Studies on the Relation between the Composition of Thermal Sensitive MnZn Ferrite and Curie Temperature

Thermal sensitive MnZn ferrite is a kind of soft magnetic ferrite material with lower Curie temperature (Tc) and can be used to make many kinds of magnetic thermal sensitive sensors with high sensitivity. In this paper, the relation between the composition of thermal sensitive ferrite and TC was studied. It was found that TC changes linearly with ZnO extent when the content of Fe2O3 is fixed. Based on lots of experiments, an experimential formula to determine was given out.

Doxycycline and hydroxypropyl-b-cyclodextrin complex in poloxamer thermal sensitive hydrogel for ophthalmic delivery

The present study aimed to prepare a chemically and physically stable formulation of doxycycline(Doxy)in an in situ thermally sensitive hydrogel for ophthalmic delivery.An inclusion complex of Doxy and hydroxypropyl-b-cyclodextrin(HP-b-CD)was first developed to increase the stability of Doxy in aqueous solution.The physical characteristics(phase solubility profiles,thermal analysis,X-ray powder diffractograms and infrared spectra)of the Doxy-HP-b-CD inclusion complex indicated the formation of a stable 1:1 complex.Poloxamers P407(16–22%)and P188(0–5%)were mixed to obtain a hydrogel with an appropriate gelation temperature for opthalmic use.Formulation of the inclusion complex in the poloxamer hydrogel exhibited a suitable gelation temperature(33.3℃)after dilution with simulated tear fluid(Gel:STF=40:7,v/v).The release of Doxy from the poloxamer hydrogel followed a zero order equation suggesting it occurs through corrosion of the poloxamer hydrogel.Stability studies demonstrated that the inclusion of Doxy by HP-b-CD markedly improved its stability in aqueous solution both at 8 and 401C.This formulation of a doxycycline-HP-b-CD inclusion complex in an in situ thermally sensitive poloxamer hydrogel represents a potentially effective ophthalmic Doxy delivery system.

Numerical simulation based on two-directional freeze and thaw algorithm for thermal diffusion model

Freeze-thaw processes significantly modulate hydraulic and thermal char- acteristics of soil. The changes in the frost and thaw fronts （FTFs） affect the water and energy cycles between the land surface and the atmosphere. Thus, the frozen soil com- prising permafrost and seasonally frozen soil has important effects on the land surface hydrology in cold regions. In this study, a two-directional freeze and thaw algorithm is incorporated into a thermal diffusion equation for simulating FTFs. A local adaptive variable-grid method is used to discretize the model. Sensitivity tests demonstrate that the method is stable and FTFs can be tracked continuously. The FTFs and soil tempera- ture at the Qinghai-Tibet Plateau D66 site are simulated hourly from September 1, 1997 to September 22, 1998. The results show that the incorporated model performs much better in the soil temperature simulation than the original thermal diffusion equation, showing potential applications of the method in land-surface process modeling.

APPLICATION OF NONIONIC TEMPERATURE SENSITIVE HYDROGEL FOR CONCENTRATION OF PROTEIN AQUEOUS SOLUTION

Six different N-alkyl substituted acrylarnide nonionic hydrogels were prepared and their swelling characteristics were measured. Poly N-isopropyl acrylamide (PNIPA) and poly N-n-propyl-acrylamide (PNNPA) temperature sensitive hydrogels were chosen as the nonionic temperature sensitive hydrogels for concentration of very dilute aqueous protein solution. The separation properties of PNIPA and PNNPA hydr0gels with different network dimensions were studied and the modification of the hydrogels was surveyed in order to decrease their surface adsorption of protein molecules. The experimental results of the concentration of BSA (Bovin serum albumin) dilute aqueous solution by hydroxylpropyl methacrylate (HPMA) copolymerized PNIPA hydrogel were given. The value and the limitation of concentration of dilute aqueous protein solution by this method was evaluated.

Study of Intelligent Approaches to Identify Impact of Environmental Temperature on Ultrasonic GWs Based SHM:A Review

Structural health monitoring(SHM)is considered an effective approach to analyze the efficient working of several mechanical components.For this purpose,ultrasonic guided waves can cover long-distance and assess large infrastructures in just a single test using a small number of transducers.However,the working of the SHM mechanism can be affected by some sources of variations(i.e.,environmental).To improve the final results of ultrasonic guided wave inspections,it is necessary to highlight and attenuate these environmental variations.The loading parameters,temperature and humidity have been recognized as the core environmental sources of variations that affect the SHM sensing mechanism.Environmental temperature has the most significant influence on SHM results.There is still a need for extensive research to develop such a damage inspection approach that should be insensitive to environmental temperature variations.In this framework,the current research study will not only illuminate the effect of environmental temperature through different intelligent approaches but also suggest the standard mechanism to attenuate it in actual ultrasonic guided wave based SHM.Hence,the work presented in this article addresses one of the open research challenges that are the identification of the effect of environmental and operating conditions in practical applications of ultrasonic guided waves and impedance-based SHM.

Novel hot-melting hyperbranched poly(ester-amine) bearing self-complementary quadruple hydrogen bonding units

Hyperbranched poly（amine-ester）s bearing self-complementary quadruple hydrogen bonding units display excellent mechanical and temperature-dependent melt rheological properties, which make them suitable as novel hot-melting materials.

APPLICATION OF SURFACE GRAFTED POLY N-ISOPROPYL ACRYLAMIDE BY RADIATION TECHNOLOGY FOR PROTEIN SOLUTION CONCENTRATION

Poly N-isopropyl acrylamide (abbreviated as PNIPA) as a kind of thermally sensitive hydrogel is utilized to concentrate Bovin Serum Albumin (BSA) solution. In order to decrease its surface adsorption to BSA in aqueous solution, surface layer grafting of the gels by radiation technology was carried out. The results showed that hydroxyl propyl methacrylate (HPMA) grained gel exhibited a low level of BSA adsorption and still kept the original thermally sensitive properties of PNIPA hydrogels.

Synthesis and Properties of pH and Temperature Responsive Copolymer with Pesudorotaxane Structure

pH and temperature responsive copolymers PNAM4VBCB of N-isopropyl acrylamide（NAM） and complex pseudorotaxane monomer N 1-（4-vinylbenzyl）-1,4-diaminobutane dihydrochloride with cucurbit[6]uril（CB[6]） threaded（4VBCB） were prepared via free-radical polymerization in aqueous solution.The copolymers were characterized by 1 H NMR,Fourier transform infrared（FTIR） spectrometry,elemental analysis,and static light scattering.The thermodynamic properties of the copolymers were studied by thermogravimetric analysis（TGA）,and the effects of pH and the concentration of the copolymer on the average hydrodynamic radius（R h） were studied by dynamic light scattering（DLS）.In addition,the thermal sensitivities of the copolymers were studied by DLS and UV-Vis.The experiment data show that CB[6] beads are localized on 1,4-diaminobutane units in the side chains of the copolymer.TGA data show that thermal stability of the copolymers increases with the adding of CB[6] threaded because of the enhanced rigidity and the bulky steric hindrance of 4VBCB in the side chain of PNAM4VBCB.DLS data show that the average hydrodynamic radius of copolymer increases with the increase of the copolymer concentration and has a jump with adjusting pH due to the existing of the small size CB[6] dethreaded from the copolymer with increasing pH.Both pH and electrical conductivity curves of the solution of PNAM4VBCB-4 have a jump because CB[6] could dethread from the copolymers with the addition of NaOH.In addition,the copolymers have thermal sensitivity and their phase-change temperatures could be controlled by adjusting the molar ratio of NAM to 4VBCB in the copolymers.

Effect comparason of thermosensitive moxibustion and estazolam on anxiety and depression in the patients of insomnia differentiated as liver qi stagnation

Objective： To observe the effect of thermosensitive moxibustion on anxiety and depression in the patients of insomnia differentiated as liver qi stagnation.Methods： From January 2015 to January 2017, 60 patients of insomnia differentiated as liver qi stagnation were collected in Shijiazhuang Municipal Chinese Medicine Hospital. According to the random number table, the patients were randomized into a moxibustion group（30 cases） and an estazolam group（30 cases）. In the moxibustion group, the thermosensitive moxibustion was adopted alternatively to the bilateral yuan-source points of the liver and gallbladder meridians. In the estazolam group, estazolam, 1 mg was prescribed for oral administration before sleep every day. After 15-day treatments, the sleep quality, the severity of anxiety and depression and the therapeutic effects were observed before and after treatment in the two groups.Results： Before treatment, the differences were not significant in the scores of Pittsburgh sleep quality index（PSQI）, the self-rating anxiety scale（SAS） and the self-rating depression scale（SDS） between the two groups（all P〉0.05）. After treatment, the scores of PSQJ, SAS and SDS were all reduced remarkably as compared with those before treatment in the two groups（all P〈0.05）. PSQI score was（6.72 ±2.311）points in the moxibustion group and was（5.37 ±2.621） points in the estazolam group. SAS score was（31.76 ± 6.511） points in the moxibustion group and was（39.62 ± 4.371） points in the estazolam group.SDS score was（35.98 ±5.161） points in the moxibustion group and was（46.38 ±4.971） points in the estazolam group. After treatment, the scores of PSQI, SAS and SDS in the moxibustion group were reduced more remarkably as compared with the estazolam group, indicating the significant differences（all P 〈0.05）. After treatment, the scores of sleep efficacy and TCM symptoms were（72.65 ± 14.36） points and（69.36 ±4.28） points respectively in the moxibustion group, better than the estazolam group, indicating the significant differences（all P〈0.05）.Conclusion： The thermosensitive moxibustion at the yuan-source points of the liver and gallbladder meridians significantly improves the sleep quality, relieves the symptoms of anxiety and depression and enhances the therapeutic effects in the patients of insomnia differentiated as liver qi stagnation. Hence,this therapy deserves to be recommended in clinical practice.

Thermally activated delayed fluorescence materialsensitized helicene enantiomer-based OLEDs:a new strategy for improving the efficiency of circularly polarized electroluminescence

A new strategy of thermally activated delayed fluorescence(TADF)material-sensitized circularly polarized luminescence(CPL)has been proposed for improving the efficiencies of fluorescent circularly polarized organic lightemitting diodes(OLEDs)(CP-OLEDs).Consequently,a pair of helicene enantiomers,(P)-HAI and(M)-HAI,were synthesized.The helicene enantiomers with the rigid helicalπ-skeleton had highly thermal and enantiomeric stabilities,and they also showed excellent photophysical properties,especially,intense mirror-image CPL activities with large luminescence dissymmetry factor(|g_(lum)|)values of about 6×10^(-3).Notably,the CP-OLEDs with the helicene enantiomers as emitters and a TADF molecule as sensitizer not only displayed better performance of lower turn-on voltage(V_(T))of 2.6 V,four-fold maxmium-external quantum efficiency(EQE_(max))of 5.3%,and lower efficiencies roll-off of 1.9%at 1000 cd m^(-2),than those of the devices without TADF sensitizer,but also exhibited intense circularly polarized electroluminescence(CPEL)with the electroluminescence dissymmetry factor(g_(EL))values of-2.3×10^(-3)and+3.0×10^(-3).Meanwhile,this study also represents the first thermally activated sensitized fluorescent CP-OLEDs with markedly enhanced efficiencies and intense CPEL.

Field body temperature and thermal preference of the big-headed turtle Platysternon megacephalum

The big-headed turtle Platysternon megacephalum is a stream-dwelling species whose ecology is poorly known. We carried out field and laboratory investigations to determine field body temperatures and thermal preference of this species. In the field, the body temperatures of the turtles conformed to the water temperature, with little diel variation in either summer or au- tumn. Over the diel cycle, the mean body temperatures ranged from 20.8℃ to 22.2℃ in summer and from 19.3℃ to 21.2℃ in autumn; the highest body temperatures ranged from 22.1℃ to 25.0℃ in summer and from 20.6℃ to 23.8℃ in autumn. In the laboratory, the preferred body temperature （Tp） was 25.3℃ Food intake was maximized at 24.0℃, whereas locomotor perfor- mance peaked at 30.0℃. Consequently, Tp was closer to the thermal optimum for food intake than for locomotion. Therefore, this freshwater turtle has relative low field body temperatures corresponding to its thermal environment. In addition, the turtle prefers low temperatures and has a low optimal temperature for food intake [Current Zoology 59 （5）： 626-632, 20＇13].

Latitudinal pattern of the thermal sensitivity of running speed in the endemic lizard Liolaemus multimaculatus

Physiological performance in lizards may be affected by climate across latitudinal or altitudinal gradients.In the coastal dune barriers in central-eastern Argentina,the annual maximum environmental temperature decreases up to 2℃ from low to high latitudes,while the mean relative humidity of the air decreases from 50%to 25%.Liolaemus multimaculatus,a lizard in the family Liolaemidae,is restricted to these coastal dunes.We investigated the locomotor performance of the species at 6 different sites distributed throughout its range in these dune barriers.We inquired whether locomotor performance metrics were sensitive to the thermal regime attributable to latitude.The thermal performance breadth increased from 7%to 82%with latitude,due to a decrease in its critical thermal minimum of up to 5℃ at higher latitudes.Lizards from high latitude sites showed a thermal optimum,that is,the body temperature at which maximum speed is achieved,up to 4℃lower than that of lizards from the low latitude.At relatively low temperatures,the maximum running speed of high-latitude individuals was faster than that of low-latitude ones.Thermal parameters of locomotor performance were labile,decreasing as a function of latitude.These results show populations of L.multimaculatus adjust thermal physiology to cope with local climatic variations.This suggests that thermal sensitivity responds to the magnitude of latitudinal fluctuations in environmental temperature.

Reduced thermal sensitivity of hybrid air-core photonic band-gap fiber ring resonator

A novel hybrid air-core photonic band-gap fiber(PBF) ring resonator with twin 90° polarization-axis rotated splices is proposed and demonstrated. Frist, we measure the temperature dependent birefringence coefficient of air-core PBF and Panda fiber. Experimental results show that the relative temperature dependent birefringence coefficient of air-core PBF is 1.42×10^(-8)/℃, which is typically ~16 times less than that of Panda fiber. Then, we extract the geometry profile of air-core PBF from scanning electron microscope(SEM) images. Numerical modal is built to distinguish the fast axis and slow axis in the fiber. By precisely setting the length difference in air-core PBF and Panda fiber between two 90° polarization-axis rotated splicing points, the hybrid air-core PBF ring resonator is constructed, and the finesse of the resonator is 8.4. Environmental birefringence variation induced by temperature change can be well compensated, and experimental results show an 18-fold reduction in thermal sensitivity, compared with resonator with twin 0° polarization-axis rotated splices.

Colloidal(Gd0.98Nd0.02)2O3 nanothermometers operating in a cell culture medium within the first and second biological windows

Non-contact,self-referenced and near-infrared luminescent nanothermometers have been recognized as emerging tools in the fields of nanomedicine and nanotechnology due to their great capability of precise temperature readout at the nanoscale and real-time deep-tissue imaging.However,the development of multifunctional and biocompatible luminescent nanothermometers operating within the optically transparent biological windows with high thermal sensitivity(>2.0%/K)remains challenging.Here,we present(Gd0.98Nd0.02)2O3 nanothermometers operated effectively within the first and second biological windows upon continuous-wave laser diode excitation at 808 nm.Ratiometric thermometric parameters are defined by the relative changes in the emission intensities originating from the two Stark components of the 4 F3/2 level(R2 and R1)to the 4 I9/2(900-1000 nm),4 I11/2(1035-1155 nm)and 4 I13/2(1300-1450 nm)multiplets.The thermo metric parameters are evaluated for colloidal samples in a cell culture medium and powder samples,and the highest thermal sensitivity(2.18%/K at 298 K)is attained for the former in the first biological window(both the excitation and emission in the 800-965 nm range).The repeatability and temperature uncertainty are 99%and 1.2 K,respectively.The nanothermometers are biocompatible with human MNT-1 melanoma and HaCaT cells for 24 h of exposure and nanoparticle concentration up to 0.400 mg/mL,showing their potential for applications in nanomedicine,e.g.,intracellular imaging and temperature mapping.

Short-term effects of maize residue biochar on kinetic and thermodynamic parameters of soil β-glucosidase

Soil β-glucosidase (BG), the rate-limiting enzyme in the final step of cellulose hydrolysis, plays a key role in microbial metabolism, carbon (C) cycling and sequestration in terrestrial ecosystems. Biochar application is known to affect soil BG activity;however, most of the biochar studies have focused on the potential activity of BG, and it is not clear how biochar influences the kinetic and thermodynamic behavior of BG in the soil. The objective of this study was to investigate the effect of maize residue biochar on soil BG kinetic and thermodynamic parameters. Soil BG kinetic (V_(max) and K_(m)) and ther-modynamic (E_(a), ΔH_(a) and Q_(10)) parameters were determined within soils (clayey and sandy loam soils) amended with either maize residue (as positive control) or its biochar (600℃) at 0.5 and 1.0% ratios (w/w), and the mixtures were incubated for 90 days. BG showed an increase in potential enzymatic activity (81%), enzyme concentration (higher V_(max) value) (25%) and substrate affinity (lower K_(m) value) (32%) in the biochar-amended sandy loam soil only at high addition rates compared with the control, and an increase by about 86% of the catalytic efficiency (V_(max)/K_(m)). In the clayey soil, biochar addition decreased potential BG activity (by 10-29%), increased the V_(max) value (by 20-25%) and had no impact on enzyme-substrate binding affinity, but still increased the catalytic efficiency by 47-72%. Adsorption of soil BG by biochar particles did not affect the catalytic efficiency in the soil. Generally, application of maize residue biochar to the soil decreased the E_(a), ΔH_(a) and Q_(10) values of BG compared with the negative controls at both biochar rates in the light-textured soil and only at low biochar rate in heavy-textured soil. The direction and magnitude of BG responses (activity, kinetics, and thermodynamics) to biochar were more related to the soil characteristics. Biochar would increase soil BG thermal stability and decrease its sensitivity to increasing temperature and global warming.