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.

A Skin-Inspired Self-Adaptive System for Temperature Control During Dynamic Wound Healing

The thermoregulating function of skin that is capable of maintaining body temperature within a thermostatic state is critical.However,patients suffering from skin damage are struggling with the surrounding scene and situational awareness.Here,we report an interactive self-regulation electronic system by mimicking the human thermos-reception system.The skin-inspired self-adaptive system is composed of two highly sensitive thermistors(thermal-response composite materials),and a low-power temperature control unit(Laserinduced graphene array).The biomimetic skin can realize self-adjusting in the range of 35–42℃,which is around physiological temperature.This thermoregulation system also contributed to skin barrier formation and wound healing.Across wound models,the treatment group healed~10%more rapidly compared with the control group,and showed reduced inflammation,thus enhancing skin tissue regeneration.The skin-inspired self-adaptive system holds substantial promise for nextgeneration robotic and medical devices.

A TAXONOMICAL AND ECOLOGICAL OVERVIEW OF RECENT AND HOLOCENE OSTRACODES OF THE NAM CO REGION, SOUTHERN TIBET

We present a list of living and (sub) fossil Ostracoda (Crustacea) from Holocene sediments from Lake NamCo,Southern Tibet, including descriptions, distribution and ecological data of the important taxa from the Nam Cocatchment. Species associations from lake surface sediments, sediment cores and outcrop samples consist of eight speciesincluding Candona candida ( O.F. Müller, 1776 ) , Candona xizangensis ( Huang, 1982 ) , Eucypris afghanistanensis( Hartmann, 1964) , Fabaeformiscandona danielopoli ( Yin & Martens, 1997 ) , Ilyocypris cf. mongolica ( Martens, 1991 ) ,? Leucocythere dorsotuberosa ( Huang, 1982 ) , Leucocytherella sinensis ( Huang, 1982 ) and Limnocythere inopinata ( Baird,1843). The dominant species are ? L. dorsotuberosa and L. sinensis. They show morphological variations with different degreesof ornamentation. We regard the variable noding and rib formation as intraspecific variability possibly driven byenvironmental factors. In general,the number and degree of ribs increases with water depth in ? L. dorsotuberosa. Thus,theornamentation may present a means to reconstruct(paleo) water depths. Our list is intended to serve as a taxonomical andpaleoecological primer for future paleolimnological work.

Prediction of adolescent subjective well being: A machine learning approach

Background Subjective well-being(SWB),also known as happiness,plays an important role in evaluating both mental and physical health.Adolescents deserve specific attention because they are under a great variety of stresses and are at risk for mental disorders during adulthood.Aim The present paper aims to predict undergraduate students1 SWB by machine learning method.Methods Gradient Boosting Classifier which was an innovative yet validated machine learning approach was used to analyse data from 10518 Chinese adolescents.The online survey included 298 factors such as depression and personality.Quality control procedure was used to minimise biases due to online survey reports.We applied feature selection to achieve the balance between optimal prediction and result interpretation.Results The top 20 happiness risks and protective factors were finally brought into the predicting model.Approximately 90%individuals'SWB can be predicted correctly,and the sensitivity and specificity were about 92%and 90%,respectively.Conclusions This result identifies at-risk individuals according to new characteristics and established the foundation for adolescent prevention strategies.

Active Control of Sound Transmission in Ship Cabins Through Multiple Independently Supported Flexible Subplates

The vibration and noise produced by the powertrain and waves inside ship cabins limit working efficiency and crew and passengers’accommodation quality.This paper simplifies ship cabins as cavities and explores active control techniques to attenuate sound transmission via multiple parallel-supported flexible subplates.The theoretical formulations of the interaction between multiple subplates and cavities were performed and the coupling relationships between them were analyzed.Based on the multiple subplates and the cavity coupling models,numerical simulations were performed using the derived optimal controller to minimize the transmission of sound into the cavities through two and nine parallel-supported subplates.The various control strategies were explored to minimize the coupling system’s acoustic potential energy,and the control performances were compared and discussed.The mechanism of reducing sound transmission through multiple supported subplates into a cavity is revealed.The simulation results showed that the vibration pattern of the controlled subplate is changed after it is regulated,which increases its radiation to subdue the other subplates’radiation,while increasing vibration of the controlled subplate.The more subplates a cavity has,the more kinetic energy the controlled subplate possess.Furthermore,the noise reduction performance of a cavity with fewer subplates is better than that with more subplates.

Homojunction structure amorphous oxide thin film transistors with ultra-high mobility

Amorphous oxide semiconductors(AOS)have unique advantages in transparent and flexible thin film transistors(TFTs)applications,compared to low-temperature polycrystalline-Si(LTPS).However,intrinsic AOS TFTs are difficult to obtain field-effect mobility(μFE)higher than LTPS(100 cm^(2)/(V·s)).Here,we design ZnAlSnO(ZATO)homojunction structure TFTs to obtainμFE=113.8 cm^(2)/(V·s).The device demonstrates optimized comprehensive electrical properties with an off-current of about1.5×10^(-11)A,a threshold voltage of–1.71 V,and a subthreshold swing of 0.372 V/dec.There are two kinds of gradient coupled in the homojunction active layer,which are micro-crystallization and carrier suppressor concentration gradient distribution so that the device can reduce off-current and shift the threshold voltage positively while maintaining high field-effect mobility.Our research in the homojunction active layer points to a promising direction for obtaining excellent-performance AOS TFTs.

Convergence of a Sinusoidal Series with an Infinite Integral

In this paper, we study the relationship between the convergence of the sinusoidal series and the infinity integrals (any real number α ∈[0,1], parameter p > 0). First of all, we study the convergence of the series (any real number α ∈[0,1], parameter p > 0), mainly using the estimation property of the order to obtain that the series diverges when 0 p ≤1-α, the series converges conditionally when 1-α p ≤1, and the series converges absolutely when p >1. In the next part, we study the convergence state of the infinite integral (any real number α ∈[0,1], parameter p > 0), and get that when 0 p ≤1-α, the infinite integral diverges;when 1-α p ≤1, the infinite integral conditionally converges;when p >1, the infinite integral absolutely converges. Comparison of the conclusions of the above theorem, it is not difficult to derive the theorem: the level of and the infinity integral with the convergence of the state (any real number α ∈[0,1], the parameter p >0), thus promoting the textbook of the two with the convergence of the state requires the function of the general term or the product of the function must be monotonically decreasing conditions.

聚集诱导发射光笼分子的设计合成及原位光激活成像研究

通过将1,2,4,5-四氮嗪基团引入到聚集诱导发射(AIE)荧光团上,制备了两个光激活的荧光小分子化合物TPA-Tz1和TPA-Tz2.光激活后, TPA-Tz1和TPA-Tz2的荧光强度分别增强了167倍和100倍.光激活的原理是光照导致四氮嗪基团转化为氰基,从而恢复荧光发射.通过密度泛函理论(DFT)计算,TPA-Tz1的猝灭机理为能量转移至暗态(ETDS). TPA-Tz1的激活产物TPA-CN1具有独特的AIE特点,其聚集态分子间发生的电荷转移是导致聚集态荧光蓝移的主要原因.通过溶剂挥发法获得的TPA-Tz1晶体结构揭示了其内部复杂的堆叠结构,氢键和C—H…π作用代替π-π相互作用是同时维持晶格稳定和AIE特性的重要原因.TPA-Tz1具有良好的生物相容性,其最高的细胞抑制率仅有25.3%.因此, TPA-Tz1在细胞水平和多细胞生物秀丽隐杆线虫体内实现了原位的光激活成像.

珠穆朗玛峰北坡桤木属大气花粉传输路径与来源

认识区域大气花粉组成及其形成条件有利于明确不同类型花粉组合的气候与环境意义。利用布卡大气花粉采样器在珠穆朗玛峰北坡开展了连续2年(2012—2013年)的大气花粉观测研究。基于后向轨迹和潜在来源区域模型,探讨了秋季主要组分桤木属花粉的传输路径与潜在来源区域,分析了桤木属花粉与其植物分布和大气环流的关系及气候指示意义。结果显示:(1)桤木属花粉季气团传输路径主要来自于采样点西南方向;(2)桤木属花粉潜在来源区域与其气团传输路径基本一致,主要是喜马拉雅山脉中段,包括尼泊尔中部和东部以及西藏南部等地区;(3)桤木属花粉数量、传输路径和来源区域的年际变化与大气环流有关,受高空西风影响的西南气团对桤木属花粉影响更大。研究结果可以为认识珠穆朗玛峰北坡外来花粉的气候意义提供科学依据。

非线性相依数据关联分析

度量和检验复杂数据非线性相依关系是统计学领域中的基本问题.在过去的一个多世纪里,非线性相依数据关联分析方法和理论取得了一些重要进展.本文讨论分布相依、均值相依和分位数相依3种不同关联关系;按照一维、多维到高维的顺序,介绍3种不同关联关系下所取得的部分重要研究进展;最后讨论这些关联分析方法和理论在高维数据变量筛选和模型检验中的应用.

Reconfigurable memlogic long wave infrared sensing with superconductors

Optical sensors with in-cell logic and memory capabilities offer new horizons in realizing machine vision beyond von Neumann architectures and have been attempted with two-dimensional materials,memristive oxides,phasechanging materials etc.Noting the unparalleled performance of superconductors with both quantum-limited optical sensitivities and ultra-wide spectrum coverage,here we report a superconducting memlogic long-wave infrared sensor based on the bistability in hysteretic superconductor-normal phase transition.Driven cooperatively by electrical and optical pulses,the device offers deterministic in-sensor switching between resistive and superconducting(hence dissipationless)states with persistence>105 s.This results in a resilient reconfigurable memlogic system applicable for,e.g.,encrypted communications.Besides,a high infrared sensitivity at 12.2μm is achieved through its in-situ metamaterial perfect absorber design.Our work opens the avenue to realize all-in-one superconducting memlogic sensors,surpassing biological retina capabilities in both sensitivity and wavelength,and presents a groundbreaking opportunity to integrate visional perception capabilities into superconductor-based intelligent quantum machines.

A Plasma Membrane Polarity Sensor Harnessing Conjoined Twisted Intramolecular Charge Transfer Modulation and Charge Number Control Strategy

Polarity is a critical microenvironmental factor of the plasma membrane,which can offer valuable insights into various biological processes.Herein,we proposed a novel strategy for the construction of fluorescent agents to measure plasma membrane polarity by conjoining twisted intramolecular charge transfer(TICT)modulation and charge number control.It is shown that compounds with a stronger TICT tendency are more sensitive to polarity shifts due to the number of dialkylated amino groups present(from 1 to 3),and the molecules with two or more charged centers remain in the plasma membrane.Therefore,we developed two fluorescent agents with high polarity sensitivity,excellent turn-on ratios,and superior ability,to target the plasma membrane.In the wash-free fluorescence imaging and fluorescence lifetime tests,our designed agent could detect plasma membrane polarity with high precision,allowing effective distinction between cancer cells and normal cells based on their differences in plasma membrane polarity.Moreover,both fluorescence and fluorescence lifetime changes of the plasma membrane in the ferroptosis model established by Sorafenib confirmed an increase in plasma membrane polarity during cell ferroptosis.

“亚洲水塔”的近期湖泊变化及气候响应:进展、问题与展望

青藏高原分布的众多封闭湖泊是'亚洲水塔'的重要组成部分.最近几十年,青藏高原的升温速率是全球平均升温速率的2倍,并且呈现了明显的降水增长.作为中低纬度分布的最大冰冻圈系统,青藏高原的气温和降水变化对湖泊变化产生了深刻的影响.湖泊水量和盐度变化是气候变化下湖泊水量平衡形成的结果,是定量反映气候变化影响程度的重要指标,而变化的时空特征可能反映了西风季风环流对地表水循环的影响.湖泊水体的物理化学参数是影响湖泊生态系统的重要因素,其在气候变化下的改变深刻地影响着湖泊生态系统的组成与变化趋势.本文基于大量的青藏高原湖泊面积、水位、水量、水体物理化学参数与气候变化关系研究的分析,梳理了青藏高原湖泊变化对气候变化响应的研究进展,提出了第二次青藏高原综合科学考察研究任务中湖泊考察研究的主要目标和内容.

偏正态混合模型的惩罚极大似然估计

在分析具有异质性和非对称性数据时,偏正态混合模型提供一种比经典的Gauss混合模型更为灵活的建模方式.然而,由于无界的似然函数和发散的形状参数,该模型的极大似然估计并未被正确定义,进一步导致不理想的推断过程.为同时解决这两个问题,本文基于惩罚似然提出一种新的估计方案,并证明在混合分布的类别个数大于或等于真实的类别个数时,相应的惩罚极大似然估计是强相合的.同时,本文也提出相应的惩罚EM (expectation maximization)算法来计算惩罚估计.最后,通过模拟分析与现有方法比较研究估计方法在有限样本下的表现,并采用两个实例说明方法的有效性.

Climatic and lake environmental changes in the Serling Co region of Tibet over a variety of timescales

The Serling Co region is located at the transitional zone of the interaction between the Indian monsoon and the westerlies over the Tibetan Plateau. The Serling Co lake covers a water area of2,389 km2(June 2017) in a 45,530 km2drainage basin. Under the dramatic hydro-meteorological changes on the Tibetan Plateau in recent decades, and complex hydrological compositions of rivers and lakes in the basin, the lake area expanded by 43%, from1,667 km2in 1976, to 2,389 km2in 2017 (1)In 2014 it surpassed Nam Co as the largest lake on the Tibetan Plateau [2], and exerts significant effect on regional environmental conditions.

Pollen-inferred Holocene vegetation and climate histories in Taro Co,southwestern Tibetan Plateau

A 310-cm-long sediment core,covering the last10,200 years,was collected from Taro Co on the southwestern Tibetan Plateau and analyzed for pollen,grain size and total inorganic carbon content.The pollen data showed that vegetation changed from alpine steppe to alpine meadow during 10,200–8,900 cal a BP,to alpine steppe dominated by Artemisia during 8,900–7,400 cal a BP,to alpine meadow during 7,400–3,300 cal a BP and to alpine steppe after 3,300 cal a BP.Correspondingly,the pollen,grain size and total inorganic carbon content results revealed climatic change in this area over four stages.The initial stage was from 10,200 to 8,900 cal a BP,during which the climate changed from cold-dry to warm-humid.The second stage(8,900–7,400 cal a BP)was characterized by a warm and dry climate.However,at approximately7,400 cal a BP,the climate began to become cold and humid,which continued until 3,300 cal a BP.The last stage,from 3,300 cal a BP to present,was characterized as cold and increasingly arid.Climatic events of the early and mid-late Holocene showed that the area was significantly affected by the westerlies.However,the mid-Holocene climate in Taro Co was controlled by the Indian monsoon.The mid-late Holocene depositional environment record of Taro Co was very important to further elaborate the degree of influence by the westerlies or Indian monsoon.

In-situ water quality investigation of the lakes on the Tibetan Plateau

The lakes on the Tibetan Plateau(TP)account for 57%of the total lake area in China[1],which is a key component of the Asia water tower[2-4].A recent study showed that there are 1424 lakes greater than 1 km^(2) on the TP,while the total lake area reached 5.0-10^(4)±791.4 km^(2) in 2018[5].Most lakes on the TP are closed and are less disturbed by human activities than the other inland water bodies in China.

Climatic significance of n-alkanes and their compound-specific dD values from lake surface sediments on the Southwestern Tibetan Plateau

The content and hydrogen isotope ratios of n-alkanes extracted from recent lake surface sediments sampled from nine lakes in three different climate zones on the Southwestern Tibetan Plateau were analyzed.Values were compared with n-alkanes in plants from lake drainages,and dD values of meteoric water,lake water,and mean annual precipitation.The results showed that n-C23was predominantly derived from aquatic plants,and n-C27–n-C33from terrestrial higher plants.The average carbon chain length of n-C27–n-C33(ACL27–33)was positively correlated with the mean annual precipitation.dD values of the long-chain n-alkanes n-C29and n-C31of terrestrial origin(varying between-214%and-169%,and-226%and-185%,respectively)were inversely correlated with mean annual precipitation;but in accordance with the average annual variations in dD(OIPC),dD values of n-C31were strongly related to the dD values of growing season meteoric water(R2=0.74).The large difference between dD values of n-C23of aquatic origin and n-C31(an average of about 27%)demonstrates the enrichment of the lake water dD compared to precipitation,caused by strong evaporation in the semiarid–arid areas of the southwestern Tibetan Plateau.Average value of en C25 31=p(-95%)is evidently higher than the value observed in European wet regions(-128%);besides,en C31(about-116%)is constant along the study transect(SD=9),which indicates that n-C31is a useful proxy for the environment.

Graphitizing N-doped mesoporous carbon nanospheres via facile single atom iron growth for highly efficient oxygen reduction reaction

Single atom catalyst is of great importance for the oxygen reduction reaction(ORR).However,facile preparation of single atom catalyst without using well-designed precursors or labor-intensive acid leaching remains an urgent challenge.Herein,a simple pyrolysis of Fe3+-loaded mesoporous phenolic resin(mPF)-melamine precursor is used to prepare the single atom iron-anchored N-doped mesoporous graphitic carbon nanospheres(Fe/N-MGN).Investigation of the synthesis reveals the appropriate Fe-assisted catalysis effect and mPF template effect,which not only spurs the highly graphitic porous framework of Fe/N-MGN with plentiful pyridinic N/graphitic N,but also assures the dispersed single atom Fe anchoring without elaborated procedures.As a result,the as-synthesized Fe/N-MGN demonstrates high catalytic activity,good durability and excellent methanol tolerance for ORR.This work promises a facile method to regulate the graphitic carbon growth and single atom Fe loading for the highly efficient electrocatalysis.

C0818,a novel curcumin derivative,interacts with Hsp90 and inhibits Hsp90 ATPase activity

The aims of the present study were to estimate the affinity between 3,5-(E)-bis(3-methoxy-4-hydroxybenzal)-4-piperidinone hydrochloride(C0818) and heat shock protein 90 (Hsp90) and to investigate the inhibitory effects of this compound on Hsp90 ATPase activity. Fluorescence spectroscopy was used to examine the affinity between varying concentrations of C0818 and Hsp90, N-Hsp90, MHsp90 and C-Hsp90. Fluorescence intensities were recorded in the range of 290–510 nm at 293, 303 and 310 K, respectively. A colorimetric assay for inorganic phosphate(based on the formation of a phosphomolybdate complex and the subsequent reaction with malachite green) were used to examine the inhibitory effects of C0818 on Hsp90 ATPase activity. The equilibrium dissociation constant K_D value of C0818 was found to be 23.41270.943 μmol/L. The interaction between C0818 and Hsp90 was driven mainly by electrostatic interactions. C0818 showed the strongest affinity with C-Hsp90. These results conclusively demonstrate the inhibitory activity of C0818 on the activity of Hsp90 ATPase.