期刊文献+
共找到88,924篇文章
< 1 2 250 >
每页显示 20 50 100
Strategic Engagement of Private Facilities to Increase Public-Private Mix (PPM) Contribution to Nigeria Tuberculosis Case Notification
1
作者 Obioma Chijioke-Akaniro Emperor Ubochioma +10 位作者 Amos Omoniyi Oluwafunmilayo Omosebi Olawumi Olarewaju Mary Etolue Sunday Asuke Elias Aniwada Anyaele Uwaezuoke Ndubuisi Victor Ombeka Aderonke Agbaje Adebola Lawanson Chukwuma Anyaike 《Journal of Tuberculosis Research》 CAS 2022年第3期99-110,共12页
Introduction: Finding the missing Tuberculosis (TB) cases remains the single most important priority for TB control in Nigeria. Between 66% - 92% of all cases of respiratory diseases including those with symptoms sugg... Introduction: Finding the missing Tuberculosis (TB) cases remains the single most important priority for TB control in Nigeria. Between 66% - 92% of all cases of respiratory diseases including those with symptoms suggestive of TB are first seen byprivate health providers. Dependable, quality surveillance systems and notification are key roles in health services delivery, particularly as it is related to TB control. However, poor notification has been a challenge. This study was to assess the contribution of the public private mix (PPM) to Nigeria Tuberculosis national case notification. Methods: It was a national cross-sectional study. Data were extracted from the National database and reviewed. Private facilities were engaged in 2017 and assessed over 2018-2020. Interventions included: enrolling private practitioners (Private-For-Profit, Faith Based Organization, Private Medicine Vendors and Community Pharmacists), engaging a private standalone Laboratory for Gene Xpert testing within the network of private facilities, use of Mobile App for easy screening and reporting, instituting a HUB and spoke, and incentives to private providers for participating. Each private provider had a customized approach. Trend analysis was performed using Cochran-Armitage χ<sup>2</sup> test for linear trends. Level of significance was at a p value of Results: Total case notification increased from 104,904 cases in 2017 to 138,591 in 2020. There were 2.0% increase in 2018, 13.0% in 2019 and 15.0% in 2020 (p < 0.001). PPM contribution to case notification increased from 10,699 cases in 2017 to 12,625 in 2018, then 17,250 in 2019 and 38,865 in 2020. There were 18.0% increase in 2018, 36.6% in 2019 and 125.3% increase in 2020 (p ). Conclusion: Effective engagement of the private sector in TB control efforts in Nigeria using a variety of approaches resulting in improved TB notification is possible. The National TB Programme should engage all private practitioners such that each practitioner will practice at least one TB service model. 展开更多
关键词 Strategic Engagement public-private mix Case Notification TUBERCULOSIS NIGERIA
下载PDF
Implementation of Tuberculosis and Human Immune-Deficiency Virus Programs Collaborative Services in Public-Private Mix Direct Observed Therapy Short Course Facilities in Addis Ababa, Ethiopia: Cross Sectional Facility Based Mixed Method
2
作者 Lakew Huluka Bahiru Mesele Damte Argaw Maeza Demissie 《Open Journal of Epidemiology》 2016年第2期109-120,共12页
Background: Ethiopia is one of the countries with the highest Human Immune-deficiency Virus (HIV) and Tuberculosis (TB) infection rates in the world. To improve TB/HIV Programs outcomes through Public Private Partners... Background: Ethiopia is one of the countries with the highest Human Immune-deficiency Virus (HIV) and Tuberculosis (TB) infection rates in the world. To improve TB/HIV Programs outcomes through Public Private Partnership Mix (PPM) approach was in place since 2006. But the status of its implementation has never been assessed. Methods: In this cross sectional study we employed mixed methods;we interviewed 272 tuberculosis patients, reviewed their records, and facilitated six in-depth interviews and four focus group discussions. The survey was conducted from January through March 2014 in Addis Ababa. Result: Among the interviewees 51.5% were males and the mean age was (32.7 ± SD 12.4) years. PPM facilities were offering HIV counseling for all TB patients;whereas 87.5% of TB patients have received HIV testing services. The TB/HIV co-infection rate was 45.4%. And only 72.2% TB/HIV patients were enrolled into chronic disease care services, 64.8% were put on Cotrimoxazol Preventive Therapy (CPT) and 50% were put on standard highly active anti-retro viral therapy (HAART) services. All PPM facilities don’t have IPT (Isoniazid Prophylaxis Therapy). The TB/HIV collaborative services strongly linked with the public health sector which was documented by developing inclusive work plan which create access to supplies and conducting joint supportive supervisions. However, the majorities of PPM facilities don’t have Multi-Disciplinary Team and lacks some essential supplies. The predictor for uptake of CPT were: being females TB patients was 86% lower than their counter part males (AOR = 0.14;95% CI = 0.04 - 0.92 P = 0.002), patients who has attended their TB/HIV care at private for the profit facilities were 84% lower than those attend in private not for profit facilities (AOR = 0.16;95% CI = 0.49 - 0.55, P = 0.003). Conclusions: The TB/HIV collaborative services at program level are stronger but only half of patients didn’t get the comprehensive TB/HIV collaborative services to achieve recommended quality of care. Strengthening the services and ensuring the availability of essential supplies was highly recommended. 展开更多
关键词 TUBERCULOSIS Human Immune-Deficiency Virus IMPLEMENTATION Collaborative Predictors Public Private mix Ethiopia
下载PDF
基于新权重函数的MIX-GARCH-L模型及其应用
3
作者 杨炜明 刘涛 王琴 《统计与决策》 北大核心 2024年第8期22-27,共6页
文章引入一种新的权重函数,并构建新的波动率模型——MIX-GARCH-L模型,新模型能够充分利用高低频数据提炼出更有价值的信息。针对新模型参数估计问题,提出MIX-GARCH-L模型的参数估计方法来分析估计量的理论性质,证明了对应的中心极限定... 文章引入一种新的权重函数,并构建新的波动率模型——MIX-GARCH-L模型,新模型能够充分利用高低频数据提炼出更有价值的信息。针对新模型参数估计问题,提出MIX-GARCH-L模型的参数估计方法来分析估计量的理论性质,证明了对应的中心极限定理以及用Service-Boostrap方法模拟检验估计量的数据表现。所提模型具有以下优势:新权重函数能够更好地根据交易特征的变动来自动调整不同交易日的权重,从而使每个高频交易日所分配到的权重与未来波动率产生的冲击效果一致;能够利用同一交易过程中多种高频交易数据,信息利用更加充分,使得MIX-GARCH-L模型具有更好的预测精度和预测优势。实证结果显示:MIX-GARCH-L模型的MSPE值明显小于GARCH-RV模型和GARCH-M模型的MSPE值,说明MIX-GARCH-L模型不仅在模型预测上有更高的预测精度,而且在稳健性上的表现也更好。 展开更多
关键词 混频数据 新权重 波动率 参数估计 数值模拟
下载PDF
Effect of aspect ratio of elliptical stirred vessel on mixing time and flow field characteristics in the absence of baffles
4
作者 Yuan Yao Peiqiao Liu +5 位作者 Qian Zhang Zequan Li Benjun Xi Changyuan Tao Yundong Wang Zuohua Liu 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第1期63-74,共12页
Elliptical tanks were used as an alternative to circular tanks in order to improve mixing efficiency and reduce mixing time in unbaffled stirred tanks(USTs). Five different aspect ratios of elliptical vessels were des... Elliptical tanks were used as an alternative to circular tanks in order to improve mixing efficiency and reduce mixing time in unbaffled stirred tanks(USTs). Five different aspect ratios of elliptical vessels were designed to compare their mixing time and flow field. Computational fluid dynamics(CFD) simulations were performed using the k–ε model to calculate the mixing time and simulate turbulent flow field features, such as streamline shape, velocity distribution, vortex core region distribution, and turbulent kinetic energy(TKE) transfer. Visualization was also carried out to track the tinctorial evolution of the liquid phase. Results reveal that elliptical stirred tanks can significantly improve mixing performance in USTs. Specifically, the mixing time at an aspect ratio of 2.00 is only 45.3% of the one of a circular stirred tank. Furthermore, the secondary flow is strengthened and the vortex core region increases with the increase of aspect ratio. The axial velocity is more sensitive to the aspect ratio than the circumferential and radial velocity. Additionally, the TKE transfer in elliptical vessels is altered. These findings suggest that elliptical vessels offer a promising alternative to circular vessels for enhancing mixing performance in USTs. 展开更多
关键词 mixing time CFD Stirred tank Secondary flow mixing performance
下载PDF
Mixed neuroendocrine non-neuroendocrine neoplasms in gastroenteropancreatic tract
5
作者 Sebastián Díaz-López Jerónimo Jiménez-Castro +2 位作者 Carlos Enrique Robles-Barraza Carlos Ayala-de Miguel Manuel Chaves-Conde 《World Journal of Gastrointestinal Oncology》 SCIE 2024年第4期1166-1179,共14页
Mixed neuroendocrine non-neuroendocrine neoplasms(MiNENs)are a hetero-geneous group of malignant neoplasms that can settle in the gastroenteropan-creatic tract.They are composed of a neuroendocrine(NE)and a non-NE com... Mixed neuroendocrine non-neuroendocrine neoplasms(MiNENs)are a hetero-geneous group of malignant neoplasms that can settle in the gastroenteropan-creatic tract.They are composed of a neuroendocrine(NE)and a non-NE compo-nent in at least 30%of each tumour.The non-NE component can include different histological combinations of glandular,squamous,mucinous and sarcomatoid phenotypes,and one or both of the components can be low-or high grade malignant.Recent changes in the nomenclature of these neoplasms might lead to great deal of confusion,and the lack of specific clinical trials is the main reason why their management is difficult.The review aims to clarify the definition of MiNEN and analyze available evidence about their diagnosis and treatment options according to their location and extension through careful analysis of the available data.It would be important to reach a general consensus on their diagnosis in order to construct a classification that remains stable over time and facilitates the design of clinical trials that,due to their low incidence,will require long recruitment periods. 展开更多
关键词 mixed neuroendocrine non-neuroendocrine neoplasms mixed adenoneuroendocrine carcinomas mixed tumours Gastroenteropancreatic Treatment Etiology Diagnosis
下载PDF
Evaluation of Nonbreaking Wave-Induced Mixing Parameterization Schemes Based on a One-Dimensional Ocean Model
6
作者 TANG Ran HUANG Chuanjiang +1 位作者 DAI Dejun WANG Gang 《Journal of Ocean University of China》 SCIE CAS CSCD 2024年第3期567-576,共10页
Surface waves have a considerable effect on vertical mixing in the upper ocean.In the past two decades,the vertical mixing induced through nonbreaking surface waves has been used in ocean and climate models to improve... Surface waves have a considerable effect on vertical mixing in the upper ocean.In the past two decades,the vertical mixing induced through nonbreaking surface waves has been used in ocean and climate models to improve the simulation of the upper ocean.Thus far,several nonbreaking wave-induced mixing parameterization schemes have been proposed;however,no quantitative comparison has been performed among them.In this paper,a one-dimensional ocean model was used to compare the performances of five schemes,including those of Qiao et al.(Q),Hu and Wang(HW),Huang and Qiao(HQ),Pleskachevsky et al.(P),and Ghantous and Babanin(GB).Similar to previous studies,all of these schemes can decrease the simulated sea surface temperature(SST),increase the subsurface temperature,and deepen the mixed layer,thereby alleviating the common thermal deviation problem of the ocean model for upper ocean simulation.Among these schemes,the HQ scheme exhibited the weakest wave-induced mixing effect,and the HW scheme exhibited the strongest effect;the other three schemes exhibited roughly the same effect.In particular,the Q and P schemes exhibited nearly the same effect.In the simulation based on observations from the Ocean Weather Station Papa,the HQ scheme exhibited the best performance,followed by the Q scheme.In the experiment with the HQ scheme,the root-mean-square deviation of the simulated SST from the observations was 0.43℃,and the mixed layer depth(MLD)was 2.0 m.As a contrast,the deviations of the SST and MLD reached 1.25℃ and 8.4 m,respectively,in the experiment without wave-induced mixing. 展开更多
关键词 wave-induced mixing surface waves sea surface temperature mixed layer depth General Ocean Turbulence Model
下载PDF
Mixed neuroendocrine and adenocarcinoma of gastrointestinal tract:A complex diagnosis and therapeutic challenge
7
作者 Santosh Shenoy 《World Journal of Gastrointestinal Oncology》 SCIE 2024年第6期2295-2299,共5页
In this editorial we comment on the manuscript describing a case of adenocarcinoma mixed with a neuroendocrine carcinoma of the gastroesophageal junction.Mixed neuroendocrine and non-neuroendocrine neoplasms of the ga... In this editorial we comment on the manuscript describing a case of adenocarcinoma mixed with a neuroendocrine carcinoma of the gastroesophageal junction.Mixed neuroendocrine and non-neuroendocrine neoplasms of the gastrointestinal system are rare heterogeneous group of tumors characterized by a high malignant potential,rapid growth,and poor prognosis.Due to the rarity of these cancers,the standard therapy is poorly defined.The diagnosis of these tumors is based on combination of morphological features,immunohistochemical and neuroendocrine and epithelial cell markers.Both endocrine and epithelial cell components can act independently of each other and thus,careful grading of each component separately is required.These cancers are aggressive in nature and the potential of each component has paramount importance in the choice of treatment and response.Regardless of the organ of origin,these tumors portend poor prognosis with increased proportion of neuroendocrine component.Multidisciplinary services and strategies are required for the management of these mixed malignancies to provide the best oncological outcomes.The etiopathogenesis of these mixed tumors remains obscure but poses interesting question.We briefly discuss a few salient points in this editorial. 展开更多
关键词 mixed adenocarcinoma and neuroendocrine carcinoma mixed neuroendocrine and non-neuroendocrine neoplasm mixed adeno-neuroendocrine cancer Cell reprograming Tumor plasticity
下载PDF
Dendroclimatological study of Sabina saltuaria and Abies faxoniana in the mixed forests of the Qionglai Mountains,eastern Tibetan Plateau
8
作者 Teng Li Jianfeng Peng +3 位作者 Tsun Fung Au Jingru Li Jinbao Li Yue Zhang 《Journal of Forestry Research》 SCIE EI CAS CSCD 2024年第1期72-82,共11页
Tree-ring chronologies were developed for Sabina saltuaria and Abies faxoniana in mixed forests in the Qionglai Mountains of the eastern Tibetan Plateau.Climate-growth relationship analysis indicated that the two co-e... Tree-ring chronologies were developed for Sabina saltuaria and Abies faxoniana in mixed forests in the Qionglai Mountains of the eastern Tibetan Plateau.Climate-growth relationship analysis indicated that the two co-exist-ing species reponded similarly to climate factors,although S.saltuaria was more sensitive than A.faxoniana.The strong-est correlation was between S.saltuaria chronology and regional mean temperatures from June to November.Based on this relationship,a regional mean temperature from June to November for the period 1605-2016 was constructed.Reconstruction explained 37.3%of the temperature variance during th period 1961-2016.Six major warm periods and five major cold periods were identified.Spectral analysis detected significant interannual and multi-decadal cycles.Reconstruction also revealed the influence of the Atlantic Multi-decadal Oscillation,confirming its importance on climate change on the eastern Tibetan Plateau. 展开更多
关键词 Tree-ring analysis mixed forests DENDROCLIMATOLOGY Qionglai Mountains
下载PDF
Soil properties and not plant factors affect both abundant and rare microbial taxa after thinning in a mixed stand of Cunninghamia lanceolata and Sassafras tzumu
9
作者 Wanxia Peng Tongqing Song +5 位作者 Hu Du Feng Wang Fuping Zeng Yang Wang Shulin Chen Yinzhu Chen 《Journal of Forestry Research》 SCIE EI CAS CSCD 2024年第2期81-94,共14页
Thinning is an effective management step for sustainable forest development,yet less attention is paid to the restoration of soil microbiota after thinning.In this study,both abundant and rare soil microbial communiti... Thinning is an effective management step for sustainable forest development,yet less attention is paid to the restoration of soil microbiota after thinning.In this study,both abundant and rare soil microbial communities(i.e.,bacterial,fungal),were evaluated under various thinning treatments in a mixed stand of Cunninghamia lanceolata and Sassafras tzumu using Mi Seq sequencing.Thinning did not significantly change either abundant or rare bacterial and fungal community composition,but affected their alpha diversity.The Shannon–Wiener indexes of rare fungal taxa under medium thinning were significantly lower than in the light thinning(P<0.05 level).Xanthobacteraceae dominated the abundant bacterial taxa,and Saitozyma and Mortierlla the abundant fungal taxa.The most common rare bacterial taxa varied;there was no prevalent rare fungal taxa under different thinnings.In addition,soil available nitrogen,total phosphorus,and p H had significant effects on rare bacterial taxa.Nutrients,especially available phosphorus,but not nitrogen,affected abundant and rare soil fungi.The results indicate that soil properties rather than plant factors affect abundant and rare microbial communities in soils of mixed stands.Thinning,through mediating soil properties,influences both abundant and rare bacterial and fungal communities in the mixed C.lanceolata and S.tzumu stand. 展开更多
关键词 Diversity Abundant taxa Rare taxa THINNING mixed stand
下载PDF
Assessing mixing uniformity in microreactors via in-line spectroscopy
10
作者 Shusaku Asano Shinji Kudo +3 位作者 Taisuke Maki Yosuke Muranaka Kazuhiro Mae Jun-ichiro Hayashi 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第2期119-124,共6页
Mixing behavior is critical for enhancing the selectivity of fast chemical reactions in microreactors.A high Reynolds number(Re)improves the mixing rate and selectivity of the reactions,but some exceptions of increasi... Mixing behavior is critical for enhancing the selectivity of fast chemical reactions in microreactors.A high Reynolds number(Re)improves the mixing rate and selectivity of the reactions,but some exceptions of increasing side product yield with the higher Re have been reported.This study investigated the mixing uniformity in microreactors with in-line UV-vis spectroscopy to clarify the relationship between reaction selectivity and chaotic mixing with the higher Re.A colorization experiment of thymolphthalein in an acidic solution was conducted with an excess acid amount to the base to indicate a non-uniformly mixed region.Non-uniformity significantly increased with Re.At the same time,the degree of mixing,which was measured by a usual decolorization experiment,showed that the mixing rate increased with Re.The in-line analysis of the Villermaux-Dushman reaction during the mixing clarified that side product yield significantly increased with Re at around 300 and then decreased at around 1100.These results suggest the compensation effect between the mixing uniformity and mixing rate on the selectivity of the mixing-sensitive reactions.Faster mixing,characterized by a larger Re,can disturb mixing uniformity and,in some cases,decrease reaction selectivity. 展开更多
关键词 MICROREACTOR Villermaux-Dushman reaction In-line analysis mixING Mass transfer UNIFORMITY
下载PDF
Stability Analysis and Performance Evaluation of Additive Mixed-Precision Runge-Kutta Methods
11
作者 Ben Burnett Sigal Gottlieb Zachary J.Grant 《Communications on Applied Mathematics and Computation》 EI 2024年第1期705-738,共34页
Additive Runge-Kutta methods designed for preserving highly accurate solutions in mixed-precision computation were previously proposed and analyzed.These specially designed methods use reduced precision for the implic... Additive Runge-Kutta methods designed for preserving highly accurate solutions in mixed-precision computation were previously proposed and analyzed.These specially designed methods use reduced precision for the implicit computations and full precision for the explicit computations.In this work,we analyze the stability properties of these methods and their sensitivity to the low-precision rounding errors,and demonstrate their performance in terms of accuracy and efficiency.We develop codes in FORTRAN and Julia to solve nonlinear systems of ODEs and PDEs using the mixed-precision additive Runge-Kutta(MP-ARK)methods.The convergence,accuracy,and runtime of these methods are explored.We show that for a given level of accuracy,suitably chosen MP-ARK methods may provide significant reductions in runtime. 展开更多
关键词 mixed precision Runge-Kutta methods Additive methods ACCURACY
下载PDF
On the Application of Mixed Models of Probability and Convex Set for Time-Variant Reliability Analysis
12
作者 Fangyi Li Dachang Zhu Huimin Shi 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第5期1981-1999,共19页
In time-variant reliability problems,there are a lot of uncertain variables from different sources.Therefore,it is important to consider these uncertainties in engineering.In addition,time-variant reliability problems... In time-variant reliability problems,there are a lot of uncertain variables from different sources.Therefore,it is important to consider these uncertainties in engineering.In addition,time-variant reliability problems typically involve a complexmultilevel nested optimization problem,which can result in an enormous amount of computation.To this end,this paper studies the time-variant reliability evaluation of structures with stochastic and bounded uncertainties using a mixed probability and convex set model.In this method,the stochastic process of a limit-state function with mixed uncertain parameters is first discretized and then converted into a timeindependent reliability problem.Further,to solve the double nested optimization problem in hybrid reliability calculation,an efficient iterative scheme is designed in standard uncertainty space to determine the most probable point(MPP).The limit state function is linearized at these points,and an innovative random variable is defined to solve the equivalent static reliability analysis model.The effectiveness of the proposed method is verified by two benchmark numerical examples and a practical engineering problem. 展开更多
关键词 mixed uncertainty probability model convex model time-variant reliability analysis
下载PDF
Effectively modulating spatial vortex four-wave mixing in a diamond atomic system
13
作者 巴诺 姜明奇 +4 位作者 费金友 王丹 蒋海林 王磊 王海华 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第4期473-478,共6页
Due to the spatial characteristics of orbital angular momentum,vortex fields can be applied in the fields of quantum storage and quantum information.We study the realization of spatially modulated vortex fields based ... Due to the spatial characteristics of orbital angular momentum,vortex fields can be applied in the fields of quantum storage and quantum information.We study the realization of spatially modulated vortex fields based on four-wave mixing in a four-level atomic system with a diamond structure.The intensity and spiral phase of the vortex field are effectively transferred to the generated four-wave mixing field.By changing the detuning of the probe field,the phase and intensity of the generated vertex four-wave mixing field can be changed.When the probe field takes a large detuning value,the spatial distribution of the intensity and phase of the vertex four-wave mixing field can be effectively tuned by adjusting the Rabi frequency or detuning value of the coupled field.At the same time,we also provide a detailed explanation based on the dispersion relationship,and the results agree well with our simulation results. 展开更多
关键词 coherent optical effects four-wave mixing orbital angular momentum
下载PDF
Amino-functionalized UiO-66-doped mixed matrix membranes with high permeation performance and fouling resistance
14
作者 Yi Zhang Di Liu +6 位作者 Zhaoli Wang Junjian Yu Yanyin Cheng Wenjing Li Zhe Wang Hongzhe Ni Yuchao Wang 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第3期68-77,共10页
For the reduction of bovine serum proteins from wastewater,a novel mixed matrix membrane was prepared by functionalizing the substrate material polyaryletherketone(PAEK),followed by carboxyl groups(C-SPAEKS),and then ... For the reduction of bovine serum proteins from wastewater,a novel mixed matrix membrane was prepared by functionalizing the substrate material polyaryletherketone(PAEK),followed by carboxyl groups(C-SPAEKS),and then adding amino-functionalized UiO-66-NH_(2)(Am-UiO-66-NH_(2)).Aminofunctionalization of UiO-66 was accomplished by melamine,followed by an amidation reaction to immobilize Am-UiO-66-NH_(2),which was immobilized on the surface of the membrane as well as in the pore channels,which enhanced the hydrophilicity of the membrane surface while increasing the negative potential of the membrane surface.This nanoparticle-loaded ultrafiltration membrane has good permeation performance,with a pure water flux of up to 482.3 L·m^(-2)·h^(-1) for C-SPAEKS/AmUiO-66-NH_(2) and a retention rate of up to 98.7%for bovine serum albumin(BSA)-contaminated solutions.Meanwhile,after several hydrophilic modifications,the flux recovery of BSA contaminants by this series of membranes increased from 56.2%to 80.55%of pure membranes.The results of ultra-filtration flux time tests performed at room temperature showed that the series of ultrafiltration membranes remained relatively stable over a test time of 300 min.Thus,the newly developed mixed matrix membrane showed potential for high efficiency and stability in wastewater treatment containing bovine serum proteins. 展开更多
关键词 ULTRAFILTRATION mixed matrix membranes Amino functionalization Hydrophilic modification Negatively charged
下载PDF
Dual-functional poly(2-methyl-2-oxazoline)/poly(2-(dimethylamine)ethyl methacrylate)mixed brushes with switchable protein adsorption and antibacterial properties
15
作者 Kang He Liangyu Zhu Yanmei Wang 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第2期19-30,共12页
Herein,binary mixed brushes consisting of poly(2-methyl-2-oxazoline)(PMOXA)and poly(2-(dimethylamine)ethyl methacrylate)(PDMAEMA)with different chain lengths were fabricated by successive grafting of NH_(2)-terminated... Herein,binary mixed brushes consisting of poly(2-methyl-2-oxazoline)(PMOXA)and poly(2-(dimethylamine)ethyl methacrylate)(PDMAEMA)with different chain lengths were fabricated by successive grafting of NH_(2)-terminated PMOXA and SH-terminated PDMAEMA onto polydopamine-anchored substrates.The mixed-brush coating was characterized by variable-angle spectroscopic ellipsometry,X-ray photoelectron spectroscopy,Fourier transform infrared spectroscopy,zeta potential measurements,water contact angle,and atomic force microscopy.The mixed brushes showed tunable surface charge,wettability,and surface roughness,depending on the degree of PDMAEMA swelling under varying pH and ionic strength(Ⅰ).Then the adsorption behaviors of pepsin,bovine serum albumin(BSA),γ-globulin,and lysozyme,four very different proteins with regard to isoelectric point,on the mixed brushes coating were studied by using fluorescence microscopy and surface plasmon resonance.When the chain length of PDMAEMA was about twice as long as PMOXA,the mixed brushes not only had high adsorption capacity for pepsin,BSA,and y-globulin but also had a desorption efficiency of 86.9%,87.1%,and 93.5%,respectively.It is explained that electrostatic attraction between the protonated PDMAEMA and positively charged acidic proteins(pepsin and BSA,whose isoelectric points were below the pK_(a) of PDMAEMA)would drive the intensive adsorption(at pH 3,I=10^(-3)mol·L^(-1)for pepsin,and pH 5,I=10^(-5)mol·L^(-1)for BSA),while desorption was dominated by the hydrophilic PMOXA when PDMAEMA was shrinking(at pH 7,I=10^(-1)mol·L^(-1)for pepsin,and pH 9,I=10^(-1)mol·L^(-1)for BSA).Furthermore,the isoelectric precipitation led to the adsorption of neutral protein(γ-globulin,whose isoelectric point was near the pK_a of PDMAEMA)at pH 7,I=10^(-5)mol·L^(-1),while electrostatic repulsion and antifouling PMOXA triggered the desorption of y-globulin at pH 3,I-10^(-1)mol·L^(-1).However,alkaline protein(lysozyme,whose isoelectric point was higher than the pK_(a) of PDMAEMA)exhibited slight adsorption on PMOXA/PDMAEMA mixed brushes under test conditions,regardless of whether PMOXA or PDMAEMA occupied the outermost layer.The antibacterial property of the mixed brushes against Escherichia coli was investigated.PMOXA/PDMAEMA mixed brushes showed significant bactericidal activity at pH 3,I=10^(-3)mol·L^(-1),while the rinse of pH 9,I=10^(-1)mol·L^(-1)solution could remove most of the residual bacteria.This work not only enables controlled adsorption of proteins with different isoelectric points but also ensures that the surface of the coating is minimized from bacterial contamination. 展开更多
关键词 Switchable conformation transition Controllable protein adsorption mixed brushes Isoelectric point Antibacterial surface
下载PDF
Recent progress in ternary mixed matrix membranes for CO_(2) separation
16
作者 Zikang Qin Yulei Ma +13 位作者 Jing Wei Hongfang Guo Bangda Wang Jing Deng Chunhai Yi Nanwen Li Shouliang Yi Yi Deng Wentao Du Jian Shen Wenju Jiang Lu Yao Lin Yang Zhongde Dai 《Green Energy & Environment》 SCIE EI CAS CSCD 2024年第5期831-858,共28页
Mixed matrix membranes(MMMs)could combine the advantages of both polymeric membranes and porousfillers,making them an effective alternative to conventional polymer membranes.However,interfacial incompatibility issues,s... Mixed matrix membranes(MMMs)could combine the advantages of both polymeric membranes and porousfillers,making them an effective alternative to conventional polymer membranes.However,interfacial incompatibility issues,such as the presence of interfacial voids,hardening of polymer chains,and blockage of micropores by polymers between common MMMsfillers and the polymer matrix,currently limit the gas sep-aration performance of MMMs.Ternary phase MMMs(consisting of afiller,an additive,and a matrix)made by adding a third compound,usually functionalized additives,can overcome the structural problems of binary phase MMMs and positively impact membrane separation performance.This review introduces the structure and fabrication processes for ternary MMMs,categorizes various nanofillers and the third component,and summarizes and analyzes in detail the CO_(2) separation performance of newly developed ternary MMMs based on both rubbery and glassy polymers.Based on this separation data,the challenges of ternary MMMs are also discussed.Finally,future directions for ternary MMMs are proposed. 展开更多
关键词 CO_(2) separation mixed matrix membranes Ternary phase
下载PDF
A unified Minorization-Maximization approach for estimation of general mixture models
17
作者 HUANG Xi-fen LIU Deng-ge +1 位作者 ZHOU Yun-peng ZHU Fei 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2024年第2期343-362,共20页
The mixed distribution model is often used to extract information from heteroge-neous data and perform modeling analysis.When the density function of mixed distribution is complicated or the variable dimension is high... The mixed distribution model is often used to extract information from heteroge-neous data and perform modeling analysis.When the density function of mixed distribution is complicated or the variable dimension is high,it usually brings challenges to the parameter es-timation of the mixed distribution model.The application of MM algorithm can avoid complex expectation calculations,and can also solve the problem of high-dimensional optimization by decomposing the objective function.In this paper,MM algorithm is applied to the parameter estimation problem of mixed distribution model.The method of assembly and decomposition is used to construct the substitute function with separable parameters,which avoids the problems of complex expectation calculations and the inversion of high-dimensional matrices. 展开更多
关键词 MM algorithm mixed distribution model parameter estimation assembly decomposition tech-nology parameter separation
下载PDF
Effect of Nozzle Inclination Angle on Fuel-Air Mixing and Combustion in a Heavy Fuel Engine
18
作者 Zhigang Wang Bin Zheng +4 位作者 Peidong Zhao Baoli Wang Fanyan Meng Wenke Xu Jian Meng 《Fluid Dynamics & Materials Processing》 EI 2024年第2期365-382,共18页
Heavy-fuel engines are widely used in UAVs(Unmanned Autonomous Vehicles)because of their reliability and high-power density.In this study,a combustion model for an in-cylinder direct injection engine has been imple-me... Heavy-fuel engines are widely used in UAVs(Unmanned Autonomous Vehicles)because of their reliability and high-power density.In this study,a combustion model for an in-cylinder direct injection engine has been imple-mented using the AVL FIRE software.The effects of the angle of nozzle inclination on fuel evaporation,mixture distribution,and combustion in the engine cylinder have been systematically studied at 5500 r/min and consider-ing full load cruise conditions.According to the results,as the angle of nozzle inclination increases,the maximum combustion explosion pressure in the cylinderfirst increases and then it decreases.When the angle of nozzle incli-nation is less than 45°,the quality of the mixture in the cylinder and the combustion performance can be improved by increasing the angle.When the angle of nozzle inclination is greater than 45°,however,the mixture unevenness increases slightly with the angle,leading to a deterioration of the combustion performances.When the angle of nozzle inclination is between 35°and 55°,the overall combustion performance of the engine is rela-tively good.When the angle of nozzle inclination is 45°,the combustion chamber’s geometry and the cylinder’s airflow are well matched with the fuel spray,and the mixture quality is the best.Compared with 25°,the peak heat release rate increases by 20%,and the maximum combustion burst pressure increases by 5.5%. 展开更多
关键词 Aviation heavy fuel piston engine nozzle inclination angle COMBUSTION fuel-air mixing
下载PDF
What induced the trend shift of mixed-layer depths in the Antarctic Circumpolar Current region in the mid-1980s?
19
作者 Shan Liu Jingzhi Su +1 位作者 Huijun Wang Cuijuan Sui 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2024年第1期11-21,共11页
An obvious trend shift in the annual mean and winter mixed layer depth(MLD)in the Antarctic Circumpolar Current(ACC)region was detected during the 1960–2021 period.Shallowing trends stopped in mid-1980s,followed by a... An obvious trend shift in the annual mean and winter mixed layer depth(MLD)in the Antarctic Circumpolar Current(ACC)region was detected during the 1960–2021 period.Shallowing trends stopped in mid-1980s,followed by a period of weak trends.The MLD deepening trend difference between the two periods were mainly distributed in the western areas in the Drake Passage,the areas north to Victoria Land and Wilkes Land,and the central parts of the South Indian sector.The newly formed ocean current shear due to the meridional shift of the ACC flow axis between the two periods is the dominant driver for the MLD trends shift distributed in the western areas in the Drake Passage and the central parts of the South Indian sector.The saltier trends in the regions north to Victoria Land and Wilkes Land could be responsible for the strengthening mixing processes in this region. 展开更多
关键词 mixed layer depth trend shift Antarctic Circumpolar Current(ACC) flow axis
下载PDF
Accurate estimation of Li/Ni mixing degree of lithium nickel oxide cathode materials
20
作者 陈鹏浩 徐磊 +1 位作者 禹习谦 李泓 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第5期631-635,共5页
Li/Ni mixing negatively influences the discharge capacity of lithium nickel oxide and high-nickel ternary cathode materials.However,accurately measuring the Li/Ni mixing degree is difficult due to the preferred orient... Li/Ni mixing negatively influences the discharge capacity of lithium nickel oxide and high-nickel ternary cathode materials.However,accurately measuring the Li/Ni mixing degree is difficult due to the preferred orientation of labbased XRD measurements using Bragg–Brentano geometry.Here,we find that employing spherical harmonics in Rietveld refinement to eliminate the preferred orientation can significantly decrease the measurement error of the Li/Ni mixing ratio.The Li/Ni mixing ratio obtained from Rietveld refinement with spherical harmonics shows a strong correlation with discharge capacity,which means the electrochemical capacity of lithium nickel oxide and high-nickel ternary cathode can be estimated by the Li/Ni mixing degree.Our findings provide a simple and accurate method to estimate the Li/Ni mixing degree,which is valuable to the structural analysis and screening of the synthesis conditions of lithium nickel oxide and high-nickel ternary cathode materials. 展开更多
关键词 lithium nickel oxide high-nickel ternary cathode Li/Ni mixing spherical harmonics function discharge capacity
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部