Controllable large-scale processing of temperature regulating sheath-core fibers with high-enthalpy for thermal management

Temperature regulating fibers(TRF_(s)) with high enthalpy and high form stability are the key factors for thermal management. However, the enthalpies of most TRFsare not high, and the preparation methods are still at the laboratory scale. It remains a great challenge to use industrial spinning equipment to achieve continuous processing of TRF_(s) with excellent thermal and mechanical properties. Here, polyamide 6(PA6) based TRF_(s) with a sheath-core structure were prepared by bicomponent melt-spinning. The sheath-core TRF(TRF_(sc)) are composed of PA6 as sheath and functional PA6 as core, which are filled with the shape stable phase change materials(ssPCM),dendritic silica@polyethylene glycol(SiO_(2)@PEG). With the aid of the sheath structure, the filling content of SiO_(2)@PEG can reach 30 %, so that the enthalpy of the TRF_(s) can be as high as 21.3 J/g. The ultra-high enthalpy guarantees the temperature regulation ability during the alternating process of cooling and heating. In hot environment, the temperature regulation time is 6.59 min, and the temperature difference is 12.93℃. In addition, the mechanical strength of the prepared TRF_(sc) reaches 2.26 cN/dtex, which can fully meet its application in the field of thermal management textiles and devices to manage the temperature regulation of the human body or precision equipment, etc.

Surface Thermal Environment and Water Temperature Regulation of Rapidly Developing Small and Medium-Sized Cities

[Objective] This study aimed to investigate the temperature regulation effect of surface thermal environment and waters on the temperature, as well as the influencing factors, in Binzhou City, Shandong Province, so as to provide scientific basis for layout planning of urban waters. [Method] Based on the Landsat image of 2009 and 2014, the surface temperature was retrieved using mono-window algorithm and the distribution characteristics of surface temperature of different land types were analyzed. By arranging temperature points on the temperature line and water characteristic statistics, the temperature regulation effect of waters, as well as the influencing factors was analyzed. [Result](1) The order of surface temperature of different land types in summer was building land > cultivated land > woodland > water body, while in winter, the order was cultivated land > woodland > building land > water body. In terms of summer-winter average thermal level, the order was building land > cultivated land > woodland > water body.(2) The temperature regulation effect of waters showed a strong nonlinear relationship with the distance.(3) Large-area water bodies had better cooling effect. Under the condition of same area, the temperature regulated area of multiple small-area water bodies was larger than that of single large-area water body.(4) The increase in the proportion of non-building land around the water body increased the range of water cooling.(5) When the area of water bodies was small, the smaller the ratio of perimeter to area was, the larger the influence range of water cooling was. [Conclusion] The temperature regulation effect of waters in Binzhou City showed a strong nonlinear relationship with the distance, and was affected by the size of the water body, the complexity of the boundary and the composition of the surrounding land.

Temperature Regulation Effect of Desert Vegetation in Minqin Desert Area

[ Objective] The paper was to study the effects of desert vegetation on temperature regulation and stabilization in desert area. [ Method] The survey data of quadrats in five kinds of plant communities in Minqin desert area were preliminarily estimated. [Result] Desert vegetation had the ecological functions of regulating desert temperature and stabilizing sharp increase of temperature, especially the irreplaceable ecological function of slowing down sandstorm each spring in northwest China compared to physical sand-fixatian measures. The air humidity in forest region was relatively large, and the climate was more stable. The climate in desert area was dry, with intense changes in air temperature. Although the solar radiation utilization rate of desert vegetation per unit area in Minqin oasis fringe was 5.8% of that of 100% coverage vegetation, it had non-ignorable significance in regulating temperature of local desert. Regulating temperature was one of the ecological functions of desert vegetation. Previous studies only considered wind proof and sand-fixation functions of desert vegetation, but ignored its temperature regulation effect, and this was the ecological function of vegetation sand control different from physical sand-fixation measures such as sand barrier. [ Conclusion] It has important theoretical guiding significance and practical use value for prevention and control of desertification by studying ecological function of desert plants/vegetation.

Simulating Experiment for Temperature Field of Frozen Subgrade Using RegulationTubes

The main factors that influence the temperature field of frozen subgrade were analyzed.The experimental equipment for simulating frozen subgrade was built up,and the declining regulating tubes were placed at the foot of the embankment. By means of this equipment two simulating experiments of controlling temperature filed of frozen sub- grade were carried out in the laboratory.One method is to collect natural cold energy,and the other one is to collect natural cold energy ccompanied by artificial refrigeration simultaneously.The result indicates that the latter is an ef- fective method for maintaining the stability of the frozen subgrade.

The Effects of Thickness and Location of PCMon the Building’s Passive Temperature-Control–A Numerical Study

Building energy consumption and building carbon emissions both account for more than 20%of their total national values in China.Building employing phase change material(PCM)for passive temperature control shows a promising prospect in meeting the comfort demand and reducing energy consumption simultaneously.However,there is a lack of more detailed research on the interaction between the location and thickness of PCM and indoor natural convection,as well as indoor temperature distribution.In this study,the numerical model of a passive temperature-controlled building integrating the developed PCM module is established with the help of ANSYS.In which,the actual weather condition of Beijing city is set as the boundary conditions and the indoor natural convection is simulated with the consideration of radiation model.The effects of PCM’s thickness and location on the internal temperature field are analyzed and discussed.The results show that the room could maintain within the human comfort temperature range with the longest ratio of 94.10%and the shortest ratio of 51.04%as integrating PCM.In comparison,the value is only 26.70%without PCM.The room’s maximum temperature fluctuation can also be improved;it could be lowered by 64.4%compared to the normal condition.When the quantity of PCM is sufficient,further increasing the PCM amount results in a temperature fluctuation reduction of less than 0.1°C and does not increase the comfort time.Placing PCM on the wall induces an apparent variation in indoor temperature along the vertical direction.Conversely,placing PCM on the roof can lead to a heat transfer rate difference of up to seven times.The optimal placement of PCM depends on the difference between the environmental and phase change temperatures.If the difference is positive,placing PCM on the roof is more effective;conversely,the opposite holds.According to the results over the entire cycle,PCM application on vertical walls yields better performance.The significant difference in natural convection caused by the same thickness of PCM but different application positions,coupled with the influence of air movement on the melting and solidification of PCM,further impacts indoor temperature fluctuations and comfort.This study can provide guidance for the application location and thickness of PCM,especially for scenarios where temperature regulation is required at a specific time.

Improved germination of threatened medicinal Prunus africana for better domestication: effects of temperature, growth regulators and salts

Prunus africana is an endangered medicinal species and has been classified as a priority for domestication in Cameroon.However,the seeds rapidly lose their viability during storage at room temperature after 2–3 months.This study aimed to improve seed germination of P.africana by germinating at different temperatures(4℃,28℃)using different concentrations of growth stimulators(sodium nitrate and gibberellic acid)and different concentrations of salts.P.africana seeds had 91.7%germination at 4C after 1 month of storage.Growth regulators considerably influenced germination after 6 months and reached 66.0%with 10 mM gibberellic acid and 100%with 10 mM sodium nitrate.Approximately three shoots per seed were developed,an indication of polyembryony.Histochemical analyses revealed the presence of protein-like bodies close to the embryo axis and accumulations of starch after 7 days of germination.After 14 days,amyloplasts and dark protein bodies of various sizes were observed.The outcome of this study will contribute to improve the germination of P.africana for better domestication and conservation.

Gate-regulated transition temperatures for electron hopping behaviours in silicon junctionless nanowire transistors

We investigate gate-regulated transition temperatures for electron hopping behaviours through discrete ionized dopant atoms in silicon junctionless nanowire transistors.We demonstrate that the localization length of the wave function in the spatial distribution is able to be manipulated by the gate electric field.The transition temperatures regulated as the function of the localization length and the density of states near the Fermi energy level allow us to understand the electron hopping behaviours under the influence of thermal activation energy and Coulomb interaction energy.This is useful for future quantum information processing by single dopant atoms in silicon.

Plant Growth Regulators, Light and Temperature Influenced Micropropagation and Successful Field Establishment of Vernonia amygdalina Del.

Vernonia amygdalina Del. is a tropical species susceptible to frost which is an annual phenomenon of the winter season of the Eastern Cape. Limited populations of the species arc in the province dieback during the winter period, thereby making large scale cultivation through conventional vegetative propagation impossible. In our effort to increasing the population of the species within the province, a micropropagation approach through tissue culture teehnology was employed. Two growth regulators （BAP ＆ NAA） were tested at four levels of concentration under continuous light and dark conditions. Plantlets were subsequently transferred to the field after acclimatization at different temperature conditions. The result of the study showed that BAP generally performs better than NAA for callus induction under continuous darkness, while direct micropropagation of shoot under continuous light condition at I mg L^-1BAP showed the best result. To achieve greater success for the rapid multiplication of the species, this study further demonstrates that the optimum temperature range for acclimatizing the species prior to the transfer of the plantlet to the field is between 23 ±3 ℃.

Mechanism of Photothermal Energy on the Growth and Yield of Rice under Water Level Regulation

The flooding caused by heavy rainfall in rice irrigation area and the drought caused by the drop of groundwater level are the research focus in the field of irrigation and drainage.Based on the comparative experiment and farmland water level control technology,this paper studied the average soil temperature under different soil layers(TM),the daily temperature change(TDC),the photosynthetic accumulation of single leaf and canopy in rice,and response of photothermal energy to rice root characteristics and growth factors in the paddy field under drought conditions.The results showed that the peak soil temperature under drought treatment was basically synchronous with the conventional irrigation,and the it was delayed by 2–6 h under flooding treatment compared to the drought treatment.Under different water gradients,the temperature decreased according to T_(L)>T_(CK)>T_(H)(L,H and CK represented water flooding,drought and control treatments),and the TDC was opposite.In addition to milky stage,the daily photosynthetic(Pn)accumulation of single leaf and canopy in the flooding and drought treated paddy fields were lower than conventional irrigation,and had a negative impact on leaf area index(LAI)and yield(YR),but did not form fatal damage.The root characteristic factors,RL(root length),RW(root weight),R-CR(root-canopy ratio)were promoted with drought,and YR under light drought was slightly higher than that under heavy drought.There was a strong positive correlation between TM and R-CR in all rice growth stages,while TDC-5 was negatively correlated with effective panicle number,TDC and R-CR in 20 cm soil layer were positively correlated.The correlation between daily Pn accumulation and YR was low,and the correlation between Pn and YR factors was negative or weak positive or negative.The total Pn was positively correlated with yield factors,and the correlation coefficient was higher than that of daily Pn.

Valuation of Air Regulation Service Value in the Honghu Lake Wetland

To assess the value of air regulation in the Honghu Lake Wetland,a quantitative study was conducted based on existing literatures. Results showed that the total service value of air regulation in the Honghu Lake Wetland was 254. 52 million yuan/a,which was 11. 6 times of that by previous studies. The net value of fixed greenhouse gases via wetland plants( including carbon emission value from methane emission conversion into carbon dioxide greenhouse gas effect) was 58. 50 million yuan/a,the data indicated that this lake wetland was a strong carbon sink. The value of oxygen released by the wetland ecosystem was 176. 51 million yuan/a,and the value of regulating air humidity and temperature was 19. 51 million yuan/a. The net value of greenhouse gases fixed by the Honghu Lake Wetland vegetation,the value of released oxygen,and the value of lifting air humidity and temperature regulation accounted for 22. 98%,69. 35%,and 7. 70% of the total value of the air regulation services,respectively.

Expression responses of five cold tolerant related genes to two temperature dropping treatments in sea cucumber Apostichopus japonicus

Environmental conditions, including ambient temperature, play important roles in survival growth development, and reproduction of the Japanese sea cucumber, Apostichopus japonicus. Low temperatures result in slowed growth and skin ulceration disease. In a previous study, we investigated the effect of low temperature on gene expression profiles inA.japonicus by suppression subtractive hybridization （SSH）. Genes encoding Ferritin, Lysozyme, Hsp70, gp96, and AjToll were selected from a subtracted cDNA library of A. japonicus under acute cold stress. The transcriptional expression profiles of these genes were investigated in different tissues （coelomocyte, respiratory tree, intestine, longitudinal muscle） after exposure to acute and mild temperature dropping treatments. The results show that （1） the five cold-tolerance-related genes were found in all four tissues and the highest mRNA levels were observed in coelomocyte and respiratory tree; （2） under the temperature dropping treatments, three types of transcriptional regulation patterns were observed： primary suppression followed by up-regulation at -2℃, suppressed expression throughout the two treatments, and more rarely an initial stimulation followed by suppression; and （3） gene expression suppression was more severe under acute temperature dropping than under mild temperature dropping treatment. The five cold-tolerance-related genes that were ,distributed mainly in coelomocyte and respiratory tissues were generally down-regulated by low temperature stress but an inverse up-regulation event was found at the extreme temperature （-2℃）.

Adaptive output-feedback power-level control for modular high temperature gas-cooled reactors

Small modular reactors(SMRs) are beneficial in providing electricity power safely and viable for specific applications such as seawater desalination and heat production. Due to its inherent safety feature, the modular high temperature gas-cooled reactor(MHTGR) is considered as one of the best candidates for SMR-based nuclear power plants. Since its dynamics presents high nonlinearity and parameter uncertainty, it is necessary to develop adaptive power-level control, which is beneficial to safe, stable, and efficient operation of MHTGR and is easy to be implemented. In this paper, based on the physically-based control design approach, an adaptive outputfeedback power-level control is proposed for MHTGRs. This control can guarantee globally bounded closedloop stability and has a simple form. Numerical simulation results show the correctness of the theoretical analysis and satisfactory regulation performance of this control.

Metamaterial terahertz device with temperature regulation function that can achieve perfect absorption and complete reflection conversion of ultrawideband

The field of terahertz devices is important in terahertz technology.However,most of the current devices have limited functionality and poor performance.To improve device performance and achieve multifunctionality,we designed a terahertz device based on a combination of VO_(2)and metamaterials.This device can be tuned using the phase-transition characteristics of VO_(2),which is included in the triple-layer structure of the device,along with SiO_(2)and Au.The terahertz device exhibits various advantageous features,including broadband coverage,high absorption capability,dynamic tunability,simple structural design,polarization insensitivity,and incidentangle insensitivity.The simulation results showed that by controlling the temperature,the terahertz device achieved a thermal modulation range of spectral absorption from 0 to 0.99.At 313 K,the device exhibited complete reflection of terahertz waves.As the temperature increased,the absorption rate also increased.When the temperature reached 353 K,the device absorption rate exceeded 97.7%in the range of 5-8.55 THz.This study used the effective medium theory to elucidate the correlation between conductivity and temperature during the phase transition of VO_(2).Simultaneously,the variation in device performance was further elucidated by analyzing and depicting the intensity distribution of the electric field on the device surface at different temperatures.Furthermore,the impact of various structural parameters on device performance was examined,offering valuable insights and suggestions for selecting suitable parameter values in real-world applications.These characteristics render the device highly promising for applications in stealth technology,energy harvesting,modulation,and other related fields,thus showcasing its significant potential.

A Temperature-Based Hysteresis Buck Converter for Dynamic Current Sharing

In this study, a temperature-based current sharing strategy rather than equal sharing for loads was applied to promote the reliability of uninterruptible power systems (UPS). According to the temperature of each power supply module in a UPS, it would be better to reduce the output current ratio for a hotter supply module in the UPS. In this design, we implemented our regulation circuits by the UMC 0.25-μm CMOS technology with an input range from 3 V to 4.2 V and the regulated output at 1.1 V. The rated output current was 100 mA for each phase. We also employed a current-mode error-correction circuit to improve the current sharing performance based on the averaged current of each phase at the same temperature. According to our simulation results, the current sharing error can be restricted within ± 5% for the supply modules at the same temperature in our system.

Transcriptional Regulation of the Ambient Temperature Response by H2A.Z Nucleosomes and HSF1 Transcription Factors in Arabidopsis

Temperature influences the distribution, range, and phenology of plants. The key transcriptional activators of heat shock response in eukaryotes, the heat shock factors （HSFs）, have undergone large-scale gene amplification in plants. While HSFs are central in heat stress responses, their role in the response to ambient temperature changes is less well understood. We show here that the warm ambient temperature transcriptome is dependent upon the HSFA1 clade ofArabidopsis HSFs, which cause a rapid and dynamic eviction of H2A.Z nucleosomes at target genes. A transcriptional cascade results in the activation of multiple downstream stress-responsive transcription factors, triggering large-scale changes to the transcriptome in response to elevated temperature. H2A.Z nucleosomes are enriched at temperature-responsive genes at non-inducible temperature, and thus likely confer inducibility of gene expression and higher responsive dynamics. We propose that the antagonistic effects of H2A.Z and HSF1 provide a mechanism to activate gene expression rapidly and precisely in response to temperature, while preventing leaky transcription in the absence of an activation signal.

Translational Regulation of Plant Response to High Temperature by a Dual-Function tRNAHls Guanylyltransferase in Rice

As sessile organisms,plants have evolved numerous strategies to acclimate to changes in environmental temperature.However,the molecular basis of this acclimation remains largely unclear.In this study we identified a tRNAHis guanylyltransferase,AET1,which contributes to the modification of pre-tRNAH,s and is required for normal growth under high-temperature conditions in rice.Interestingly,AET1 possibly interacts with both RACK1A and elF3h in the endoplasmic reticulum.Notably,AET1 can directly bind to OsARF mRNAs including the uORFs of OsARF19 and OsARF23,indicating that AET1 is associated with translation regulation.Furthermore,polysome profiling assays suggest that the translational status remains unaffected in the aet1 mutant,but that the translational efficiency of OsARF19 and OsARF23 is reduced;moreover,OsARF23 protein levels are obviously decreased in the aet1 mutant under high temperature,implying that AET1 regulates auxin signaling in response to high temperature.Ourfindings provide new insights into the molecular mechanisms whereby AET1 regulates the environmental temperature response in rice by playing a dual role in tRNA modification and translational control.

Interaction between temperature and photoperiod in regulation of flowering time in rice

Photoperiod and temperature are two pivotal regulatory factors of plant flowering. The floral transition of plants depends on accurate measurement of changes in photoperiod and temperature. The flowering time of rice （Oryza sativa） as a facultative short-day （SD） plant is delayed under long-day （LD） and/or low temperature conditions. To elucidate the regulatory functions of photoperiod and temperature on flowering time in rice, we systematically analyzed the expression and regulation of several key genes （Hd3a, RFT1, Ehdl, Ghd7, RID1/Ehd2/OsIdl, Se5） involved in the photoperiodic flowering regulatory pathway under different temperature and photoperiod treatments using a photoperiod-insensitive mutant and wild type plants. Our re- sults indicate that the Ehdl-Hd3a/RFT1 pathway is common to and conserved in both the photoperiodic and temperature flow- ering regulatory pathways. Expression of Ehdl, Hd3a and RFT1 is dramatically reduced at low temperature （23~C）, suggesting that suppression of Ehdl, Hd3a and RFT1 transcription is an essential cause of delayed flowering under low temperature con- dition. Under LD condition, Ghd7 mRNA levels are promoted at low temperature （23~C） compared with normal temperature condition （28℃）, suggesting low temperature and LD treatment have a synergistic role in the expression of Ghd7. Therefore, upregulation of Ghd7 might be a crucial cause of delayed flowering under low temperature condition. We also analyzed Hdl regulatory relationships in the photoperiodic flowering pathway, and found that Hdl can negatively regulate Ehdl transcription under LD condition. In addition, Hdl can also positively regulate Ghd7 transcription under LD condition, suggesting that the heading-date of rice under LD condition is also regulated by the Hdl-Ghd7-Ehdl-RFT1 pathway.

Regulation of Calvin-Benson cycle enzymes under high temperature stress

The Calvin Benson cycle(CBC)consists of three critical processes,including fixation of CO_(2) by Rubisco,reduction of 3-phosphoglycerate(3PGA)to triose phosphate(triose-P)with NADPH and ATP generated by the light reactions,and regeneration of ribulose 1,5-bisphosphate(RuBP)from triose-P.The activ-ities of photosynthesis-related proteins,mainly from the CBC,were found more significantly affected and regulated in plants challenged with high temperature stress,incuding Rubisco,Rubisco activase(RCA) and the enzymes involved in RuBP regeneration,such as sedoheptulose-1,7-bisphosphatase(SBPase).Over the past years,the regulatory mechanism of CBC,especially for redox-regulation,has attracted major interest,because balancing flux at the various enzymatic reactions and maintaining metabolite levels in a range are of critical importance for the optimal operation of CBC under high temperature stress,providing insights into the genetic manipulation of photosynthesis.Here,we summarize recent progress regarding the identification of various layers of regulation point to the key enzymes of CBC for acclimation to environmental temperature changes along with open questions are also discussed.

STUDY OF HIGH-STABILITY CURRENT REGULATORS FOR CURRENT FROM 0.1A TO 8A

Improving the temperature stability and widening the constant current range are two important problems to be solved in the application of the current regulators. This paper introduces a modular approach for the design of the current regulator with a very wide current range. The test results show that their output current ranges from 0.1A to 8A, with its current temperature coefficient as low as 10-4/℃ to 10-5/℃ and limiting voltage lower than 0.4V.

Study on the Flowering Regulator of the Paeonia suffruticosa ＂Hongdan Lan＂

In the study, Southwest peony varieties group of Paeonia suffruticosa ＂Hongdan Lan＂ were analyzed, test was mainly divided into two parts, one is the nature of the low temperature, through the external environment is mainly （temperature, light） gibberellin and nutrition solution regulation, on the Tianpeng peony florescence control technological research. The second is to explore the flower forcing peony after anthesis regeneration technique. The main research results： comprehensive gibberellin peony flower induction of morphological and physiological indexes, such as gibberellin concentration of 150 mgFL and 200 mg/L the effect of flower induction was better than the other treatments; gibberelin （GA3） breaking the dormancy of the peony to blossom ahead of time has the promoter action, also has certain effect on nutritional growth; to premature flowering the abscisic acid （ABA） has opposite effect; whereas auxin （IAA） and corn （ZT） effect was not obvious; rejuvenation results showed that after a year of conservation and managemental measures, flower induction after the flower of peony played a very important role in the restoration. After the winter flower induction, peony flowerpot of soil hardening, through the soil replacement, repair of roots, flower peony recovery showed a very significant effect.