检索结果-南通市图书馆

Chinese Physics C 2024年第8期48卷 198-212页

作者： Zhi-chao Wang xian Gao School of Physics and Astronomy Sun Yat-sen UniversityZhuhai 519082China

We investigate a class of gravity theories respecting only spatial covariance,termed spatially covariant gravity,in the presence of an auxiliary scalar *** examine the conditions on the Lagrangian required to eliminate scalar degrees of freedom,allowing only two tensorial degrees of freedom to *** of strict constraint analysis,in this paper,we employ the perturbation method and focus on the necessary conditions to evade the scalar mode at the linear order in perturbations around a cosmological *** with a general action and solving the auxiliary perturbation variables in terms of a would-be dynamical scalar mode,we derive the condition to remove its kinetic term,thus ensuring that no scalar mode *** an application of the general condition,we study a polynomial-type Lagrangian as a concrete example,in which all monomials are spatially covariant scalars containing two *** find that the auxiliary scalar field is essential,and new terms in the Lagrangian are *** analysis provides insights into constructing gravity theories with two degrees of freedom in the extended framework of spatially covariant gravity.

关键词： modified gravity cosmological perturbation theory gravitational theory

Calculation of Mass Concrete Temperature and Creep Stress under the Influence of Local Air Heat Transfer

在线全文

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & Sciences 2024年第9期140卷 2977-3000页

作者： Heng zhang chao Su Xiaohu Chen Zhizhong Song Weijie zhan Academy of Science and Technology Changjiang Institute of Survey Planning Design and ResearchWuhan430010China College of Water Conservancy and Hydropower Engineering Hohai UniversityNanjing210098China Chief Engineer Office Wujiang Company of Goupitan Power Construction CooperationYuqing564408China

Temperature-induced cracking during the construction of mass concrete is a significant *** simulations of concrete temperature have primarily assumed that the concrete is placed in an open *** problem of heat transfer between the air and concrete has been simplified to the concrete’s heat dissipation ***,in the case of tubular concrete structures,where air inlet and outlet are relatively limited,the internal air temperature does not dissipate promptly to the external environment as it *** accurately simulate the temperature and creep stress in tubular concrete structures with enclosed air spaces during construction,we establish an air–concrete coupled heat transfer model according to the principles of conjugate heat transfer,and the accuracy of the model is verified through ***,we conduct a case study to analyze the impact of airflow within the ship lock corridor on concrete temperature and creep *** results demonstrate that enhancing airflow within the corridor can significantly reduce the maximum concrete *** with cases in which airflow within the corridor is neglected,the maximum concrete temperature and maximum tensile stress can be reduced by 12.5℃ and 0.7 MPa,respectively,under a wind speed of 4 m/*** results of the traditional calculation method are relatively close to those obtained at a wind speed of 1 m/***,the temperature reduction process in the traditional method is faster,and the method yields greater tensile stress values for the corridor location.

关键词： Conjugate heat transfer temperature field mass concrete creep stress

Microplastics may reduce the fish bioaccumulation of organic pollutants

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Technological Sciences 2024年第10期67卷 3079-3090页

作者： YANG Bing ZHOU xian HU XiaoJie QIN chao WANG Jian GAO YanZheng Institute of Organic Contaminant Control and Soil Remediation College of Resource and Environmental SciencesNanjing Agricultural University

Microplastics have frequently been regarded as a threat to aquatic organisms due to their potential to enhance the accessibility of organic pollutants. However, studies of microplastics as “carriers” in the process of bioaccumulation have only been conducted on a few organic contaminants. In this study, we employed machine learning algorithms to predict the sorption capacity of 83 exogenous organic pollutants(in CCL4) on microplastics, the prediction model exhibits exceptional predictive performance,achieving R2values of 0.8651 and 0.6962, RMSE values of 0.4625 and 0.1841 for the sorption coefficients Kfand n, respectively,and quantitatively estimated the contribution of microplastics to the bioaccumulation levels of organic pollutants in Gadus morhua. By considering both natural and microplastic-ingesting pathways, we demonstrated that the ingestion of microplastics containing organic pollutants facilitates the entry of organic pollutants into Gadus morhua. However, due to their robust sorption capacity, microplastics transport the organic pollutants accumulated through the natural pathway out of the fish, thereby preventing bioaccumulation. These findings elucidate the “cleaning” mechanism of microplastics concerning various organic pollutants in aquatic organisms, providing valuable insights for accurately assessing the risk of microplastics in aquatic environments.

关键词： microplastics aquatic organisms organic pollutants machine learning risks

同方期刊数据库

Host-induced silencing of MpPar6 confers Myzus persicae resistance in transgenic rape plants

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2024年第1期23卷 187-194页

作者： Qi zhang Wenqin zhan chao Li Ling Chang Yi Dong Jiang zhang State Key Laboratory of Biocatalysis and Enzyme Engineering School of Life SciencesHubei UniversityWuhan 430062China Oil Crops Research Institute Chinese Academy of Agricultural SciencesWuhan 430062China Agricultural Genomics Institute at Shenzhen Chinese Academy of Agricultural SciencesShenzhen 518000China

Plant-mediated RNA interference(RNAi)has emerged as a promising technology for insect *** green peach aphid,Myzus persicae,feeds on over 400 species of host *** napus(rape)is the second most important oilseed crop *** persicae is highly reproductive and causes severe damage to the rape plants due to its quite flexible life *** this study,we tested the RNAi effects of transgenic rape plants on *** in vitro feeding *** with artificial diets containing double-stranded RNAs(dsRNAs)targeting seven aphid genes,we identified a new gene encoding the partitioning-defective protein 6(Par6)as the most potent RNAi ***-and stage-expression analysis of Par6 suggested this gene is highly expressed in the embryo and adult stage of *** next generated transgenic rape plants expressing ds Par6 by Agrobacteriummediated transformation and obtained nine independent transgenic *** to wild-type control plants,transgenic rape lines expressing ds Par6 showed strong resistance to *** assays revealed that feeding transgenic rape plants to *** significantly decreased MpPar6 expression and survival rate and impaired ***,we showed that the resistance levels to *** are positively correlated with ds Par6 expression levels in transgenic rape *** study demonstrates that transgenic rape plants expressing ds Par6 are efficiently protected from *** with the genes involved in embryo development could be the effective RNAi targets for controlling aphids and potentially other insect pests.

关键词： oilseed rape pest control aphid double-stranded RNA RNA interference

A highly reduced Mo_(74) polyoxometalate featuring high proton conductivity accessed by building block strategy

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第3期67卷 862-868页

作者： Shi-Yi Liu Xue-Xin Li Wei-chao Chen Kui-zhan Shao Xin-Long Wang chao Qin Zhong-Min Su Key Laboratory of Polyoxometalate and Reticular Material Chemistry of Ministry of Education Department of ChemistryNortheast Normal UniversityChangchun 130024China State Key Laboratory of Supramolecular Structure and Materials Institute of Theoretical ChemistryCollege of ChemistryJilin UniversityChangchun 130021China

Highly reduced polyoxometalates(POMs) are predicted to be used as rather high energy density materials;however,it still suffers from the limited cluster species and reduction *** we demonstrate that it is possible to employ the building block strategy to generate a highly reduced polyoxomolybdate(C_(2)H_(8)N)_(14)(NH_(4))_(4)H_(14)[Mo_(48)-ⅤMo_(26)ⅥO_(202)(OH)_(12)(SO_(4))_(6)]·46H_(2)O(Mo_(74)).The fundamental Mo-based{Mo_x}(x=4,5,and 6) building blocks,which are templated by tetra-coordinated anions{MoO_(4)}or{SO_(4)},not only lay foundation for the formation of Mo_(74) featuring an unprecedented reduction ratio of 65%,but also give rise to SBBs-mediated(secondary building blocks) supramolecular dense packing interactions among the isolated Mo_(74) clusters that are favorable for proton ***,high proton conductivity(2.04×10^(-2)S cm^(-1)) had been realized at 50℃ and 90% relative humidity,revealing one of the well-known POMs-based crystalline proton conducting *** result highlights that this building block approach possesses great potential in producing highly reduced POM systems that can achieve controllable reduced ratio and desirable properties.

关键词： polyoxometalate building block molybdenum highly reduced state proton conduction

Wellbore-heat-transfer-model-based optimization and control for cooling downhole drilling fluid

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2024年第3期21卷 1955-1968页

作者： chao Wang He Liu Guo-Wei Yu Chen Yu xian-Ming Liu Peng Huang Yangtze University Jingzhou434023HubeiChina State Key Laboratory of Petroleum Resources and Engineering China University of Petroleum(Beijing)Beijing2249China CNPC Bohai Drilling Engineering Co. LtdTianjin300280China Exploration Development and Construction Engineering Division of PetroChina Jidong Oilfield Company Tangshan63200HebeiChin Henan University of Urban Construction Pingdingshan467036HenanChina

To address the two critical issues of evaluating the necessity of implementing cooling techniques and achieving real-time temperature control of drilling fluids underground in the current drilling fluid cooling technology,we first established a temperature and pressure coupled downhole heat transfer model,which can be used in both water-based and oil-based drilling ***,fourteen factors,which could affect wellbore temperature,were *** on the standard deviation of the downhole temperature corresponding to each influencing factor,the influence of each factor was *** influencing factors that can be used to guide the drilling fluid's cooling technology were drilling fluid thermal conductivity,drilling fluid heat capacity,drilling fluid density,drill strings rotation speed,pump rate,viscosity,ROP,and injection *** nondominated sorting genetic algorithm was used to optimize these six parameters,but the optimization process took 182 *** these eight parameters'influence rules with the nondominated sorting genetic algorithm can reduce the optimization time to 108 ***,the downhole temperature has been demonstrated to increase with the inlet temperature increasing linearly under quasi-steady *** this law and PID,the downhole temperature can be controlled,which can reduce the energy for cooling the surface drilling fluid and can ensure the downhole temperature reaches the set value as soon as possible.

关键词： Drilling Cooling Influencing factors Analysis Optimization Control

Relationship between diastolic blood pressure and adverse outcomes in ST-elevation myocardial infarction undergoing percutaneous coronary intervention

在线全文

学校读者我要写书评

暂无评论

South China Journal of Cardiology 2020年第1期21卷 1-5,11页

作者： YANG Da-hao LI Hua-long LIU Qiang xian zhan-chao CHEN Jun-yu LIAO Zhi-yong Department of Cardiology Fuwai Hospital Chinese Academy of Medical SciencesShenzhen 518000GuangdongChina

Background Low diastolic blood pressure(DBP)was reported to be associated with reduced coronary blood flow,subclinical myocardial damage,and cardiovascular events. The aim of this study was to explore the impact of low DBP on clinical outcomes in patients with ST-elevation myocardial infarction(STEMI)undergoing percutaneous coronary intervention(PCI). Methods A total of 1232 patients with STEMI were retrospectively enrolled and divided into two groups according to admission DBP level:≥70 mm Hg(n=817)and < 70 mm Hg(n=415). The relationship between DBP and in-hospital and 1-year adverse events was *** In-hospital death occurred in 2.4% of patients. The in-hospital mortality(5.3% vs. 1.0%,P<0.001)and major adverse clinical events(11.1% vs. 7.5%,P=0.033)were significantly higher in patients with a low *** <70 mm Hg was associated with in-hospital death(adjusted odds rate=3.31,95%CI:1.36-8.07,P=0.009).Additional significant indicators included eGFR < 60 mL/min/1.73 m^2 and intra aorta balloon pump(IABP)treatment. Seventy-seven(6.3%)patients died in the one-year follow-up. DBP < 70 mm Hg was associated with increased risk of 1-year death(8.9% vs. 4.8%,Log-rank=9.9,P=0.002). Conclusion Low DBP was associated with increased risk of in-hospital and 1-year adverse prognosis in patients with STEMI undergoing PCI,which could be a tool for risk assessment.

关键词： diastolic blood pressure ST-elevation myocardial infarction prognosis

Hemoglobin loss method calculates blood loss during pancreaticoduodenectomy and predicts bleeding-related risk factors

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastrointestinal Surgery 2024年第2期16卷 419-428页

作者： chao Yu Yi-Min Lin Guo-Zhe xian Department of Hepatobiliary Surgery Shandong Provincial Hospital Affiliated to Shandong First Medical UniversityJinan 250021Shandong ProvinceChina

BACKGROUND The common clinical method to evaluate blood loss during pancreaticoduoden-ectomy(PD)is visual inspection,but most scholars believe that this method is extremely subjective and ***,there is no accurate,objective me-thod to evaluate the amount of blood loss in PD *** retrospectively analyzed the clinical data of 341 patients who underwent PD in Shandong Provincial Hospital from March 2017 to February *** to different surgical methods,they were divided into an open PD(OPD)group and a laparoscopic PD(LPD)*** differences and correlations between the in-traoperative estimation of blood loss(IEBL)obtained by visual inspection and the intraoperative calculation of blood loss(ICBL)obtained using the Hb loss method were ***,IEBL and perioperative calculation of blood loss(PCBL)were compared between the two groups,and single-factor regression analysis was *** There was no statistically significant difference in the preoperative general patient information between the two groups(P>0.05).PD had an ICBL of 743.2(393.0,1173.1)mL and an IEBL of 100.0(50.0,300.0)mL(P200μmol/L(95%CI:7.09-644.26;P=0.045)were independent risk factors for *** ICBLs of the LPD group and OPD group were 767.7(435.4,1249.0)mL and 663.8(347.7,1138.2)mL,respectively(P>0.05).The IEBL of the LPD group 200.0(50.0,200.0)mL was slightly greater than that of the OPD group 100.0(50.0,300.0)mL(P>0.05).PCBL was greater in the LPD group than the OPD group[1061.6(612.3,1632.3)mL vs 806.1(375.9,1347.6)mL](P<0.05).CONCLUSION The ICBL in patients who underwent PD was greater than

关键词： Pancreaticoduodenectomy Hemoglobin loss Calculated blood loss Estimated blood loss

Integration of morphology and electronic structure modulation on cobalt phosphide nanosheets to boost photocatalytic hydrogen evolution from ammonia borane hydrolysis

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Green Energy & Environment 2024年第2期9卷 333-343页

作者： chao Wan Yu Liang Liu Zhou Jindou Huang Jiapei Wang Fengqiu Chen Xiaoli zhan Dang-guo Cheng School of Chemistry and Chemical Engineering Anhui Province Key Laboratory of Coal Clean Conversion and High Valued UtilizationAnhui University of TechnologyMa'anshan243002China College of Chemical and Biological Engineering Zhejiang UniversityZhejiang Provincial Key Laboratory of Advanced Chemical Engineering Manufacture Technology38 Zheda RoadHangzhou310027China Key Laboratory of New Energy and Rare Earth Resource Utilization of State Ethnic Affairs Commission Key Laboratory of Photosensitive Materials&Devices of Liaoning ProvinceSchool of Physics and Materials EngineeringDalian Nationalities University 18 Liaohe West RoadDalian116600China Institute of Zhejiang University-Quzhou 78 Jiuhua Boulevard NorthQuzhou324000China Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology Changzhou University213164China

The controllable and safe hydrogen storage technologies are widely recognized as the main bottleneck for the accomplishment of sustainable hydrogen *** borane(AB)has regarded as a competitive candidate for chemical hydrogen ***,developing efficient yet high-performance catalysts towards hydrogen evolution from AB hydrolysis remains an enormous ***,cobalt phosphide nanosheets are synthesized by a facile salt-assisted along with low-temperature phosphidation strategy for simultaneously modulating its morphology and electronic structure,and function as hydrogen evolution ***,the Co_(2)P nanosheets display extraordinary performance with a record high turnover frequency of 44.9 min^(-1),outperforming most of the noble-metal-free catalysts reported to *** remarkable performance is attributed to its desired nanosheets structure,featuring with high specific surface area,abundant exposed active sites,and short charge diffusion *** findings provide a novel strategy for regulating metal phosphides with desired phase structure and morphology for energy-related applications and beyond.

关键词： Ammonia borane Hydrogen generation Hydrolysis Cobalt phosphide nanosheets Photocatalysis

Interpenetrating network-reinforced gel polymer electrolyte for ultra-stable lithium−iodine batteries

在线全文

学校读者我要写书评

暂无评论

Carbon Energy 2024年第6期6卷 234-247页

作者： Ying Jiang Peng Huang Minman Tong Bingxin Qi Tao Sun Zhongyun xian Wen Yan chao Lai School of Chemistry and Materials Science Jiangsu Normal UniversityXuzhouJiangsuChina

Li-I_(2) batteries have attracted much interest due to their high capacity,exceptional rate performance,and low *** so,the problems of unstable Li anode/electrolyte interface and severe polyiodide shuttle in Li-I_(2) batteries need to be ***,the interfacial reactions on the Li anode and I_(2) cathode have been effectively optimized by employing a well-designed gel polymer electrolyte strengthened by cross-linked Ti-O/Si-O(GPETS).The interpenetrating network-reinforced GPETS with high ionic conductivity(1.88×10^(-3)S cm^(-1)at 25℃)and high mechanical strength endows uniform Li deposition/stripping over 1800 h(at 1.0mA cm^(-2),with a plating capacity of 3.0mAh cm^(-2)).Moreover,the GPETS abundant in surface hydroxyls is capable of capturing soluble polyiodides at the interface and accelerating their conversion kinetics,thus synergistically mitigating the shuttle *** from these properties,the use of GPETS results in a high capacity of 207 mAh g^(-1)(1 C)and an ultra-low fading rate of 0.013%per cycle over 2000 cycles(5 C).The current study provides new insights into advanced electrolytes for Li-I_(2) batteries.

关键词： electrode/electrolyte interface gel polymer electrolytes lithium dendrites lithium−iodine batteries polyiodide shuttle