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Copyright of Rare Metals is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Two new non‐centrosymmetric chalcogenides, ACuGa6S10 (A=Rb, Cs) have been successfully synthesized by an “iterative substitution” strategy based on chalcopyrite CuFeS2 structural template. Benefiting from the substitution of Fe3+ cations by Ga3+ cations, ACuGa6S10 (A = Rb, Cs) exhibit wide suitable band gap of 2.48 and 2.40 eV, respectively, which is about five times higher than their structure template CuFeS2, and a large second harmonic generation response (1.5 and 1.8×AgGaS2). Combining theoretical calculation and structural analysis confirms that the [GaS4] tetrahedra make the main contribution on their good liner and nonlinear optical (NLO) performances. The “iterative substitution” strategy expands the design idea of materials and can lead to the discovery of a large number of IR NLO compounds. [ABSTRACT FROM AUTHOR]

Heteroatom doping of graphitic carbon is of high interest for tuning its physicochemical properties. Aluminum is commonly reported as a high-interest dopant, but few synthetic strategies have been reported owing to the low equilibrium solubility of Al within graphite. Herein we report several strategies to achieve metastable aluminum-substituted turbostratic graphitic carbon materials with aluminum contents up to ~ 0.5 at%, via co-pyrolysis of two molecular precursors between 800 and 1100°C. The resulting materials exhibit turbostratic graphitic structure and a previously unreported aluminum environment detectable by X-ray absorption spectroscopy (XAS), a likely signature of trigonal planar or puckered AlC3-type sites. [ABSTRACT FROM AUTHOR]

Bi-substituted M-type hexaferrites, BaFe 12-x Bi x O 19 (0.1 ≤ x ≤ 1.2), or Bi-BaM, were produced by the solid-state reactions. The correlation between the phase content, chemical composition, crystal structure features, and peculiarities of the magnetic properties of Bi-BaM was established using XRD (X-ray diffraction), SEM (scanning electron microscopy), and VSM (vibrational sample magnetometry). XRD phase analysis made it possible to establish the limit of substitution of Fe3+ ions by Bi3+ ions. It was shown that at a low substitution level (x ≤ 0.3), no impurity phases were detected, and the samples are characterized by a single-phase state with the space group (SG) P6 3 /mmc. As the degree of substitution (x ≥ 0.6) increases, the formation of impurity phases was observed, which can be explained by the difficulties of ion diffusion in the process of solid-phase synthesis as well as the formation of defects in the magnetoplumbite structure due to the large ionic radius of Bi3+. As impurity phases in the studied compositions (x ≥ 0.6) the following were noted: BiFeO 3 (SG: Pnma); BiO 2 (SG: Fm-3m); BaBi 2 O 6 (SG: R-3); and Ba 0.5 Bi 1.5 O 2.16 (SG: Im-3m). The content of the main phase (SG: P6 3 /mmc) decreases from 95.11 to 88.27 vol% with an increase in x from 0.6 to 1.2, respectively. Analysis of SEM images showed the growth of particles up to 10 μm, depending on the concentration of bismuth oxide during hexaferrite synthase. The Bi-BaM magnetic characteristics were examined using VSM in the range of 3 T at 300 K. Due to the magnetic structure's frustration, with increased x a decrease in saturation magnetization (M s) was found. There were two concentration diapasons with different speeds of M s decrease. In the first diapason, the main contribution belong to the magnetic structure frustration in the frame of the main phase (P6 3 /mmc) due to the long-range Fe-O-Fe exchange interaction weakening (under Bi substitution). In the second diapason, the main contribution belong to the impurity phase formation and decrease of the main magnetic phase concentration in samples. [ABSTRACT FROM AUTHOR]

Incorporation of silicate ions in calcium phosphate ceramics (CPC) and modification of their multiscale architecture are two strategies for improving the vascularization of scaffolds for bone regenerative medicine. The response of endothelial cells, actors for vascularization, to the chemical and physical cues of biomaterial surfaces is little documented, although essential. We aimed to characterize in vitro the response of an endothelial cell line, C166, cultivated on the surface CPCs varying either in terms of their chemistry (pure versus silicon-doped HA) or their microstructure (dense versus microporous). Adhesion, metabolic activity, and proliferation were significantly altered on microporous ceramics, but the secretion of the pro-angiogenic VEGF-A increased from 262 to 386 pg/mL on porous compared to dense silicon-doped HA ceramics after 168 h. A tubulogenesis assay was set up directly on the ceramics. Two configurations were designed for discriminating the influence of the chemistry from that of the surface physical properties. The formation of tubule-like structures was qualitatively more frequent on dense ceramics. Microporous ceramics induced calcium depletion in the culture medium (from 2 down to 0.5 mmol/L), which is deleterious for C166. Importantly, this effect might be associated with the in vitro static cell culture. No influence of silicon doping of HA on C166 behavior was detected. [ABSTRACT FROM AUTHOR]

Understanding the local environment of luminescent centers in phosphors serves as a blueprint for designing the luminescent properties of phosphors. Chemical substitution is a general strategy for engineering the local structure around luminescent center ions. In this study, we systematically investigate the luminescent properties of Ga-substituted Eu-doped CaYAlO4 (CYAGO:Eu) phosphors and the local structure of the Eu ions. The Ga substitution at the Al sites leads to a significant enhancement in the electric dipole transition of Eu3+ (5D0 → 7F2). The Judd–Ofelt analysis reveals that Eu3+ ions are substituted for Ca/Y, and the Ga substitution increases the asymmetricity of the local structure around the Eu ions because of the different ionic radii and electronegativities of Al and Ga. In addition, Eu2+ emission is missing regardless of the Ga substitution and post-hydrogen treatments. The present work provides deeper insight into the role of chemical substitution in oxide phosphors. [ABSTRACT FROM AUTHOR]

Herein, using first-principles density functional theory (DFT) calculations, we have investigated the effects of Bi substitution on the structural, electronic, and magnetic properties of barium hexaferrite (BaFe 12-x Bi x O 19 , x = 0; 0.5; 1.5 and 2). As a result of the calculation, it was determined that the most stable structure exists if the spin of the Fe atom on the 2a, 2b, and 12k positions of the barium hexaferrite compound is taken in the upward direction. The calculated lattice constant c a = 3.9 and magnetic moment (4.24 μ B) of iron ions are in reasonable agreement with other experimental works. Moreover, the presence of bismuth reduces the electronic band gap. Energy gain and magnetic anisotropy energy calculations for FIM, FM, and NM states were performed for the most stable states. It has been established that the most stable structural state is characteristic of х = 0.5. It has been calculated that substitution by the large Bi3+ ion dramatically changed the electronic structure and sharply reduced the band gap. This paper is the first step towards establishing the nature of the distribution of ions in M-type hexaferrites under conditions of substitution by ions with a large ionic radius. [ABSTRACT FROM AUTHOR]

Copyright of SDU Journal of Engineering Sciences & Design / Mühendislik Bilimleri ve Tasarım Dergisi is the property of Journal of Engineering Sciences & Design and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The structural characterization and electrical transport measurements at ambient and applied pressures of the compounds of the LaAg 1 − x Au x Sb 2 family are presented. Up to two charge density wave (CDW) transitions could be detected upon cooling from room temperature and an equivalence of the effects of chemical and physical pressure on the CDW ordering temperatures was observed with the unit cell volume being a salient structural parameter. As such LaAg 1 − x Au x Sb 2 is a rare example of a non-cubic system that exhibits good agreement between the effects of applied, physical, pressure and changes in unit cell volume from steric changes induced by isovalent substitution. Additionally, for LaAg 0.54 Au 0.46 Sb 2 anomalies in low temperature electrical transport were observed in the pressure range where the lower charge density wave is completely suppressed. [ABSTRACT FROM AUTHOR]

Improved birefringence, given its capacity to modulate polarized light, holds a lively role in the optoelectronic industry. Traditionally, alkaline-earth metal halides have possessed low birefringence due to their nearly optical isotropic properties. Herein, the substitution of interlayer anion with linear S─S unit that meticulously engineered by reduced valence state and strong covalent bond is integrated into the optically isotropic BaF 2 , offering the new salt-inclusion chalcogenide BaFS. Notably, it has dramatically enhanced optical anisotropy, thereby significantly boosting birefringence of 0.238@546 nm, achieved by overall considering experimental observations with theoretical analysis. Theoretical investigation has established the significant effect of the covalent S─S bond on the birefringence index. Additionally, BaFS demonstrates a remarkable laser-induced damage threshold (LIDT, 12.0 × AgGaS 2 @1064 nm), illuminating a promising pathway for designing materials with significant birefringence properties in laser applications., (© 2024 Wiley‐VCH GmbH.)

Incorporation of silicate ions in calcium phosphate ceramics (CPC) and modification of their multiscale architecture are two strategies for improving the vascularization of scaffolds for bone regenerative medicine. The response of endothelial cells, actors for vascularization, to the chemical and physical cues of biomaterial surfaces is little documented, although essential. We aimed to characterize in vitro the response of an endothelial cell line, C166, cultivated on the surface CPCs varying either in terms of their chemistry (pure versus silicon-doped HA) or their microstructure (dense versus microporous). Adhesion, metabolic activity, and proliferation were significantly altered on microporous ceramics, but the secretion of the pro-angiogenic VEGF-A increased from 262 to 386 pg/mL on porous compared to dense silicon-doped HA ceramics after 168 h. A tubulogenesis assay was set up directly on the ceramics. Two configurations were designed for discriminating the influence of the chemistry from that of the surface physical properties. The formation of tubule-like structures was qualitatively more frequent on dense ceramics. Microporous ceramics induced calcium depletion in the culture medium (from 2 down to 0.5 mmol/L), which is deleterious for C166. Importantly, this effect might be associated with the in vitro static cell culture. No influence of silicon doping of HA on C166 behavior was detected.

[Display omitted] • Achievements on 100 representative examples of RE-based NLO crystals with [XO 3 ] (X = B, C, and N) units are overviewed. • A thorough summary of the structure–property in RE-based NLO crystals with [XO 3 ] (X = B, C, and N) units are conducted. • Gave information about potential future paths for the creation of high-performing UV/DUV NLO crystals. Nonlinear optical (NLO) crystals serve as the pivotal core materials for laser frequency conversion and play an indispensable role in various areas such as information technology, optical communication, national defense, and security. With rapid advancements in modern science and technology, the existing ultraviolet (UV) and deep ultraviolet (DUV) NLO crystals are facing challenges in meeting the growing demands of diverse applications. Consequently, the quest for novel UV and DUV NLO crystals with exceptional comprehensive performance remains a daunting and urgent task. The [XO 3 ] (X = B, C, N) planar π-conjugated groups, renowned for their outstanding NLO active properties, typically exhibit robust microscopic second-order polarizability and broad UV transmission ranges, making them prime candidates for the development of novel UV/DUV NLO crystals. Incorporating rare-earth (RE) cations, characterized by their unique electronic configurations and large ionic radii, into planar π-conjugated [XO 3 ] structures has attracted considerable attention in the UV/DUV NLO field over the past decades. However, a comprehensive analysis and review of RE-based UV/DUV NLO crystals with [XO 3 ] groups are currently lacking. In this review, we classify over 100 examples of UV/DUV NLO crystals with [XO 3 ] reported since 2010 into three main categories: (1) RE-based NLO crystals with [BO 3 ]3− groups; (2) RE-based NLO crystals with [CO 3 ]2− groups; (3) RE-based NLO crystals with [NO 3 ]− groups. We compare their synthesis methods, crystal structures, and optical properties, shedding light on the structure–activity relationships. The findings reveal that the majority of non-centrosymmetric RE-based materials with [XO 3 ] groups exhibit significant second-harmonic-generation intensities, moderate birefringence, and short UV cut-off edges, positioning them as promising candidates for UV/DUV NLO applications. Finally, we deliberate on the opportunities and challenges for the future development of RE-based NLO materials with [XO 3 ] groups, offering valuable insights for the discovery and design of future RE-based NLO materials and planar π-conjugated NLO crystals. [ABSTRACT FROM AUTHOR]

The aim of chemical substitution is to replace hazardous chemicals with a less hazardous alternative in a certain product or process to make it safer for human health and the environment. While a lot has been done by researchers, industries and regulatory bodies on chemical substitution for safer products, very little has been reported in the field of safer processes. On the other hand, chemical substitution is one of the core principles of inherently safer design, a concept frequently used in the chemical industry for the prevention of major accidents. This work presents an analysis of implementing chemical substitution methodology for safer processes through inherently safer design. Chemical industries, nowadays, are frequently asked to phase out hazardous chemicals from their processes. This paper provides an insight into the issues and practicability of chemical substitution in processes with the help of case studies and a review of the existing frameworks of inherently safer design. [ABSTRACT FROM AUTHOR]

Deterministic control of substitution sites is the holy grail of chemical engineering in materials science. The substitution of the dopants in the host crystal lattice usually obeys the empirical Hume‐Rothery rules, in which the mismatch of atomic size must be small and thus site‐specific. Herein, we report an unconventional case of mixed‐site substitution in highly‐strained BiFeO3 thin films. Driven by the delicate balance between chemical strain and epitaxial strain energies, the solid‐solution system demonstrates a self‐regulation behavior in dopant site occupancy to minimize the total free energy. This proposed mechanism offers valuable insight into the chemical substitution pathway in epitaxial thin films and provides a potential route to selectively control the substitution sites. [ABSTRACT FROM AUTHOR]

The toxicity of benzothiazole derivatives obtained from 2-cyanomethyl benzothiazole against cotton leafworm Spodoptera littoralis 2nd and 4th instar larvae has been documented. The main objective of this research was to formulate two previously reported chromen derivatives and test their biological activity against cotton leafworm S. littoralis 2nd and 4th instar larvae under laboratory conditions. According to the standard method, two chromen derivatives with two distinct substituents (salicylaldehyde and 2-hydroxy-1-naphthaldehyde) were synthesized. Their physical and chemical properties were evaluated, and both were formulated as 10 and 9.5 percent dustable powder formulations. Both formulae were then evaluated in the laboratory on cotton leafworm S. littoralis 2nd and 4th instar larvae for mortality and developmental effect percentage. Formulation (F2) was more efficient than formulation (F3) in both cases and for both stages. Furthermore, when comparing the developmental effects on the 2nd and 4th instar larvae, the 4th instar larvae demonstrated marked tolerance. Both stages were unable to complete their life cycle. Histopathological analysis of samples from the affected stages was performed to assess the mode of action of these formulations on 4th instar larvae at their LC50 values. Experimental data showed that Formulation (F3) resulted in epidermal cells separated from the cuticular layer, necrosis, ruptured columnar cells with pyknotic nuclei, disrupted basement membrane, and weak epicuticle necrosis and separation. In comparison, formulation (F2) revealed a midgut with vacuoles, damaged columnar, muscle cell necrosis, and a ruined peritrophic matrix. Thus, the cotton leafworm S. littoralis could be combated with the newly prepared formulations (F2) and (F3). [ABSTRACT FROM AUTHOR]

Herein, we report the intercalation of t-butyl hydrazinecarboxylate on the surface of GO through the epoxide ring opening on the basal plane. Upon the intercalation, the interlayer d-spacing has increased from 0.78 to 1.21 nm and further treatment with acid, and the interlayer d-spacing was decreased from 1.21 to 0.94 nm, which was referred as Jacky-Lifting approach. DFT calculations confirm the intercalation with the energetically favorable profound interactions with GO. The as-prepared GO nanosheets were characterized by spectroscopic and microscopic techniques. This approach of tuning interlayer d-spacing between the GO nanosheets paves the way to stuff the biological sensor materials for stimuli-based biosensor applications. [ABSTRACT FROM AUTHOR]

It remains a critical challenge to develop narrow‐band emitters for wide color gamut displays. Herein, it is designed by the selective site occupancy engineering and an unprecedented narrow‐band green‐emitting phosphor is prepared through chemical substitution. By introducing Ga3+ ions into Sr2LiAlO4:Eu2+ phosphor, the distribution of Eu2+ ions in Sr1 and Sr2 sites is effectively controlled, and only one type of luminescent centers Eu2+(Sr1) is remained in Sr2LiAl0.6Ga0.4O4:Eu2+ due to the compression effect of Sr2O8 polyhedra. Sr2LiAl0.6Ga0.4O4:Eu2+ phosphor presents an extremely narrow‐band green emission centered at 512 nm with a full‐width at half‐maximum of only 40 nm. The wide color gamut (107% National Television System Committee) of the as‐fabricated white liquid crystal displays and the vivid figures captured from the projector demonstrate the potential application of narrow‐band emitter for wide‐color gamut displays. This work provides the design principles of realizing narrow‐band emission by selective site occupancy engineering and can set the stage for the exploring of Eu2+‐activated phosphor for high definition displays. [ABSTRACT FROM AUTHOR]

The structural characterization and electrical transport measurements at ambient and applied pressures of the compounds of the LaAg1−xAuxSb2 family are presented. Up to two charge density wave (CDW) transitions could be detected upon cooling from room temperature and an equivalence of the effects of chemical and physical pressure on the CDW ordering temperatures was observed with the unit cell volume being a salient structural parameter. As such LaAg1−xAuxSb2 is a rare example of a non-cubic system that exhibits good agreement between the effects of applied, physical, pressure and changes in unit cell volume from steric changes induced by isovalent substitution. Additionally, for LaAg0.54Au0.46Sb2 anomalies in low temperature electrical transport were observed in the pressure range where the lower charge density wave is completely suppressed.

Hydrazine oxidation assisted water electrolysis offers a unique rationale for energy‐saving hydrogen production, yet the lack of effective non‐noble‐metal bifunctional catalysts is still a grand challenge at the current stage. Here, the Mo doped Ni3N and Ni heterostructure porous nanosheets grow on Ni foam (denoted as MoNi3N/Ni/NF) are successfully constructed, featuring simultaneous interface engineering and chemical substitution, which endow the outstanding bifunctional electrocatalytic performances toward both hydrazine oxidation reaction (HzOR) and hydrogen evolution reaction (HER), demanding a working potential of −0.3 mV to reach 10 mA cm−2 for HzOR and −45 mV for that of HER. Impressively, the overall hydrazine splitting (OHzS) system requires an ultralow cell voltage of 55 mV to deliver 10 mA cm−2 with remarkable long‐term durability. Moreover, as a proof‐of‐concept, economical H2 production systems utilizing OHzS unit powered by a waste AAA battery, a commercial solar cell, and a homemade direct hydrazine fuel cell (DHzFC) are investigated to inspire future practical applications. The density functional theory calculations demonstrate that the synergy of Mo substitution and abundant Ni3N/Ni interface owns a more thermoneutral value for H* absorption ability toward HER and optimized dehydrogenation process for HzOR. [ABSTRACT FROM AUTHOR]

Al 2 Mo 3 O 12 is a typical negative thermal expansion (NTE) material, whose thermal expansion behavior depends on its crystal phase. The thermal shock caused by temperature-induced phase transition limits its wide application. The two series of Al 2. x Sc x Mo 3 O 12 (0 ≤ x ≤ 1) and Al 2 Mo 3-x W x O 12 (0 ≤ x ≤ 2.5) solid solutions with controllable phase transition temperature were synthesized via single cation substitution at the A or B position. The problem of thermal shock caused by the change of temperature is effectively solved in the synthesized Al 1.6 Sc 0.4 Mo 3 O 12 and Al 2 Mo 0.5 W 2.5 O 12 , showing stable NTE performance above room temperature, and the coefficients of thermal expansion of which are −2.19 × 10−6 °C−1 in 100–550 °C and −4.25 × 10−6 °C−1 in 85–500 °C, respectively. A-site cation substitution is a more effective way to tune the thermal expansion properties of Al 2 Mo 3 O 12 , which is attributed to the fact that the bond strength of A-O is weaker than that of B–O in the compound. [ABSTRACT FROM AUTHOR]

Chemicals assessment and management frameworks rely on regulatory toxicity values, which are based on points of departure (POD) identified following rigorous dose-response assessments. Yet, regulatory PODs and toxicity values for inhalation exposure ( i.e. , reference concentrations [RfCs]) are available for only ∼200 chemicals. To address this gap, we applied a workflow to determine surrogate inhalation route PODs and corresponding toxicity values, where regulatory assessments are lacking. We curated and selected inhalation in vivo data from the U.S. EPA's ToxValDB and adjusted reported effect values to chronic human equivalent benchmark concentrations (BMC h ) following the WHO/IPCS framework. Using ToxValDB chemicals with existing PODs associated with regulatory toxicity values, we found that the 25th %-ile of a chemical's BMC h distribution ( POD p 25 BMC h ) could serve as a suitable surrogate for regulatory PODs (Q 2 ≥ 0.76, RSE ≤ 0.82 log 10 units). We applied this approach to derive POD p 25 BMC h for 2,095 substances with general non-cancer toxicity effects and 638 substances with reproductive/developmental toxicity effects, yielding a total coverage of 2,160 substances. From these POD p 25 BMC h , we derived probabilistic RfCs and human population effect concentrations. With this work, we have expanded the number of chemicals with toxicity values available, thereby enabling a much broader coverage for inhalation risk and impact assessment.

This study aimed to decrease chemical costs and increase productivity and environmental performance by applying various practices for chemical minimization and substitution in an integrated textile mill producing woolen textile fabric. Detailed on-site process investigations and data collection studies were carried out in the mill. Process-based specific auxiliary chemical and dyestuff consumptions were calculated. Process and composite wastewater samples were collected at different periods and analyzed. The chemical loads of wastewaters were also calculated. The specific dyestuff and auxiliary chemical consumptions of the mill were compared with the data of a similar textile mill in the literature and the Integrated Pollution Prevention and Control (IPPC), Textile Best Available Techniques Reference (BREF) document. Thus, the chemical saving potential of the mill was evaluated. A detailed chemical inventory study was also carried out in the mill. The material safety data sheets (MSDSs) of 371 chemicals were examined in terms of biodegradation ratio, toxicity, and micropollutant content. As a result, 23 chemicals were proposed to be replaced with environmentally friendly substitutes. A total of 10 minimization and substitution practices were identified for the mill according to the investigation and analysis results. After the implementation of the suggested practices, reductions of 15–32 and 13–37% are estimated to be achieved in total chemical consumption and chemical oxygen demand (COD) load of wastewater, respectively. The potential payback periods of the suggested practices were calculated to range between 4 and 36 months. The employed methodology and the findings of this study may be useful for similar textile mills, stakeholders, and regulators. This study may also provide a road map to the textile industry for their sustainable and green production applications. [ABSTRACT FROM AUTHOR]

A series of cerium samarium tungstates Ce(2–x)Smx (WO4)3 with x ≤ 0.3 was synthesized by a coprecipitation method followed by thermal treatment at 1000 °C. The polycrystalline compounds were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and photoluminescence (PL) experiments. Using the Rietveld procedure, the decrease in cell parameters showed that a solid solution was obtained. A comparative analysis of diffraction profiles allowed determining structural distortions increasing with increasing composition x. The PL experiments were performed under UV and XR excitations. The variations with composition x of emission intensities observed in the wavelength range of 500–1000 nm, corresponding to complex charge transfers (CTs) and quenching effects, were interpreted in terms of transitions proper to Ce3+ and Sm3+ cations, accompanied by additional transitions due to oxygen vacancies and other point defects due to substitution and synthesis conditions. [ABSTRACT FROM AUTHOR]

[Display omitted] • Achievements on 51 representative series (including 7 crystal systems, 34 space groups and more than 200 non-centrosymmetric compounds) of Ga-based IR-NLO chalcogenides are overviewed. • The interrelationship of "chemical composition–NCS structure–NLO property" is studied and summarized systematically. • Several useful conclusions and future considerations have been provided. Infrared nonlinear optical (IR-NLO) crystals play a crucial role in the field of all-solid state lasers. They enable the generation of tunable coherent radiations through frequency conversion technology, which is urgently required for the advancement of numerous advanced sciences and technologies. Currently, the chalcopyrite-type AgGaS 2 , AgGaSe 2 , and ZnGeP 2 are leading IR-NLO materials, but their applications are significantly restricted due to their inherent drawbacks. Therefore, exploring new promising IR-NLO crystals with excellent comprehensive performance is an urgent task that remains challenging. Benefiting from their diverse structure, wide IR transmission range, and adjustable optical performance, non-centrosymmetric Ga-based materials have garnered significant attention. Research on the IR-NLO properties of Ga-based chalcogenides began in 1971, resulting in the discovery of many Ga-based materials that exhibit exceptional IR-NLO performance. However, a comprehensive review of this field is currently lacking. In this review, Ga-based IR-NLO materials, which comprise over 200 reported chalcogenides and their derivatives, with 7 crystal systems and 34 space groups, are classified based on the assembly method of their Ga-based tetrahedral asymmetric units into five categories: (1) zero-dimensional (0D) molecular structures, (2) one-dimensional (1D) chain structures, (3) two-dimensional (2D) layer structures, (4) three-dimensional (3D) framework structures, and (5) mixed-dimensional (MD) structures. Furthermore, this review systematically summarizes and discusses the synthesis, crystal structures, and structure–property relationships of Ga-based materials. Additionally, valuable suggestions and opportunities for further exploration and development of novel Ga-based IR-NLO materials are addressed. This comprehensive review not only consolidates the existing knowledge but also lays the groundwork for broader research opportunities in the field of high-performance IR-NLO candidates. [ABSTRACT FROM AUTHOR]

Most alternatives assessments (AAs) published to date are largely hazard‐based rankings, thereby ignoring potential differences in human and/or ecosystem exposures; as such, they may not represent a fully informed consideration of the advantages and disadvantages of possible alternatives. Building on the 2014 US National Academy of Sciences recommendations to improve AA decisions by including comparative exposure assessment into AAs, the Health and Environmental Sciences Institute's (HESI) Sustainable Chemical Alternatives Technical Committee, which comprises scientists from academia, industry, government, and nonprofit organizations, developed a qualitative comparative exposure approach. Conducting such a comparison can screen for alternatives that are expected to have a higher or different routes of human or environmental exposure potential, which together with consideration of the hazard assessment, could trigger a higher tiered, more quantitative exposure assessment on the alternatives being considered, minimizing the likelihood of regrettable substitution. This article outlines an approach for including chemical ingredient‐ and product‐related exposure information in a qualitative comparison, including ingredient and product‐related parameters. A classification approach was developed for ingredient and product parameters to support comparisons between alternatives as well as a methodology to address exposure parameter relevance and data quality. The ingredient parameters include a range of physicochemical properties that can impact routes and magnitude of exposure, whereas the product parameters include aspects such as product‐specific exposure pathways, use information, accessibility, and disposal. Two case studies are used to demonstrate the application of the methodology. Key learnings and future research needs are summarized. Integr Environ Assess Manag 2018;00:000–000. © 2018 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals, Inc. on behalf of Society of Environmental Toxicology & Chemistry (SETAC) Key Points: Alternatives Assessment (AA) describes the approach to identify, compare, and select safer and more sustainable alternatives to chemicals of concern.Alternatives Assessments have often been hazard‐based rankings used to substitute individual ingredients and may not represent a fully informed consideration of advantages or disadvantages of possible alternative solutions.Chemical alternatives that may have a higher or different route of exposure potential (human or environmental) can be identified via a qualitative exposure approach, which could trigger a higher tiered, more quantitative assessment to minimize the likelihood of regrettable substitution.This work outlines a classification approach for including chemical ingredient‐ and product‐related exposure information to support comparisons between alternatives in a qualitative manner using 2 case studies. [ABSTRACT FROM AUTHOR]

[Display omitted] • Chemical substitution of N-methyl-2-pyrrolidone. • One-pot reductive amination of bio-derived levulinates. • Sustainable synthesis via heterogeneous catalysts. • Design of bifunctional catalysts. N-methyl-2-pyrrolidone (NMP) is a chemical widely used as solvent in several industrial applications. However, many studies and regulations, including REACH, have indicated NMP as a potential toxic agent. Therefore, functional substitutes with high marketability are actively sought. This paper reviews the methods reported in the literature for the sustainable synthesis of the 5-methyl-homologues of NMP. Focus is on liquid phase processes using heterogeneous catalysts and bio-derived feedstock, i.e. levulinates, since N-substituted-5-methyl-2-pyrrolidones (5 M Ps) are readily obtainable from them through one-pot reductive amination. The contributions appeared up to July 2018 are covered and discussed in terms of reaction mechanism, catalysts' properties and applicability. [ABSTRACT FROM AUTHOR]

Highlights • Post-crystallization interactions between uraninites and fluids can result in strong chemical (major, minor, trace element) and isotopic (U-Pb-O) heterogeneities. • U-Th-Pb chemical and 207Pb/206Pb clustering ages should be used with caution as they may represent clusters of analyses of similar alteration intensity rather than distinct fluid flow events. • Elements that have been considered immobile, like REEs, may in fact be significantly affected by fluid-driven post-crystallization interactions. Abstract This study presents systematic chemical (U, Pb, Ca, Si, Fe) mapping coupled with in situ analyses of major, minor and trace elements, U/Pb, 207Pb/206Pb, and O isotopic compositions of natural uraninites (UO 2) from two samples of the high-grade uranium ore from the Cigar Lake unconformity-related uranium deposit (Athabasca Basin, Saskatchewan, Canada). The studied uraninites are characterized by major chemical and isotopic heterogeneities expressed at small scale (µm to tens of µm), from almost pristine zones to strongly altered material. The 206Pb/238U and 207Pb/235U ratios of the different areas are widely spread and depict two similar and well-defined Discordia, providing an upper intercept age of crystallization at ca. 1300 Ma (1299 ± 4 and 1308 ± 14 Ma, respectively) and lower intercepts at 38 ± 13 and 72 ± 22 Ma, respectively. The freshest areas are characterized by sub-concordant 206Pb/238U and 207Pb/235U ratios, identical chemical compositions and similar very low δ18O values (−39.3 to −31.4‰). These data indicate that the two uraninites both crystallized at ca. 1300 Ma, from the same fluid and under identical physico-chemical conditions. Alteration is characterized by (i) the progressive incorporation of Ca, Si, and Fe, reaching several wt.%, which substitute to the radiogenic Pb and cause a progressive decrease in the Pb/U isotopic ratios. The radiogenic Pb is also substituted by water during the alteration, (ii) concomitant variations in trace element contents (As, Mn, V, LREEs, Sr, Th, B, Ba, Nb, for example) and (iii) heavier δ18O signatures (−22.5 to −8.91‰), typical of meteoric waters, in the altered zones. This combined approach demonstrates that fluid-driven post-crystallization exchanges affected each uraninite during recent fluid flow events (ca. 40 Ma and 70 Ma respectively). The relatively high dispersion of the Pb/U ratios in relation to the Discordia for both samples is considered as linked to a local (nm to µm-scale) differential mobility between lead and uranium within the uranium oxides. The chemical changes affecting elements previously considered as immobile in uraninite, such as REEs, indicate that these elements are not preserved during the post-crystallization alteration process studied here. Alteration processes may therefore have a major impact on the classical geochemical tracers, such as REE patterns or LREE/HREE ratios, currently used in nuclear forensic studies. The isotopic and chemical tracers currently used to track back the origin, age and history of natural uraninites should therefore be considered with a high degree of caution to avoid misleading and erroneous conclusions. Moreover, the comparison of calculated U-Th-Pb chemical, 207Pb/206Pb, and Pb/U isotopic ages shows that the use of age clustering for determining U-Th-Pb chemical ages and 206Pb/207Pb ages is not appropriate for constraining crystallization stage(s) of altered uraninites and for deciphering the different fluid events that potentially altered or recrystallized the uraninites over time. This study also indicates that estimation of the crystallization age of uraninite from substitution trends of Pb to Ca is not applicable to unconformity-related U deposits and results in overestimated ages because of an initial integration of calcium in the uraninite lattice at the time of crystallization. [ABSTRACT FROM AUTHOR]

• A series of La 3 Cr 1- x V x As 5 (x = 0–0.8) samples were synthesized under high-temperature and high-pressure conditions. • As the V-doped content increases, the ferromagnetism of La 3 Cr 1- x V x As 5 for x ≤ 0.3 is gradually suppressed. • La 3 Cr 1- x V x As 5 for x = 0.4 involves into a new ground magnetic state like spin glass. In this work, we successfully synthesized a series of hexagonal La 3 Cr 1- x V x As 5 (x = 0–0.8) polycrystalline samples under high-temperature and high-pressure conditions. A systematic study was carried out via the measurements of X-ray powder diffraction, temperature- and field-dependent magnetic susceptibility and magnetization. The X-ray diffraction data show that the lattice constant. a -parameter gradually increases, while c -parameter decreases with increasing V-doping level. In this series, the ferromagnetic behavior has been observed for x ≤ 0.3, and the Curie temperature T C decreases from 50 K for the parent compound to 20 K for x = 0.3, which indicates that the ferromagnetism is suppressed as the V-doped increases. For x = 0.4, the system begins to enter into a new magnetic state like spin glass at low temperature, and no magnetic order can be observed down to 2 K for x ≥ 0.8. In addition, the Weiss temperature T ϴ gradually decreases and changes to be negative for x = 0.6, which suggests that ferromagnetic interaction at first is weakened by the V substitution, and then transforms into anti-magnetic predominant interaction. The above results indicate that there is no quantum criticality occurred in the La 3 Cr 1- x V x As 5 system. [ABSTRACT FROM AUTHOR]

Noncentrosymmetric phosphides have garnered significant attention as promising systems of infrared (IR) nonlinear optical (NLO) materials. Herein, a new quaternary diamond-like phosphide family I-III-IV 2 -V 4 and its inaugural member, namely, CuInSi 2 P 4 (CISP), were successfully fabricated by isovalent and aliovalent substitution based on ZnGeP 2 . First-principles calculations revealed that CISP has a large NLO coefficient ( d 14 = 110.8 pm/V), which can be attributed to the well-aligned tetrahedral [CuP 4 ], [InP 4 ], and [SiP 4 ] units. Remarkably, the extremely small thermal expansion anisotropy (0.09) of CISP enables it to exhibit a considerable laser-induced damage threshold (LIDT, 5.0 × AgGaS 2 @1.06 μm) despite the relatively narrow band gap (0.81 eV). This work improves the chemical diversity of inorganic phosphide and promotes the development of phosphide systems, which may provide valuable perspectives for future exploration of IR NLO materials.

Machine Learning (ML) is increasingly applied to fill data gaps in assessments to quantify impacts associated with chemical emissions and chemicals in products. However, the systematic application of ML-based approaches to fill chemical data gaps is still limited, and their potential for addressing a wide range of chemicals is unknown. We prioritized chemical-related parameters for chemical toxicity characterization to inform ML model development based on two criteria: (1) each parameter's relevance to robustly characterize chemical toxicity described by the uncertainty in characterization results attributable to each parameter and (2) the potential for ML-based approaches to predict parameter values for a wide range of chemicals described by the availability of chemicals with measured parameter data. We prioritized 13 out of 38 parameters for developing ML-based approaches, while flagging another nine with critical data gaps. For all prioritized parameters, we performed a chemical space analysis to assess further the potential for ML-based approaches to predict data for diverse chemicals considering the structural diversity of available measured data, showing that ML-based approaches can potentially predict 8-46% of marketed chemicals based on 1-10% with available measured data. Our results can systematically inform future ML model development efforts to address data gaps in chemical toxicity characterization.

In the general framework of the development of materials with tunable photoluminescence, a series of cerium samarium tungstates Ce(2-x)Smx(WO4)3 with x≤0.3 was synthesized by a coprecipitation method followed by thermal treatment at 1000 °C. The polycrystalline compounds were characterized by X-ray diffraction, scanning electron microscopy and photoluminescence experiments. In the present work, the objective would be to determine the role of PL emitting centers in the variations of PL intensities. Firstly, Rietveld analysis showed a decrease of cell parameters and confirmed that a solid solution was obtained. Diffraction profile analyses showed that structural distortions increasing with composition x were observed: they were ascribed to difference in cation sizes of Ce3+ and Sm3+, and to defects generated during crystal growth. The photoluminescence (PL) spectra were obtained under X-Ray (45 kV-35 mA) and UV (364.5 nm) excitations. Two PL emissions of Ce3+ were observed only under UV excitation. Four PL emissions of Sm3+ were observed under UV and X-ray excitations, and their intensities decreased with increasing composition x. Two additional transitions were observed under UV and X-ray excitations: they were attributed to oxygen vacancy defects. In the range 800 to 1000 nm, an increasing IR emission is observed: it was ascribed to emissions due to other oxygen vacancies. The main results are reported in Table 1. The chromaticity diagram (see Figure 1) showed that the colors associated with PL responses vary with Sm composition and excitation energies. This offers the opportunity to develop materials with tunable PL. To better understand this complex behavior, now, we plan to study the solid solution in the composition range x>0.3.

Prompted by the success in functionalizing 2D sheets of MoS2 and MoSe2 by their reaction with organic halides, we have investigated the functionalization of layered tungsten chalcogenides, WS2, WSe2, and WTe2, by their reaction with substituted iodobenzenes as well as fluorophores based on pyrene and coumarin. Carbon–chalcogenide bonds are formed readily in the case of metallic chalcogenides while there is need for the Pd(0) catalysts in the case of insulating chalcogenides. Thus, the formation of carbon–chalcogen (S, Se, and Te) bonds is accomplished with the metallic 1T as well as the semiconducting 2H phases of the tungsten chalcogenides. Functionalization in the case of substituted iodobenzenes is favored by the electron withdrawing groups in the benzene ring. Interestingly, functionalization has been successful with other insulating layered chalcogenides such as GaS and GaSe. Reaction with organic halides emerges as a general method for the covalent functionalization of chalcogenide nanosheets, suggesting the possible use of this strategy to functionalize various chalcogenide structures. [ABSTRACT FROM AUTHOR]

The household refrigerators consume large amounts of energy and emit vast refrigerants which contribute to global warming indirectly and directly. The intervention of energy efficiency standard, aging process, and refrigerants substitution result in the performance of the household refrigerator sector varying with time. The present study analyzed dynamic global warming impact of the household refrigerator sector in Japan from the 1950s to 2030 taking into account both the energy effect and chemical effect. The energy effect modelling integrated energy efficiency improvement over year and energy efficiency deterioration over age. The chemical effect modelling involved substitution of three generations of refrigerants on the basis of the flow and stock model. The results showed that the global warming impact of the household refrigerator sector peaked at 25,104 kt CO 2 eq. in 1990 and then decreased to 6506 kt CO 2 eq. in 2030. The energy effect accounted for at least 91% and this ratio would be much higher in the future. Both implementation of minimum energy efficiency programs and substitution of refrigerants reduced the global warming impact significantly. This dynamic analysis could provide a holistic picture of the global warming impact of the household refrigerator sector both retrospectively and prospectively from accessing to the market, through rapid growth, to saturation. [ABSTRACT FROM AUTHOR]

The influences of the substitution of Ni with Mg on crystallographic and magnetic properties of the intermetallic alloys LaNi5-xMgx (x ≤ 0.4) were investigated. The X-ray diffraction patterns showed that all samples were of single phase, and the lattice parameters, a and c, decreased slightly upon chemical doping. LaNi5 is well known as an exchange-enhanced Pauli paramagnet. Interestingly, in LaNi5-xMgx, the ferromagnetic order existed even with a small amount of dopants; the Curie temperature reached the value of room temperature for x = 0.2, and enhanced with increasing x.