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Morphology of Rat Testis Preserved in Three Different Fixatives
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作者 屠丽回 玉丽丽 章慧平 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 2011年第2期178-180,共3页
Histopathological examination of testes is important in assessing spermatogenesis and testicular function. Modified Davidson's fluid (mDF) has been proposed as a superior substitute for Bouin's fluid (BF) for fi... Histopathological examination of testes is important in assessing spermatogenesis and testicular function. Modified Davidson's fluid (mDF) has been proposed as a superior substitute for Bouin's fluid (BF) for fixation of adult animal testes. Besides, 4% paraformaldehyde (PFA) has been commonly used to fix testes with convenience. We compared the morphology of the rat testis fixed in 4% PFA, mDF, or BF using hematoxylin and eosin (HE)-stained sections. Fixation in 4% PFA resulted in obvious tissue shrinkage artifacts, especially between seminiferous epithelium cells. Shrinkage artifacts were also observed in the central area of the testes fixed in BF. Use of mDF did not cause shrinkage artifacts between seminiferous tubules, though a small amount can be observed in seminiferous tubules between germ cells. Clarity of nuclear detail in testes fixed in mDF and BF is better compared to 4% PFA. Our study demonstrated that fixation in mDF provided better morphologic details in the rat testis as compared with 4% PFA and BF. 展开更多
关键词 FIXATIVE TESTIS HE staining
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The impact of Internet access on household dietary quality:Evidence from rural China 被引量:1
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作者 Yi Cui Qiran Zhao +1 位作者 Thomas Glauben Wei Si 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2024年第2期374-383,共10页
Over the past few decades,the Internet has rapidly diffused across China.The spread of the Internet has had a profound economic and social impact on Chinese rural areas.Existing research shows that Internet access sig... Over the past few decades,the Internet has rapidly diffused across China.The spread of the Internet has had a profound economic and social impact on Chinese rural areas.Existing research shows that Internet access significantly impacts agricultural production and improves smallholder farmers’income.Beyond these,the Internet can affect other dimensions of social welfare.However,research about the impact of Internet access on dietary quality in rural China remains scarce.This study utilizes multi-period panel data from Fixed Observation Point in rural China from 2009 to 2015 to estimate the impact of Internet access on dietary quality and food consumption of rural households and conducts a causal analysis.Regression models with time and household fixed effects allow robust estimation while reducing potential issues of unobserved heterogeneity.The estimates show that Internet access has significantly increased rural household dietary quality(measured by the Chinese Diet Balance Index).Further research finds that Internet access has increased the consumption of animal products,such as aquatic and dairy products.We also examine the underlying mechanisms.Internet access improves dietary quality and food consumption mainly through increasing household income and food expenditure.These results encourage the promotion of Internet access as a valuable tool for nutritional improvements,especially in rural areas. 展开更多
关键词 dietary quality fixed effect model Internet access rural China
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间伐对长白落叶松人工林碳汇木材复合经济效益的影响
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作者 许欣野 董灵波 陈冠谋 《中南林业科技大学学报》 CAS CSCD 北大核心 2024年第9期201-210,共10页
【目的】为量化不同间伐策略对长白落叶松人工林碳汇木材复合经营中木材产量、碳储量及其经济效益的综合影响。通过比较不同的管理方案,优化林业管理以增强其碳汇功能和木材产量,从而提升林地的总体经济价值。【方法】以帽儿山实验林场... 【目的】为量化不同间伐策略对长白落叶松人工林碳汇木材复合经营中木材产量、碳储量及其经济效益的综合影响。通过比较不同的管理方案,优化林业管理以增强其碳汇功能和木材产量,从而提升林地的总体经济价值。【方法】以帽儿山实验林场长白落叶松人工林为研究对象,以CO_(2)FIX模型为基础,结合气象数据、调查数据和文献数据,探讨由间伐起始期(11、13 a)、间隔期(5、8和10 a)和间伐强度(10%、20%和30%)组成的不同间伐方案(即起始期、间隔期、间伐强度)对长白落叶松人工林木材产量、碳储量、碳流通以及经济效益的影响。【结果】1)较早的间伐起始期有助于提升林分木材产量和碳储量,起始期11 a的林分比13 a的林分木材产量、碳储量增加了约6%和2%;轻度间伐优化碳汇,重度间伐则可提前获得经济效益,10%间伐强度下的林分木材产量、碳储量相较于间伐强度30%的增加了约28.9%和13.2%;而30%间伐强度下林分的经济效益比10%强度下林分增加了19.5%。短间伐间隔(5 a)在木材收获、提升碳汇能力和经济效益比较长的间伐间隔(10 a)增加了10%、5.3%和1.4%。2)当以碳汇和木材为经营目标时,方案A1(11 a,5 a,10%)的效果均为最佳,其木材蓄积、碳储量和经济效益分别为758.49 m^(3)/hm^(2)、124.28 Mg/hm^(2)、32.48万元;当以碳汇木材复合经营为目标时,方案D3(13 a,5 a,30%)效果最佳,其木材蓄积、碳储量分别比方案A1减少了187.8 m^(3)/hm^(2)、13.5 Mg/hm^(2),但经济效益却比A1方案高9.62万元。3)当以碳汇和木材为最优先考虑时,长白落叶松人工林每公顷储碳约246.11 Mg/hm^(2),49%的碳进入土壤碳库,51%的碳进入木材加工。一个轮伐期后,42%的碳进入大气,20%的碳由林产品分解释放,31%的碳留存于木材产品碳库,7%的碳仍存于土壤碳库。而当以碳汇木材复合经营为目标时,长白落叶松人工林每公顷储碳约246.21 Mg/hm^(2),49%的碳进入土壤碳库,51%的碳进入木材加工。一个轮伐期后,43%的碳进入大气,20%的碳由林产品分解释放,31%的碳保存于木材产品碳库,6%的碳仍存于土壤碳库。【结论】研究量化分析了不同间伐策略对长白落叶松人工林在碳汇、木材产量及其经济效益方面的影响,证明根据具体的经营目标(碳汇、木材产量或二者综合经济效益),合理选择和调整间伐策略的重要性。 展开更多
关键词 长白落叶松 CO_(2)FIX模型 间伐方案 经济效益 碳储量 木材产量
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Fixed-Time Consensus-Based Nash Equilibrium Seeking
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作者 Mengwei Sun Jian Liu +1 位作者 Lu Ren Changyin Sun 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2024年第1期267-269,共3页
Dear Editor,This letter examines the fixed-time stability of the Nash equilibrium(NE)in non-cooperative games.We propose a consensus-based NE seeking algorithm for situations where players do not have perfect informat... Dear Editor,This letter examines the fixed-time stability of the Nash equilibrium(NE)in non-cooperative games.We propose a consensus-based NE seeking algorithm for situations where players do not have perfect information and communicate via a topology graph.The proposed algorithm can achieve NE in a fixed time that does not depend on initial conditions and can be adjusted in advance. 展开更多
关键词 Fixed SEEKING LETTER
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Secure Tracking Control via Fixed-Time Convergent Reinforcement Learning for a UAV CPS
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作者 Zhenyu Gong Feisheng Yang 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2024年第7期1699-1701,共3页
Dear Editor,This letter is concerned with the secure tracking control problem in the unmanned aerial vehicle(UAV) system by fixed-time convergent reinforcement learning(RL). By virtue of the zero-sum game,the false da... Dear Editor,This letter is concerned with the secure tracking control problem in the unmanned aerial vehicle(UAV) system by fixed-time convergent reinforcement learning(RL). By virtue of the zero-sum game,the false data injection(FDI) attacker and secure controller are viewed as game players. 展开更多
关键词 SECURE Fixed false
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Existence and numerical approximation of a solution to frictional contact problem for electro-elastic materials
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作者 Othman Baiz EL-Hassan Benkhira Rachid Fakhar 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2024年第2期201-219,共19页
In this paper,a frictional contact problem between an electro-elastic body and an electrically conductive foundation is studied.The contact is modeled by normal compliance with finite penetration and a version of Coul... In this paper,a frictional contact problem between an electro-elastic body and an electrically conductive foundation is studied.The contact is modeled by normal compliance with finite penetration and a version of Coulomb’s law of dry friction in which the coefficient of friction depends on the slip.In addition,the effects of the electrical conductivity of the foundation are taken into account.This model leads to a coupled system of the quasi-variational inequality of the elliptic type for the displacement and the nonlinear variational equation for the electric potential.The existence of a weak solution is proved by using an abstract result for elliptic variational inequalities and a fixed point argument.Then,a finite element approximation of the problem is presented.Under some regularity conditions,an optimal order error estimate of the approximate solution is derived.Finally,a successive iteration technique is used to solve the problem numerically and a convergence result is established. 展开更多
关键词 piezoelectric material frictional contact variational Inequality fixed point process finite element method error estimation iteration method
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Effect of the Particle Packing Configuration on Fixed Bed Performance
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作者 Li Ziqi Bao Di +1 位作者 Zhou Han Tang Xiaojin 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS CSCD 2024年第1期152-160,共9页
Fixed-bed reactors are generally considered the optimal choice for numerous multi-phase catalytic reactions due to their excellent performance and stability.However,conventional fixed beds often encounter challenges r... Fixed-bed reactors are generally considered the optimal choice for numerous multi-phase catalytic reactions due to their excellent performance and stability.However,conventional fixed beds often encounter challenges related to inadequate mass transfer and a high pressure drop caused by the non-uniform void fraction distribution.To enhance the overall performance of fixed beds,the impact of different packing configurations on performance was investigated.Experimental and simulation methods were used to investigate the fluid flow and mass transfer performances of various packed beds under different flow rates.It was found that structured beds exhibited a significantly lower pressure drop per unit length than conventional packed beds.Furthermore,the packing configurations had a critical role in improving the overall performance of fixed beds.Specifically,structured packed beds,particularly the H-2 packing configuration,effectively reduced the pressure drop per unit length and improved the mass transfer efficiency.The H-2 packing configuration consisted of two parallel strips of particles in each layer,with strips arranged perpendicularly between adjacent layers,and the spacing between the strips varied from layer to layer. 展开更多
关键词 packing configurations fixed bed Computational Fluid Dynamics simulation pressure drop mass transfer
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AGGREGATE SPECIAL FUNCTIONS TO APPROXIMATE PERMUTING TRI-HOMOMORPHISMS AND PERMUTING TRI-DERIVATIONS ASSOCIATED WITH A TRI-ADDITIVEψ-FUNCTIONAL INEQUALITY IN BANACH ALGEBRAS
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作者 Safoura Rezaei ADERYANI Azam AHADI +1 位作者 Reza SAADATI Hari M.SRIVASTAVA 《Acta Mathematica Scientia》 SCIE CSCD 2024年第1期311-338,共28页
In this paper,we define a new class of control functions through aggregate special functions.These class of control functions help us to stabilize and approximate a tri-additiveψ-functional inequality to get a better... In this paper,we define a new class of control functions through aggregate special functions.These class of control functions help us to stabilize and approximate a tri-additiveψ-functional inequality to get a better estimation for permuting tri-homomorphisms and permuting tri-derivations in unital C*-algebras and Banach algebras by the vector-valued alternative fixed point theorem. 展开更多
关键词 permuting tri-homomorphism in Banach algebra permuting tri-derivation on C*-algebra fixed point theorem Ulam-Hyers-Rassias stability aggregate special functions tri-additiveψ-functional inequality
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Does community-based health insurance affect lifestyle and timing of treatment seeking behavior?Evidence from Ethiopia
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作者 Zecharias Fetene Anteneh Anagaw D.Mebratie +2 位作者 Zemzem Shigute Getnet Alemu Arjun S.Bedi 《Global Health Journal》 2024年第2期83-90,共8页
Objectives This paper aims to investigate the effects of enrollment in the Ethiopian community-based health insurance(CBHI)scheme on household preventive care activities and the timing of treatment-seeking behavior fo... Objectives This paper aims to investigate the effects of enrollment in the Ethiopian community-based health insurance(CBHI)scheme on household preventive care activities and the timing of treatment-seeking behavior for illness symptoms.There is growing concern about the financial sustainability of CBHI schemes in developing countries.However,few empirical studies have identified potential contributors,including ex-ante and ex-post moral hazards.Methods We implement a household fixed-effect panel data regression model,drawing on three rounds of household survey data collected face to face in districts where CBHI scheme is operational and in districts where it is not operational in Ethiopia.Results The findings show that enrolment in CBHI does not significantly influence household behaviour regarding preventive care activities such as water treatment before drinking and handwashing before meals.However,CBHI significantly increases delay in treatment-seeking behaviour for diseases symptoms.Particularly,on average,we estimate about 4-6 h delay for malaria symptoms,a little above 4 h for tetanus,and 10-11 h for tuberculosis among the insured households.Conclusions While there is evidence that CBHI improve the utilization of outpatient or primary care services,our study suggests that insured members may wait longer before visiting health facilities.This delay could be partly due to moral hazard problems,as insured households,particularly those from rural areas,may consider the opportunity costs associated with visiting health facilities for minor symptoms.Overall,it is essential to identify the primary causes of delays in seeking medical services and implement appropriate interventions to encourage insured individuals to seek early medical attention. 展开更多
关键词 Community-based health insurance Financial sustainability Preventive care Treatment-seeking behavior Household fixed effect Ethiopia
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Employment and development levels in rural areas of the Russian Federation
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作者 Guzel SALIMOVA Gulnara NIGMATULLINA +2 位作者 Gamir HABIROV Alisa ABLEEVA Rasul GUSMANOV 《Regional Sustainability》 2024年第3期124-134,共11页
The development of agro-industrial complex is important for ensuring national food security and national health.The development of rural areas is subject to the development of agriculture and local infrastructure,as w... The development of agro-industrial complex is important for ensuring national food security and national health.The development of rural areas is subject to the development of agriculture and local infrastructure,as well as the availability of various services.This study selected 15 indicators in 2021 to analyze the employment and development levels in rural areas of 71 regions of the Russian Federation using the analytical grouping method.The results indicated that 20 regions(Group 1)had the highest percentage of rural population(33.10%).The percentage of population engaged in agriculture had the highest value(12.40%)in 31 regions(Group 2).Moreover,20 regions(Group 3)had the highest investments in fixed assets at the expense of municipal budget(11.80 USD/person).Increasing the investments in fixed assets carried out from the budget of the municipality can improve the employment level in rural areas.Then,we used cluster analysis to divide 14 regions of the Volga Federal District in the Russian Federation into 3 clusters.Cluster 1 covered Kirov Region and Republic of Mari El;Cluster 2 included Ulyanovsk Region,Saratov Region,Nizhny Novgorod Region,Perm Territory,Orenburg Region,Chuvash Region,and Republic of Mordovia;and Cluster 3 contained Republic of Tatarstan,Samara Region,Udmurtian Republic,Penza Region,and Republic of Bashkortostan.Results indicated that the 2 regions of Cluster 1 need to increase the availability of resources and natural gas and improve the investment attractiveness of rural areas.The 7 regions of Cluster 2 needed to develop infrastructure,public services,and agricultural production.We found the highest employment level in rural areas,the largest investments in fixed assets at the expense of municipal budget,the largest residential building area per 10,000 persons,and the largest individual residential building area in the 5 regions of Cluster 3.This study makes it possible to draw up a comprehensive regional development program and proves the need for the development of rural areas,which is especially important for the sustainable development of the Russian Federation. 展开更多
关键词 Rural areas Employment level Labor productivity Investments in fixed assets Sustainable Development Goal(SDG) Russian Federation
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Flexible Load Participation in Peaking Shaving and Valley Filling Based on Dynamic Price Incentives
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作者 Lifeng Wang Jing Yu Wenlu Ji 《Energy Engineering》 EI 2024年第2期523-540,共18页
Considering the widening of the peak-valley difference in the power grid and the difficulty of the existing fixed time-of-use electricity price mechanism in meeting the energy demand of heterogeneous users at various ... Considering the widening of the peak-valley difference in the power grid and the difficulty of the existing fixed time-of-use electricity price mechanism in meeting the energy demand of heterogeneous users at various moments or motivating users,the design of a reasonable dynamic pricing mechanism to actively engage users in demand response becomes imperative for power grid companies.For this purpose,a power grid-flexible load bilevel model is constructed based on dynamic pricing,where the leader is the dispatching center and the lower-level flexible load acts as the follower.Initially,an upper-level day-ahead dispatching model for the power grid is established,considering the lowest power grid dispatching cost as the objective function and incorporating the power grid-side constraints.Then,the lower level comprehensively considers the load characteristics of industrial load,energy storage,and data centers,and then establishes a lower-level flexible load operation model with the lowest user power-consuming cost as the objective function.Finally,the proposed method is validated using the IEEE-118 system,and the findings indicate that the dynamic pricing mechanism for peaking shaving and valley filling can effectively guide users to respond actively,thereby reducing the peak-valley difference and decreasing users’purchasing costs. 展开更多
关键词 Demand response fixed time-of-use electricity price mechanism dynamic price incentives mechanism bi-level model flexible load
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A related degree-based frequent pattern mining algorithm for railway fault data
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作者 Jiaxu Guo Ding Ding +2 位作者 Peihan Yang Qi Zou Yaping Huang 《High-Speed Railway》 2024年第2期101-109,共9页
It is of great significance to improve the efficiency of railway production and operation by realizing the fault knowledge association through the efficient data mining algorithm.However,high utility quantitative freq... It is of great significance to improve the efficiency of railway production and operation by realizing the fault knowledge association through the efficient data mining algorithm.However,high utility quantitative frequent pattern mining algorithms in the field of data mining still suffer from the problems of low time-memory performance and are not easy to scale up.In the context of such needs,we propose a related degree-based frequent pattern mining algorithm,named Related High Utility Quantitative Item set Mining(RHUQI-Miner),to enable the effective mining of railway fault data.The algorithm constructs the item-related degree structure of fault data and gives a pruning optimization strategy to find frequent patterns with higher related degrees,reducing redundancy and invalid frequent patterns.Subsequently,it uses the fixed pattern length strategy to modify the utility information of the item in the mining process so that the algorithm can control the length of the output frequent pattern according to the actual data situation and further improve the performance and practicability of the algorithm.The experimental results on the real fault dataset show that RHUQI-Miner can effectively reduce the time and memory consumption in the mining process,thus providing data support for differentiated and precise maintenance strategies. 展开更多
关键词 High utility QUANTITATIVE Frequent pattern mining Related degree pruning Fixed pattern length
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On Perron’s Formula and the Prime Numbers
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作者 Michael M. Anthony 《Advances in Pure Mathematics》 2024年第6期487-494,共8页
The Riemann hypothesis is intimately connected to the counting functions for the primes. In particular, Perron’s explicit formula relates the prime counting function to fixed points of iterations of the explicit form... The Riemann hypothesis is intimately connected to the counting functions for the primes. In particular, Perron’s explicit formula relates the prime counting function to fixed points of iterations of the explicit formula with particular relations involving the trivial and non-trivial roots of the Riemann Zeta function and the Primes. The aim of the paper is to demonstrate this relation at the fixed points of iterations of explicit formula, defined by functions of the form limT∈Ν→∞fT(zw)=zw,where, zwis a real number. 展开更多
关键词 Perron Fixed Points ITERATIONS Number Theory Riemann Hypothesis ITERATIONS INVARIANCE PRIMES
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A Bioequivalence Study of Empagliflozin/Metformin Fixed-Dose Combination in Healthy Subjects under Fasting Conditions
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作者 Evelyn Pena Alfredo Inatti +2 位作者 Anyoly Taly José Chacón Xenon Serrano-Martin 《Journal of Biosciences and Medicines》 2024年第9期235-250,共16页
Background: This study evaluated the bioequivalence of empagliflozin 12.5 mg/metformin 1000 mg tablets compared to Synjardy® (Empagliflozin 12.5 mg/metformin 1000 mg) tablets in healthy male subjects under fastin... Background: This study evaluated the bioequivalence of empagliflozin 12.5 mg/metformin 1000 mg tablets compared to Synjardy® (Empagliflozin 12.5 mg/metformin 1000 mg) tablets in healthy male subjects under fasting conditions. Methods: This was a phase I, randomized, single-dose, two-period, two-sequence, crossover study to evaluate the bioequivalence (BE) profiles of two fixed-dose combinations (FDCs) of empagliflozin/metformin. Cmax, AUC0-t and AUC0-∞ from test and reference formulations were evaluated to access BE. The plasma concentrations were measured using a validated liquid chromatography-mass spectrometry (LC-MS/MS) method. Of the 24 subjects enrolled, 23 completed both periods of the study. The two formulations test and reference were considered bioequivalent if 90% confidence interval (CI) fell within 80.00% - 125.00% for Cmax, AUC0-t and AUC0-∞. Tolerability and safety were assessed throughout the study. Results: The pharmacokinetic (PK) parameters were similar between the test product (T) and reference product (R) Synjardy®. The 90% CI of the test/reference ratios of log-transformed PK parameters point estimates was Cmax: 89.87% (85.68% - 94.27%), AUC0-t: 87.91% (83.65% - 92.39%) and AUC0-∞: 87.16% (82.80% - 91.75%) to empagliflozin and Cmax: 92.19% (87.95% - 96.65%), AUC0-t: 91.38% (84.42% - 98.91%) and AUC0-∞: 93.78% (83.82% - 104.93%) to metformin respectively (90% CI for all PK parameters fell within 80.00% - 125.00%). Conclusion: Our results demonstrated BE between the test and reference formulations of oral tablets of empagliflozin 12.5 mg/metformin 1000 mg (FDC) in healthy male subjects under fasting conditions. 展开更多
关键词 BIOEQUIVALENCE Fix Dose Combinations PHARMACOKINETIC Empagliflozin
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The Impact of Nitrogen-Fixing Bacteria, Iron, and Zinc Foliar Application on Dry Land Yellow Mustard (Brassica juncea) Grain and Oil Production
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作者 Saeid Zehtab Salmasi Haleh Nasiri +2 位作者 Rezvan Heshmati Mohammad Reza Sarikhani Yagoub Raei 《Agricultural Sciences》 2024年第7期719-728,共10页
The study, conducted at the Research Farm of the College of Agriculture, University of Tabriz in 2021, focused on the effects of various nitrogen-fixing bacterial isolates, biofertilizers containing nitrogen and phosp... The study, conducted at the Research Farm of the College of Agriculture, University of Tabriz in 2021, focused on the effects of various nitrogen-fixing bacterial isolates, biofertilizers containing nitrogen and phosphorus, as well as iron and zinc foliar applications on mustard growth under rainfed conditions. The results indicated that biofertilizers, whether used alone or in combination with chemical fertilizers, produced comparable grain and oil outputs compared to chemical fertilizers alone. Additionally, the application of iron and zinc through foliar spraying significantly enhanced both grain and oil production. These findings suggest that integrating nitrogen-fixing bacteria and biofertilizers could reduce reliance on chemical nitrogenous fertilizers, leading to decreased production expenses, improved product quality, and minimized environmental impact. This study highlights the potential for sustainable agricultural practices in dry land farming as a viable alternative to traditional chemical-intensive methods. Substituting chemical nitrogenous fertilizers with nitrogen-fixing bacteria or biofertilizers could result in cost savings in mustard grain and oil production while promoting environmental sustainability. 展开更多
关键词 Nitrogen Fixing Bacteria Yellow Mustard Dry Land Farming IRON ZINC Foliar Application
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Oral Hygiene in the Presence of Orthodontic Therapy
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作者 Emmanuel John Aryeetey Hicham Benyahia Fatima Zaoui 《Journal of Biosciences and Medicines》 2024年第2期98-110,共13页
Orthodontic treatment offers great advantages in improving facial and smile aesthetics, self-confidence and the function of the stomatognathic apparatus. The pursuit of these advantages makes use of orthodontic applia... Orthodontic treatment offers great advantages in improving facial and smile aesthetics, self-confidence and the function of the stomatognathic apparatus. The pursuit of these advantages makes use of orthodontic appliances that could be fixed or removable. However, it’s worth stating that these appliances interfere with tooth brushing, making it more difficult to brush teeth effectively. Orthodontics appliances therefore promote the accumulation of dental plaque, which results in both quantitative and qualitative changes in the oral microbiota, hence, exposing patients to several adverse effects such as White spot lesions, dental caries, periodontal pathologies and halitosis. For this reason, oral assessment of patients before, during and after treatment is necessary as well as oral hygiene instructions and motivation. Orthodontists therefore, should educate patients on oral and periodontal hygiene in order to control dental and periodontal complications. Prescriptions of plaque control materials adapted to each patient are done in order to optimize the final result and minimize unwanted complications. 展开更多
关键词 Orthodontic Treatment Oral Microbiome Oral Hygiene PERIODONTITIS GINGIVITIS Orthodontic Fixed Appliances Orthodontic Removable Appliances White Spot Lesions (WSL)
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Existence of Solutions of a Convolution Integral Equation
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作者 Henry Otoo Benjamin Dadzie Mensah Lewis Brew 《Journal of Applied Mathematics and Physics》 2024年第5期1835-1847,共13页
In this study, we prove the of existence of solutions of a convolution Volterra integral equation in the space of the Lebesgue integrable function on the set of positive real numbers and with the standard norm defined... In this study, we prove the of existence of solutions of a convolution Volterra integral equation in the space of the Lebesgue integrable function on the set of positive real numbers and with the standard norm defined on it. An operator P was assigned to the convolution integral operator which was later expressed in terms of the superposition operator and the nonlinear operator. Given a ball B<sub>r</sub> belonging to the space L it was established that the operator P maps the ball into itself. The Hausdorff measure of noncompactness was then applied by first proving that given a set M∈ B r the set is bounded, closed, convex and nondecreasing. Finally, the Darbo fixed point theorem was applied on the measure obtained from the set E belonging to M. From this application, it was observed that the conditions for the Darbo fixed point theorem was satisfied. This indicated the presence of at least a fixed point for the integral equation which thereby implying the existence of solutions for the integral equation. 展开更多
关键词 VOLTERRA Integral Equation CONVOLUTION Fixed Point EXISTENCE Noncompactness
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Simultaneous Adsorption of Aqueous Pb2+, Cu2+, Zn2+, and Cd2+ Using Surfactant-Modified and Unmodified Activated Carbon in a Fixed Bed Column
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作者 Morufu A. Olatunji Kamoru A. Salam Abdullahi M. Evuti 《Journal of Encapsulation and Adsorption Sciences》 2024年第1期1-24,共24页
The goal of this work is to improve the simultaneous removal of Pb2+, Cu2+, Zn2+, and Cd2+ ions from synthetic wastewater in a fixed bed column by incorporating sodium dodecyl sulfate (SDS) onto the surface of activat... The goal of this work is to improve the simultaneous removal of Pb2+, Cu2+, Zn2+, and Cd2+ ions from synthetic wastewater in a fixed bed column by incorporating sodium dodecyl sulfate (SDS) onto the surface of activated carbon made from coconut shells. The activated carbons were characterized using Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy-energy dispersive x-ray (SEM-EDX). The adsorption column dynamics were studied by varying the flow rates (5, 10 and 15 mL/min), bed heights (10, 15 and 20 cm), and initial concentrations (50, 150, and 250 mg/L). The activated carbon has a pore volume of 0.715 cm3/g and a BET-specific surface area of 1410 m2/g. Sodium dodecyl sulfate (SDS) surfactant incorporation onto the surface of the activated carbon enhances its capacity for simultaneous adsorption of Pb2+, Cu2+, Zn2+, and Cd2+ from the aqueous medium. The affinity of the heavy metals to both unmodified (AC) and modified (AC-SDS) activated carbons followed the order of Pb2+ > Cu2+ > Zn2+ > Cd2+. The dynamic adsorption of the column depends on the flow rate, bed height, initial metal concentration, and SDS surface modification. With a 5 mL/min flow rate, a 20 cm bed height, and a 50 mg/L initial metal concentration, a maximum break-through time of 150 minutes for the unmodified activated carbon (AC) and 180 minutes for the SDS-modified activated carbon (AC-SDS) was reached. 展开更多
关键词 ADSORPTION Surfactant-Modified Activated Carbon MULTICOMPONENT Breakthrough Adsorption Capacity Fixed Bed Column
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The Dynamical Properties of a Class of Discrete Smith Diffusion Model
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作者 Yu-Ming Yan Min-Hong Yang +2 位作者 Ying Lin Lu-Di Chen Xiao-Liang Zhou 《International Journal of Modern Nonlinear Theory and Application》 2024年第1期1-10,共10页
In this paper, the dynamical properties of Smith type diffusion model with Dirichlet boundary conditions are studied. The properties of hyperbolic fixed points and non-hyperbolic fixed points of the model are analyzed... In this paper, the dynamical properties of Smith type diffusion model with Dirichlet boundary conditions are studied. The properties of hyperbolic fixed points and non-hyperbolic fixed points of the model are analyzed. By using the central manifold theorem, the bifurcation phenomenon of the model is studied. The results show that flip, transcritical, pitchfork and Fold-flip bifurcations exist at non-hyperbolic fixed points. 展开更多
关键词 Hyperbolicfixed Point Non-Hyperbolic Fixed Point Central Manifold Theorem BIFURCATION
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Qualitative Properties of Equilibrium Point in a Discrete Predator-Prey Model
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作者 Weijie Lin Minhong Yang +2 位作者 Chenhao Sun Kaiwen Guan Xiaoliang Zhou 《Journal of Applied Mathematics and Physics》 2024年第8期2920-2927,共8页
In this paper, the dynamic properties of a discrete predator-prey model are discussed. The properties of non-hyperbolic fixed points and hyperbolic fixed points of the model are analyzed. First, by using the classic S... In this paper, the dynamic properties of a discrete predator-prey model are discussed. The properties of non-hyperbolic fixed points and hyperbolic fixed points of the model are analyzed. First, by using the classic Shengjin formula, we find the existence conditions for fixed points of the model. Then, by using the qualitative theory of ordinary differential equations and matrix theory we indicate which points are hyperbolic and which are non-hyperbolic and the associated conditions. 展开更多
关键词 Discrete Predator-Prey Model Non-Hyperbolic Fixed Point NODE Saddle Point
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