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Open Journal of Microphysics 2024年第3期14卷 79-88页

作者： Calford Odhiambo Otieno Alice Makonjo Wekesa Physics Department Kisii University Kisii Kenya

We present the result of groundwater stability assessment on three major springs in the Manga region in Nyamira County found in Kenya in 2018. These springs are Kiangoso (SP1), Kerongo (SP2) and Tetema (SP3). The corrosion and scaling tendency indices were obtained using the Langelier saturation index (LSI), Ryznar stability index (RSI), and Puckorius scaling index (PSI). The LSI values obtained for SP1, SP2, and SP3 are −3.93, −4.71, and −4.17, respectively, while using RSI, the values obtained for SP1, SP2, and SP3 are 14.15, 14.53, and 13.74, respectively. Using PSI, the values of SP1, SP2, and SP3 are 5.58, 5.45, and 5.58, respectively. From the interpretation of the indices, the groundwater from the three springs in the Manga region using LSI and RSI showed intolerable corrosion;hence, it is unlikely to scale as obtained from PSI.

关键词： Langelier Saturation Index Ryznar Stability Index Puckorius Scaling Index

Wavelength Dependent Nonlinear Spectroscopic Study of Third Harmonic Generation Probed by Rotational Maker Fringes Method

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Open Journal of Microphysics 2024年第2期14卷 13-23页

作者： Calford Odhiambo Otieno Department of Physics Kisii University Kisii Kenya

Efficient third-order nonlinearities of the Zinc Oxide and Al-doped Zinc Oxide were studied by Third Harmonic Generation (Third Harmonic Generation) Maker fringes to establish the effect Aluminum of Aluminum doping (Al-doping) on the cubic nonlinearities. Adding the Al-dopant to the Zinc Oxide crystal structure results in changes that affect the optical and nonlinear characteristics. Presented results indicate that the magnitude of X(3) was enhanced at single experimental wavelengths;however, across the broadband experimental spectrum, the effect of Al-doping remained relatively constant. The observed enhancement of third-order nonlinearity was purely from the bound electronic response. The observation is attributed to increased charge carriers and spontaneous polarization in the Zinc Oxide and Al-doped Zinc Oxide crystal structure.

关键词： Nonlinear Optics Harmonic Generation Maker Fringes Zinc Oxide

Fe3O4/Fe/FeS Tri-Heterojunction Node Spawning N-Carbon Nanotube Scaffold Structure for High-Performance Sodium-Ion Battery

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Energy & Environmental Materials 2024年第4期7卷 143-152页

作者： Yuan Liu Qing Lin Xiaocui Chen Xufeng Meng Baoxiu Hou Haiyan Liu Shuaihua Zhang Ningzhao Shang Zheng Wang Chaoyue Zhang Jianjun Song Xiaoxian Zhao Department of Chemistry College of Science Hebei Agricultural University college of Chemistry and Chemical Engineering Qingdao University college of Physics Qingdao University

The Fe-based anode of sodium-ion batteries attracts much attention due to the abundant source,low-cost,and high specific ***,the low electron and ion transfer rate,poor structural stability,and shuttle effect of NaS2intermediate restrain its further ***,the Fe3O4/Fe/FeS tri-heterojunction node spawned N-carbon nanotube scaffold structure（FHNCS） was designed using the modified MIL-88B（Fe） as a template followed by catalytic growth and sulfidation process.

关键词： anode core-shell heterojunction hollow structure sodium ion batteries

Practical cloud storage auditing using serverless computing

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Science China(Information Sciences) 2024年第3期67卷 33-47页

作者： Fei CHEN Jianquan CAI Tao XIANG Xiaofeng LIAO college of Computer Science and Software Engineering Shenzhen University college of Computer Science Chongqing University

Cloud storage auditing research is dedicated to solving the data integrity problem of outsourced storage on the cloud. In recent years, researchers have proposed various cloud storage auditing schemes using different techniques. While these studies are elegant in theory, they assume an ideal cloud storage model;that is, they assume that the cloud provides the storage and compute interfaces as required by the proposed schemes. However, this does not hold for mainstream cloud storage systems because these systems only provide read and write interfaces but not the compute interface. To bridge this gap, this work proposes a serverless computing-based cloud storage auditing system for existing mainstream cloud object storage. The proposed system leverages existing cloud storage auditing schemes as a basic building block and makes two adaptations. One is that we use the read interface of cloud object storage to support block data requests in a traditional cloud storage auditing scheme. Another is that we employ the serverless computing paradigm to support block data computation as traditionally required. Leveraging the characteristics of serverless computing, the proposed system realizes economical, pay-as-you-go cloud storage auditing. The proposed system also supports mainstream cloud storage upper layer applications(e.g., file preview) by not modifying the data formats when embedding authentication tags for later auditing. We prototyped and open-sourced the proposed system to a mainstream cloud service, i.e., Tencent Cloud. Experimental results show that the proposed system is efficient and promising for practical use. For 40 GB of data, auditing takes approximately 98 s using serverless computation. The economic cost is 120.48 CNY per year, of which serverless computing only accounts for 46%. In contrast, no existing studies reported cloud storage auditing results for real-world cloud services.

关键词： cloud storage auditing serverless computing object storage usability

Impact of Storage Temperature on Microbial Diversity and Probiotic Effect of Liquid Brewers’ Yeast

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Open Journal of Animal Sciences 2024年第3期14卷 168-182页

作者： Peter Alphonce Obuong Alaru Alfred Anakalo Shitandi Symon Maina Mahungu John Muasya Kilumba Muia Department of Dairy and Food Science and Technology Egerton University Nakuru Kenya Dairy Research Institute Kenya Agricultural and Livestock Research Organization Naivasha Kenya School of Pure and Applied Sciences Kisii University Kisii Kenya

Using probiotics as animal feed additives instead of antibiotics is gaining momentum to avert adverse negative effects on human health. Liquid brewers yeast (LBY) is an industrial by-product containing probiotic microorganisms and is also used as a protein supplement for dairy animals. Nevertheless, value chain actors lack of appropriate handling practices compromises the by-products quality and safety. This study aimed to determine the effect of variation in temperature on microbial diversity and probiotic effects during the storage time of LBY sampled from distributors and farmers from Githunguri sub-county of Kenya. The samples were stored at 20C, 25C and 30C, then tested on 0, 5, 10, 15 and 20 days. The studys parameters involved determining the pH levels, lactic acid bacteria (LAB), total coliform count (TCC), mould, and yeast in LBY. The rate (k) of the reaction kinetics model was used to extrapolate the expected probiotic shelf life. The LAB and yeast populations were reduced in a first-order reaction at all storage temperatures. The rate of reduction in the numbers of LAB reduced with an increase in temperature (k = 0.019 and 0.023) at 20C and 30C, respectively. Yeasts highest rate of growth reduction was 25C (k = 0.009) and least at 30C (k = 0.043). The minimum effective concentration for probiotics of 106 CFU/mL needed to observe the beneficial physiological impact on farm animals was achieved between 34.9 and 35.5 days at the tested storage temperatures. The study provides insight into the unexploited low-cost probiotic potential of LBY in dairy production. Conversely, handling practices and environmental microbial contamination along the value chain can compromise product quality and safety. There is a need to advocate its use in dairy for improved productivity and sensitize farmers to appropriate hygienic measures along the LBY value chain.

关键词： Liquid Brewers’ Yeast Microbial Diversity Probiotics Shelf Life

A novel graph oversampling framework for node classification in class-imbalanced graphs

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Science China(Information Sciences) 2024年第6期67卷 214-229页

作者： Riting XIA Chunxu ZHANG Yan ZHANG Xueyan LIU Bo YANG Key Laboratory of Symbolic Computation and Knowledge Engineering of Ministry of Education Jilin University college of Artificial Intelligence Jilin University college of Computer Science and Technology Jilin University college of Communication Engineering Jilin University

Graph neural network(GNN) is a promising method to analyze graphs. Most existing GNNs adopt the class-balanced assumption, which cannot deal with class-imbalanced graphs well. The oversampling technique is effective in alleviating class-imbalanced problems. However, most graph oversampling methods generate synthetic minority nodes and their edges after applying GNNs. They ignore the problem that the representations of the original and synthetic minority nodes are dominated by majority nodes caused by aggregating neighbor information through GNN before oversampling. In this paper, we propose a novel graph oversampling framework, termed distribution alignment-based oversampling for node classification in classimbalanced graphs(named Graph-DAO). Our framework generates synthetic minority nodes before GNN to avoid the dominance of majority nodes caused by message passing in GNNs. Additionally, we introduce a distribution alignment method based on the sum-product network to learn more information about minority nodes. To our best knowledge, it is the first to use the sum-product network to solve the class-imbalanced problem in node classification. A large number of experiments on four real datasets show that our method achieves the optimal results on the node classification task for class-imbalanced graphs.

关键词： graph neural network class-imbalanced graphs sum-product network oversampling node classification

Adsorption behavior of CO2/H2S mixtures in calcite slit nanopores for CO2 storage:An insight from molecular perspective

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Petroleum Science 2024年第4期21卷 2444-2456页

作者： Cheng Qian Zhen-Hua Rui Yue-Liang Liu Kai Du Chen Liu Yang Zhao Xiao-Min Ma State Key Laboratory of Petroleum Resources and Engineering China University of Petroleum college of Petroleum Engineering China University of Petroleum college of Carbon Neutrality Future Technology China University of Petroleum college of Petroleum China University of Petroleum-Beijing at Karamay college of Mining Engineering Taiyuan University of Technology

It is acknowledged that injecting CO2into oil reservoirs and saline aquifers for storage is a practical and affordable method for *** CO2produced from industrial exhaust contains impurity gases such as H2S that might impact CO2sequestration due to competitive *** study makes a commendable effort to explore the adsorption behavior of CO2/H2S mixtures in calcite slit *** Canonical Monte Carlo（GCMC） simulation is employed to reveal the adsorption of CO2,H2S as well as their binary mixtures in calcite *** show that the increase in pressure and temperature can promote and inhibit the adsorption capacity of CO2and H2S in calcite nanopores,***2exhibits stronger adsorption on calcite surface than *** energy plays the dominating role in the adsorption *** energy accounts for 97.11% of the CO2-calcite interaction energy and 56.33% of the H2S-calcite interaction energy at 10 MPa and 323.15 *** presence of H2S inhibits the CO2adsorption in calcite nanopores due to competitive adsorption,and a higher mole fraction of H2S leads to less *** quantity of CO2adsorbed is lessened by approximately 33% when the mole fraction of H2S reaches ***2molecules preferentially occupy the regions near the po re wall and H2S molecules tend to reside at the center of nanopore even when the molar ratio of CO2is low,indicating that CO2has an adsorption priority on the calcite surface over *** addition,moisture can weaken the adsorption of both CO2and H2S,while CO2is more *** interestingly,we find that pure CO2is more suitable to be sequestrated in the shallower formations,i.e.,500-1500 m,whereas CO2with H2S impurity should be settled in the deeper reservoirs.

关键词： Adsorption behavior CO 2 /H 2 S binary mixtures Molecular perspective Calcite slit nanopores CO 2 sequestration

Viscoacoustic generalized screen propagator in constant-Q model

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Petroleum Science 2024年第4期21卷 2356-2369页

作者： Zhong-Kui Dai Jia-Chun You Xing-Guo Huang Wei Liu college of Geophysics Chengdu University of Technology college of Instrumentation and Electrical Engineering Jilin University

When seismic waves propagate through the geological formation, there is a significant loss of energy and a decrease in imaging resolution, because of the viscoacoustic properties of subsurface medium. This profoundly impacts seismic wavefield propagation, imaging and interpretation. To accurately image the true structure of subsurface medium, the consensus among geophysicists is to no longer treat subsurface medium as ideal homogeneous medium, but rather to incorporate the viscoacoustic properties of subsurface medium. Based on the generalized screen propagator using conventional acoustic wave equation(acoustic GSP), our developed method introduces viscoacoustic compensation strategy, and derives a one-way wave generalized screen propagator based on time-fractional viscoacoustic wave equation(viscoacoustic GSP). In numerical experiments, we conducted tests on two-dimensional multi-layer model and the Marmousi model. When comparing with the acoustic GSP using the acoustic data, we found that the imaging results of the viscoacoustic GSP using the viscoacoustic data showed a significant attenuation compensation effect, and achieved imaging results for both algorithms were essentially consistent. However, the imaging results of acoustic GSP using viscoacoustic data showed significant attenuation effects, especially for deep subsurface imaging. This indicates that we have proposed an effective method to compensate the attenuated seismic wavefield. Our application on a set of real seismic data demonstrated that the imaging performance of our proposed method in local areas surpassed that of the conventional acoustic GSP. This suggests that our proposed method holds practical value and can more accurately image real subsurface structures while enhancing imaging resolution compared with the conventional acoustic GSP. Finally, with respect to computational efficiency, we gathered statistics on running time to compare our proposed method with conventional Q-RTM, and it is evid

关键词： One-way wave equation Viscoacoustic wave equation Generalized screen propagator Attenuation and dispersion effects

Shor's algorithm does not factor large integers in the presence of noise

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Science China(Information Sciences) 2024年第7期67卷 305-320页

作者： Jin-Yi CAI college of Letters and Science University of Wisconsin

We consider Shor's quantum factoring algorithm in the setting of noisy quantum gates. Under a generic model of random noise for(controlled) rotation gates, we prove that the algorithm does not factor integers of the form pq when the noise exceeds a vanishingly small level in terms of n—the number of bits of the integer to be factored, where p and q are from a well-defined set of primes of positive density. We further prove that with probability 1-o(1) over random prime pairs(p, q), Shor's factoring algorithm does not factor numbers of the form pq, with the same level of random noise present.

关键词： random noise Shor's algorithm rotation gates quantum computing prime factorization

Elucidating the Degradation Pathways of Human Insulin in the Solid State

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Journal of Analysis and Testing 2024年第03期8卷 288-299页

作者： Andrew Fagan Lorraine M.Bateman Joseph P.O'Shea Abina M.Crean SSPC the SFI Centre for Pharmaceutical Research School of Pharmacy University College Cork School of Pharmacy University College Cork Analytical and Biological Chemistry Research Facility (ABCRF) University College Cork School of Chemistry University College Cork

While there have been significant advances in the development of peptide oral dosage forms in recent years, highlighted by the clinical and commercial success of approved peptides such as Rybelsus?, there remain several barriers in the way of broad range applicability of this approach to peptide delivery. One such barrier includes the poor physical and chemical stability inherent to their structures, which persists in the solid state although degradation typically occurs at different rates and via different pathways in comparison to the solution state. Using insulin as a model peptide, this work sought to contribute to the development of analytical techniques for investigating common insulin degradation pathways. Chemically denatured,deamidated and aggregated samples were prepared and used to benchmark circular dichroism spectroscopy, reverse phase HPLC and size exclusion chromatography methods for the investigation of unfolding, chemical modifications and covalent aggregation of the insulin molecule respectively. Solid state degraded samples were prepared by heating insulin powder at 60 °C and 75% relative humidity for 1, 3, 5 and 7 d, and the degradation profiles of the samples were evaluated and compared with those observed in solution. While no unfolding was observed to occur, significant deamidation and covalent aggregation were detected. Reductive disulfide bond cleavage using dithiothreitol allowed for separation of the insulin A-and B-chains,offering a facile yet novel means of assessing the mechanisms of deamidation and covalent aggregation occurring in the solid state.

关键词： Biopharmaceutical analysis Covalent aggregation Deamidation Disulfide cleavage Insulin Solid state Stability