Conventional error cancellation approaches separate molecules into smaller fragments and sum the errors of all fragments to counteract the overall computational error of the parent molecules.However,these approaches m...Conventional error cancellation approaches separate molecules into smaller fragments and sum the errors of all fragments to counteract the overall computational error of the parent molecules.However,these approaches may be ineffective for systems with strong localized chemical effects,as fragmenting specific substructures into simpler chemical bonds can introduce additional errors instead of mitigating them.To address this issue,we propose the Substructure-Preserved Connection-Based Hierarchy(SCBH),a method that automatically identifies and freezes substructures with significant local chemical effects prior to molecular fragmentation.The SCBH is validated by the gas-phase enthalpy of formation calculation of CHNO molecules.Therein,based on the atomization scheme,the reference and test values are derived at the levels of Gaussian-4(G4)and M062X/6-31+G(2df,p),respectively.Compared to commonly used approaches,SCBH reduces the average computational error by half and requires only15%of the computational cost of G4 to achieve comparable accuracy.Since different types of local effect structures have differentiated influences on gas-phase enthalpy of formation,substituents with strong electronic effects should be retained preferentially.SCBH can be readily extended to diverse classes of organic compounds.Its workflow and source code allow flexible customization of molecular moieties,including azide,carboxyl,trinitromethyl,phenyl,and others.This strategy facilitates accurate,rapid,and automated computations and corrections,making it well-suited for high-throughput molecular screening and dataset construction for gas-phase enthalpy of formation.展开更多
Chemical warfare agents(CWAs)remain a persistent hazard in many parts of the world,necessitating a deeper exploration of their chemical and physical characteristics and reactions under diverse conditions.Diisopropyl m...Chemical warfare agents(CWAs)remain a persistent hazard in many parts of the world,necessitating a deeper exploration of their chemical and physical characteristics and reactions under diverse conditions.Diisopropyl methylphosphonate(DIMP),a commonly used CWA surrogate,is widely studied to enhance our understanding of CWA behavior.The prevailing thermal decomposition model for DIMP,developed approximately 25 years ago,is based on data collected in nitrogen atmospheres at temperatures ranging from 700 K to 800 K.Despite its limitations,this model continues to serve as a foundation for research across various thermal and reactive environments,including combustion studies.Our recent experiments have extended the scope of decomposition analysis by examining DIMP in both nitrogen and zero air across a lower temperature range of 175??C to 250??C.Infrared spectroscopy results under nitrogen align well with the established model;however,we observed that catalytic effects,stemming from decomposition byproducts and interactions with stainless steel surfaces,alter the reaction kinetics.In zero air environments,we observed a novel infrared absorption band.Spectral fitting suggests this band may represent a combination of propanal and acetone,while GCMS analysis points to vinyl formate and acetone as possible constituents.Although the precise identity of these new products remains unresolved,our findings clearly indicate that the existing decomposition model cannot be reliably extended to lower temperatures or non-nitrogen environments without further revisions.展开更多
Lithium metal batteries(LMBs)have been regarded as one of the most promising alternatives in the post-lithium battery era due to their high energy density,which meets the needs of light-weight electronic devices and l...Lithium metal batteries(LMBs)have been regarded as one of the most promising alternatives in the post-lithium battery era due to their high energy density,which meets the needs of light-weight electronic devices and long-range electric vehicles.However,technical barriers such as dendrite growth and poor Li plating/stripping reversibility severely hinder the practical application of LMBs.However,lithium nitrate(LiNO_(3))is found to be able to stabilize the Li/electrolyte interface and has been used to address the above challenges.To date,considerable research efforts have been devoted toward understanding the roles of LiNO_(3) in regulating the surface properties of Li anodes and toward the development of many effective strategies.These research efforts are partially mentioned in some articles on LMBs and yet have not been reviewed systematically.To fill this gap,we discuss the recent advances in fundamental and technological research on LiNO_(3) and its derivatives for improving the performances of LMBs,particularly for Li-sulfur(S),Li-oxygen(O),and Li-Li-containing transition-metal oxide(LTMO)batteries,as well as LiNO_(3)-containing recipes for precursors in battery materials and interphase fabrication.This review pays attention to the effects of LiNO_(3) in lithium-based batteries,aiming to provide scientific guidance for the optimization of electrode/electrolyte interfaces and enrich the design of advanced LMBs.展开更多
Chemical exchange saturation transfer magnetic resonance imaging is an advanced imaging technique that enables the detection of compounds at low concentrations with high sensitivity and spatial resolution and has been...Chemical exchange saturation transfer magnetic resonance imaging is an advanced imaging technique that enables the detection of compounds at low concentrations with high sensitivity and spatial resolution and has been extensively studied for diagnosing malignancy and stroke.In recent years,the emerging exploration of chemical exchange saturation transfer magnetic resonance imaging for detecting pathological changes in neurodegenerative diseases has opened up new possibilities for early detection and repetitive scans without ionizing radiation.This review serves as an overview of chemical exchange saturation transfer magnetic resonance imaging with detailed information on contrast mechanisms and processing methods and summarizes recent developments in both clinical and preclinical studies of chemical exchange saturation transfer magnetic resonance imaging for Alzheimer’s disease,Parkinson’s disease,multiple sclerosis,and Huntington’s disease.A comprehensive literature search was conducted using databases such as PubMed and Google Scholar,focusing on peer-reviewed articles from the past 15 years relevant to clinical and preclinical applications.The findings suggest that chemical exchange saturation transfer magnetic resonance imaging has the potential to detect molecular changes and altered metabolism,which may aid in early diagnosis and assessment of the severity of neurodegenerative diseases.Although promising results have been observed in selected clinical and preclinical trials,further validations are needed to evaluate their clinical value.When combined with other imaging modalities and advanced analytical methods,chemical exchange saturation transfer magnetic resonance imaging shows potential as an in vivo biomarker,enhancing the understanding of neuropathological mechanisms in neurodegenerative diseases.展开更多
Twisted multilayers of two-dimensional materials attract widespread research interest due to their intriguing electronic and optical properties related to their chiral symmetry breaking and moiréeffects.The two-d...Twisted multilayers of two-dimensional materials attract widespread research interest due to their intriguing electronic and optical properties related to their chiral symmetry breaking and moiréeffects.The two-dimensional transition metal dichalcogenide MoSe_(2) is a particularly promising material for twisted multilayers,capable of sustaining moiréexcitons.Here,we report on a rational bottomup synthesis approach for twisted MoSe_(2) flakes by chemical vapor transport(CVT).Screw dislocation-driven growth was forced by surface-fused SiO_(2)nanoparticles on the substrates that serve as potential nucleation points in low supersaturation condition.Thus,crystal growth by in-situ CVT under addition of MoCl_(5) leads to bulk 2H-MoSe_(2) in a temperature gradient from 900 to 820℃ with a dwell time of 96 h.Hexagonally shaped 2H-MoSe_(2) flakes were grown from 710 to 685℃ with a dwell time of 30 min on SiO_(2)@Al_(2)O_(3)(0001)substrates.Electron backscatter diffraction as well as electron microscopy reveals the screw dislocation-driven growth of triangular 3R-MoSe_(2) with individual step heights between 0.9 and 2.9 nm on SiO_(2)@Si(100)under the same conditions.Finally,twisted MoSe_(2) flakes exhibiting a twist angle of 19°with respect to the[010]zone axis could be synthesized.展开更多
Parkinson’s disease is a common neurodegenerative disease with movement disorders associated with the intracytoplasmic deposition of aggregate proteins such asα-synuclein in neurons.As one of the major intracellular...Parkinson’s disease is a common neurodegenerative disease with movement disorders associated with the intracytoplasmic deposition of aggregate proteins such asα-synuclein in neurons.As one of the major intracellular degradation pathways,the autophagy-lysosome pathway plays an important role in eliminating these proteins.Accumulating evidence has shown that upregulation of the autophagy-lysosome pathway may contribute to the clearance ofα-synuclein aggregates and protect against degeneration of dopaminergic neurons in Parkinson’s disease.Moreover,multiple genes associated with the pathogenesis of Parkinson’s disease are intimately linked to alterations in the autophagy-lysosome pathway.Thus,this pathway appears to be a promising therapeutic target for treatment of Parkinson’s disease.In this review,we briefly introduce the machinery of autophagy.Then,we provide a description of the effects of Parkinson’s disease–related genes on the autophagy-lysosome pathway.Finally,we highlight the potential chemical and genetic therapeutic strategies targeting the autophagy–lysosome pathway and their applications in Parkinson’s disease.展开更多
This study examines the evolving use of synthetic chemicals in intensive agriculture over the past decade.It highlights the negative impacts of chemical inputs on soil health and ecosystem integrity and recommends kno...This study examines the evolving use of synthetic chemicals in intensive agriculture over the past decade.It highlights the negative impacts of chemical inputs on soil health and ecosystem integrity and recommends knowledge-sharing platforms,soil protection laws,and collaborative efforts between regulatory agencies and agricultural experts.The study emphasizes the need for a balanced approach that includes natural methods alongside synthetic chemicals,particularly herbicides.Ten years ago,farmers primarily used urea,DAP,and potassium for nutrients.However,increased awareness,market forces,and government subsidies have led to a significant rise in herbicide use as a cost-effective weed management strategy.Over the past decade,synthetic fertilizer use for cotton cultivation has increased by 80%,leading to deteriorating soil quality.Paddy cultivation has decreased by 23%,while cotton cultivation has increased by 20.4%due to higher economic incentives.Currently,89.1%of farmers use herbicides,compared to 97.2%who did not a decade ago.Insecticide use has also surged,with 97.8%of farmers applying 1.5 liters or more per acre.The excessive use of chemicals threatens soil fertility and disrupts the ecosystem’s balance.This article explores the reasons behind the adoption of chemical-intensive farming practices and offers insights into farmers’decision-making processes.The careful use of synthetic chemicals is essential to safeguard soil health and maintain ecological balance.展开更多
Recently,diffusion models have emerged as a promising paradigm for molecular design and optimization.However,most diffusion-based molecular generative models focus on modeling 2D graphs or 3D geom-etries,with limited ...Recently,diffusion models have emerged as a promising paradigm for molecular design and optimization.However,most diffusion-based molecular generative models focus on modeling 2D graphs or 3D geom-etries,with limited research on molecular sequence diffusion models.The International Union of Pure and Applied Chemistry(IUPAC)names are more akin to chemical natural language than the simplified molecular input line entry system(SMILES)for organic compounds.In this work,we apply an IUPAC-guided conditional diffusion model to facilitate molecular editing from chemical natural language to chemical language(SMILES)and explore whether the pre-trained generative performance of diffusion models can be transferred to chemical natural language.We propose DiffIUPAC,a controllable molecular editing diffusion model that converts IUPAC names to SMILES strings.Evaluation results demonstrate that our model out-performs existing methods and successfully captures the semantic rules of both chemical languages.Chemical space and scaffold analysis show that the model can generate similar compounds with diverse scaffolds within the specified constraints.Additionally,to illustrate the model’s applicability in drug design,we conducted case studies in functional group editing,analogue design and linker design.展开更多
Solid-state electrolytes(SSEs),as the core component within the next generation of key energy storage technologies-solid-state lithium batteries(SSLBs)-are significantly leading the development of future energy storag...Solid-state electrolytes(SSEs),as the core component within the next generation of key energy storage technologies-solid-state lithium batteries(SSLBs)-are significantly leading the development of future energy storage systems.Among the numerous types of SSEs,inorganic oxide garnet-structured superionic conductors Li7La3Zr2O12(LLZO)crystallized with the cubic Iaˉ3d space group have received considerable attention owing to their highly advantageous intrinsic properties encompassing reasonable lithium-ion conductivity,wide electrochemical voltage window,high shear modulus,and excellent chemical stability with electrodes.However,no SSEs possess all the properties necessary for SSLBs,thus both the ionic conductivity at room temperature and stability in ambient air regarding cubic garnet-based electrolytes are still subject to further improvement.Hence,this review comprehensively covers the nine key structural factors affecting the ion conductivity of garnet-based electrolytes comprising Li concentration,Li vacancy concentration,Li carrier concentration and mobility,Li occupancy at available sites,lattice constant,triangle bottleneck size,oxygen vacancy defects,and Li-O bonding interactions.Furthermore,the general illustration of structures and fundamental features being crucial to chemical stability is examined,including Li concentration,Li-site occupation behavior,and Li-O bonding interactions.Insights into the composition-structure-property relations among cubic garnet-based oxide ionic conductors from the perspective of their crystal structures,revealing the potential compatibility conflicts between ionic transportation and chemical stability resulting from Li-O bonding interactions.We believe that this review will lay the foundation for future reasonable structural design of oxide-based or even other types of superionic conductors,thus assisting in promoting the rapid development of alternative green and sustainable technologies.展开更多
Oxygen release and electrolyte decomposition under high voltage endlessly exacerbate interfacial ramifications and structu ral degradation of high energy-density Li-rich layered oxide(LLO),leading to voltage and capac...Oxygen release and electrolyte decomposition under high voltage endlessly exacerbate interfacial ramifications and structu ral degradation of high energy-density Li-rich layered oxide(LLO),leading to voltage and capacity fading.Herein,the dual-strategy of Cr,B complex coating and local gradient doping is simultaneously achieved on LLO surface by a one-step wet chemical reaction at room temperature.Density functional theory(DFT)calculations prove that stable B-O and Cr-O bonds through the local gradient doping can significantly reduce the high-energy O 2p states of interfacial lattice O,which is also effective for the near-surface lattice O,thus greatly stabilizing the LLO surface,Besides,differential electrochemical mass spectrometry(DEMS)indicates that the Cr_(x)B complex coating can adequately inhibit oxygen release and prevents the migration or dissolution of transition metal ions,including allowing speedy Li^(+)migration,The voltage and capacity fading of the modified cathode(LLO-C_(r)B)are adequately suppressed,which are benefited from the uniformly dense cathode electrolyte interface(CEI)composed of balanced organic/inorganic composition.Therefore,the specific capacity of LLO-CrB after 200 cycles at 1C is 209.3 mA h g^(-1)(with a retention rate of 95.1%).This dual-strategy through a one-step wet chemical reaction is expected to be applied in the design and development of other anionic redox cathode materials.展开更多
Ubiquitous contamination of the soil environment with volatile organic compounds(VOCs)has raised considerable concerns.However,there is still limited comprehensive surveying of soil VOCs on a national scale.Herein,65 ...Ubiquitous contamination of the soil environment with volatile organic compounds(VOCs)has raised considerable concerns.However,there is still limited comprehensive surveying of soil VOCs on a national scale.Herein,65 species of VOCswere simultaneously determined in surface soil samples collected from 63 chemical industrial parks(CIPs)across China.The results showed that the total VOC concentrations ranged from 7.15 to 1842 ng/g with a mean concentration of 326 ng/g(median:179 ng/g).Benzene homologs and halogenated hydrocarbons were identified as the dominant contaminant groups.Positive correlations between many VOC species indicated that these compounds probably originated from similar sources.Spatially,the hotspots of VOC pollution were located in eastern and southern China.Soils with higher clay content and a higher fraction of total organic carbon(TOC)content were significantly associated with higher soil VOC concentrations.Precipitation reduces the levels of highly water-soluble substances in surface soils.Both positive matrix factorization(PMF)and principal component analysis-multiple linear regression(PCA-MLR)identified a high proportion of industrial sources(PMF:59.2%and PCA-MLR:66.5%)and traffic emission sources(PMF:32.3%and PCA-MLR:33.5%).PMF,which had a higher R^(2) value(0.7892)than PCA-MLR(0.7683),was the preferred model for quantitative source analysis of soil VOCs.The health risk assessment indicated that the non-carcinogenic and carcinogenic risks of VOCs were at acceptable levels.Overall,this study provides valuable data on the occurrence of VOCs in soil from Chinese CIPs,which is essential for a comprehensive understanding of their environmental behavior.展开更多
Precipitation plays a pivotal role in wet deposition,significantly affecting aerosol purification.The efficacy of precipitation in removing aerosols depends on its type and the characteristics of the particulates invo...Precipitation plays a pivotal role in wet deposition,significantly affecting aerosol purification.The efficacy of precipitation in removing aerosols depends on its type and the characteristics of the particulates involved.However,further research is necessary to fully understand how precipitation impacts PM_(2.5)components.This study utilized high-temporalresolution data on PM_(2.5),its components and meteorological factors to examine varying responses influenced by precipitation intensity and duration.The findings indicate that increased rainfall intensity and duration enhance PM_(2.5)and its constituents removal efficiency.Specifically,longer precipitation periods significantly improve PM_(2.5)purification,especially with drizzle and light rain.Moreover,there is a direct correlation between preprecipitation PM_(2.5)levels and its scavenging rates,with drizzle potentially exacerbating PM_(2.5)pollution under cleaner conditions(≤35μg/m^(3)).Seasonally,the efficacy of removing PM_(2.5)components varies notably in response to drizzle and light rain.In spring,higher PM_(2.5)levels after drizzlewere primarily due to increased organic carbon concentrations favored by higher relative humidity and lower pH conditions compared to other seasons,conducive to secondary organic aerosol production.Lower wind speeds and higher temperatures further contribute to water-soluble organic carbon accumulation.Daytime and nighttime precipitation exerted differing influences on PM_(2.5)components,particularly in spring where daytime drizzle and light rain significantly increased PM_(2.5)and its constituents,notably NO_(3)-,potentially associated with phase distribution changes between gas and aerosol phases in low-temperature,high-RH conditions compared to nighttime.These results propose a dualimpact mechanism of precipitation on PM_(2.5)and provide scientific basis for designing effective control strategies.展开更多
With the rapid development of virtual reality(VR)and augmented reality(AR)technologies,their application potential in the field of education has become increasingly significant.For a long time,fire safety education in...With the rapid development of virtual reality(VR)and augmented reality(AR)technologies,their application potential in the field of education has become increasingly significant.For a long time,fire safety education in university laboratories has faced numerous challenges,and traditional teaching methods have been insufficiently effective,with high-risk scenarios difficult to realistically recreate.Especially in special scenarios involving hazardous chemicals,conventional training methods struggle to enable learners to achieve deep understanding and behavioral formation.This study systematically integrates immersive technology theory with safety education needs,providing a replicable technical solution for safety education in high-risk environments.Its modular design approach has reference value for expansion into other professional fields,offering practical evidence for innovation in safety education models in the digital age.展开更多
Hanyu Xu 1,Xuedan Song 1,*,Qing Zhang 1,Chang Yu 1,Jieshan Qiu 1,2,*1 Liaoning Key Lab for Energy Materials and Chemical Engineering,State Key Laboratory of Fine Chemicals,School of Chemical Engineering,Dalian Univers...Hanyu Xu 1,Xuedan Song 1,*,Qing Zhang 1,Chang Yu 1,Jieshan Qiu 1,2,*1 Liaoning Key Lab for Energy Materials and Chemical Engineering,State Key Laboratory of Fine Chemicals,School of Chemical Engineering,Dalian University of Technology,Dalian 116024,Liaoning Province,China.展开更多
Atomic surfaces are strictly required by high-performance devices of diamond.Nevertheless,diamond is the hardest material in nature,leading to the low material removal rate(MRR)and high surface roughness during machin...Atomic surfaces are strictly required by high-performance devices of diamond.Nevertheless,diamond is the hardest material in nature,leading to the low material removal rate(MRR)and high surface roughness during machining.Noxious slurries are widely used in conventional chemical mechanical polishing(CMP),resulting in the possible pollution to the environment.Moreover,the traditional slurries normally contain more than four ingredients,causing difficulties to control the process and quality of CMP.To solve these challenges,a novel green CMP for single crystal diamond was developed,consisting of only hydrogen peroxide,diamond abrasive and Prussian blue(PB)/titania catalyst.After CMP,atomic surface is achieved with surface roughness Sa of 0.079 nm,and the MRR is 1168 nm·h^(-1).Thickness of damaged layer is merely 0.66 nm confirmed by transmission electron microscopy(TEM).X-ray photoelectron spectroscopy,electron paramagnetic resonance and TEM reveal that·OH radicals form under ultraviolet irradiation on PB/titania catalyst.The·OH radicals oxidize diamond,transforming it from monocrystalline to amorphous atomic structure,generating a soft amorphous layer.This contributes the high MRR and formation of atomic surface on diamond.The developed novel green CMP offers new insights to achieve atomic surface of diamond for potential use in their high-performance devices.展开更多
The journal Chemical Research in Chinese Universities is a comprehensive academic journal in the field of chemistry,published bimonthly since 1984.The journal publishes research articles,letters/communications and rev...The journal Chemical Research in Chinese Universities is a comprehensive academic journal in the field of chemistry,published bimonthly since 1984.The journal publishes research articles,letters/communications and reviews written by faculty members,researchers and postgraduates in universities,colleges and research institutes all over China and overseas.展开更多
Peng et al.in[Phys.Rev.Research,2020,2(3):033089,11 pp.]formulated one-way fluxes for a general chemical reaction far from equilibrium,with arbitrary complex mechanisms,multiple intermediates,and internal kinetic cycl...Peng et al.in[Phys.Rev.Research,2020,2(3):033089,11 pp.]formulated one-way fluxes for a general chemical reaction far from equilibrium,with arbitrary complex mechanisms,multiple intermediates,and internal kinetic cycles.They defined the limit of the ratio of mesoscopic one-way fluxes and the volume of the tank reactor when the volume tends to infinity as macroscopic one-way fluxes,but a rigorous proof of existence of the limit is still awaiting.In this article,we fill this gap under a mild hypothesis:the Markov chain associated with the chemical master equation has finite states and any two columns in the stoichiometric matrices are not identical.In fact,an explicit expression of the limit is obtained.展开更多
Objective: We describe patients with MCS, the evolution of the Quick Environmental Exposure and Sensitivity Inventory (QEESI) score with a special focus on people whose fillings were removed. Methods: We have conducte...Objective: We describe patients with MCS, the evolution of the Quick Environmental Exposure and Sensitivity Inventory (QEESI) score with a special focus on people whose fillings were removed. Methods: We have conducted a retrospective longitudinal cohort study in patients diagnosed with MCS and attended in the outpatient Internal Medicine department of the University Hospital of San Juan de Alicante, from January 1, 2008 to January 1, 2021. Sociodemographic, clinical, QEESI and treatment-related variables were collected. We performed descriptive and inferential analyses. Mixed linear models were used to analyze the QEESI. Calculations were carried out with an α error of 5%. Results: Thirty-three patients were included (72.7% women, mean age 56.2). MCS was mainly triggered by mercury (N = 20) and food intolerance (N = 22). The mean interval from symptoms onset was 120 months (SD 81.6). 114 QEESIs were analyzed: 82 (N = 17 without amalgams) and 32 (N = 16 with amalgams). In patients without amalgams, severity scores increased across all subscales except the masking index (vs. with amalgams). Mean scores for the group without amalgams (vs. with amalgams) were: chemical intolerance, 62.8 points (vs. 63.4 and 46.7);other intolerances, 52.7 points (vs. 62.8 and 50.3);symptom severity, 63.2 (vs. 76.7 and 63.3);masking index, 3.9 (vs. 3.2 and 2.8);and life impacts, 63.1 (vs. 58.4 and 49.8). Conclusion: The profile of patient with MCS is a middle-aged woman who is a frequent user of healthcare services, presents a long diagnostic delay and has borne a great personal, work and socioeconomic impact. The QEESI is useful for the clinical follow-up of patients, including the optimal treatment response in the case of amalgams. Clinical Significance: People affected by Multiple Chemical Sensitivity deserve the attention, understanding and help of health professionals and family members, to face an invisible illness for those who do not suffer from it. Support is needed and doctors must raise awareness, and make an effort to understand and address this pathology. We suggest that protocolized amalgam extraction in accredited and prepared centers can reduce symptoms and improve quality of life, generating clinical, personal, family, occupational, social and occupational benefits.展开更多
To improve the mechanical properties of 2024 aluminum alloy,a kind of diamond-like carbon(DLC)film was deposited on the surface of 2024 aluminum alloy by plasma-enhanced chemical vapor deposition technique.The effects...To improve the mechanical properties of 2024 aluminum alloy,a kind of diamond-like carbon(DLC)film was deposited on the surface of 2024 aluminum alloy by plasma-enhanced chemical vapor deposition technique.The effects of acetylene gas on the microstructure,hardness,wear resistance,and adhesion of DLC film were investigated by field emission scanning electron microscope,nano-indentation tester,and friction-wear tester.The results indicate that the thickness of the DLC film increases gradually with increasing the proportion of acetylene.There is an obvious transition layer between the DLC film and matrix.When the ratio of argon to acetylene is 1:3,the hardness of DLC film is enhanced significantly because of the content changes of sp^(3) and sp^(2) bonds within the film.At the same time,the friction coefficient of DLC film is reduced.展开更多
基金the support of the National Natural Science Foundation of China(22575230)。
文摘Conventional error cancellation approaches separate molecules into smaller fragments and sum the errors of all fragments to counteract the overall computational error of the parent molecules.However,these approaches may be ineffective for systems with strong localized chemical effects,as fragmenting specific substructures into simpler chemical bonds can introduce additional errors instead of mitigating them.To address this issue,we propose the Substructure-Preserved Connection-Based Hierarchy(SCBH),a method that automatically identifies and freezes substructures with significant local chemical effects prior to molecular fragmentation.The SCBH is validated by the gas-phase enthalpy of formation calculation of CHNO molecules.Therein,based on the atomization scheme,the reference and test values are derived at the levels of Gaussian-4(G4)and M062X/6-31+G(2df,p),respectively.Compared to commonly used approaches,SCBH reduces the average computational error by half and requires only15%of the computational cost of G4 to achieve comparable accuracy.Since different types of local effect structures have differentiated influences on gas-phase enthalpy of formation,substituents with strong electronic effects should be retained preferentially.SCBH can be readily extended to diverse classes of organic compounds.Its workflow and source code allow flexible customization of molecular moieties,including azide,carboxyl,trinitromethyl,phenyl,and others.This strategy facilitates accurate,rapid,and automated computations and corrections,making it well-suited for high-throughput molecular screening and dataset construction for gas-phase enthalpy of formation.
基金sponsored by the Department of Defense,Defense Threat Reduction Agency under the Materials Science in Extreme Environments University Research Alliance,HDTRA1-20-2-0001。
文摘Chemical warfare agents(CWAs)remain a persistent hazard in many parts of the world,necessitating a deeper exploration of their chemical and physical characteristics and reactions under diverse conditions.Diisopropyl methylphosphonate(DIMP),a commonly used CWA surrogate,is widely studied to enhance our understanding of CWA behavior.The prevailing thermal decomposition model for DIMP,developed approximately 25 years ago,is based on data collected in nitrogen atmospheres at temperatures ranging from 700 K to 800 K.Despite its limitations,this model continues to serve as a foundation for research across various thermal and reactive environments,including combustion studies.Our recent experiments have extended the scope of decomposition analysis by examining DIMP in both nitrogen and zero air across a lower temperature range of 175??C to 250??C.Infrared spectroscopy results under nitrogen align well with the established model;however,we observed that catalytic effects,stemming from decomposition byproducts and interactions with stainless steel surfaces,alter the reaction kinetics.In zero air environments,we observed a novel infrared absorption band.Spectral fitting suggests this band may represent a combination of propanal and acetone,while GCMS analysis points to vinyl formate and acetone as possible constituents.Although the precise identity of these new products remains unresolved,our findings clearly indicate that the existing decomposition model cannot be reliably extended to lower temperatures or non-nitrogen environments without further revisions.
基金supported by the Yunnan Fundamental Research Projects(Grant Nos.202401AU070163 and 202501AT070298)the Yunnan Engineering Research Center Innovation Ability Construction and Enhancement Projects(Grant No.2023-XMDJ-00617107)+5 种基金the University Service Key Industry Project of Yunnan Province(Grant No.FWCY-ZD2024005)the Expert Workstation Support Project of Yunnan Province(Grant No.202405AF140069)the Scientific Research Foundation of Kunming University of Science and Technology(Grant No.20220122)the Analysis and Test Foundation of Kunming University of Science and Technology(Grant No.2023T20220122)the Natural Science Foundation of Inner Mongolia Autonomous Region of China(Grant No.2025QN02057)the Ordos City Strategic Pioneering Science and Technology Special Program for New Energy(Grant No.DC2400003365).
文摘Lithium metal batteries(LMBs)have been regarded as one of the most promising alternatives in the post-lithium battery era due to their high energy density,which meets the needs of light-weight electronic devices and long-range electric vehicles.However,technical barriers such as dendrite growth and poor Li plating/stripping reversibility severely hinder the practical application of LMBs.However,lithium nitrate(LiNO_(3))is found to be able to stabilize the Li/electrolyte interface and has been used to address the above challenges.To date,considerable research efforts have been devoted toward understanding the roles of LiNO_(3) in regulating the surface properties of Li anodes and toward the development of many effective strategies.These research efforts are partially mentioned in some articles on LMBs and yet have not been reviewed systematically.To fill this gap,we discuss the recent advances in fundamental and technological research on LiNO_(3) and its derivatives for improving the performances of LMBs,particularly for Li-sulfur(S),Li-oxygen(O),and Li-Li-containing transition-metal oxide(LTMO)batteries,as well as LiNO_(3)-containing recipes for precursors in battery materials and interphase fabrication.This review pays attention to the effects of LiNO_(3) in lithium-based batteries,aiming to provide scientific guidance for the optimization of electrode/electrolyte interfaces and enrich the design of advanced LMBs.
基金supported by The University of Hong Kong,China(109000487,109001694,204610401,and 204610519)National Natural Science Foundation of China(82402225)(to JH).
文摘Chemical exchange saturation transfer magnetic resonance imaging is an advanced imaging technique that enables the detection of compounds at low concentrations with high sensitivity and spatial resolution and has been extensively studied for diagnosing malignancy and stroke.In recent years,the emerging exploration of chemical exchange saturation transfer magnetic resonance imaging for detecting pathological changes in neurodegenerative diseases has opened up new possibilities for early detection and repetitive scans without ionizing radiation.This review serves as an overview of chemical exchange saturation transfer magnetic resonance imaging with detailed information on contrast mechanisms and processing methods and summarizes recent developments in both clinical and preclinical studies of chemical exchange saturation transfer magnetic resonance imaging for Alzheimer’s disease,Parkinson’s disease,multiple sclerosis,and Huntington’s disease.A comprehensive literature search was conducted using databases such as PubMed and Google Scholar,focusing on peer-reviewed articles from the past 15 years relevant to clinical and preclinical applications.The findings suggest that chemical exchange saturation transfer magnetic resonance imaging has the potential to detect molecular changes and altered metabolism,which may aid in early diagnosis and assessment of the severity of neurodegenerative diseases.Although promising results have been observed in selected clinical and preclinical trials,further validations are needed to evaluate their clinical value.When combined with other imaging modalities and advanced analytical methods,chemical exchange saturation transfer magnetic resonance imaging shows potential as an in vivo biomarker,enhancing the understanding of neuropathological mechanisms in neurodegenerative diseases.
基金funding from SFB 1415 subproject B04(Deutsche Forschungsgemeinschaft,No.417590517)supported by the Deutsche Forschungsgemeinschaft through the Würzburg-Dresden Cluster of Excellence on Complexity and Topology in Quantum Matter-ct.qmat(EXC 2147,No.390858490)the support provided by the DRESDEN-concept alliance of research institutions.
文摘Twisted multilayers of two-dimensional materials attract widespread research interest due to their intriguing electronic and optical properties related to their chiral symmetry breaking and moiréeffects.The two-dimensional transition metal dichalcogenide MoSe_(2) is a particularly promising material for twisted multilayers,capable of sustaining moiréexcitons.Here,we report on a rational bottomup synthesis approach for twisted MoSe_(2) flakes by chemical vapor transport(CVT).Screw dislocation-driven growth was forced by surface-fused SiO_(2)nanoparticles on the substrates that serve as potential nucleation points in low supersaturation condition.Thus,crystal growth by in-situ CVT under addition of MoCl_(5) leads to bulk 2H-MoSe_(2) in a temperature gradient from 900 to 820℃ with a dwell time of 96 h.Hexagonally shaped 2H-MoSe_(2) flakes were grown from 710 to 685℃ with a dwell time of 30 min on SiO_(2)@Al_(2)O_(3)(0001)substrates.Electron backscatter diffraction as well as electron microscopy reveals the screw dislocation-driven growth of triangular 3R-MoSe_(2) with individual step heights between 0.9 and 2.9 nm on SiO_(2)@Si(100)under the same conditions.Finally,twisted MoSe_(2) flakes exhibiting a twist angle of 19°with respect to the[010]zone axis could be synthesized.
基金supported by the National Natural Science Foundation of China,No.82101340(to FJ).
文摘Parkinson’s disease is a common neurodegenerative disease with movement disorders associated with the intracytoplasmic deposition of aggregate proteins such asα-synuclein in neurons.As one of the major intracellular degradation pathways,the autophagy-lysosome pathway plays an important role in eliminating these proteins.Accumulating evidence has shown that upregulation of the autophagy-lysosome pathway may contribute to the clearance ofα-synuclein aggregates and protect against degeneration of dopaminergic neurons in Parkinson’s disease.Moreover,multiple genes associated with the pathogenesis of Parkinson’s disease are intimately linked to alterations in the autophagy-lysosome pathway.Thus,this pathway appears to be a promising therapeutic target for treatment of Parkinson’s disease.In this review,we briefly introduce the machinery of autophagy.Then,we provide a description of the effects of Parkinson’s disease–related genes on the autophagy-lysosome pathway.Finally,we highlight the potential chemical and genetic therapeutic strategies targeting the autophagy–lysosome pathway and their applications in Parkinson’s disease.
文摘This study examines the evolving use of synthetic chemicals in intensive agriculture over the past decade.It highlights the negative impacts of chemical inputs on soil health and ecosystem integrity and recommends knowledge-sharing platforms,soil protection laws,and collaborative efforts between regulatory agencies and agricultural experts.The study emphasizes the need for a balanced approach that includes natural methods alongside synthetic chemicals,particularly herbicides.Ten years ago,farmers primarily used urea,DAP,and potassium for nutrients.However,increased awareness,market forces,and government subsidies have led to a significant rise in herbicide use as a cost-effective weed management strategy.Over the past decade,synthetic fertilizer use for cotton cultivation has increased by 80%,leading to deteriorating soil quality.Paddy cultivation has decreased by 23%,while cotton cultivation has increased by 20.4%due to higher economic incentives.Currently,89.1%of farmers use herbicides,compared to 97.2%who did not a decade ago.Insecticide use has also surged,with 97.8%of farmers applying 1.5 liters or more per acre.The excessive use of chemicals threatens soil fertility and disrupts the ecosystem’s balance.This article explores the reasons behind the adoption of chemical-intensive farming practices and offers insights into farmers’decision-making processes.The careful use of synthetic chemicals is essential to safeguard soil health and maintain ecological balance.
基金supported by the Yonsei University graduate school Department of Integrative Biotechnology.
文摘Recently,diffusion models have emerged as a promising paradigm for molecular design and optimization.However,most diffusion-based molecular generative models focus on modeling 2D graphs or 3D geom-etries,with limited research on molecular sequence diffusion models.The International Union of Pure and Applied Chemistry(IUPAC)names are more akin to chemical natural language than the simplified molecular input line entry system(SMILES)for organic compounds.In this work,we apply an IUPAC-guided conditional diffusion model to facilitate molecular editing from chemical natural language to chemical language(SMILES)and explore whether the pre-trained generative performance of diffusion models can be transferred to chemical natural language.We propose DiffIUPAC,a controllable molecular editing diffusion model that converts IUPAC names to SMILES strings.Evaluation results demonstrate that our model out-performs existing methods and successfully captures the semantic rules of both chemical languages.Chemical space and scaffold analysis show that the model can generate similar compounds with diverse scaffolds within the specified constraints.Additionally,to illustrate the model’s applicability in drug design,we conducted case studies in functional group editing,analogue design and linker design.
基金supported by the National Natural Science Foundation of China(Nos.22171102 and 22090044)the National Key R&D Program of China(Nos.2021YFF0500502 and 2023YFA1506304)+2 种基金the Jilin Province Science and Technology Development Plan(No.20230101024JC)the"Medicine+X"crossinnovation team of Bethune Medical Department of Jilin University"Leading the Charge with Open Competition"construction project(No.2022JBGS04)the Jilin University Graduate Training Office(Nos.2021JGZ08 and 2022YJSJIP20).
文摘Solid-state electrolytes(SSEs),as the core component within the next generation of key energy storage technologies-solid-state lithium batteries(SSLBs)-are significantly leading the development of future energy storage systems.Among the numerous types of SSEs,inorganic oxide garnet-structured superionic conductors Li7La3Zr2O12(LLZO)crystallized with the cubic Iaˉ3d space group have received considerable attention owing to their highly advantageous intrinsic properties encompassing reasonable lithium-ion conductivity,wide electrochemical voltage window,high shear modulus,and excellent chemical stability with electrodes.However,no SSEs possess all the properties necessary for SSLBs,thus both the ionic conductivity at room temperature and stability in ambient air regarding cubic garnet-based electrolytes are still subject to further improvement.Hence,this review comprehensively covers the nine key structural factors affecting the ion conductivity of garnet-based electrolytes comprising Li concentration,Li vacancy concentration,Li carrier concentration and mobility,Li occupancy at available sites,lattice constant,triangle bottleneck size,oxygen vacancy defects,and Li-O bonding interactions.Furthermore,the general illustration of structures and fundamental features being crucial to chemical stability is examined,including Li concentration,Li-site occupation behavior,and Li-O bonding interactions.Insights into the composition-structure-property relations among cubic garnet-based oxide ionic conductors from the perspective of their crystal structures,revealing the potential compatibility conflicts between ionic transportation and chemical stability resulting from Li-O bonding interactions.We believe that this review will lay the foundation for future reasonable structural design of oxide-based or even other types of superionic conductors,thus assisting in promoting the rapid development of alternative green and sustainable technologies.
基金financially supported by the National Natural Science Foundation of China(No.12304077)the Natural Science Foundation of Science and Technology Department of Sichuan Province(No.23NSFSC6224)+3 种基金Sichuan Science and Technology Program(No.2024NSFSC0989)the Key Laboratory of Computational Physics of Sichuan Province(No.YBUJSWL-YB-2022-03)the Material Corrosion and Protection Key Laboratory of Sichuan Province(No.2023CL14 and No.2023CL01)the National Innovation Practice Project(No.202411079005S).
文摘Oxygen release and electrolyte decomposition under high voltage endlessly exacerbate interfacial ramifications and structu ral degradation of high energy-density Li-rich layered oxide(LLO),leading to voltage and capacity fading.Herein,the dual-strategy of Cr,B complex coating and local gradient doping is simultaneously achieved on LLO surface by a one-step wet chemical reaction at room temperature.Density functional theory(DFT)calculations prove that stable B-O and Cr-O bonds through the local gradient doping can significantly reduce the high-energy O 2p states of interfacial lattice O,which is also effective for the near-surface lattice O,thus greatly stabilizing the LLO surface,Besides,differential electrochemical mass spectrometry(DEMS)indicates that the Cr_(x)B complex coating can adequately inhibit oxygen release and prevents the migration or dissolution of transition metal ions,including allowing speedy Li^(+)migration,The voltage and capacity fading of the modified cathode(LLO-C_(r)B)are adequately suppressed,which are benefited from the uniformly dense cathode electrolyte interface(CEI)composed of balanced organic/inorganic composition.Therefore,the specific capacity of LLO-CrB after 200 cycles at 1C is 209.3 mA h g^(-1)(with a retention rate of 95.1%).This dual-strategy through a one-step wet chemical reaction is expected to be applied in the design and development of other anionic redox cathode materials.
基金supported by the Medical and Health Projects in Zhejiang Province(No.2022PY049)the Basic Scientific Research Project of Hangzhou Medical College(No.YS2021006)Key Discipline of Zhejiang Province in Public Health and Preventive Medicine(First Class,Category A),Hangzhou Medical College.
文摘Ubiquitous contamination of the soil environment with volatile organic compounds(VOCs)has raised considerable concerns.However,there is still limited comprehensive surveying of soil VOCs on a national scale.Herein,65 species of VOCswere simultaneously determined in surface soil samples collected from 63 chemical industrial parks(CIPs)across China.The results showed that the total VOC concentrations ranged from 7.15 to 1842 ng/g with a mean concentration of 326 ng/g(median:179 ng/g).Benzene homologs and halogenated hydrocarbons were identified as the dominant contaminant groups.Positive correlations between many VOC species indicated that these compounds probably originated from similar sources.Spatially,the hotspots of VOC pollution were located in eastern and southern China.Soils with higher clay content and a higher fraction of total organic carbon(TOC)content were significantly associated with higher soil VOC concentrations.Precipitation reduces the levels of highly water-soluble substances in surface soils.Both positive matrix factorization(PMF)and principal component analysis-multiple linear regression(PCA-MLR)identified a high proportion of industrial sources(PMF:59.2%and PCA-MLR:66.5%)and traffic emission sources(PMF:32.3%and PCA-MLR:33.5%).PMF,which had a higher R^(2) value(0.7892)than PCA-MLR(0.7683),was the preferred model for quantitative source analysis of soil VOCs.The health risk assessment indicated that the non-carcinogenic and carcinogenic risks of VOCs were at acceptable levels.Overall,this study provides valuable data on the occurrence of VOCs in soil from Chinese CIPs,which is essential for a comprehensive understanding of their environmental behavior.
基金supported by the National Natural Science Foundation of China(No.42175124)the Science and Technology Department of Sichuan Province(No.23YFS0383)the Fundamental Research Funds for the Central Universities,China(No.2023CDSN-18).
文摘Precipitation plays a pivotal role in wet deposition,significantly affecting aerosol purification.The efficacy of precipitation in removing aerosols depends on its type and the characteristics of the particulates involved.However,further research is necessary to fully understand how precipitation impacts PM_(2.5)components.This study utilized high-temporalresolution data on PM_(2.5),its components and meteorological factors to examine varying responses influenced by precipitation intensity and duration.The findings indicate that increased rainfall intensity and duration enhance PM_(2.5)and its constituents removal efficiency.Specifically,longer precipitation periods significantly improve PM_(2.5)purification,especially with drizzle and light rain.Moreover,there is a direct correlation between preprecipitation PM_(2.5)levels and its scavenging rates,with drizzle potentially exacerbating PM_(2.5)pollution under cleaner conditions(≤35μg/m^(3)).Seasonally,the efficacy of removing PM_(2.5)components varies notably in response to drizzle and light rain.In spring,higher PM_(2.5)levels after drizzlewere primarily due to increased organic carbon concentrations favored by higher relative humidity and lower pH conditions compared to other seasons,conducive to secondary organic aerosol production.Lower wind speeds and higher temperatures further contribute to water-soluble organic carbon accumulation.Daytime and nighttime precipitation exerted differing influences on PM_(2.5)components,particularly in spring where daytime drizzle and light rain significantly increased PM_(2.5)and its constituents,notably NO_(3)-,potentially associated with phase distribution changes between gas and aerosol phases in low-temperature,high-RH conditions compared to nighttime.These results propose a dualimpact mechanism of precipitation on PM_(2.5)and provide scientific basis for designing effective control strategies.
文摘With the rapid development of virtual reality(VR)and augmented reality(AR)technologies,their application potential in the field of education has become increasingly significant.For a long time,fire safety education in university laboratories has faced numerous challenges,and traditional teaching methods have been insufficiently effective,with high-risk scenarios difficult to realistically recreate.Especially in special scenarios involving hazardous chemicals,conventional training methods struggle to enable learners to achieve deep understanding and behavioral formation.This study systematically integrates immersive technology theory with safety education needs,providing a replicable technical solution for safety education in high-risk environments.Its modular design approach has reference value for expansion into other professional fields,offering practical evidence for innovation in safety education models in the digital age.
文摘Hanyu Xu 1,Xuedan Song 1,*,Qing Zhang 1,Chang Yu 1,Jieshan Qiu 1,2,*1 Liaoning Key Lab for Energy Materials and Chemical Engineering,State Key Laboratory of Fine Chemicals,School of Chemical Engineering,Dalian University of Technology,Dalian 116024,Liaoning Province,China.
基金financial support from the National Key Research and Development Program of China(2018YFA0703400)the Fundamental Research Funds for the Provincial Universities of Zhejiang(GK239909299001021)+1 种基金the Ninth China Association for Science and Technology Youth Talent Lift Project Support Plan(KYZ015324002)the Changjiang Scholars Program of Chinese Ministry of Education。
文摘Atomic surfaces are strictly required by high-performance devices of diamond.Nevertheless,diamond is the hardest material in nature,leading to the low material removal rate(MRR)and high surface roughness during machining.Noxious slurries are widely used in conventional chemical mechanical polishing(CMP),resulting in the possible pollution to the environment.Moreover,the traditional slurries normally contain more than four ingredients,causing difficulties to control the process and quality of CMP.To solve these challenges,a novel green CMP for single crystal diamond was developed,consisting of only hydrogen peroxide,diamond abrasive and Prussian blue(PB)/titania catalyst.After CMP,atomic surface is achieved with surface roughness Sa of 0.079 nm,and the MRR is 1168 nm·h^(-1).Thickness of damaged layer is merely 0.66 nm confirmed by transmission electron microscopy(TEM).X-ray photoelectron spectroscopy,electron paramagnetic resonance and TEM reveal that·OH radicals form under ultraviolet irradiation on PB/titania catalyst.The·OH radicals oxidize diamond,transforming it from monocrystalline to amorphous atomic structure,generating a soft amorphous layer.This contributes the high MRR and formation of atomic surface on diamond.The developed novel green CMP offers new insights to achieve atomic surface of diamond for potential use in their high-performance devices.
文摘The journal Chemical Research in Chinese Universities is a comprehensive academic journal in the field of chemistry,published bimonthly since 1984.The journal publishes research articles,letters/communications and reviews written by faculty members,researchers and postgraduates in universities,colleges and research institutes all over China and overseas.
基金partially supported by NSFC(Nos.11701265,11961033).
文摘Peng et al.in[Phys.Rev.Research,2020,2(3):033089,11 pp.]formulated one-way fluxes for a general chemical reaction far from equilibrium,with arbitrary complex mechanisms,multiple intermediates,and internal kinetic cycles.They defined the limit of the ratio of mesoscopic one-way fluxes and the volume of the tank reactor when the volume tends to infinity as macroscopic one-way fluxes,but a rigorous proof of existence of the limit is still awaiting.In this article,we fill this gap under a mild hypothesis:the Markov chain associated with the chemical master equation has finite states and any two columns in the stoichiometric matrices are not identical.In fact,an explicit expression of the limit is obtained.
文摘Objective: We describe patients with MCS, the evolution of the Quick Environmental Exposure and Sensitivity Inventory (QEESI) score with a special focus on people whose fillings were removed. Methods: We have conducted a retrospective longitudinal cohort study in patients diagnosed with MCS and attended in the outpatient Internal Medicine department of the University Hospital of San Juan de Alicante, from January 1, 2008 to January 1, 2021. Sociodemographic, clinical, QEESI and treatment-related variables were collected. We performed descriptive and inferential analyses. Mixed linear models were used to analyze the QEESI. Calculations were carried out with an α error of 5%. Results: Thirty-three patients were included (72.7% women, mean age 56.2). MCS was mainly triggered by mercury (N = 20) and food intolerance (N = 22). The mean interval from symptoms onset was 120 months (SD 81.6). 114 QEESIs were analyzed: 82 (N = 17 without amalgams) and 32 (N = 16 with amalgams). In patients without amalgams, severity scores increased across all subscales except the masking index (vs. with amalgams). Mean scores for the group without amalgams (vs. with amalgams) were: chemical intolerance, 62.8 points (vs. 63.4 and 46.7);other intolerances, 52.7 points (vs. 62.8 and 50.3);symptom severity, 63.2 (vs. 76.7 and 63.3);masking index, 3.9 (vs. 3.2 and 2.8);and life impacts, 63.1 (vs. 58.4 and 49.8). Conclusion: The profile of patient with MCS is a middle-aged woman who is a frequent user of healthcare services, presents a long diagnostic delay and has borne a great personal, work and socioeconomic impact. The QEESI is useful for the clinical follow-up of patients, including the optimal treatment response in the case of amalgams. Clinical Significance: People affected by Multiple Chemical Sensitivity deserve the attention, understanding and help of health professionals and family members, to face an invisible illness for those who do not suffer from it. Support is needed and doctors must raise awareness, and make an effort to understand and address this pathology. We suggest that protocolized amalgam extraction in accredited and prepared centers can reduce symptoms and improve quality of life, generating clinical, personal, family, occupational, social and occupational benefits.
基金National Natural Science Foundation of China(52274296,52071091,52001081)College Student Innovation and Entrepreneurship Training Program Project from Guangdong Province in 2023(S20230125)。
文摘To improve the mechanical properties of 2024 aluminum alloy,a kind of diamond-like carbon(DLC)film was deposited on the surface of 2024 aluminum alloy by plasma-enhanced chemical vapor deposition technique.The effects of acetylene gas on the microstructure,hardness,wear resistance,and adhesion of DLC film were investigated by field emission scanning electron microscope,nano-indentation tester,and friction-wear tester.The results indicate that the thickness of the DLC film increases gradually with increasing the proportion of acetylene.There is an obvious transition layer between the DLC film and matrix.When the ratio of argon to acetylene is 1:3,the hardness of DLC film is enhanced significantly because of the content changes of sp^(3) and sp^(2) bonds within the film.At the same time,the friction coefficient of DLC film is reduced.
