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1

Badanie jednoczesnego oznaczania popularnych słodzików w zielonej żywności metodą chromatografii cieczowej

Zhao Liang

Przemysł Chemiczny

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2023

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T. 102, nr 8

825--828

PL

Acesulfam, sacharynian sodu, aspartam, neotam i słodziki glikozydowe stewiolu ekstrahowano z zielonej żywności wodą z dodatkiem metanolu i oznaczano za pomocą wysokosprawnej chromatografii cieczowej. Współczynniki odzysku wyniosły 85-109%, a wartości względnego odchylenia standardowego były mniejsze niż 10%.

EN

Acesulfame, Na saccharin, aspartame, neotame and steviol glycoside sweeteners were extd. with MeOH-contg. water from green foods and detd. by high performance liq. chromatog. The extn. recovery rates were 85-109% and relative std. deviation values were lower than 10%.

2

Badania nad syntezą i przygotowaniem zielonego dodatku do żywności

Zhao Liang

Przemysł Chemiczny

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2023

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T. 102, nr 8

821--824

PL

Etylomaltol został zsyntetyzowany przez elektrolityczną konwersję α-furanopropanolu do 1,4-dialkoksy-α-furanopropanolu, a następnie zakwaszenie kwasem siarkowym, utlenienie H₂O₂ i hydrolizę. Optymalne parametry procesu były następujące: ładunek 2,5 F/mol, NaBr jako elektrolit, zakwaszanie w temperaturze pokojowej, czas utleniania 150 min i temperatura hydrolizy 100°C.

EN

Etylomaltol was synthesized by electrolytic conversion of α-furanopropanol to 1,4-dialkoxy-α-furanopropanol and subsequent acidification with sulfuric acid, oxidn. with H₂O₂ and hydrolysis. The optimum process parameters were: 2.5 F/mol energization, NaBr as electrolyte, acidification at room temp., oxidn. time 150 min and hydrolysis temp. of 100°C.

3

Bulldoze and rebuild: Modifying cratonic lithosphere via removal and replacement induced by continental subduction

Meng Lingtong, Chu Yang, Lin Wei, Mitchell Ross N., Zhao Liang

Geotourism / Geoturystyka

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2023

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nr 1-2 (72-73)

47--48

EN

Establishing the mechanisms for craton modification is critical for understanding cratonic stability and architecture. Both plate tectonics and mantle plumes can cause weakening, mechanical decoupling, and even lithospheric removal. But craton modification – craton destruction accompanied or followed by craton rejuvenation – has received less attention. It is well-known that oceanic subduction dominantly destroys cratonic lithosphere with replacement to a lesser degree, and mantle plumes have been related to both destruction and rejuvenation. The role of continental subduction in craton modification, however, remains a comparatively open question. The North China Craton, as a previously stable continent with a lithosphere of more than 200 km since the Paleoproterozoic, was reworked and substantially destroyed since the Mesozoic, with intensive destruction occurring in the Early Cretaceous. Earlier in the Mesozoic, North China Craton experienced a continent-continent collision (as the upper plate) with the South China Block, forming the Sulu orogenic belt, providing an opportunity to understand the potential for craton modification due to deep continental subduction In the North China craton, we report the presence of material (i.e., Yunshan unit) sourced from the underlying subducted plate. It is composed of foliated monzonitic granite and metamorphic sedimentary rocks that locally experienced crustal anatexis. Through detailed zircon U-Pb dating, it formed at latest Triassic (ca. 212 Ma). Importantly, the 800–700 Ma inherited zircons from the Yunshan foliated granite resemble those from the South China Block rather than the North China Craton. According to structural and magnetic data, the fabrics of the Yunshan foliated granite, characterized by gentle magnetic/mesoscopic foliations and conspicuous NW-SE-trending magnetic/mesoscopic lineations with a top-to-the-NW shearing. Its geometry, kinematics, and timing all compare favorably with the latest Triassic extensional structure accounting for the exhumation of the Sulu orogenic belt. We thus interpret the Yunshan unit to have been sourced from the subducted South China Block, then exhumed and emplaced into the overriding North China Craton (Fig. 1A). Combining our new results with previous geological and geophysical data, we argue that from 250–220 Ma a 200-km-long tract of North China Craton lithosphere was bulldozed by the subducted South China Block, resulting in a lithospheric suture far from the suture zone at the surface. This lithospheric removal occurred at mid-lower crustal levels (16–20 km depth) – much shallower than previously thought possible. The bulldozed North China Craton lithosphere was simultaneously replaced by the reworked underlying South China Block plate. Such a “bulldoze and rebuild” lithospheric modification process minimized asthenosphere-lithosphere interaction, thus preventing the North China Craton from further modification (Fig. 1B–1D). Because there was essentially no net loss of lithosphere during deep continental subduction, the North China Craton largely maintained its stability for the time and did not suffer intensive destruction until later Early Cretaceous palaeo-Pacific oceanic subduction. This “bulldoze and rebuild” model can thus account for how a craton can maintain its stability during a collision with another continental plate.

4

Influence of kaolinite crystallinity and calcination conditions on the pozzolanic activity of metakaolin

Liu Yuanyuan, Huang Qian, Zhao Liang, Lei Shaomin

Gospodarka Surowcami Mineralnymi

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2021

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T. 37, z. 1

39--56

EN

Two kaolin ores with the almost same fineness and purity of original kaolinite but possessing different kaolinite crystallinity (Hinckley Index) were selected to study the influence of crystallinity and calcination conditions on the pozzolanic activity of metakaolin after dehydroxylation. The different calcination conditions were conducted by altering the calcination temperature and holding time to obtain different metakaolin samples with different degrees of dehydroxylation. Then pozzolanic activities of metakaolin samples were tested by the modified Chapelle test, Frattini test and strength evaluations. Additionally, the apparent activation energies of two kaolin ores were calculated to study the thermal properties of kaolinite by isoconversional methods followed by iterative computations. The results showed that pozzolanic activities were dependent on the degree of dehydroxylation, except for the metakaolins calcined at 900°C due to the fact that recrystallization and high pozzolanic activity was conducted by complete dehydroxylation (degree of dehydroxylation ≥ 90%). Moreover, the lower crystallinity of original kaolinite favored the removal of the structural hydroxyls, leading to a reduction of apparent activation energy and increase of pozzolanic activity, indicating that the higher calcination temperature or longer holding time was required during calcination to reach the same degree of dehydroxylation and finally highly ordered kaolinite converted into the less active metakaolinite, which was confirmed by the lower Ca(OH)2 consumption in the modified Chapelle test, higher [CaO] and [OH] in the Frattini test and weaker compressive strength.

PL

Do zbadania wpływu krystaliczności i warunków kalcynacji na aktywność pucolanową metakaolinu po dehydroksylacji wybrano dwie rudy kaolinitu o prawie takiej samej jakości i czystości jak oryginalny kaolinit, ale o różnej krystaliczności kaolinitu (indeks Hinckleya). Przeprowadzono różne warunki kalcynacji, zmieniając temperaturę kalcynacji i czas przetrzymywania w celu uzyskania różnych próbek metakaolinu o różnych stopniach dehydroksylacji. Następnie zbadano aktywność pucolanową próbek metakaolinu za pomocą zmodyfikowanego testu Chapelle’a, testu Frattiniego i oceny wytrzymałości. Ponadto obliczono pozorne energie aktywacji dwóch rud kaolinu w celu zbadania właściwości termicznych kaolinitu metodami izokonwersji, a następnie obliczeń iteracyjnych. Wyniki pokazały, że aktywność pucolanowa była zależna od stopnia dehydroksylacji, z wyjątkiem metakaolinów kalcynowanych w temperaturze 900°C z powodu rekrystalizacji, a wysoką aktywność pucolanową przeprowadzono przez całkowitą dehydroksylację (stopień dehydroksylacji ≥ 90%). Ponadto niższa krystaliczność oryginalnego kaolinitu sprzyjała usuwaniu strukturalnych grup hydroksylowych, prowadząc do zmniejszenia pozornej energii aktywacji i wzrostu aktywności pucolanowej, co wskazuje, że wyższa temperatura kalcynacji lub dłuższy czas przebywania były wymagane podczas kalcynacji, aby osiągnąć ten sam stopień dehydroksylacji i wreszcie wysoce uporządkowany kaolinit przekształcony w mniej aktywny metakaolinit, co zostało potwierdzone przez mniejsze zużycie Ca(OH)2 w zmodyfikowanym teście Chapelle’a, wyższe [CaO] i [OH] w teście Frattiniego oraz słabszą wytrzymałość na ściskanie.

5

Correlation between compressive strengths and water absorption of fly ash cement mortar immersed in water

Huang Qian, Zhao Liang

Archives of Civil Engineering

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2019

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Vol. 65, nr 3

141--152

EN

The compressive strength and water absorption of cement mortars with different water-binder ratio (0.35, 0.45 and 0.55) and fly ash content (0, 10%, 20% and 30%) under water immersion were investigated, and the correlation between them was further analyzed. The internal microstructure and phase composition of mortar was studied by scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. The results show that the inside of mortar mixed with fly ash displayed the loose and porous microstructure. Therefore, the incorporation of fly ash reduced the compressive strength of mortar, especially the early strength, and the strength decreased with the increase of fly ash content, and the water absorption of mortar also increased. There was a linear correlation between the compressive strength and water absorption of mortar with the equation: fc = -3.838β + 62.332, where fc and β represented the compressive strength and water absorption, respectively. Therefore, when the water absorption of mortar immersed in water was measured, its corresponding compressive strength could be preliminarily inferred through this equation, which was of great significance for detecting and identifying the stability and safety of hydraulic structures.