the long-term micro-swelling of red-bed mudstone, gaseous moisture absorption-swelling tests under four ambient humidities were conducted (60%, 70%, 85% and 99%) by developing a set of experimental devices. Based on the moisture absorption characteristics of mudstone, the effects of a vapor pressure gradient on the equilibrium time, moisture absorption rate and swelling rate were discussed. Combined with its mineral composition and pore structure, the correlation mechanism between gaseous moisture absorption and swelling was explained in depth. The experimental results suggested that the whole process was long-term and slow. The swelling rate was lower than the moisture absorption rate by two orders of magnitude. As a result, the duration of a stable swelling strain was two orders of magnitude higher than that of a stable moisture absorption. The characteristic curve of moisture absorption went through three stages: the rapid stage, dominated by crystal layer adsorption; the intermittent expansion stage, dominated by adsorbed water film; and the decelerated stage, dominated by capillary condensation. In the intermittent expansion stage, as the relative humidity declined, the duration of an intermittency increased, and the number of intermittencies decreased. The evolution of the swelling rate obviously lagged the proportion of moisture absorption. This hysteresis effect reached its maximum when the moisture absorption transitioned from the intermittent expansion stage to the decelerated stage. Moreover, the equilibrium time, moisture absorption ratio and swelling strain all had a non-linear proportional relationship with the relative humidity. In this case, the critical value was 85%. Finally, a unified mathematical expression for the gaseous moisture absorption curve was acquired and the relationship between the swelling strain and the increment of moisture content was fitted; this will provide the necessary research basis for a subsequent simulation of its volume change under changing ambient humidity.

Genus Corydalis s. l. (Papaveraceae) in the flora of Ukraine: wild and cultivated taxa and the success of naturalization of alien species

Taxonomic composition of native and alien plants of the genus Corydalis s. l. in the flora of Ukraine has been analyzed. Based on literature, herbarium, inventory and other information, it was established for the first time that 3 native taxa (outside natural ranges) and 16 alien taxa of the genus Corydalis were recorded among ergasiophytes in botanical gardens and dendrological parks of Ukraine. The majority of these ergasiophytes (73.7 %) have not been preserved in the collections of living plants, indicating a low level of naturalization. The leading scientific center for the plant cultivation, where 82.4 % of alien taxa of the genus Corydalis have been cultivated, is the M. M. Gryshko National Botanical Garden of the National Academy of Sciences of Ukraine (Kyiv). Additionally, 4 alien taxa at different stages of naturalization were noted in the spontaneous flora of Ukraine. These include the ephemerophyte C. bracteata, colonophyte C. lutea, epecophyte C. cava subsp. marschalliana (outside the natural range) and hemiagryophyte C. caucasica. In the conditions of M. M. Gryshko National Botanical Garden and Syretsky Dendrological Park (Kyiv) ontogenetic structure of native coenopopulations of C. solida and introduced coenopopulations of naturalized alien taxa C. cava subsp. marschalliana and C. caucasica have been found. It was found that the coenopopulations of C. solida belong to the mature or aging types; C. cava subsp. marshalliana – to the young type; C. caucasica – young with a bias towards an invasive type. The highest density and a high seed germination in various coenotic conditions, which emphasizes the invasive nature of this species, distinguish coenopopulations of C. caucasica. Its expansion in the conditions of the M. M. Gryshko National Botanical Garden corresponds to the existing trend of the invasive spread of alien species from the southern regions, which is intensified by Global Climate Change. Due to the invasive activity of C. caucasica, this alien taxon, according to existing recommendations, should be considered as an invasive plant at the initial stage of expansion, so it should not be recommended for introduction to other countries and should be prevented from spreading in Ukraine.

The Roles of Hormone Signals Involved in Rhizosphere Pressure Response Induce Corm Expansion in Sagittaria trifolia.

Soil is the base for conventional plant growth. The rhizosphere pressure generated from soil compaction shows a dual effect on plant growth in agricultural production. Compacted soil leads to root growth stagnation and causes bending or thickening, thus affecting the growth of aboveground parts of plants. In arrowhead (Sagittaria trifolia L.), the corms derived from the expanded tips of underground stolons are its storage organ. We found that the formation of corms was significantly delayed under hydroponic conditions without rhizosphere pressure originating from soil/sand. In the initial stage of corm expansion, the anatomic structure of arrowhead corm-forming parts harvested from hydroponics and sand culture was observed, and we found that the corm expansion was derived from cell enlargement and starch accumulation. Comparative transcriptome analysis indicated that the corm expansion was closely related to the change in endogenous hormone levels. Endogenous abscisic acid and salicylic acid concentrations were significantly increased in sand-cultured corms. Higher ethylene and jasmonic acid contents were also detected in all arrowhead samples, demonstrating that these hormones may play potential roles in the rhizosphere pressure response and corm expansion. The expression of genes participating in hormone signaling could explain the rising accumulation of certain hormones. Our current results draw an extensive model to reveal the potential regulation mechanism of arrowhead corm expansion promoted by rhizosphere pressure, which will provide important references for further studying the molecular mechanism of rhizosphere pressure modulating the development of underground storage organs in other plants.

Soliton solutions of the equations of hydrodynamics in describing collisions and oscillations of atomic nuclei

The hydrodynamic approach was used to find an analytical solution of the hydrodynamic equations in the soliton approximation for layer collisions in the one- and two-dimensional cases. The compression stage, the decompression stage, and the expansion stage are considered within the framework of a single formula for layers with energies on the order of ten MeV per nucleon. Our generalization to the two-dimensional case leads to the idea of the formation of a rarefied bubble region at the stage of expansion. The approach can be used in other fields for calculations of the nonlinear dynamics of oscillations of complex systems.

Genetic Characteristics of the Baikal Seal Pusa sibirica Population.

Nucleotide sequence diversity in two mtDNA loci (the cytochrome b gene and the control region) was for the first time studied in the Baikal seal Pusa sibirica with the use of several spatiotemporal samples. The population was found to be evolutionarily young and to be in the stage of demographic expansion.

Технологические режимы раздачи и обжима при локальном нагреве

The processes of spread and reduction of a heated rough piece under visco-plasticity conditions are viewed. The ratio for force stress calculating in operations, damage to the material of the rough pieces is obtained. In the branches of special en-gineering, high-strength alloys based on titanium and aluminum are used. In the branches of special engineering, high-strength alloys based on titanium and aluminum are used. These alloys have mechanical properties anisotropy. Processing of these alloys is difficult. For this reason, the pressure treatment operation is performed with heating of the deformation zone. The material in the deformation zone exhibits viscous properties. Deformation hardening and softening (stress relaxa-tion) of the material take place simultaneously. Besides, the lower the deformation rate, the greater the softening. In this regard, a constitutive equation representing these processes is found. The factor of hardening and softening creates condi-tions for reducing the power mode of pressure treatment operations and increasing the degree of primary part forming. Stress relaxation calculation with the help of analytical dependencies is necessary at the stage of expansion and pressing development. The calculated ratios are recorded as a function of the speed of these operations. In this case, the specified deformation (the change in the degree of forming) is taken into account, adjusted depending on the speed and mechanical characteristics of the bearing alloy anisotropy. The calculated ratios are obtained under conditions of a flat voltage scheme, which corresponds to expansion and pressing. Stress equilibrium equation and yield condition of anisotropic material are used. The joint solutions of this equation and yield conditions determine values of the meridional and circumferential stress-es arising in the piece part material. The values of the stresses allow calculating the forces of operations. It is shown that the speed of expansion and pressing and mechanical properties anisotropy affect the damage to the material of the «green body». Dependences for the calculation of damage are obtained on the basis of energy and deformation strength criteria. These dependencies allow predicting the quality of products. It is also shown that anisotropy affects the technological modes of expansion and pressing. As the anisotropy coefficient increases, the stresses and forces of operations decrease. Calculations of stresses, forces and material damage in the process of expansion of anisotropic titanium alloy VT14 at 875 ℃ are made.

Molten pool air-liquid interface in high-power laser manufacturing: Evolution law and energy absorption characteristics

During modern high-power laser manufacturing, the laser beam-heat energy conversion mainly occurs in the air-liquid interface of laser-induced molten pool evaporation. The molten pool air-liquid interface's evolution law and laser energy coupling characteristics were performed by using in-situ optical observations and numerical simulation in this study. They revealed the four stages of this evolution process: preheating, expansion, oscillation, and contraction. In the expansion stage of the molten pool, the molten metal will flow from the center of the molten pool to the periphery due to the joint action of surface tension and laser-induced evaporation recoil pressure, and the air-liquid interface exhibits a middle depression. When the laser is turned off, the evaporative recoil pressure drop causes the molten pool's oscillation, which amplitude and duration positively correlate with laser power. Due to the effects of the solid state and the air-liquid interface depression after melting, the absorptivity first drops and then grows with the increase of laser power. Eventually, the melting efficiency increases with laser power.

The General Trends of Genetic Diversity Change in Alien Plants' Invasion.

Genetic diversity is associated with invasion dynamics during establishment and expansion stages by affecting the viability and adaptive potential of exotics. There have been many reports on the comparison between the genetic diversity of invasive alien species (IAS) in and out of their native habitats, but the conclusions were usually inconsistent. In this work, a standard meta-analysis of the genetic diversity of 19 invasive plants based on 26 previous studies was carried out to investigate the general trend for the change of IASs' genetic diversity during their invasion process and its real correlation with the invasion fate. Those 26 studies were screened from a total of 3557 peer-reviewed publications from the ISI Web of Science database during the period of January 2000 to May 2022. Based on the selected studies in this work, a general reduction of IASs' genetic diversity was found in non-native populations compared to that in native ones, while the difference was not significant. This finding suggested that regardless of the change in genetic diversity, it had no substantial effect on the outcome of the invasion process. Therefore, genetic diversity might not serve as a reliable indicator for risk assessment and prediction of invasion dynamic prediction in the case of IASs.