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In order to address the challenges of resource utilization posed by construction waste, the substitution of natural aggregate (NA) with public fill (PF) contents was investigated for load reclamation and road grassroots applications. A comprehensive assessment of road performance for the recycled mixture was conducted, focusing on parameters such as unconfined compressive strength, splitting strength, compressive resilience modulus, dry shrinkage, and frost resistance. Additionally, the impact of incorporating PF at various types and replacement ratios on the microstructure of cement-stabilized aggregate (CSA) was analyzed. The results indicated that the unconfined compressive strength of cement-stabilized recycled mixture with varying PF contents meets the base strength requirements for heavy, medium, and light traffic pavement on secondary and sub-secondary roads in China. Notably, the unconfined compressive strength and resilience modulus follow a similar pattern, reaching their peak at a 25% PF content. Microscopic examination reveals that an appropriate PF content leads to the predominant formation of C(N)-A-S-H, hydrotalcite, Ca(OH)2, and CaCO3 as paste reaction products. As the replacement of public fill increases from 0% to 25%, there is a gradual stacking of gel products, which enhances the compactness of the microstructure by cementing together unreacted particles. Consequently, this process reduces dry shrinkage strain and effectively mitigates the formation of reflection cracks. Applying large quantities of public fill to road construction can effectively deal with various waste accumulation problems and produce a novel road material with significant social, economic, and environmental benefits. [ABSTRACT FROM AUTHOR]

As the second most significant metal following steel, aluminum plays a vital role in the advancement of both strategic emerging industries and national economic development. The existing oil and gas drilling data indicate that the deep bauxite deposits is abundant around the Ordos Basin in China, at the depths ranging from several hundred meters to several kilometers. Based on the geological and hydrogeological characteristics analysis, it is found that deep bauxite deposits in the basin have distinct electrical characteristics, characterized by four highs and two lows. While there is scarcity of prior research on the exploration topic for the technique limitation. In this paper, a logging interpretation model has been developed, which allows the evaluation of bauxite deposits. An efficient technology was proposed for deep bauxite exploration, utilizing an in-situ leaching mining technique. This technology is well-suited to the geological conditions of the Ordos Basin, ensuring that the solution flows within the bauxite ore bed without any seepage loss. To prevent the leaching solution from seeping into and polluting the main aquifer around the basin, several measures have been proposed. These include filling with polymer resin, well pattern seepage control plugging, and establishing monitoring systems. The results of this study provide a theoretical basis for the adoption of environmentally sustainable mining techniques and the mitigation of water pollution in deep bauxite exploration. [ABSTRACT FROM AUTHOR]

Glasses cooled from impact melt and vapor are a common component in lunar regolith, carrying important information about protolith composition, regolith formation, and impact flux on the Moon. Interpretations, however, are frequently challenged due to widespread ambiguity in determining their provenances. Regolith samples returned by China's Chang'E‐5 mission provide a unique opportunity to study the microscopic mechanism of regolith reworking on the Moon, because as evidenced by the coherent radioisotope ages and petrographic characteristics of basaltic clasts in the regolith, the Chang'E‐5 regolith was mainly evolved from local mare materials, containing minor exotic components. Here, we report 153 glass particles larger than 20 μm in diameters that were screened from 500 mg of Chang'E‐5 regolith. Most glass particles have rotational shapes and contain structural and/or compositional heterogeneities in interiors, and geochemical analyses reveal a dominant origin as impact melt of local mare materials. Surfaces of the impact glasses are observed to have abundant protruded and dented microstructures, which are classified as different groups based on their morphology and geochemistry. Similar microstructures were observed on impact spherules collected by the Apollo and Luna missions, but those on the Chang'E‐5 impact glasses were formed without substantial involvement of exotic ejecta. Microstructures such as silicate melt pancakes that frequently exhibit flow spikes at margins, nano‐phase iron‐rich mounds that are arranged with semi‐equidistant spaces in curves and patches, spatially clustered microcraters that are indicative of secondary impacts, and blunt linear scratches with terminal particles all suggest that regolith reworking mainly occurred among local materials at low speeds. Plain Language Summary: Regolith particles on the Moon exhibit an abundance of small‐scale surface texture or microstructures that were formed during regolith reworking. Lunar impact glasses are mainly melted from surface regolith, and microstructures on their surfaces record the history of subsequent regolith reworking. The possible contribution of exotic ejecta in regolith gardening is an interesting topic in lunar science. However, resolving this issue has been a persistent difficulty by both remote observations and sample analyses. China's Chang'E‐5 mission returned regolith samples from one of the youngest mare units on the Moon, and earlier sample analyses revealed little exotic components. In 500 mg of Chang'E‐5 regolith, we handpicked 153 glass particles that are larger than 20 μm. Most of the particles are heterogeneous impact glasses that contain voids and unmelted fragments, and geochemical analyses showed that the remaining structurally homogeneous particles were also impact glasses formed from local regolith. Based on high‐resolution microscopic imaging and elemental mapping, we recognized and classified the abundant protruded and dented microstructures on the glass particles. Morphology and crosscutting relationship of the microstructures suggest that they were mostly formed during regolith reworking by low‐speed events of local materials that had various thermophysical states (vapor, melt, and solid). Key Points: 153 glass particles larger than 20 μm in diameters are separated from 500 mg of Chang'E‐5 regolithCrosscutting relationships among surface microstructures reveal intricate regolith reworking processesProtruded and dented microstructures on surfaces of Chang'E‐5 glass particles were formed with velocities lower than primary impacts [ABSTRACT FROM AUTHOR]

Alkali-activated materials are produced by chemically polymerizing the aluminosilicate materials using alkaline activators, which can effectively lower the greenhouse-gas emissions (approximately 73%) released by ordinary Portland cement (OPC). Silicomanganese slag is a large solid waste discharged from the ferroalloy industry in China that can pollute the environment and occupy resources. In this paper, the slag in alkali-activated material was replaced with silicomanganese slag to address the disposal of silicomangaese slag. The flowability, setting times, compressive and flexural strengths, micro-structure and freeze-thaw resistance of alkali-activated silicomanganese slag concrete (AASSC) with varied substitution ratios, volume fractions of steel fibers and alkali-activated modulus (MS) were exploited. As a results the compressive strengths at 56 days of AASSC with a 10% substitution ratio of silicomanganese slag reached over 80 MPa and over 132 MPa with the 3% steel fiber dosage. AASSC still reached 91 MPa and 45 MPa with 60% and 100% substitution ratios by cooperating 2% steel fibers, respectively. When the freeze-thaw cycle number reached 300, the compressive strengths of AASSC with the replacement ratios of 10%, 60% and 100% were 84%, 74% and 51% of their original values by cooperating 2% steel fibers, respectively; AASSC with the numerous substitutions of 60% and 100% were destroyed at 600 and 300 freeze-thaw cycles, respectively. AASSC with a 10% substitution ratio and 2% steel fiber content is suitable for excellent performance, and a 60% substitution ratio can also be applied to construction for the massive utilization of silicomanganese slag. [ABSTRACT FROM AUTHOR]

Abstract: Dehua is one of the most famous white porcelain production areas and one of the main porcelain exporting centers in Southern China. In this part of the study, white porcelain samples from the Song to Qing Dynasties excavated from Wanpinglun, Qudougong, Zulonggong, Jiabeishan and Xingjiao kiln sites were analyzed to investigate microstructure and its physicochemical basis. Physical properties of the samples were also studied, to evaluate the quality of porcelain production of Dehua kiln in ancient times. [ABSTRACT FROM AUTHOR]

Sandstone reservoir is one of the main types of oil and gas reservoirs in China. It has porous microstructure, which directly affects the transport properties of a sandstone. Hence, the study of porous microstructure is important to the exploration and exploitation of oil and gas. Three-dimensional microstructure of a sandstone can be reconstructed using the simulated annealing method based on statistical properties of its two-dimensional micrograph. The aim of reconstruction is to minimize the discrepancy between the statistical properties of the reconstructed microstructure and those of the two-dimensional image. To accelerate the rate of convergence, we proposed a different-phase neighbours (DPNs)-based pixel selection rule to replace the random pixel selection rule of the simulated annealing reconstruction. In this rule, pixels with the largest number of DPNs have the largest selection probability. The selection probabilities of other pixels are proportional to their DPNs. Microstructure reconstructed with the DPNs-based rule is compared with those with the random selection rule and two other biased pixel selection rules. The DPNs-based rule is the most effective in enhancing convergence. Permeability of the microstructure reconstructed with the DPNs-based rule is estimated by the Kozeny–Carman formula and is in good agreement with the one reconstructed with the random pixel selection rule. [ABSTRACT FROM AUTHOR]

Abstract: The Jian kiln, located in present-day Jianyang county of Fujian province, mainly produced black-glazed tea bowls. Jian tea bowl was used as a utensil for tea tasting and was greatly appreciated by emperor Huizong of the Northern Song dynasty. The black glaze of Jian bowl was sometimes marked with streaks or spots, usually called “hare''s fur” or “oil spot”, which are the crystalline markings of iron oxide precipitated during firing in the dragon kiln. In this study, black-glazed Jian bowl sherds excavated from the late Northern Song strata of Luhuaping and Daluhoumen Jian kiln sites were adopted as test samples. Based on the physico-chemical foundation for the formation of glaze microstructure, the correlation among composition, microstructure, and visual appearance has been investigated by means of energy-dispersive X-ray fluorescence, X-ray diffraction, and field emission electron microscopy. For the first time, the study provides realizing proofs for two kinds of microstructural forming mechanics. [Copyright &y& Elsevier]

A method of mask-shift filtering is presented for forming microstructures with irregular profile. When a three-dimensional (3D) microstructure is quantized to a number of microslices in one direction with equal interval, their two-dimensional average projections are calculated, respectively. A shift filtering mask is constructed by arranging the submasks converted from the corresponding subprojections. Filtering is carried out during exposure by moving the mask in the quantized direction to form a 3D microprofile on resist. The experimental results for forming irregular continuous relief profile in the larger areas are demonstrated and analyzed in this letter. [ABSTRACT FROM AUTHOR]

The persimmon-red glazed wares, characterized by a reddish-brown appearance with high gloss, were one of the main varieties of glazes manufactured in Jian kilns (Fujian province, China) during the Song Dynasty. Densely packed dendritic ε-Fe 2 O 3 crystals in microns size composed of several branches were observed in the glazes surfaces of Jian persimmon-red wares. The branches, consisting of well-arranged rod-like crystals with offset around 110 or 220 nm, could serve as sub-micron mirrors to improve the glaze gloss. A number of Al and few Ti and Mn ions were detected to substitute Fe ions in ε-Fe 2 O 3 crystals. The Al substitution could play a dual role in ε-Fe 2 O 3 structure: (1) stabilizes the structure through increasing of cationic disorder and (2) makes the appearance less dark, which could account for the nice persimmon-red appearance of Jian wares. Besides, zircon, quartz, hematite, jacobsite and mullite were also observed in the glaze surfaces. • Dendritic ε-Fe 2 O 3 crystals in microns size composed of several branches were observed in the glazes surfaces of Jian persimmon-red wares. • The branches consisting of well-arranged rod-like crystals with offset ~110 or 220 nm could serve as sub-micron mirrors to improve glaze gloss. • Al substitutions in ε-Fe 2 O 3 crystals could play a dual role of acting as stabilizers to increase cationic disorder and making appearance less dark. • A few impurity crystals including zircon, quartz, hematite, jacobsite and mullite were detected in the glazes surfaces. [ABSTRACT FROM AUTHOR]

Sintered and fused magnesia (FM) produced from the macrocrystalline magnesite in China have attracted attention worldwide for the production of various refractories. Herein, dead burnt magnesia (DBM) with varying compositions was investigated. The results revealed that the periclase crystals of the DBM92 sample were subrounded to rounded euhedral, whereas the periclase crystals of the DBM95 sample were subhedral and idiomorphic. In addition, a significant amount of periclase–periclase bonding with straight boundaries was observed in the DBM97 sample. The periclase crystals of the DBM98 sample with no clear boundaries exhibited the densest packing among the samples. The silicate matrix around the periclase grains of the DBM92 sample contained forsterite and monticellite, whereas that around the periclase grains of the DBM95 sample was mainly composed of monticellite and merwinite. Dicalcium silicate and merwinite were observed in small amounts as interstitial phases in the DBM97 sample. In contrast, only dicalcium silicate, which was concentrated in small triangular pockets, was observed in the densely packed periclase grains of the DBM98 sample. The hot modulus of rupture tests revealed that an alkali-resistant DBM95-based brick can be prepared at a lime–silica ratio of <0.5. The best-quality DBM97-based brick can be prepared at a lime–silica ratio of approximately 2.2, which ensures that dicalcium silicate is the only interstitial phase. The periclase crystals of the two-step FM were significantly larger than those of the one-step FM and exhibited remarkably fewer silicate boundaries. The superior structure and large crystal size of the two-step FM can endow magnesia–carbon bricks with slag corrosion resistance. [ABSTRACT FROM AUTHOR]

• 52 tensile coupons of high-performance bolt material are tested. • Effects of test strain-rate on the elevated temperatures are clarified. • Elevated-temperature behaviour of the steel is elucidated at microstructure level. • Prediction equations are proposed for elevated-temperature performance. • Constitutive model of full-range stress-strain relation is developed. Mechanical properties of steel at elevated temperatures are critical to the fire-resistant analysis and the fire safety design of steel structures. Thus, one solution for improving the fire resistance is use of high-performance (HP) steel, such as fire-resistant (FR) steel. However, practical use of the FR steel in steel structures implies requirements of sufficient fire resistance for the high-strength (HS) bolts as well, so that the loading capacities of bolted connections commonly used in steel structures can be guaranteed in case of fire. In this paper, material properties of grade 10.9 HP bolts recently developed in China, possessing both fire resistance and corrosion resistance, are tested at various elevated temperatures. Their stress-strain curves, modulus of elasticity, yield strength, ultimate tensile strength (UTS), and elongation percentage after fracture are obtained. These results are compared with that of conventional HS bolts and with reduction factors given in national standards. Constitutive models and prediction equations of the HP bolts at elevated temperatures are proposed. Besides, the relationship between degradation in macro mechanical properties and change in microstructure is clarified. The research outcomes may provide essential bases for the fire response analysis of steel structures applying the FR steel and the HP bolts. [ABSTRACT FROM AUTHOR]

• Developed a composite high-density ceramic process made entirely from fly ash. • Discovered and explained the triple microstructure of composite ceramics. • By the new structural design, the water absorption of composite ceramics was close to zero. • Analyzed the effect of raw materials with different particle sizes on ceramics. The value-added utilization of high-aluminum fly ash (HAFA) is of significance to China's solid waste development strategy because of the country's large amount of emissions. Mullite is the main component of HAFA, which is an important raw material that is used for the preparation of high-performance ceramics. Therefore, a new technology for the preparation of ceramics from HAFA is proposed in this study. Based on the combination of the concept of particle grading used in engineering geology with ceramics preparation, rearrangement of the ceramic microstructure, and the use of production experience and the Furnas model to calculate the best particle reorganization solution, a 100% HAFA-based high-density mullite ceramic with a triple microstructure was successfully designed. By analyzing the ceramic body using X-ray diffraction, scanning electron microscopy, and a mineral liberation analyzer, the roles of the three different structures and strengthening principles of the ceramics were determined. Given the synergy of the triple microstructure, the ceramic exhibits excellent physical properties (bulk density of 2.29 g/cm3; rupture modulus of 116.74 MPa; apparent porosity of 0.00%; and water absorption of 0.00%). Therefore, the mullite-based ceramic can be used as a high-strength waterproof material in high-temperature and/or high-corrosion environments. The proposed microstructure opens up a new route for the utilization of HAFA, greatly improves the value of its utilization, and provides new research ideas for future studies. [ABSTRACT FROM AUTHOR]