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Comprehensive Summary: Advanced radiative cooling materials with both heating and cooling mode is of pivotal importance for all‐season energy‐saving in buildings. In this work, we report the design and fabrication of bacterial cellulose‐based Janus films (J‐BC) with radiative cooling and solar heating properties, which were developed by two‐step vacuum‐assisted filtration of modified MXene‐doped bacterial cellulose and modified silicon nitride (Si3N4)‐doped bacterial cellulose, followed by hot‐pressing and drying treatments. The as‐prepared J‐BC films show a unique Janus structure where modified MXene nanosheets and cellulose nanofibers are on the bottom surface, and modified silicon nitride (Si3N4) nanoparticles and cellulose nanofibers are on the top surface. The radiative cooling effect of J‐BC films is enabled by the Si3N4‐doped bacterial cellulose due to the high mid‐infrared emissivity of Si3N4 nanoparticles, which shows a high solar reflection of ~98.1% and high emissivity of ~93.6% in the atmospheric transparency window (8—13 μm). Thanks to the enhanced photothermal conversion of the modified MXene nanosheets, a reduced solar reflection (6.6%) and relatively low thermal emissivity in the atmospheric window (71.4%) are achieved, making sure the solar heating effect of J‐BC films. In the outdoor tests, J‐BC films achieve a sub‐ambient temperature drop of ~3.8 °C and an above‐ambient temperature rise of ~14.2 °C. Numerical prediction demonstrated that the J‐BC films with dual modes have great potential of all‐season energy saving for buildings and a corresponding energy‐saving map in China is also created. The work disclosed herein can provide an avenue for the shaping of advanced radiative cooling materials for emerging applications of personal thermal management, sustainable energy‐efficient buildings, and beyond. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Advanced radiative cooling materials with both heating and cooling mode is of pivotal importance for all‐season energy‐saving in buildings. In this work, we report the design and fabrication of bacterial cellulose‐based Janus films (J‐BC) with radiative cooling and solar heating properties, which were developed by two‐step vacuum‐assisted filtration of modified MXene‐doped bacterial cellulose and modified silicon nitride (Si3N4)‐doped bacterial cellulose, followed by hot‐pressing and drying treatments. The as‐prepared J‐BC films show a unique Janus structure where modified MXene nanosheets and cellulose nanofibers are on the bottom surface, and modified silicon nitride (Si3N4) nanoparticles and cellulose nanofibers are on the top surface. The radiative cooling effect of J‐BC films is enabled by the Si3N4‐doped bacterial cellulose due to the high mid‐infrared emissivity of Si3N4 nanoparticles, which shows a high solar reflection of ~98.1% and high emissivity of ~93.6% in the atmospheric transparency window (8—13 μm). Thanks to the enhanced photothermal conversion of the modified MXene nanosheets, a reduced solar reflection (6.6%) and relatively low thermal emissivity in the atmospheric window (71.4%) are achieved, making sure the solar heating effect of J‐BC films. In the outdoor tests, J‐BC films achieve a sub‐ambient temperature drop of ~3.8 °C and an above‐ambient temperature rise of ~14.2 °C. Numerical prediction demonstrated that the J‐BC films with dual modes have great potential of all‐season energy saving for buildings and a corresponding energy‐saving map in China is also created. The work disclosed herein can provide an avenue for the shaping of advanced radiative cooling materials for emerging applications of personal thermal management, sustainable energy‐efficient buildings, and beyond. [ABSTRACT FROM AUTHOR]

BACKGROUND: Chestnut has recently attracted attention because of its exceptional functional properties, which are mainly influenced by the structural properties of chestnut starch (CS). In this study, ten varieties of chestnut from the northern, southern, eastern, and western regions of China were selected, and their functional properties, including thermal properties, pasting properties, in vitro digestibility, and multi‐scale structural characteristics were characterized. The relationship between structure and functional properties was clarified. RESULTS: In the varieties that were studied, the pasting temperature of CS was in the range of 67.2–75.2 °C and the pastes displayed diverse viscosity characteristics. Slowly digestible starch (SDS), and resistant starch (RS) of CS were in the range of 17.17–28.78% and 61.19–76.10%, respectively. Chestnut starch from north‐eastern China exhibited the highest RS content of 74.43–76.10%. Structural correlation analysis revealed that smaller size distribution, fewer B2 chains, and thinner lamellae thickness contributed to higher RS content. Meanwhile, CS with smaller granules, more B2 chains, and thicker amorphous lamellae displayed lower peak viscosities, stronger resistance to shear, and higher thermal stability. CONCLUSION: Overall, this study clarified the relationship between the functional properties and the multi‐scale structure of CS, revealing the structural contributions to its high RS content. These findings provide significant information and basic data for use in the creation of nutritional chestnut food. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Fritillaria hupehensis (Hubeibeimu) widely grows in the mid-western zones of China. In the present work, we investigated the physicochemical compositions, antioxidant abilities, and thermal properties of the bulbs of F. hupehensis dehydrated by heat-pump drying (HD), vacuum drying (VD), natural drying (ND), freeze drying (FD), and microwave drying (MD). Total contents of nucleosides and nucleobases in F. hupehensis flours ranged from 727.64 to 1,654.25 µg/g, and total free amino acids ranged from 88.03 to 128.21 mg/g. FD flour had high contents of total nucleosides and nucleobases, and free amino acids. MD flour had low contents of total starch, amylose, protein, nucleosides and nucleobases, and VB1 and VB2, and high levels of total phenolic content (TPC) and antioxidant abilities. Furthermore, MD flour facilitated gelatinisation, while FD flour displayed opposite trend. HD flour had high total starch content, while ND flour weakened the bitter taste due to the percentage of sweet and bitter taste of amino acids. [ABSTRACT FROM AUTHOR]

Construction of biomass-based wearable aerogel heater with enhanced thermal insulation property plays a significant role in preventing heat loss for personal thermal management. Inspired by natural creatures' utilization own hollow microstructures to resist the extremely cold surroundings, we report an eco-friendly strategy to construct calcium alginate (CA) /kapok fiber (KF)/carbon nanotubes (CNTs) active-cum-passive aerogel heater with desired economic feasibility, sustainability and efficient thermal insulation performance. The renewable cellulose hollow KF disrupts the heat transfer pathway and enabled CA/KF/CNT lower thermal conductivity (0.024 W/m·K) and ultralight density (0.027 g/cm3). The CNTs in the aerogel heater not only provided excellent conductivity for realizing Joule-heating but also enhanced the photothermal conversion capability from solar irradiation, ensuring extra self-heating ability without power supply. According to energy-saving analysis, the total energy saved in China per year was 6.03 × 109 kWh when using the developed aerogel heater instead of the traditional heating method. This developed biomass aerogel heater in this work exhibits great potential to be applicable in the fields of wearable personal thermal management to enhance the adaptability of human body in cold environment. Our work may inspire the study of biomass-derived wearable heaters for solving global energy issues. [ABSTRACT FROM AUTHOR]

The development of geothermal resources in the Dongpu Depression can improve not only the economic benefits of the oilfield but also the ecological environment. Therefore, it is necessary to evaluate the geothermal resources in the region. Based on the heat flow, geothermal gradient and thermal properties, the temperatures and their distribution in different strata are calculated using geothermal methods, and the geothermal resource types of the Dongpu Depression are identified. The results show that the geothermal resources include low-temperature, medium-temperature and high-temperature geothermal resources in the Dongpu Depression. The Minghuazhen and Guantao Formations mainly include low-temperature and medium-temperature geothermal resources; the Dongying and Shahejie Formations include low-temperature, medium-temperature and high-temperature geothermal resources; the Ordovician rocks mainly include medium-temperature and high-temperature geothermal resources. The Minghuazhen, Guantao and Dongying Formations can form good geothermal reservoirs and are favorable layers for exploring low-temperature and medium-temperature geothermal resources. The geothermal reservoir of the Shahejie Formation is relatively poor, and the thermal reservoirs may be developed in the western slope zone and the central uplift. The Ordovician carbonate strata can provide thermal reservoirs for geothermal resources, and the Cenozoic bottom temperature is more than 150 °C except for most of the western gentle slope zone. In addition, for the same stratum, the geothermal temperatures in the southern Dongpu Depression are higher than those in the northern depression. [ABSTRACT FROM AUTHOR]

Carbonate rocks are one of major geothermal reservoir types around the world. Understanding the thermal properties of carbonate rocks is of significance to the assessment and utilization of deep geothermal reservoirs. Different from conventional test methods, this paper introduced a new approach, molecular dynamics calculation (MDC), to studying the thermal properties of carbonate rocks. By means of MDC, the thermal properties including specific heat, thermal conductivity and thermal diffusivity of four types of carbonate rocks including calcite, dolomite, magnesite, and smithsonite were investigated. The intrinsic relationship among the Debye temperature, elastic and thermal properties of carbonate rocks was revealed. The variations of the thermal properties with the average atom weight and temperature (300–800K) were obtained and regressed as functional formulas for applications. Further, taking carbonate rock samples from North China as an example, the specific heat and thermal conductivity were tested and compared with the MDC results based on actual lattice parameters by using X-ray diffraction method (XRD). The results showed that there was a good agreement between the test and calculation results. Finally, the thermal properties of ferroan dolomite samples were predicted. The present method can provide a promising extension tool for analyzing other crystalline rocks for geothermal applications. [ABSTRACT FROM AUTHOR]

The use of bio-based building materials is a sustainable opportunity to reduce the environmental footprint associated with the construction sector. The achievement of this objective is primely achieved through the valorisation of vegetable waste, resulting in a reduction in the use of primary source material and waste generation. Within the scope of this study, the focus is directed towards research concerning the thermal, acoustic, and fire behaviour properties of bio-based building materials. This study conducts a comprehensive bibliometric analysis encompassing all documents meeting these criteria within the Scopus database, spanning two decades, from 2003 to 2023. The comprehensive analysis covered a total of 1081 documents, which were analysed. This analysis furnishes insight into various facets, including the temporal evolution of publications, journals boasting the highest publication counts and impact, influential research areas, countries with substantial contributions and their collaborative patterns, noteworthy affiliations, prolific authors, and seminal documents, alongside recurrent keywords. The objective of this comprehensive study is to provide a detailed analysis of the documents published up to the present day, in order to identify research gaps and potential opportunities in this field, to assist new researchers interested in the subject. The analysis reveals that bio-based building materials have gained substantial attention over the past decade. With each passing year, the published documents have increased their impact and become more specific, underscoring the growing importance of this subject. This evolution has also fostered a broader network of researchers engaged in this field. However, it is noteworthy that the characterization of these materials focuses predominantly on their thermal properties, while research avenues related to acoustic and fire properties remain less explored and present opportunities for future investigation. • This study contributes to identify research gaps and potential opportunities in the field of bio-based building materials. • Studies in bio-based building materials have shown an annual growth of the 25% since 2014, being a topic on the rise. • France and China are the countries with the highest scientific publication on bio-based building materials. • Keywords play a crucial role in making visible the research within bio-based building materials. • "Thermal Conductivity" and "Thermal insulation" are the most repeated keywords in this field. [ABSTRACT FROM AUTHOR]

We report the transport properties of a topological insulator candidate, LiMgBi. The electric resistivity of the title compound exhibits a metal-to-semiconductor-like transition at around 160 K and tends to saturation below 50 K. At low temperatures, the magnetoresistance is up to ∼260 % at 9 T and a clear weak antilocalization effect is observed in the low magnetic-field region. The Hall measurement reveals that LiMgBi is a multiband system, where hole-type carriers (n h ∼ 1018 cmâˆ'3) play a major role in the transport process. Remarkably, LiMgBi possess a large Seebeck coefficient ∼440 ÎĽV/K) and a moderate thermal conductivity at room temperature, which indicate that LiMgBi is a promising candidate in thermoelectric applications. [ABSTRACT FROM AUTHOR]

This paper focuses on the stability of the high-level radioactive waste (HLW) in the proposed clay rock in Tamusu area of China. The in-situ stress as well as the variational characteristics of ambient temperature caused by nuclide decay during HLW storage should be noticeable. A series of thermal property tests and thermo-mechanical coupled strength (T-M) tests of rock samples in the target formation are carried out. Then the stability of surrounding rock of an HLW under the combination of heat release from HLW and in-situ stress is simulated and analyzed by numerical method. Thermal properties of Tamusu clay rock samples are obtained by testing their thermal conductivity. In order to obtain the characteristics and the failure modes of rock samples at different temperatures, the T-M coupling experiments in the temperature range of 100°C are conducted. Numerical model for simulating the state of operation of the nuclear waste tank buried in the tunnel within 100 years is constructed. A thermal boundary by the heat release equation of HLW and the real in-situ stress level in Tamusu area are considered in the model. While, the variation law of surrounding rock's temperature, stress, and deformation corresponding to the embedding time is obtained from the numerical calculation. Finally, the stability of the deep geological repository is comprehensively evaluated. The results show that the temperature has a significant impact on the T-M coupling characteristics of Tamusu clay rock, and the proposed repository numerical model has no large deformation and failure problems in 100 years. However, the temperature of the surrounding rock of the repository may exceed the safety standard value during the operation period. [ABSTRACT FROM AUTHOR]

At present, the yield of common buckwheat, which is mainly grown in northern Shaanxi of China, is low and the grain quality is poor. Nitrogen is an important nutrient for the growth of common buckwheat, and appropriate nitrogen application can improve the grain quality. Nitrogen fertilizer could alter the starch granule morphology shapes and the granule size distribution. With increasing nitrogen levels, branch number, flower clusters number, grain number per plant, contents of protein and fat, size distribution of "C" granules, and percentages of light transmittance significantly increased, whereas amylose content and retrogradation decreased. All the samples displayed typical A-type X-ray diffraction patterns. Starch showed higher pasting temperature and gelatinization enthalpy but lower trough and final viscosities under high nitrogen levels. These results suggested N 2 treatment was more suitable for common buckwheat growth, principal components and correlation analysis revealed that nitrogen fertilizer significantly affected the physicochemical properties of common buckwheat starches. [ABSTRACT FROM AUTHOR]

Nelumbo nucifera Gaertn., Eleocharis dulcis , Sagittaria sagittifolia L., and Trapa bispinosa Roxb. are common aquatic vegetables that are rich in starch. Starches from these four aquatic vegetables and their applications in edible films were studied to facilitate full use of starch resources. Significant differences in transparency, freeze–thaw stability, water solubility index, swelling power, water and oil absorption capacities, starch particle morphology, and rheology were observed among the starches from these four aquatic vegetables. All starches exhibited a typical "A" type diffraction pattern. N. nucifera , E. dulcis , and S. sagittifolia starches have similar thermal properties, while T. bispinosa starch has a higher gelatinization temperature. S. sagittifolia starch film has the highest transparency and lower WVP and water solubility. These results will promote the development of products based on starch obtained from aquatic vegetables. [ABSTRACT FROM AUTHOR]

• Variation of atomic ratio and microcrystalline structure with temperature under nitrogen atmosphere were explored. • Abrupts of H/C and O/C occured as rising the temperature of coal samples. • Correlation was established by thermal property with atomic ratio and microcrystalline structure. To explore the main influencing factors of atomic ratio (O/C, N/C, and H/C) as well as microcrystalline structure (d 002 , L a , L c , and M c) on thermal properties (specific heat capacity, thermal conductivity, and thermal diffusivity) at certain temperatures within 30.0–300.0 °C, three coal samples were collected from coal mines of Dafosi, Yangjiaping, and Hujiahe in Binchang coalfield, Shaanxi Province, PR China. Thermal properties of coal samples were determined by laser-flash apparatus in nitrogen atmosphere. After temperature treated at 30.0, 60.0, 90.0, ..., 300.0 °C in nitrogen atmosphere, the atomic ratio and microcrystalline structure of samples were measured by proximate analyser and X-ray diffractometer. The results indicated that with an increment in the temperature, the value of H/C for three coal samples diminished slightly and then promptly, whereas O/C diminished slightly and then increased before 120.0 °C, as well as finally increasing, and the N/C had no obvious change. Concurrently, the microcrystalline structure of coal samples became more orderly and complete. Furthermore, the TD decreased with temperature, the SHC and TC showed an opposite trend with TD. Based upon grey correlation analysis, the major influencing factors of atomic ratio and microcrystalline structure on thermal property were approached. The results provided insight into the physicochemical properties of the coal of interest for predicting the progress of coal spontaneous combustion. [ABSTRACT FROM AUTHOR]

The optimal development of hot dry rock (HDR) geothermal is deep HDR geothermal. Because of different diagenesis environments, the mineral composition and micro-structure of deep granite are quite different than those of shallow granite. To reveal the characteristics of deep granite and guide HDR geothermal development, the difference in thermal and mechanical properties between the granite in Luya Mountain, Shanxi Province, China (coarse-grained granite) and the granite in Shandong Province, China (fine-grained granite) under high-temperature (100–400 ℃) triaxial stress was studied. The results show that the thermal expansion coefficient of the coarse-grained granite increases linearly with increasing temperature, and the thermal expansion coefficient of the coarse-grained granite is 1.52 times that of the fine-grained granite on average, and the difference reaches a maximum at 400 ℃. The elastic modulus of the coarse-grained granite increases slowly first and then decreases sharply with increasing temperature, and its threshold temperature varies with temperature at approximately 300 ℃. The elastic modulus of the fine-grained granite is 1.4–2.6 times that of the coarse-grained granite, and the difference increases with increasing temperature and confining pressure. According to the failure test under triaxial stress (confining pressure (σc) = 25 MPa) and at 400 ℃, for the coarse-grained granite, the peak strength, elastic modulus and its threshold temperature change with temperature are smaller, the peak strain is larger and the elasto-plastic transition occurs easier than those for the fine-grained granite. Micro-observation shows that the larger crystal particles and the extreme heterogeneity of the coarse-grained granite lead to larger thermal deformation and greater deterioration of the mechanical properties, compared with those of the fine-grained granite, further leading to higher permeability of the coarse-grained granite under high temperature and high pressure. The existence of coarse-grained granite provides a good geological foundation for high-efficiency, low-cost and large-scale construction of artificial reservoirs in the process of HDR geothermal development. [ABSTRACT FROM AUTHOR]

The biochemical properties and thermal inactivation of polyphenol oxidase (PPO) from three main planted lily cultivars in China, namely, Lilium lancifolium Thunb, Lilium brownie var. viridulum, and Lilium davidii var. unicolor cotton were evaluated. Data indicate that the PPO from three cultivars showed two optimum pH levels of 4.0 and 6.5–7.0 and temperature of 15°C and exhibited the highest affinity toward 4‐methylcatechol. However, this enzyme did not exhibit monophenolase activity. Thiourea and L‐cysteine were more effective than other inhibitors. The enzymatic activity of L. lancifolium Thunb PPO crude extract was higher than that of L. brownie var. viridulum and L. davidii var. unicolor cotton. For thermal inactivation, L. davidii var. unicolor cotton PPO showed the best thermal resistance at 65–75°C, and L. lancifolium Thunb showed stability at 45°C. The deactivation of the three types of PPO followed the first‐order reaction kinetics, and the activation energy (Ea) was 144.28, 138.00, and 107.12 kJ/mol for L. lancifolium Thunb PPO, L. brownie var. viridulum PPO, and L. davidii var. unicolor cotton PPO, respectively. Practical applications: Lilium is an ornamental and edible plant typically used for food and traditional Chinese medicine. Its flowers are used for decoration, and its underground bulbs are rich in various bioactive substances. Fresh lily bulbs easily turn brown and lose economic value during storage and processing. Polyphenol oxidase (PPO) is a crucial molecule involved in the enzymatic browning of fruit and vegetables. In this study, PPO was extracted from three main planted lily cultivars in China. Namely, Lilium lancifolium Thunb, Lilium brownie var. viridulum, Lilium davidii var. unicolor cotton and was partially characterized. The results are of considerable importance to further understand the PPO of lily bulbs and provide guidance for the inactivation of enzymes and the processing of lily bulb juice. [ABSTRACT FROM AUTHOR]

Common buckwheat starch (CBS) has extensive using value in the human diet. In this study, the molecular structure and physicochemical properties of CBS isolated from five cultivars collected from three regions of China were studied. Variations in molecular structure, crystalline structure, complexity, water solubility (WS), swelling power (SP), pasting properties, and thermal characteristics were recorded among the starches. The CBS had both similarities and differences in its properties by comparison with maize starch (MS) and potato starch (PS). The average molecular weight (M W) and amylopectin average chain length (ACL) of CBS ranged from 3.86 × 107 g/mol to 4.68 × 107 g/mol and from 21.29% to 22.68%, respectively. CBS and MS were divided into one subgroup and showed typical A diffraction patterns, while PS was divided into two subgroups and exhibited a typical B polymorphic pattern. The WS and SP of all the starches significantly increased with increasing temperature and had great variation at 70 °C and 90 °C. Pearson's correlation analysis showed that the molecular structure of starches greatly affected the physicochemical properties. This study revealed that the physicochemical properties of CBS could be affected by the molecular structures. • Common buckwheat and maize starches showed typical A diffraction patterns. • Structural complexity of five common buckwheat cultivars were similar. [ABSTRACT FROM AUTHOR]

The annual output of crops in China is about 900 million tons. Improper handling of large amounts of straw waste increases the negative impact on the environment. Recently, many scholars have studied the rational use of crop straw, and found that straw was rich in plant fiber, which combined with some kinds of building materials could be used to produce new green composite building materials. The composite building materials are more environment friendly and economical than the traditional materials, which can greatly improve the wall insulation performance. However, there are numerous factors affecting the thermal insulation performance of composite building materials. Conducting an in-depth analysis of the main factors and trends influencing the thermal insulation performance of composite building materials is necessary. This paper firstly introduced the current situation and existing problems of crop straw waste utilization, then discussed the influence of main factors on the thermal insulation properties of composite building materials. According to the analysis, the straw content is the most principal factor affecting the thermal insulation performance of composites. In a certain value range, the thermal conductivity of the composites decreases with the increase of straw content and the decrease of moisture content. Composites produced with pretreated plant fiber have better thermal insulation performance than composites without pretreatment. The thermal conductivity value of the composites decreases with increase in fiber length. Based on the research of functional rule of various influencing factors on the thermal insulation performance of composites, composite building materials with better thermal insulation performance could be obtained. [ABSTRACT FROM AUTHOR]

In the process of multi-seam mining, the measure of water exploration is usually employed for the upper coal seam to prevent and control water accumulation. The residual coal immersed in water for a long time in the upper layer is dried under the action of air leakage, leading to the enhancement of the risk of coal spontaneous combustion. Therefore, it is necessary to study the water soaking–drying process (WSD) on the spontaneous ignition characteristics of coal. In this study, a laser thermal conductivity analyzer was used to investigate the changes in thermal properties of bituminous coal collected from mines in western China after WSD. The results show that compared with the raw (unsoaked) coal samples, the thermal diffusivity, specific heat capacity, and thermal conductivity of the bituminous coal are considerably reduced after WSD; the maximum reductions in the three parameters are 11.11%, 6.64%, and 12.39%, respectively. These reduced thermal parameters indicate that after WSD, bituminous coal is more prone to self-heating, resulting in an increase in the rate of coal–oxygen compound reactions and a significantly increased risk of spontaneous combustion. [ABSTRACT FROM AUTHOR]

A geological stratum is a rock or soil layer that has internally consistent characteristics and is distinguishable from adjacent layers. A stratigraphic section contains reference information for the strata of an associated sedimentary area. In this paper, the thermal properties of 36 rock formations in a succession of the Yangtze plate in China are studied. Thermal properties are analyzed with an emphasis on rock formations, rock lithological types and dry/saturated conditions. The results show that thermal conductivity varies dramatically with different rock lithological types, which range from 0.72 W m−1 K−1 to 4.49 W m−1 K−1. The analysis of biochemical sedimentary rocks shows that silicate has the highest thermal conductivity, followed by dolomite and limestone; this variation is due to the differences in rock-forming minerals. The thermal conductivity of the clastic rocks is mainly determined by the type of minerals, the porosity and the water content. Compared to dry samples, the thermal conductivity and volumetric heat capacity of saturated samples are higher. Moreover, the thermal conductivity data of nine other locations in the Yangtze plate are compared with the stratigraphic data. This analysis shows that thermal conductivity matches very well for most of the geological formations, with the exception of sandstone, which exhibits a significant deviation across formations. Finally, the thermal properties for the Yangtze plate are mapped for insight on their spatial distribution. • Thermal properties of 36 rock formations in a sedimentary succession are measured. • Thermal conductivity varies dramatically with lithological types of rocks. • Two categories rocks are studied with emphasis on sedimentogenesis. • Thermal properties of Yangtze plate are mapped for insights on spatial distribution. [ABSTRACT FROM AUTHOR]

Porous asphalt concrete (PAC) can obviously improve vehicle driving safety on rainy days and reduce environmental noise. It has been widely used in China. The existence of a large number of interconnected voids in PAC makes a significant difference in heat transfer and temperature distribution from conventional dense-graded asphalt concretes (AC). In this paper, the internal structure images of three dense-graded asphalt mixtures and one PAC were obtained by X-ray CT scanning technology, and the internal meso-structure finite element simulation models of asphalt mixtures were established by using the mapped meshing method. The temperature variations of asphalt mixture specimens during laboratory cooling and heating processes were simulated in this study, and laboratory tests were carried out to verify the simulation accuracy. Due to the simulation results, it was found that the thermal characteristics of the PAC mixture were different from those of the dense-graded asphalt mixture due to the large interconnected air void content in the PAC mixture. The temperature field in the PAC mixture was more sensitive to ambient air temperature under laboratory conditions. Moreover, in PAC specimens, temperature distributed more unevenly than in dense-grade asphalt mixtures. Therefore, it is necessary to consider the internal meso-structure of porous asphalt mixtures while simulating the temperature field in PAC specimens or pavement structures. [ABSTRACT FROM AUTHOR]

Rice husks as common agricultural remnants with low density and good thermal conductivity properties have been used in infill walls in the northern area of China. Accordingly, many tests and numerical simulations were conducted to address a difficult issue, the inaccurate estimation on the lateral load-bearing capacity of different types of husk mortar energy-saving (HMES) wallboards. The difficulty has not been overcome so far, implying that the novel methods are anticipated to achieve the accurate estimation. This paper tests the full-scale HMES wallboards with different openings and obtains the strains at the points distributed on the wallboard sides. The experimental strains are modeled as the approximate strain energy values to produce the characteristic parameter of the HMES wallboard's stressing state. Furthermore, the inherent working state characteristic points of HMES wallboards are revealed from the evolution of the characteristic parameter called as the normalized approximate strain energy sum, leading to the redefinition of the failure loads for the HMES wallboards. Finally, it investigates the stressing state mode evolution of the HMES wallboard around the failure loads. The achieved results provide the reference to the accurate estimation of the bearing capacity of the HMES wallboards. [ABSTRACT FROM AUTHOR]

• Building energy conservation is very important in today's society. • A bio-insulation material using wheat straw as aggregate is made by experiment. • The binder adopted in this material is geopolymer with H 2 O 2 as foaming agent. • The thermal conductivity varies from 0.092 to 0.18623 W m−1 K−1. • The compressive strength varies from 0.18 to 5.622 MPa. During the process of China's rural urbanization and agricultural supply-side reform, the disposal of a large number of agricultural and forestry wastes will be a big problem. This study deals with effect of four variables on the thermal, mechanical, hydraulic properties and microscopic morphology of the bio-insulation materials using wheat straw as aggregate and geopolymer as binder. The four variables are wheat straw length dimension (L), prewetting water /wheat straw mass ratio1 (Wp/W), wheat straw/solid content of binder mass ratio (W/S) and H 2 O 2 /solid content of binder mass ratio (H/S), respectively. The results show that all the four variables have a great influence on the foaming process and skeleton structure of the geopolymer, which greatly affect the properties of the bio-insulation materials. In conclusion, the thermal conductivity of bio-insulation materials varies from 0.092 to 0.186 W m−1 K−1, and the compressive strength varies from 0.18 to 5.622 MPa with the density being 235–894.1 kg m−3. Moreover, the values of water and moisture absorption rates are 32–107% and 4–33% respectively. A desirable bio-insulation material with wheat straw length of 0.2 cm, Wp/W being 1, W/S being 0.124, and H/S being 0.0124, is recommended, of which the thermal conductivity is 0.101 W m−1 K−1 with the compressive strength being 1.2 MPa and the density being 302.4 kg m−3. This new kind of bio-insulation material exhibits good thermal and mechanical performances, which allows it to be applied as a thermal insulation material in buildings, especially the prefabricated buildings. And it is beneficial to energy saving and environmental protection. [ABSTRACT FROM AUTHOR]

Windmill palm, a tree species that is native to China, has gained attention with regard to the production of substantial amounts of biomass fibers via yearly pruning. This study investigates the structure and thermal properties of cellulose nanofibrils (CNFs) obtained from windmill palm biomass, with the goal of promoting the usage of these CNFs. Alkali–ultrasound treatments are employed herein to prepare samples of the CNFs. The micromorphology of the prepared samples is observed using scanning electron microscopy, atomic force microscopy, and transmission electron microscopy. Furthermore, X-ray diffraction analysis is used to examine the aggregated structure of the samples, and thermogravimetric analysis is used to investigate their thermal properties. Results indicate that during alkali hydrolysis when obtaining CNFs, the fiber cell wall exhibits distinct spiral cracking. The diameter of the obtained nanocellulose is <90 nm. The removal of lignin and hemicellulose materials from the fiber cell enhances the crystallinity of CNFs to as high as 60 %, surpassing that of windmill palm single fibers. The thermal decomposition temperatures of the CNFs are found to be 469 °C and 246 °C for the crystalline and amorphous regions, respectively. [ABSTRACT FROM AUTHOR]

The additional 0.5 °C warming from 1.5 to 2°C global target has a significant impact on the occurrence of extreme temperature events. While the arid and semi‐arid areas (ASA) and humid areas (HA) present different response characteristics to the additional global mean 0.5 °C warming due to their differences in thermal properties. In this study, both the stabilized and transient 1.5 °C (2 °C) global warming scenarios projected by the Community Earth System Model (CESM) are used to compare the extreme temperature responses between the ASA and HA to the 2 and 1.5 °C global warming targets over East–central Asia. The results indicate that cold fixed‐threshold indices (frost days [FD] and icing days [ID]) will decrease more rapidly in ASA, by approximately 10 days (1.5 °C) and 15 days (2 °C) compared to the historical period, respectively. Warm fixed‐threshold indices (summer days [SU] and tropical nights [TR]) will become more common in HA, especially southeast of China. Under 1.5 °C target, the increase of intensity indices is equal to the average temperature warming response (1.5 °C), while the additional 0.5 °C warming makes the response of intensity indices much greater than 0.5 °C. Under 0.5 °C warmer world, the daily temperature range (DTR) will experience a 0.5 °C increase in most HA and a 0.2–0.5 °C decrease in ASA during winter. As a whole, the additional 0.5 °C warming has an amplified effect and the 1.5 °C global warming target could reduce the extreme temperature events significantly over East–central Asia. [ABSTRACT FROM AUTHOR]

This study was to compare the characteristics of 21 starches isolated from chestnuts produced in different regions in China, also to investigate their potential food applications. Starches were isolated from chestnuts under the Castanea mollisima Blume variety with sub-varieties of Banli, Youli, and Maoli. Several properties of the starch samples were examined, including the moisture content, amylose content, morphological characteristics, color values, light transmittance, syneresis, swelling power, water solubility index, pasting properties, FTIR characteristics, X-ray diffraction (XRD) patterns, and thermal properties. The results showed that starches isolated from Youli presented higher resistance to shear and swelling during heating, indicating more suitability for high-heat cooking. The FTIR spectra confirmed the polysaccharide nature of all the chestnut starches. The XRD patterns showed most chestnut starches were in C b -type, while only five were in C a -type. Overall, this comparative study would be relevant for the further exploration of the potential utilization of chestnut starch in both food and non-food industries. • Physiochemical properties of 21 chestnuts starches were examined. • Starches presented significant differences in morphology, pasting, and thermal properties. • Starches from Maoli had generally smaller granule sizes. • Starches from Youli presented higher resistance to shear and thermal swelling. • All chestnuts had C-type starch, among which most starches were in C b -type. [ABSTRACT FROM AUTHOR]

• A PVT collector with a roll-bond absorber is designed for rural home application. • Thermo-laminating is a novel and convenient method for PV-absorber connection. • The validated PVT model can simulate the roll-bond PVT performance accurately. • The model is available for predicting the dynamic performance of PVT systems. This paper mainly investigated the performance of a low-cost roll-bond water-type photovoltaic thermal (PVT) collector from both experimental and modelling approaches under the climatic conditions of Sichuan Basin of China. The design and manufacturing process of the PVT prototype adopted the available commercial PV panels for convenience and for reducing the manufacturing cost. The experiment measured all the main properties of the developed PVT module. The excellent heat transfer performance of its roll-bond absorber plate was also validated by outdoor steady-state tests. Then, the steady-state numerical models were used to simulate the performance of the PVT prototype in TRNSYS. By comparing the simulation and experimental results, two robust models were selected which have their own advantages in charactering the thermal and electrical properties of the PVT collector. Through validating the numerical models with experimental data, the deviation between the simulated and the measured values was further reduced. In addition, a complete photovoltaic thermal–domestic hot water (PVT-DHW) system with such PVT collectors was developed in TRNSYS, by which the annual system output and efficiency were predicted and analysed. [ABSTRACT FROM AUTHOR]

Yam (Dioscorea spp.) is a major food source in many countries due to its tuber rich in starch (60 %–89 % of the dry weight) and various important micronutrients. Orientation Supergene Cultivation (OSC) pattern is a simple and efficient cultivation mode developed in China in recent years. However, little is known about its effect on yam tuber starch. In this study, the starchy tuber yield, starch structure and physicochemical properties were compared and analyzed in detail between OSC and Traditional Vertical Cultivation (TVC) with Dioscorea persimilis "zhugaoshu", a widely cultivated variety. The results proved that OSC significantly increased tuber yield (23.76 %–31.86 %) and commodity quality (more smooth skin) compared with TVC in three consecutive years of field experiments. Moreover, OSC increased amylopectin content, resistant starch content, granule average diameter and average degree of crystallinity by 2.7 %, 5.8 %, 14.7 % and 9.5 %, respectively, while OSC decreased starch molecular weight (Mw). These traits resulted in starch with lower thermal properties (To, Tp, Tc, ΔH gel), but higher pasting properties (PV, TV). Our results indicated that cultivation pattern affected the yam production and starch physicochemical properties. It would not only provide a practical basis for OSC promotion, but also provide valuable information on how to guide the yam starch end use in food and non-food industries. [ABSTRACT FROM AUTHOR]

Abstract: Accurate information on the distribution of permafrost and its thermal and hydrological properties is critical for environmental management and engineering development. This study modeled the current state of permafrost on the Qinghai‐Tibet Plateau (QTP), including the spatial distribution of permafrost, active‐layer thickness (ALT), mean annual ground temperature (MAGT), depth of zero annual amplitude (DZAA) and ground‐ice content using an improved Noah land surface model (LSM). The improved model was examined at a typical permafrost site and then applied to the entire QTP using existing gridded meteorological data and newly developed soil data. The simulated permafrost distribution and properties were validated against existing permafrost maps in three representative survey areas and with measurements from 54 boreholes. The results indicate that the Noah LSM with augmented physics and proper soil data support can model permafrost over the QTP. Permafrost was simulated to underlie an area of 1.113 × 106 km2 in 2010, accounting for 43.8% of the entire area of the QTP. The modeled regional average ALT and MAGT were 3.23 m and −1.56°C, respectively. Spatially, MAGT increases and DZAA becomes shallower from north to south. Thermally unstable permafrost (MAGT above −0.5°C) is predominant, accounting for 38.75% of the whole permafrost area on the QTP. Ice‐rich permafrost was mainly simulated around lakes across the north‐central QTP. [ABSTRACT FROM AUTHOR]

To be better understand the hydrological and thermal behavior of karst systems in South China, seasonal variations in flow, hydrochemistry and stable isotope ratios of five karst springs were used to delineate flow paths and recharge processes, and to interpret their thermal response. Isotopic data suggest that mean recharge elevations are 200–820 m above spring outlets. Springs that originate from high elevations have lower NO3− concentrations than those originating from lower areas that have more agricultural activity. Measured Sr2+ concentrations reflect the strontium contents of the host carbonate aquifer and help delineate the spring catchment’s saturated zone. Seasonal variations of NO3− and Sr2+ concentrations are inversely correlated, because the former correlates with event water and the latter with baseflow. The mean annual water temperatures of springs were only slightly lower than the local mean annual surface temperature at the outlet elevations. These mean spring temperatures suggest a vertical gradient of ~6 °C/vertical km, which resembles the adiabatic lapse rate of the Earth’s stable atmosphere. Seasonal temperature variations in the springs are in phase with surface air temperatures, except for Heilongquan (HLQ) spring. Event-scale variations of thermal response are dramatically controlled by the circulation depth of karst systems, which determines the effectiveness of heat exchange. HLQ spring undergoes the deepest circulation depth of 820 m, and its thermal responses are determined by the thermally effective regulation processes at higher elevations and the mixing processes associated with thermally ineffective responses at lower elevations. [ABSTRACT FROM AUTHOR]

The Local Climate Zone (LCZ) scheme aims to provide an objective and standardized classification protocol for urban temperature studies in any city. The field observed temperature data from 12 selected LCZ sites in Nanjing, China, for the period from July to November 2016, was used to evaluate the LCZ scheme. The results here are the first to assess the LCZ scheme in a high-density city in mainland China. Distinct thermal differences among the LCZ sites provide preliminary evidence to support that the LCZ concept is applicable for urban temperature studies in cities of China. [ABSTRACT FROM AUTHOR]

Thermal properties of glazing facades and windows system may affect the solar heat gain through its heat transfer area to an enclosed built environment, eventually affects the electricity consumption of air-conditioning system. Advanced glazing technologies offer a lower solar heat gain. This research project examines the relationship between the types of glazing, orientation and window-to-wall ratio (WWR) against the solar heat gain through the fenestration and annual electricity end uses for a window-typed air-conditioning system, by means of building energy simulation software, EnergyPlus. Reduction of electricity end uses and windows heat addition for the same windows configuration with different advanced glazing ranges are 13.8% and 69.1% respectively, in Hong Kong. The relationship among different construction configuration and climate is investigated. The optimum choice of glazing for minimizing the heat gain and maximizing the visual transmissibility is also suggested in accordance to the simulation results. [ABSTRACT FROM AUTHOR]

Super-long urban road tunnels have become prevalent in China recently. This study established a three-dimension CFD model containing two adjacent super-long urban road tunnels to estimate characteristics of pollution dispersion outside the tunnels. The results indicated that crossflow between two adjacent tunnels was quite severe, which contributed to carbon monoxide concentration was almost 50 ppm exceeding the 10 ppm limit of National Standard in China for 1h exposure level when exhaust shafts were absent. When the shafts exhausted 80% pollutants from the tunnel portal, crossflow between two adjacent tunnels could at least decrease to 20% of the conditions without shafts. The simulation results could not only demonstrate the importance of shafts for super-long urban road tunnels, but also provide a fundamental and guideline for evaluation of urban environment and design of the tunnel exhaust shafts, including locations and types. [ABSTRACT FROM AUTHOR]

• Large-sized InSe single crystal. • The ground simulation apparatus of China space station. • γ-Phase with space group of standard R 3 m. • A positive thermal expansion at 30–500 °C. • No element volatilization even the temperature as high as 1000 °C. Indium selenide (InSe) semiconductor crystal was grown by using the ground simulation apparatus of China space station in this work. The furnace was controlled at 715 °C and the temperature gradient for crystal growth was ∼30 °C/cm. The as-grown InSe crystalizes in γ-phase with space group of R 3 m. The average etching pits density (EPD) is estimated to be about 104/cm2. Thermal analysis indicates a positive thermal expansion at 30–500 °C and no volatilization occurred even as high as 1000 °C. This work not only establishes a reliable process for preparing large-sized InSe single crystal but also creates a foundation for further work in outer space in the future. [ABSTRACT FROM AUTHOR]

In this work, Huadian oil shale from China was treated by hydrothermal pretreatment at 200 °C with 1.0–2.5 h in order to investigate the effect of hydrothermal pretreatment on pyrolysis product distribution and characteristics of oil. The differences in the elemental composition and thermal behavior between the untreated and treated oil shale were analyzed and compared. The hydrothermal treatment process could decompose oxygen functional groups and remove some water soluble inorganics in oil shale, which decreased the formation of gas and water during the pyrolysis. However, hydrothermal pretreatment was conducive to increasing shale oil yield. The maximum of oil yield was obtained at the pretreatment time of 2.0 h. The enhancement of the free-radical reactions during the pyrolysis and the reduction of the secondary cracking reactions of the generated oil vapors were considered as the main reasons. The oil obtained by the treated oil shale had a higher H/C ratio, indicating it had high energy content. The analysis results of chemical compositions in oils showed that the relative content of aliphatic hydrocarbons significantly increased after hydrothermal pretreatment. The further analysis demonstrated that the increase in the pretreatment time caused the generated long chain hydrocarbons tended to be directly released from oil shale particles, and were condensed into the oil. [ABSTRACT FROM AUTHOR]

Among coal-producing countries, China has witnessed the highest frequency and severity of coal fires. During mining in the re-mining face and the lower part of the thick coal seam (or coal seam group), second or multiple oxidations of the residual coal can readily occur in mined-out areas, severely increasing the risk of coal fires. The study of multiple oxidations of coal aids in the early detection of spontaneous combustion of remaining coal in the mined-out areas. The characteristics of coal fires are demonstrated using fresh coal samples (first-oxidized coal) and oxidized coal samples (second-oxidized coal) from four different ranks of coals. Proximate and elemental analysis, Fourier transform spectroscopy, and thermogravimetry-differential scanning calorimetry were adopted to investigate the quality, microcharacteristics, characteristic temperatures, and apparent activation energy of second-oxidized coal. In addition, the effect of spontaneous combustion at heating rates of 5.0, 10.0, and 15.0 °C min was studied. Compared with the four samples of first-oxidized coal, those of second-oxidized coals cause fire easily under the same conditions. [ABSTRACT FROM AUTHOR]

[Display omitted] • LT + LL (low temperature and low light) reduced thermal stability in the cultivars. • Poor-quality cultivar deteriorated starch physicochemical properties under LT + LL. • Good-quality rice cultivar improved starch pasting properties under LT + LL. • Poor-quality cultivar decreased compactness of starch in grains under LT + LL. Late-season indica rice frequently encounters low temperature (LT) along with low light (LL) after heading in southern China, which deteriorates the grain quality by altering starch quality. However, the detailed effects on starch properties of these stressors remain unclear. Herein, two indica rice cultivars with good and poor grain quality were grown under control (CK), LT, and LT + LL conditions after heading and the structural and physicochemical properties of their starch were evaluated. Compared with CK, LT and LT + LL worsened thermal and pasting properties of starch in the two cultivars, mainly because they increased branch chain branching and A chain (DP ≤12), and decreased average branch chain length and crystallinity. Compared with LT, LT + LL deteriorated the pasting properties of the poor-quality cultivar, such as reducing breakdown (BD), final and peak viscosity, which mainly owing to decreasing the starch branching and crystallinity degrees, and increasing the small starch granules (d < 10 μm). Gelatinization enthalpy and BD both had significant and positive correlations with amylose content, the ratio of amylose and amylopectin, B3 chain and crystallinity. Taken together, these results suggest that LT and LT + LL during grain filling can deteriorate the physicochemical properties of starch in late-season indica rice cultivars by disrupting starch multilevel structure, especially upon LT + LL. In particular, while poor-quality cultivar had poorer physicochemical properties, the good-quality cultivar had poorer thermal properties under LT + LL. [ABSTRACT FROM AUTHOR]

With the increase of coal energy mining depth in China, coal spontaneous combustion phenomenon becomes more frequent, which makes the safe mining of coal energy in China under serious threat. In order to prevent coal spontaneous combustion, it is significant to investigate the process of coal oxidation and spontaneous combustion by combining thermal and microstructural properties, which is a necessary study to figure out the mechanism of coal spontaneous combustion. A series of coal oxidation experiments were conducted with the aid of high precision Calorimeter and X-ray diffractometer. The results show that the thermal properties of coal spontaneous combustion have obvious segmentation characteristics which is not affected by the degree of metamorphism and heating rates, and the initial exothermic temperature is positively correlated with heating rates. The effect of temperature on microscopic characteristics is not uniform, but the degree of metamorphism has a regular change for microscopic characteristics. Although temperature does not play a decisive role, the spatial structure of coal oxidation process has some reversibility with the change of temperature. Besides, thermal dynamic balance is an important cause of microstructure changes. It is expected that this work will contribute to the refinement of the theory of coal spontaneous combustion. [Display omitted] • The thermal properties have obvious segmentation characteristics. • The initial exothermic temperature is positively correlated with heating rates. • The thermal dynamic balance is an important cause of microstructure changes. [ABSTRACT FROM AUTHOR]

Engineering construction has major influence on the permafrost environment. This paper analyzes the interaction between engineering construction and permafrost environment along the Chaidaer-Muli Railway (simply, CMR) based on the press-state-response (PSR) framework. The permafrost environmental system is divided into three subsystems, consisting of permafrost thermal stability, proneness to the freeze-thawing erosion and permafrost ecological fragility. Each subsystem considers its most important influencing factors. Catastrophe Progression Method (CPM) is applied to calculate the current environment condition along the railway. The result indicates that: (1) as far as the thermal stability is concerned, most sections along the CMR are mainly concentrated in rank III (fair situation), and a few in II (good situation) and IV (bad situation), respectively; (2) for the proneness to the freeze-thawing erosion, the entire railway route falls largely in rank II (good situation); (3) along the CMR, the ecological fragility of the permafrost environment is in rank II (good situation), or slightly fragile; (4) overall, the permafrost environments along the CMR are in rank III (fair situation) or II condition (good situation). In general, the permafrost environment along the CMR is fair. It is mainly because a series of active measures of protecting permafrost were taken for stabilizing the CMR foundation soils. On the one hand, we should try our best to minimize the influences that engineering activities have exerted on ecology and environment, on the other hand, the positive measures have made improvements to prevent the permafrost environment from deterioration. [ABSTRACT FROM AUTHOR]

• Neural network regression analysis is performed when studying red mud-AAC with different w/s ratios. • Relationship between pore structures and performances of red mud-based AAC is clarified. • A model reflecting pore structures and compressive strength of AAC is proposed with better regression and applicability. • A modified series–parallel model of thermal conductivity is provided in red mud-based AAC. • Neural network regression analysis could be effective based on a mass of measured data. A large amount of red mud needs to be disposed of in China, which causes environmental pollution. The feasibility of using red mud in autoclaved aerated concrete (AAC) has been confirmed, and its strength and thermal properties are highly related to its pore structures. To further clarify the relationship between the pore diameter (shape) and performances of red mud-based AAC, this study aims to establish a quantitative relationship between the compressive strength and the pore structure of AAC with red mud as well as its average shape factor of pores with a diameter above 0.5 mm, which was relied on the principle of elasticity. The experimental results show the strength formula of red mud-based AAC considering its porosity and its pore shape is R = R 0 0.03 1 - 1.21 V p 2 3 + 0.95 S H π 2 - 4 π + 8 + S H 2 π 4 + 16 S H π 2 - 8 S H π 3 16 + S H π 2 - 4 π + 8 + S H 2 π 4 + 16 S H π 2 - 8 S H π 3 . At the same time, to explore the constitutive relationship between the pore structure and thermal properties of red mud-based AAC, the series–parallel model of thermal conductivity is analyzed and modified, indicating that the series model has greater contribution to the effective thermal conductivity of AAC, where the expression is λ eff = 0.9 1 v 1 / λ 1 + v 2 / λ 2 + 0.19 (v 1 λ 1 + v 2 λ 2). Finally, through the neural network regression analysis, it is proved that the established model reveals good accuracy. [ABSTRACT FROM AUTHOR]

Traditional methods for studying surface water and groundwater interactions have usually been limited to point measurements, such as geochemical sampling and seepage measurement. A new methodology is presented for quantifying groundwater discharge to a river, by using river surface temperature data obtained from airborne thermal infrared remote sensing technology. The Hot Spot Analysis toolkit in ArcGIS was used to calculate the percentage of groundwater discharge to a river relative to the total flow of the river. This methodology was evaluated in the midstream of the Heihe River in the arid and semiarid northwest China. The results show that the percentage of groundwater discharge relative to the total streamflow was as high as 28%, which is in good agreement with the results from previous geochemical studies. The data analysis methodology used in this study is based on the assumption that the river water is fully mixed except in the areas of extremely low flow velocity, which could lead to underestimation of the amount of groundwater discharge. Despite this limitation, this remote sensing-based approach provides an efficient means of quantifying the surface water and groundwater interactions on a regional scale. [ABSTRACT FROM AUTHOR]

Although temperature is considered a key factor influencing rock decay, little is known about the quantitative relationship between a rock's decay rate and temperature, which makes it difficult to quantitatively predict the rate of rock decay under varied temperature during wetting–drying cycle conditions. Thus, the aim of the present paper was to observe the decay rate of various purple mudstones and to develop a model with which to calculate their decay rates under varied temperature conditions. Three types of purple mudstone were sampled from the Tuodian group (J 3 t), Matoushan group (K 2 m) and Lufeng group (J 1 l), located in the Chuxiong district of Yunnan province, south-western China. All samples were manually cut into cubes of 50 × 50 × 50 mm, before being subjected to 39 wetting–drying cycles in a 2 mm sieve under artificial constant temperature, natural daily temperature variation and artificial temperature alternation (minimum and maximum) treatments in the laboratory. Decay rates were calculated by weighing the mass remaining in the sieve after each treatment cycle. The results showed that the decay rates of the tested rocks rose with an increase in temperature and temperature difference (maximum–minimum), with the rank order of decay rate being J 3 t > K 2 m > J 1 l. Quantitative analysis revealed rock decay rate to be significantly related to temperature by a power function, and exponentially related to temperature difference. Our results suggested that temperature difference has a stronger effect on purple mudstone decay than that of temperature magnitude during the wetting–drying processes. [ABSTRACT FROM AUTHOR]

ABSTRACT Temporal and spatial changes in the annual and seasonal temperatures in a typical basin of the Qiantang River were analysed based on the time series databases of daily temperatures from 14 meteorological stations. Both the Mann-Kendall ( MK) trend test and simple linear regression analyses were employed to detect trends in the mean and extreme temperatures. The temperature changes during the three periods of 1960-1990, 1960-2000 and 1960-2006 were investigated at each meteorological station and over the entire basin as an average. The spatial and temporal changes were characterized by significant warming throughout the region, with the minimum temperature (Tn) increasing the most, particularly after 1990. Various percentiles of extreme temperatures, as well as their corresponding frequencies, were chosen to explore the trends of extreme climate change in this region. Linear regression analyses showed a significant warming trend in cold events both on an annual and seasonal basis, especially in the winter. Conversely, the hot events were dominated by an insignificant warming trend ( p > 0.05). When comparing the time series before and after 1990, trend shifts were apparent in both the mean and extreme temperatures, particularly in the spring and winter. In addition to the large-scale circulation, regional factors may have influenced the observed climate change in the studied region. Climate change has already influenced human society by, for example, increasing the frequency of haze in the study region. We conclude that the warming here is mainly attributed to changes in the minimum temperature. [ABSTRACT FROM AUTHOR]

This study investigated the structural and physical properties of starches extracted from six varieties of millet mainly grown in China. The amylose content of millet starches ranged from 17.6 to 28.4 g/100 g (dry weight basis, db), and a variety of waxy proso millet starch (0.38 g/100 g, db) was identified. These starches exhibited a majority of large polygonal granules with several indentations, few small spherical granules, and A-type crystallinity. Proso millet starch showed prominent paste clarity and freeze-thaw stability, whereas finger millet starch exhibited the highest solubility. Moreover, barnyard millet starch had the lowest sediment volume. The gelatinization enthalpy of proso millet starch was the highest (5.16 J/g). For non-waxy millet starch, the ratio of retrogradation (R%) was positively correlated with amylose content. Among all starches, the storage modulus (G′) was higher than the loss modulus (G″) during heating and cooling. The G′ and G″ of proso millet starch and barnyard millet starch pastes were significantly lower than other starches during cooling. The pasting properties of six millet starches significantly differed, had positive correlation with amylose content, and were affected by NaCl, sucrose, and pH values. [ABSTRACT FROM PUBLISHER]

We present the first data on the mode of occurrence of Au in fly ashes from the Wulantuga and Lincang power plants in China, which burn high-Ge coal. Gold occurs as fine-grained drop-like particles with a size of n*0.01-0.2 μm on the surface of the glass globules. These features of the Au particles are proof for Au condensation from the gas phase and deposition on the surface of fly ash in the cooler zone of the electrostatic precipitator and baghouse filter. [ABSTRACT FROM AUTHOR]

To meet the prospect of carbon neutrality, Deep borehole heat exchanger (DBHE) shows good potentiality in extracting deep geothermal energy for building heating, especially in densely populated urban areas of northern China. To investigate the influence on different soil thermal properties and system layouts of the DBHE array, a comprehensive numerical model has been established by OpenGeoSys software coupled TESPy toolkit and a series of scenarios are simulated. Results show that thermal conductivity lay a more important influence on heat extraction performance for DBHE array, rather than volumetric heat capacity. The thermal plume of DBHE array will grow larger along with higher thermal diffusivity. For typical geological parameters in Xi'an, the inter-borehole spacing should not be set below 15 m or it will bring a risk of freeze in circulation. The heat extraction performance and long-term sustainability of single-line layout are obviously better than other layout patterns, also with a smaller ground area needed to deploy the boreholes. This study implies that soil thermal conductivity is the core factor in determining the heat extraction performance of DBHE array and also gives suggestions for the system design of DBHE array in the aspect of borehole spacing and system arrangement. • Long-term performance evaluation under different soil thermal properties for DBHE array. • The level of soil thermal conductivity has a crucial impact on the heat extraction of DBHE array. • Radius of thermal plume after long-term operation increases with soil thermal diffusivity. • Proper inter-borehole spacing and arrangement geometry are suggested for DBHE array. [ABSTRACT FROM AUTHOR]

Abstract: The ventilation condition is one of the main factors that determine the Heat Release Rate (HRR). In order to reveal the influence of ventilation condition on the HRR of China Railways High-speed (CRH) passenger rail car and help the fire protection engineers to choose the right HRR during the fire risk assessment of high-speed rail system in China, the HRR and other thermal parameters of the individual materials and component assemblies of CRH passenger rail car, are measured with the Cone Calorimeter and other test instruments, as the input parameters of Fire Dynamics Simulator (FDS), and 2 fire scenarios have been designed to obtain the HRR vs. time curves of CRH passenger rail car on the different ventilation conditions, such as the location and number of the open windows. The research results show that the ventilation condition exerts a significant influence on the HRR of CRH passenger rail car, which is in the range of 18.4∼37.9 MW according to the different ventilation conditions; if only one window is open, the closer the open window gets to the ignition source, the higher the HRR is; if several windows are open at the time, the HRR is the highest as 2 windows are open, which is 37.9 MW. The HRR of CRH passenger rail car dramatically fluctuates with the different ventilation conditions, so the HRR of CRH passenger rail car should be chosen and applied carefully. [Copyright &y& Elsevier]

The thermal insulation of clothing needs to be easily adjusted in an unsteady environment, but this is extremely difficult for most clothing. To reveal the effect of different styles of Tibetan clothing on their thermal property, the total thermal insulations of Tibetan clothing in three typical styles were measured using a thermal manikin. The clothing area factors (fcl) of the Tibetan clothing and body surface area covered by a Tibetan robe were tested with a photographic method. The results showed the following: 1) For similar insulation, fcl of Tibetan clothing is about 0.23 bigger than that of western clothing, estimated from ISO 11079; 2)the style of Tibetan clothing significantly affects the fcl (p < 0.05, fcl = 1.229 + 0.007 BSAC) and the intrinsic thermal insulation (p < 0.05, Icl = 0.166 + 0.016 BSAC); 3)the adjustable thermal insulation of Tibetan clothing proved its adaptability to the large air temperature difference environment on the Tibetan plateau ,which should be valuable for the product development of clothing used in a unsteady environment. [ABSTRACT FROM AUTHOR]

As an important engineering material, polycarbonate (PC) has been used widely. When exposed to the environment, PC will have aging process, which will reduce its performance and efficiency. This article studies the changing regularities of PCs structure and properties of ageing in western areas of China by measuring the change of intrinsic viscosity (IV), thermal decomposition temperature, glass transition temperature, and the groups within PC. The analysis of its IV, DSC, and thermo gravimetric analysis exhibited the same changing regularity, i.e., the aged PC (in Lasa, Yuli, and Jiangjin) experienced degradation and crosslinking, while degradation occurred earlier in the process of ageing, crosslinking predominated in later period. In addition, the results of UV absorption spectra and infrared absorption spectra showed the evidence of decomposition of the ester groups, resulting in the production of alcohol and phenol. And the results of mechanical tests indicated that the ductility disappeared mainly in the first year of outdoor aging. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012 [ABSTRACT FROM AUTHOR]

The article offers information on the study regarding the changes in the active layer thickness (ALT) and the temperature of permafrost along the Qinghai-Xizang Railway in Tibet, China gathered from 2006-2010. It states that based on the estimation through linear regression using the five year data, the permafrost temperature increase at the depth of 6.0 meters. It adds that changes in the colder permafrost is much greater than those on warmer permafrost.

The evacuated tube solar water heaters are widely in use today. But so far their thermal performance has not been systematically evaluated, despite the increased popularity. An experimental solar hot water system including two collector types, namely water-in-glass and heat-pipe, of evacuated tube solar water heater has been set up. Their capacity is typical for serving single family domestic hot water system. Performance tests were carried out in Hong Kong and under almost identical boundary conditions by placing the two collectors side-by-side. The energy performance has been analysed and the daily efficiency, transient efficiency and night-time heat loss were compared. While the energy acquisition performance of the heat-pipe collector design is found slightly better, the heat loss performance is found weaker than the water-in-glass collector design. [ABSTRACT FROM AUTHOR]