Mutual Transformation Research Articles

A Crawling Robot with Temperature-Controlled Variable Stiffness Feet: Strong Surface Adaptability

Abstract Existing soft robots have not shown the same level of adaptability on diverse terrains when compared to natural animals that possess variable stiffness characteristics. In this paper, utilizing the mutual transformation between the glassy and molten states of rosin materials, temperature-controlled variable stiffness feet (TVSF) are achieved by filling the rosin into an array of soft cavity villi. A single motor is utilized as the vibration-driven actuator of the robot. It is found that the feet stiffness can be changed ranging from 0.6227 N/mm to 0.9611 N/mm, which has a significant impact on the robot’s velocity and follows a nonlinear relationship. A smooth motion surface requires a high-stiffness foot to provide support and stability for the robot, while a rough motion surface necessitates a low-stiffness foot to reduce friction and resistance allowing for quick movement for the driving voltage of 1.6 V. Furthermore, the TVSF enable stable operation on complex surfaces, including a 30°slope, pipes, and pothole surfaces. This research provides a new technological approach to designing and manufacturing variable stiffness robots with enhanced surface adaptability.

The Comprehensive Profiling of the Chemical Components in the Raw and Processed Roots of Scrophularia ningpoensis by Combining UPLC-Q-TOF-MS Coupled with MS/MS-Based Molecular Networking

Scrophulariae Radix (SR), the dried root of Scrophularia ningpoensis Hemsl (S. ningpoensis), has been extensively used as traditional Chinese medicine for thousands of years. However, since the mid-20th century, the traditional processing technology of S. ningpoensis has been interrupted. Therefore, ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry technology, together with a Global Natural Product Social Molecular Networking (GNPS) method, was applied to comprehensively analyze the characteristic changes and mutual transformation of chemical constituents in the differently processed roots of S. ningpoensis, as well as to scientifically elucidate the processing mechanism of differently processed SR. As a result, a total of 149 components were identified. Notably, with the help of the GNPS data platform and MS2 fragment ions, the possible structures of four new compounds (47, 48, 50, and 73) were deduced in differently processed SR samples, in which 47, 48, and 50 are iridoid glycosides, and 73 is a phenylpropanoid glycoside. Five cyclopeptides (78, 86, 97, 99, and 104) derived from leucine (isoleucine) were identified in SR for the first time. The heatmaps analysis results indicated that leucine or isoleucine may be converted to cyclopeptides under the prolonged high-temperature conditions. Moreover, it is found that short-time steaming can effectively prevent the degradation of glycosides by inactivating enzymes. This study provides a new and efficient technical strategy for systematically identifying the chemical components, rapidly discovering the components, and preliminarily clarifying the processing mechanism of S. ningpoensis, as well as also providing a scientific basis for the improvement of the quality standards and field processing of S. ningpoensis.

Solvates and Polymorphs of Axitinib: Characterization and Phase Transformation.

Axitinib (AXTN) is an oral tyrosine kinase inhibitor for the treatment of early to advanced renal cell carcinoma. In this work, solvates of AXTN were prepared in five solvents and subjected to desolvation treatment. The crystal form A of AXTN can form solvates in acetonitrile, DMF, acetic acid, acetic acid + water, and methanol. Different ratios of AXTN and acetic acid will form different products (solvate or directly crystallized into another crystal form (form IV)). The characterization results of thermal analyses confirmed the types of the five solvates. The obtained solvates were desolvated using methods of solid-phase desolvation (heating, exposure to solvent steam, microwave) and solvent-mediated phase transformation (SMPT). The desolvated solids were characterized by PXRD, TGA, DSC, FT-IR, and SEM, and it was ultimately inferred that a new crystal form (form Z) of AXTN could be formed after desolvation. In addition, the solvates obtained in this work experienced mutual transformation via SMPT, which depends on the type of solvents or mixed solvents. The phase transformations of different solid forms were summarized. This study is instructive for exploring solvates and polymorphs of AXTN and understanding phase transitions under different environments.

Catalytic modification of MgH2 hydrogen storage properties by La–Ni catalysts

In this paper, it is experimentally demonstrated that the La–Ni catalyst contributes to the hydrogen storage performance of MgH2. Firstly, La–Ni (La: Ni = 1: 5.7) catalysts are prepared by CaH2 reduction method, and then MgH2+x wt.% La–Ni (x = 0, 3, 5, 7) composite alloys were prepared by ball milling method. The present work focuses on the structural and hydrogen ab/desorption properties of the composite alloys, and analysis the modulatory effect and influence mechanism of different La–Ni catalyst additions on the hydrogen storage properties of MgH2. The findings show that the composite alloys have the same diffraction peaks and that the main phase of the composite alloys is the MgH2 phase, with the addition of the LaNi5 phase, the Mg2Ni phase and a small amount of Mg phase. The mutual reversible transformations of LaH3 and Mg2Ni and Mg2NiH4 play a catalytic role in the hydrogen ab/desorption process. Moreover, the addition of La–Ni catalyst plays a dramatic improvement effect on the kinetic performance of MgH2 ab/desorption. When the addition of La–Ni catalyst is 5 wt.%, the composite alloy exhibits the most excellent hydrogen uptake and release kinetics. The MgH2+5 wt.% La–Ni composite alloy absorbs 4.2 wt.% H2 within 2 min at 473 K and releases 3.43 wt.% H2 within 150 min at 503 K. Fitting the hydrogen release activation energy of the composite alloys shows that the hydrogen release activation energy of the composite alloys decreases first and then increases, and there is a minimum hydrogen release activation energy of 101.81 kJ/mol H2 when the addition amount x = 5 wt.%.

Integration of vacuum UV/peroxydisulfate and reductive processes for the thorough defluorination of 8:3 fluorotelomer carboxylates: The critical contribution of preoxidation

Fluorotelomers have been systematically developed in bulk quantities and extensively applied in the fluoropolymer industry. Reductive treatments of fluorotelomers are different from those of perfluoroalkyl substances. In this study, vacuum UV/peroxydisulfate (VUV/PDS) was used for the first time to preoxidize 8:3 fluorotelomer carboxylates (8:3FTCA). Subsequently, it was integrated with the VUV/sulfite/iodide reductive process to accomplish the comprehensive defluorination of the oxidized products. The performance and mechanisms of 8:3FTCA degradation in the preoxidation process were mainly explored. pH values from 6.0 to 8.0 were conducive to 8:3FTCA decomposition. Hydrogen peroxide, hydroxyl radical (•OH), and hydroperoxyl radical (HO2•) were observed to be in a dynamic equilibrium state of mutual transformation, and the contributions of •OH and HO2• were 76.8 % and 17.4 %, respectively. The investigation of the influences of background water matrices demonstrated minimal adverse effects of sulfate and chloride, whereas bicarbonate, carbonate, and natural organic matter exhibited inhibitory effects. The degradation pathways of 8:3FTCA were speculated through density functional theory calculation and intermediate identification. The Ecological Structure–Activity Relationships simulation showed that VUV/PDS preoxidation decreased the aquatic toxicity of 8:3FTCA. These findings provide valuable insights for addressing challenges associated with fluorotelomer carboxylates.

Spatial–Temporal Evolution Characteristics and Driving Mechanism Analysis of the “Three-Zone Space” in China’s Ili River Basin

The Ili River Basin (IRB) is located in the northwest of China. With its large-scale zone and abundant resources, it is believed to be a “wet island” and a biotic resource storehouse in the dry regions of Eurasia. The IRB has stable ecological conditions and abundant water resources, providing natural conditions for agricultural production and human settlements. With the population increasing and economic development advancing, the competition for land resources is becoming fierce, leading to some ecological problems in this region. Therefore, understanding the spatiotemporal changes and driving mechanisms of the “three-zone space” (TZS) in the IRB is of significant practical importance for promoting sustainable development and optimizing the territorial spatial pattern. This study first analyzes the characteristics and intensity of the TZS changes from 2000 to 2020. Then, it utilizes the optimized parameter Geodetector (OPGD) to analyze the driving mechanisms behind these changes. The results show the following. Firstly, the agricultural space (AS) increased by a total of 837.5 km2, the urban space (US) increased by 519.64 km2, and other ecological space (OES) increased by 1518.83 km2. Green ecological space (GES) decreased by 2875.97 km2. Secondly, intensity analysis indicated that the total TZS change in IRB was 11.07%. At the spatial-type level, the increased intensities of OES, US, and AS were active. In spatial transformation intensity, US and OES tended to transform into AS; AS tended to transform into US; and OES and GES had a mutual transformation tendency. Thirdly, AS converted into US around emerging cities like Khorgas and Cocodala. The conversion towards GES was scattered. The mutual conversion between OES and GES showed spatial distribution consistency, mainly occurring in the Borohoro ranges and the Halik ranges. Lastly, regarding the driving mechanisms, the evolution of US in the IRB was driven by social and economic factors. Location and climate factors accelerated agricultural development, facilitating the transformation of GES and OES into AS. Climate and economic factors played a crucial role in the scale of conversions between OES and GES. The findings can provide a basis for the governance and protection of the IRB, help to form a rational territorial spatial pattern, and offer scientific guidance for sustainable land management.

Producing Human Life or Protecting Wildlife?

A series of biodiversity conservation campaign since 1980s and the establishment of Siberut National Park on Siberut Island (West Sumatra, Indonesia) have seriously unsettled the relationship between the Mentawai and forest as well as between the Mentawai with powerful external agencies. For the Mentawai, forest and nature should be managed and utilized. Claiming and contesting forests have been part of the Mentawai social fabric and histories, while cultivating and transforming them into social spaces (agroforest, sago garden, settlements) and extracting uncultivated animals and plants are valued human activities and important criteria in the construction of Mentawai personhood. The park has tried to persuade people keeping the forest intact and not using and transforming it. The establishment of the park also implies that the state claims the land and the forest. This paper argues that establishing a national park and protecting forests contradicts the value of productive activities and the history of human labour attached and spent on the land and forest. The resistance over forest protection offers vital clues in understanding how producing nature is inseparable from producing humans and discusses how people can coexist with forests and nonhuman entities, not just by conserving it, but by transforming it. Understanding the mutual production and transformation of human nature is crucial to the future of biodiversity conservation activities on the island.

The Hydration Activity Enhancement Method of Mayenite in Ladle Slag: A Review

As a byproduct of the steelmaking process, ladle slag has the potential to be used as an auxiliary cement material in the construction field. However, ladle slag generated after secondary refining is typically handled by air cooling and stacking, leading to the presence of the typical mineral phase mayenite (Ca12Al14O33, abbreviated as C12A7) in a crystalline form within the slag. This reduces its early hydration activity, which adversely affects the compressive strength of concrete and consequently lowers the resource utilization rate of ladle slag. Based on this, this article provides a comprehensive review of the generation process and composition of ladle slag. By discussing the hydration process and hydration products of the typical mineral phase C12A7 in ladle slag, as well as the mutual transformation of hydration products, it is shown that hydration products undergo transformation with increasing temperature. Compared to crystalline C12A7, amorphous, C12A7 exhibits excellent hydration activity. Building upon this, methods for amorphizing C12A7 are elucidated, wherein thermal activation or chemical activation is employed to alter the ordered arrangement of atoms within the crystal structure, thereby reducing the stability of the crystal structure to achieve amorphization of C12A7.

Mutual Transformations of Polysulfide Chromophore Species in Sodalite-Group Minerals: A DFT Study on S6 Decomposition.

It is known that various polysulfide species determine the color of sodalite-group minerals (haüyne, lazurite, and slyudyankaite), and that heating induces their transformations and color change, but the mechanisms of the transitions are unknown. A prominent example is the decay of cyclic S6 molecule. Using density-functional simulations, we explore its main decay pathways into the most probable final reaction products (the pairs of radical anions S3⋅-+S3⋅- and S2⋅-+S4⋅-). It was found that the most favorable reaction path involves initial capture of one electron by the S6 molecule, which greatly facilitates its decay of S6 and leads to the opening of the S6 cycle, and subsequent decomposition of the thus formed chain radical anion, with a limiting energy barrier of ~0.4 eV. Neutral polysulfide molecules capture one electron with a significant energy reduction. The radical anions Sn⋅- (n=2-6) are the most stable ones among corresponding species with the same n values and different charges. The capture of the second electron by S6⋅- occurs with a huge energy barrier (~2 eV). The results of the DFT calculations are in agreement with experimental data on the products of thermal conversions of extra-framework S-bearing groups in sodalite-group minerals.

Another in Oneself: Hybridity of the narrative identity and followability as narrative hospitality for others

The following article investigates the hybridity of narrative identity. It explores how idem-identity and the ipse-identity interrelate through time and otherness and illustrates the process of self’s reflexive re-cognition via others. It posits that narrative identity encompasses both private and public dimensions, requiring a co-authorship that integrates collective identities. This article argues for an ethical dimension to this identity, emphasizing the reciprocal movement between self and other. It introduces the concept of followability, which involves reconstructing narratives in a resonance relationship, fostering narrative hospitality and mutual transformation. The study concludes by proposing an eschatological perspective as a horizon for followability, enhancing narrative refiguration through future-oriented imagination.

The impact of land-use change on the ecological environment quality from the perspective of production-living-ecological space: A case study of the northern slope of Tianshan Mountains

Elucidating the relationships between production-living-ecological space (PLES) and ecological environments can help identify new strategies to promote sustainable development. The northern slope of the Tianshan Mountains represents a typical complex ecosystem characterized by mountain-oasis-desert interactions in arid regions with prominent human-land conflicts and intricate ecological environments. Here, we analyzed the spatiotemporal variations in land use in the study area from the perspective of PLES. Based on moderate resolution imaging spectroradiometer (MODIS) data, an improved remote sensing ecological index (IRSEI) suitable for arid areas was established to evaluate the eco-environment quality (EEQ) by introducing salinity and cleanliness indexes. A stepwise regression model was then used to identify and quantify the impact of the PLES transfer modes on EEQ. The results showed that: (1) The oasis area was dominated by agricultural production land, whereas the desert and alpine areas were dominated by other and pasture ecological lands, respectively. The oasis area primarily involved the conversion of pasture ecological land to agricultural production land, whereas the desert and alpine areas showed mutual transformation of ecological space. (2) The size relationship of the EEQ in each sub-region was alpine region (0.555) > oasis region (0.509) > desert region (0.424). The EEQ in the study area showed an overall upward trend but decreased in the alpine region. (3) Changes in the PLES and IRSEI primarily occurred in the oasis region. Among the 21 PLES transfer modes that affect EEQ, an increase in agricultural production land was the primary mode that enhanced IRSEI, whereas an increase in impervious surfaces significantly decreased IRSEI. The degree of influence was as follows: industrial and mining production (−0.594) > urban living (−0.462) > rural living land (−0.316). In addition, EEQ is also affected by the combined effects of climate, topography, and other factors. By proposing IRSEI, we highlight the impact of land-use transfer mode on ecological environment quality from the perspective of PLES, which can provide a reference for ecological environment evaluation in arid areas and is of great significance for land-use planning and ecological environment protection.

HEDehazeNet: Unpaired image dehazing via enhanced haze generation

Unpaired image dehazing models based on Cycle-Consistent Adversarial Networks (CycleGAN) typically consist of two cycle branches: dehazing-rehazing branch and hazing-dehazing branch. In these two branches, there is an asymmetry of information in the mutual transformation process between haze images and haze-free images. Previous models tended to focus more on the transformation process from haze images to haze-free images within the dehazing-rehazing branch, overlooking the provision of effective information for the formation of haze images in the hazing-dehazing branch. This oversight results in the production of haze patterns that are both monotonous and simplistic, ultimately impeding the overall performance and generalization capabilities of dehazing networks. In light of this, this paper proposes a novel model called HEDehazeNet (Dehazing Net based on Haze Generation Enhancement), which provides crucial information for the generation process of haze images through a dedicated haze generation enhancement module. This module is capable of producing three distinct modes of transmission maps - random transmission map, simulated transmission map, and mixed transmission maps combining both. Employing these transmission maps to generate hazing images with varying density and patterns provides the dehazing network with a more diverse and dynamically complex set of training samples, thereby enhancing its capacity to handle intricate scenes. Additionally, we made minor modifications to the U-Net, replacing residual blocks with multi-scale parallel convolutional blocks and channel self-attention, to further enhance the network's performance. Experiments were conducted on both synthetic and real-world datasets, substantiating the superiority of HEDehazeNet over the current state-of-the-art unpaired dehazing models.

Investigation of water variation and surface crust of Polygonati Rhizoma extract during vacuum drying

In order to better understand the drying process, the water variation and surface crust of Polygonati Rhizoma extract during drying were investigated. Water variation investigation showed that the total water content decreased gradually over drying time, mainly attributed to the removal of most of the immobile and all of the free water; As drying progressed, the mobility of immobile water and free water increased, while the bound water increased; water in different status underwent mutual transformation. Surface crust investigation showed that the extract surface gradually shrunk and became roughness during drying; crust with a dark color circle appeared on the extract surface, and some cracks connected between pores were found; as drying progressed, the porosity, total pore number and pore volume increased, the number of pores for all volume distributions below 1 mm3, 1–2 mm3 and over 2 mm3 initially increased and then decreased.

A Novel Multi-Timescale Optimal Scheduling Model for a Power–Gas Mutual Transformation Virtual Power Plant with Power-to-Gas Conversion and Comprehensive Demand Response

A Novel Multi-Timescale Optimal Scheduling Model for a Power–Gas Mutual Transformation Virtual Power Plant with Power-to-Gas Conversion and Comprehensive Demand Response

Triple-Phosphorescent Gold Nanoclusters Enabled by Isomerization of Terminal Thiouracils in the Surface Motifs.

Metal nanoclusters (NCs) hold great promise for expressing multipeak emission based on their well-defined total structure with diverse luminescent centers. Herein, we report the surface motif-dictated triple phosphorescence of Au NCs with dynamic color turning. The deprotonation-triggered isomerization of terminal thiouracils can evolve into a mutual transformation among their hierarchical motifs, thus serving a multipeak-emission expression with good tailoring. More importantly, the underlying electron transfer is thoroughly identified by excluding the radiative and nonradiative energy transfer, where electrons flow from the first phosphorescent state to the last two ones. The findings shed light on finely tailing motifs at the molecular level to motivate studies on customizable luminescence characteristics of metal NCs.

Spatiotemporal evolution and interaction of water constraints and their socio-ecological drivers in the Taihu Lake Basin

To effectively manage water constraints (WCs) within a basin, it is crucial to first scientifically delineate their spatial distribution and thoroughly understand the interactions between WCs. Investigating the complex driving mechanisms at multiple scales is also essential. In this study, a basin WC evaluation framework is constructed using a conflict risk assessment model. The spatiotemporal variations of four types of WCs across three spatial scales in the Taihu Lake Basin (TLB) are thoroughly investigated. Furthermore, the study quantifies the trade-offs, synergy effects, and bundle patterns of these water constraints. The study employs the Optimal Parameters-based Geographic Detector (OPGD) and multivariate linear regression to identify the key socio-ecological drivers of WCs. Our findings indicate that between 2010 and 2020, water resource constraint (WREC), water environment constraint (WENC), water safety constraint (WSAC), water ecology constraint (WECC), and the comprehensive WC (CWC) displayed varying degrees of heterogeneity. Particularly, the mean values of WSAC, WECC, and CWC witnessed an increase over the decade. Additionally, all WCs exhibited a strong positive spatial autocorrelation. Synergistic interactions among WCs were predominantly observed in pairs such as WREC-WSAC, WREC-WECC, and WSAC-WECC, while a weaker trade-off effect was noted in the WENC-WECC pair. At multiple scales, we identified eight types of WC bundles capable of undergoing mutual transformations, especially at the basin scale. The primary drivers of WCs varied across different stages and scales, with most factors collectively exerting a more significant impact than individually. Notably, factors like secondary and tertiary industry GDP (X2), population density (X3), precipitation (X6), and elevation (X7) were identified as core drivers influencing the evolution of WCs in the TLB. Integrating these spatiotemporal characteristics and driving mechanisms of WC interactions into basin planning and management can significantly support the alleviation of multidimensional water constraints in territorial spaces.

Lithium Tris(Oxalato)Aaluminate and its Hydrates: Structure, Dehydration and Thermal Decomposition

AbstractThe double oxalates MI3[MIII(C2O4)3] possess rich crystallochemistry and can be used as precursors for various ceramic materials. The article discusses a case of Li3[Al(C2O4)3]. A series of previously unknown hydrates (Li3[Al(C2O4)3] ⋅ 5.5H2O, Li3[Al(C2O4)3] ⋅ 4H2O, Li3[Al(C2O4)3] ⋅ H2O) was found for this composition, their crystal structure and temperatures of mutual transformations determined. Transformation from Li3[Al(C2O4)3] ⋅ 4H2O to Li3[Al(C2O4)3] ⋅ H2O was found to be accompanied by a change in the topology of the bonding network. Uniaxial negative thermal expansion was found for anhydrous Li3[Al(C2O4)3]. Thermal decomposition of Li3[Al(C2O4)3] was demonstrated to be a promising way to obtain precursors for aluminate ceramics.

Evaluation and Prediction of Ecosystem Services Value in Urban Agglomerations Using Land Use/Cover Change Analysis: Case Study of Wuhan in China

The evaluation of ecosystem service value (ESV) is crucial for decision making in regional sustainable development. The close relationship between ecosystem services and land use/cover change (LUCC) is well acknowledged. However, the impact of the mutual transformation among different land use types on the temporal and spatial differences in the ESV is still unclear. To fulfill this gap, this study evaluates the ESV in the Wuhan Urban Agglomerations based on LUCC, taking the spatiotemporal characteristics into consideration. The results show that (1) The land use structure in the Wuhan Urban Agglomerations has undergone great changes from 2012 to 2021, and the area of cultivated land converted to forest land is the largest, which may be related to policies such as returning farmland to forests. (2) The total amount of ESV shows a downward trend, and the spatial distribution of ESV is “low in the west and high in the central and eastern regions”, which may be related to the natural factors in study area. (3) The spatial distribution of ESV in the study area will remain unchanged in the future. However, the transformation among land use types may exacerbate the reduction in the total ESV, which will have an adverse impact on the ecological environment and sustainable development of the region. This study initiates a more comprehensive framework to better reflect the real scenario of ESV, which will hopefully provide a reference for regional sustainable development.

Dynamics of resonant magnetoelectric effect in a magnetoactive elastomer based cantilever: Magnetic field induced orientation transition and giant frequency tuning

Magnetoelectric (ME) effects in composite heterostructures containing mechanically coupled ferromagnetic and piezoelectric layers enable the mutual transformation of magnetic and electric fields and form the basis for the development of magnetic field sensors, actuators and energy harvesters. Promising materials for such composite structures are magnetoactive elastomers (MAE), which are silicone matrices with ferromagnetic particles uniformly distributed within them. The strong dependence of MAE properties on magnetic fields and their low rigidity enable contactless control of ME effects characteristics within such structures. In this work we have experimentally investigated the dynamics of resonant ME effects in a structure consisting of a MAE layer with carbonyl iron particles and a layer of polyvinylidene fluoride piezopolymer in a cantilever geometry. For the structure magnetized in a plane along the axis, the frequency tuning of the bending oscillations reached 360 % at the fields up to 2 kOe, and the maximum ME conversion coefficient was 1.74 V/(Oe·cm). For the structure magnetized perpendicular to the plane, an orientation transition was observed, which manifested itself as a jump-like bending of the structure to the angle up to ∼850 at magnetic field above the critical value. The frequency tuning by the magnetic field reached 185 %, and the maximum ME conversion coefficient was 135 V/(Oe·cm). A model has been developed that qualitatively describes the dynamics of ME effect in composite cantilever structures with a MAE layer for different orientations of the applied magnetic field.

In suit decorating PdPt bimetals on titanium dioxide nanosheets for detecting ppb level of carbon monoxide and hydrogen

The catalyst with strong metal-support interactions often exhibits high catalytic activity. This study aims to prepare sensitive materials with strong metal-MOS interactions and explore their sensitization mechanism. Sn-PdPt/TiO2 was obtained by in-situ decorating PdPt bimetals on the surface of TiO2 NSs using Sn2+ as the reducing agent, and PdPt/TiO2 was prepared by traditional reduction method. Compared with TiO2 sensor, PdPt/TiO2 and Sn-PdPt/TiO2 sensors exhibited higher sensitivity, selectivity, lower operating temperature (200 °C) and detection limit (ppb level) to CO and H2. The sensitization of PdPt bimetal to TiO2 should be ascribed to the high catalytic activity of PdPt bimetal towards O2, H2 and CO, Schottky barrier at the interface between TiO2 and PdPt NPs, and the multiple valence states (Pd0, Pd2+ and Pd4+) of Pd will undergo mutual transformation during gas sensing reactions. And Sn-PdPt/TiO2 sensor exhibited higher sensitivity, selectivity and better stability than those of PdPt/TiO2 sensor, which can be attributed to the introduction of SnO2 and the stronger interaction between PdPt and TiO2 due to the in-situ reduction reaction. This study can provide some reference for preparing the MOS based gas sensing materials with strong metal-support interactions and understanding the sensitization mechanism of PdPt bimetal.