期刊文献+
共找到3,211篇文章
< 1 2 161 >
每页显示 20 50 100
Noether Symmetry Can Lead to Non-Noether Conserved Quantity of Holonomic Nonconservative Systems in General Lie Transformations 被引量:4
1
作者 LUOShao-Kai JIALi-Qun CAIJian-Le 《Communications in Theoretical Physics》 SCIE CAS CSCD 2005年第2期193-196,共4页
For the holonomic nonconservative system, by using the Noether symmetry, a non-Noether conserved quantity is obtained directly under general infinitesimal transformations of groups in which time is variable. At first,... For the holonomic nonconservative system, by using the Noether symmetry, a non-Noether conserved quantity is obtained directly under general infinitesimal transformations of groups in which time is variable. At first,the Noether symmetry, Lie symmetry, and Noether conserved quantity are given. Secondly, the condition under which the Noether symmetry is a Lie symmetry under general infinitesimal transformations is obtained. Finally, a set of nonNoether conserved quantities of the system are given by the Noether symmetry, and an example is given to illustrate the application of the results. 展开更多
关键词 holonomic conservative system noether symmetry non-Noether conservedquantity general inifinitesimal transformations of groups
下载PDF
A series of non-Noether conservative quantities and Mei symmetries of nonconservative systems 被引量:2
2
作者 刘鸿基 傅景礼 唐贻发 《Chinese Physics B》 SCIE EI CAS CSCD 2007年第3期599-604,共6页
In this paper Mei symmetry is introduced for a nonconservative system. The necessary and sufficient condition for a Mei symmetry to be also a Lie symmetry is derived. It is proved that the Mei symmetry leads to a non-... In this paper Mei symmetry is introduced for a nonconservative system. The necessary and sufficient condition for a Mei symmetry to be also a Lie symmetry is derived. It is proved that the Mei symmetry leads to a non-Noether conservative quantity via a Lie symmetry, and deduces a Lutzky conservative quantity via a Lie point symmetry. 展开更多
关键词 Mei symmetry non-Noether conservative quantity Lutzky conservative quantity nonconservative system
原文传递
Homo-& Heteroclinic Orbits in Conservative Systems with 3-wells Potential 被引量:1
3
作者 黄明游 李松涛 +1 位作者 张凯 李勇 《Northeastern Mathematical Journal》 CSCD 2002年第4期287-290,共4页
Consider the following 2×2 nonlinear system:where f(u): R→R is a, smooth function. Setwhere F’(u)= f(u). Then (1) can be rewritten as an equivalent Hamiltonian system:
关键词 conservative systems 3-wells potential homoclinic and heteroclinicorbits
下载PDF
About One-Dimensional Conservative Systems with Position Depending Mass 被引量:2
4
作者 Gustavo López Velázquez Carlos Rodrigo Martínez Prieto 《Journal of Modern Physics》 2014年第9期900-907,共8页
For a one-dimensional conservative system with position depending mass, one deduces consistently a constant of motion, a Lagrangian, and a Hamiltonian for the nonrelativistic case. With these functions, one shows the ... For a one-dimensional conservative system with position depending mass, one deduces consistently a constant of motion, a Lagrangian, and a Hamiltonian for the nonrelativistic case. With these functions, one shows the trajectories on the spaces (x,v) and (x,p) for a linear position depending mass. For the relativistic case, the Lagrangian and Hamiltonian cannot be given explicitly in general. However, we study the particular system with constant force and mass linear dependence on the position where the Lagrangian can be found explicitly, but the Hamiltonian remains implicit in the constant of motion. 展开更多
关键词 MASS VARIABLE systems conservative system POSITION Depending MASS
下载PDF
Characteristic analysis of 5D symmetric Hamiltonian conservative hyperchaotic system with hidden multiple stability
5
作者 黄丽莲 马衍昊 李创 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第1期303-315,共13页
Conservative chaotic systems have unique advantages over dissipative chaotic systems in the fields of secure communication and pseudo-random number generator because they do not have attractors but possess good traver... Conservative chaotic systems have unique advantages over dissipative chaotic systems in the fields of secure communication and pseudo-random number generator because they do not have attractors but possess good traversal and pseudorandomness. In this work, a novel five-dimensional(5D) Hamiltonian conservative hyperchaotic system is proposed based on the 5D Euler equation. The proposed system can have different types of coordinate transformations and time reversal symmetries. In this work, Hamilton energy and Casimir energy are analyzed firstly, and it is proved that the new system satisfies Hamilton energy conservation and can generate chaos. Then, the complex dynamic characteristics of the system are demonstrated and the conservatism and chaos characteristics of the system are verified through the correlation analysis methods such as phase diagram, equilibrium point, Lyapunov exponent, bifurcation diagram, and SE complexity. In addition, a detailed analysis of the multistable characteristics of the system reveals that many energy-related coexisting orbits exist. Based on the infinite number of center-type and saddle-type equilibrium points, the dynamic characteristics of the hidden multistability of the system are revealed. Then, the National Institute of Standards and Technology(NIST)test of the new system shows that the chaotic sequence generated by the system has strong pseudo-random. Finally, the circuit simulation and hardware circuit experiment of the system are carried out with Multisim simulation software and digital signal processor(DSP) respectively. The experimental results confirm that the new system has good ergodicity and realizability. 展开更多
关键词 Hamilton conservative hyperchaotic system symmetry wide parameter range hide multiple stability
原文传递
Acupuncture therapies in combination with conservative treatments for postoperative ileus:a systematic review and network meta-analysis
6
作者 Zi-Wen Chen Zi-Han Yin +2 位作者 Tao Xu Jian Xiong Fan-Rong Liang 《TMR Integrative Medicine》 2023年第8期1-12,共12页
Background:Although acupuncture therapies have been widely used in combination with conservative treatments(CT)for postoperative ileus(POI),evidence of their safety and efficacy remains scarce.To evaluate and rank the... Background:Although acupuncture therapies have been widely used in combination with conservative treatments(CT)for postoperative ileus(POI),evidence of their safety and efficacy remains scarce.To evaluate and rank the efficacy of different acupuncture therapies combined with CT for POI.Methods:A comprehensive search was carried out in several databases(Embase,PubMed,Cochrane Library,Chinese National Knowledge Infrastructure,Wanfang Data,VIP Chinese Science and Technology Periodical Database and China Biology Medicine disc)for relevant randomized controlled trials(RCTs)investigating different acupuncture therapies for POI from inception to February 17,2023.The Cochrane risk of bias tool was used to determine the risks of bias of the included RCTs.The primary outcomes included the time to first defecation,time to first flatus,and time to first bowel movement;and the secondary outcome was the response rate.Pairwise meta-analysis was performed by Review Manager 5.3 software,and network meta-analysis was carried out by Stata v.15.0 software.The cumulative ranking curve was obtained with Stata v.15.0 and was utilized to rank the included treatments.Results:29 studies with 2,600 participants were included in this systematic review.This meta-analysis demonstrated that all acupuncture therapies combined with CT were superior to conservative treatments alone in time to first defecation,time to first flatus,time to first bowel movement,and response rate.Among 10 evaluated methods,auricular needle with CT was the most effective treatment to reduce the time to first defecation.Furthermore,moxibustion with CT was the most effective in reducing the time to first flatus,and warm needling with CT most markedly reduced the time to first bowel movement among 9 interventions.Moreover,manual acupuncture with CT showed the largest improvement in response rate.Conclusion:This meta-analysis revealed that all acupuncture therapies are effective and safe for POI,with warm needling+CT being the most effective way to relieve symptoms.These results indicated that acupuncture therapies combined with CT should be considered for POI patients.However,most of the included trials were ranked as moderate quality,and further large-scale,high-quality RCTs are required to confirm the optimal interventions for POI patients. 展开更多
关键词 acupuncture therapies conservative treatments postoperative ileus network meta-analysis randomized controlled trials
下载PDF
Input-to-State Stability of Impulsive Switched Systems Involving Uncertain Impulse-Switching Moments
7
作者 Chang Liu Wenlu Liu +1 位作者 Tengda Wei Xiaodi Li 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2024年第6期1515-1517,共3页
Dear Editor,This letter studies the input-to-state stability(ISS)for a class of impulsive switched systems,where uncertain impulse-switching moments are involved.The robustness of ISS with respect to the perturbations... Dear Editor,This letter studies the input-to-state stability(ISS)for a class of impulsive switched systems,where uncertain impulse-switching moments are involved.The robustness of ISS with respect to the perturbations of the occurrence time of impulse-switching moments is revealed by several less conservative dwell-time conditions for the uncertain impulse-switching moments combined with Lyapunov conditions.Moreover,the Lyapunov conditions have multiple coefficients at discrete time so as to handle the hybrid effect of impulse-switching moments,and the case that time derivative of Lyapunov function is indefinite is also taken into account.Finally,a numerical example is proposed to illustrate the effectiveness of the theoretical results. 展开更多
关键词 LETTER conservative DERIVATIVE
下载PDF
A Local Macroscopic Conservative(LoMaC)Low Rank Tensor Method with the Discontinuous Galerkin Method for the Vlasov Dynamics
8
作者 Wei Guo Jannatul Ferdous Ema Jing-Mei Qiu 《Communications on Applied Mathematics and Computation》 EI 2024年第1期550-575,共26页
In this paper,we propose a novel Local Macroscopic Conservative(LoMaC)low rank tensor method with discontinuous Galerkin(DG)discretization for the physical and phase spaces for simulating the Vlasov-Poisson(VP)system.... In this paper,we propose a novel Local Macroscopic Conservative(LoMaC)low rank tensor method with discontinuous Galerkin(DG)discretization for the physical and phase spaces for simulating the Vlasov-Poisson(VP)system.The LoMaC property refers to the exact local conservation of macroscopic mass,momentum,and energy at the discrete level.The recently developed LoMaC low rank tensor algorithm(arXiv:2207.00518)simultaneously evolves the macroscopic conservation laws of mass,momentum,and energy using the kinetic flux vector splitting;then the LoMaC property is realized by projecting the low rank kinetic solution onto a subspace that shares the same macroscopic observables.This paper is a generalization of our previous work,but with DG discretization to take advantage of its compactness and flexibility in handling boundary conditions and its superior accuracy in the long term.The algorithm is developed in a similar fashion as that for a finite difference scheme,by observing that the DG method can be viewed equivalently in a nodal fashion.With the nodal DG method,assuming a tensorized computational grid,one will be able to(i)derive differentiation matrices for different nodal points based on a DG upwind discretization of transport terms,and(ii)define a weighted inner product space based on the nodal DG grid points.The algorithm can be extended to the high dimensional problems by hierarchical Tucker(HT)decomposition of solution tensors and a corresponding conservative projection algorithm.In a similar spirit,the algorithm can be extended to DG methods on nodal points of an unstructured mesh,or to other types of discretization,e.g.,the spectral method in velocity direction.Extensive numerical results are performed to showcase the efficacy of the method. 展开更多
关键词 Hierarchical Tucker(HT)decomposition conservative SVD Energy conservation Discontinuous Galerkin(DG)method
下载PDF
A LOW-REGULARITY FOURIER INTEGRATOR FOR THE DAVEY-STEWARTSON II SYSTEM WITH ALMOST MASS CONSERVATION
9
作者 Cui NING Chenxi HAO Yaohong WANG 《Acta Mathematica Scientia》 SCIE CSCD 2024年第4期1536-1549,共14页
In this work,we propose a low-regularity Fourier integrator with almost mass conservation to solve the Davey-StewartsonⅡsystem(hyperbolic-elliptic case).Arbitrary order mass convergence could be achieved by the suita... In this work,we propose a low-regularity Fourier integrator with almost mass conservation to solve the Davey-StewartsonⅡsystem(hyperbolic-elliptic case).Arbitrary order mass convergence could be achieved by the suitable addition of correction terms,while keeping the first order accuracy in H~γ×H^(γ+1)for initial data in H^(γ+1)×H^(γ+1)withγ>1.The main theorem is that,up to some fixed time T,there exist constantsτ_(0)and C depending only on T and‖u‖_(L^(∞)((0,T);H^(γ+1)))such that,for any 0<τ≤τ_(0),we have that‖u(t_(n),·)-u^(n)‖H_γ≤C_(τ),‖v(t_(n),·)-v^(n)‖_(Hγ+1)≤C_(τ),where u^(n)and v^(n)denote the numerical solutions at t_(n)=nτ.Moreover,the mass of the numerical solution M(u^(n))satisfies that|M(u^(n))-M(u_0)|≤Cτ~5. 展开更多
关键词 Davey-StewartsonⅡsystem low-regularity exponential integrator first order accuracy mass conservation
下载PDF
Sustaining forest biodiversity:Exploring the effect of long-term natural disturbance dynamics on contemporary lichen communities in primary forest ecosystems
10
作者 Rhiannon Gloor Marek Svitok +11 位作者 Martin Mikolas Jenyk Hofmeister Josef Halda Pavel Janda Francesco Maria Sabatini Lucie Zemanova Arne Buechling Daniel Kozak Matej Ferencik Michal Frankovic Martin Dusatko Miroslav Svoboda 《Forest Ecosystems》 SCIE CSCD 2024年第4期556-567,共12页
In this era of biodiversity loss and climate change,quantifying the impacts of natural disturbance on forest communities is imperative to improve biodiversity conservation efforts.Epiphytic and epixylic lichens are ef... In this era of biodiversity loss and climate change,quantifying the impacts of natural disturbance on forest communities is imperative to improve biodiversity conservation efforts.Epiphytic and epixylic lichens are effective forest quality bioindicators,as they are generally long-lived organisms supported by continuity of specific forest structures and their associated microclimatic features.However,how lichen communities respond to the effects of fluctuating historical disturbances remains unclear.Using a dendrochronological approach,this study investigates how natural disturbance dynamics indirectly influence various lichen community metrics in some of Europe's best-preserved primary mixed-beech forests.Mixed modelling revealed that natural historical disturbance processes have decades-long effects on forest structural attributes,which had both congruent and divergent impacts on lichen community richness and composition.Total species richness indirectly benefited from both historical and recent higher-severity disturbances via increased standing dead tree basal area and canopy openness respectively-likely through the presence of both pioneer and late-successional species associated with these conditions.Red-listed species richness showed a dependence on habitat continuity(old trees),and increased with disturbance-related structures(standing dead trees)whilst simultaneously benefiting from periods without severe disturbance events(old trees and reduced deadwood volume).However,if the disturbance occurred over a century in the past,no substantial effect on forest structure was detected.Therefore,while disturbance-mediated forest structures can promote overall richness,threatened species appear vulnerable to more severe disturbance events-a concern,as disturbances are predicted to intensify with climate change.Additionally,the high number of threatened species found reinforce the critical role of primary forest structural attributes for biodiversity maintenance.Hence,we recommend a landscape-scale conservation approach encompassing forest patches in different successional stages to support diverse lichen communities,and the consideration of long-term disturbance dynamics in forest conservation efforts,as they provide critical insights for safeguarding biodiversity in our changing world. 展开更多
关键词 Mixed-beech forests Species richness Old-growth forests Carpathian mountains Biodiversity conservation DENDROECOLOGY Fagus sylvatica
下载PDF
Physico-chemical properties and macrofauna of soils under various farming systems of cold arid region in Balochistan,Pakistan
11
作者 KHAN Mehmood GUL Shamim +5 位作者 KAKAR Hidayatullah PANEZAI Sanaullah KHAN Nayab ZIAD Tariq NASEEM Mahrukh SHAHEEN Umbreen 《Journal of Mountain Science》 SCIE CSCD 2024年第8期2618-2630,共13页
Barshore is a small village in the Pishin District,Balochistan,Pakistan,with dry summers and cold rainy winters.This is an agrarian region,mostly with orchards of various fruit trees.This study investigated the physic... Barshore is a small village in the Pishin District,Balochistan,Pakistan,with dry summers and cold rainy winters.This is an agrarian region,mostly with orchards of various fruit trees.This study investigated the physico-chemical properties and macrofauna of soils under various agricultural management practices of this region.The concentrations of soil organic matter(SOM),soil organic carbon(SOC),nutrients,pH,electrical conductivity,soil texture,and the abundance and number of species of soil macrofauna of the agricultural fields were measured.Fifteen agricultural fields were sampled.Fourteen fields were orchards of apple,apricot or the mixture of apple and apricot trees and one field was a cropland,cultivated with wheat as a monocrop.The orchards were under conservation agricultural practices;whereas,the cropland was under conventional management.These agricultural lands were 2-26 years old.The concentration of soil organic matter(SOM)in the upper 0-10 cm depth of these field sites ranged from 11.6 g kg^(-1)to 32.8 g kg^(-1)soil.As compared to cropland,orchards had significantly higher concentration of SOM and SOC.A total of 18 soil macrofauna species were found and the most common and abundant were ants(Monomorium minimum,Camponotus pennsylvanicus,Solenopsis invicta,and Lasius niger)followed by Arion ssp.(Brown Slug)and earthworm Lumbricus terrestris.Regression analysis revealed non-significant relationship of the age and the concentration of SOM with the number of macrofauna species and with the concentrations of total mineral nitrogen,bioavailable phosphorus and clay.The existence of ants had no relationship with the concentration of SOM;whereas,existence of Lumbricus terrestris tended to had a positive relationship with the concentration of SOM.The field of tree-based intercropping system was 2 years of age since the land was converted from rangeland to a cropland,had two ant species coexisting.This indicates the positive influence of crop diversification on soil macrofauna. 展开更多
关键词 Soil organic matter MACROFAUNA Land use history Tree-based intercropping Conservation agriculture
原文传递
Indication of conservative treatment by antibiotics for uncomplicated and complicated acute appendicitis
12
作者 Yuichi Hosokawa Masato Moritani +1 位作者 Yosuke Makuuchi Yuichi Nagakawa 《World Journal of Gastrointestinal Surgery》 SCIE 2024年第8期2538-2545,共8页
BACKGROUND Acute appendicitis is one of the most common emergency abdominal disease,and recent studies have evaluated conservative treatment using antibiotics for uncomplicated appendicitis.Although the efficacy of co... BACKGROUND Acute appendicitis is one of the most common emergency abdominal disease,and recent studies have evaluated conservative treatment using antibiotics for uncomplicated appendicitis.Although the efficacy of conservative treatment for uncomplicated appendicitis is known,its efficacy for complicated appendicitis remains unknown,so are risk factors for the conservative treatment of appendi-citis.In our institution,conservative treatment has long been the first choice for most appendicitis cases,except for perforation.Therefore,this novel study inves-tigated the outcomes of conservative treatment for uncomplicated and compli-cated acute appendicitis and the risk factors associated with conservative treat-ment.treatment.The significant and independent predictors of resistance to conservative treatment were body temperature≥37.3℃,appendicolith and Douglas sinus fluid visible on computed tomography(CT).The rate of resistance to conservative treatment was 66.7%(6/9)for patients with the above three factors,22.9%(8/35)for patients with two factors(appendicolith and body temperature≥37.3℃),16.7%(2/12)for patients with two factors(Douglas sinus fluid and appendicolith)and 11.1%(1/9)for patients with two factors(Douglas sinus fluid and body temperature≥37.3℃).CONCLUSION A temperature≥37.3℃,appendicolith and Douglas sinus fluid on CT might be clinical risk factors of resistance to conservative treatment for acute appendicitis. 展开更多
关键词 Acute appendicitis conservative treatment ANTIBIOTICS APPENDICOLITH Uncomplicated appendicitis
下载PDF
New High-Order Numerical Methods for Hyperbolic Systems of Nonlinear PDEs with Uncertainties
13
作者 Alina Chertock Michael Herty +3 位作者 Arsen S.Iskhakov Safa Janajra Alexander Kurganov Maria Lukacova-Medvid'ova 《Communications on Applied Mathematics and Computation》 EI 2024年第3期2011-2044,共34页
In this paper,we develop new high-order numerical methods for hyperbolic systems of nonlinear partial differential equations(PDEs)with uncertainties.The new approach is realized in the semi-discrete finite-volume fram... In this paper,we develop new high-order numerical methods for hyperbolic systems of nonlinear partial differential equations(PDEs)with uncertainties.The new approach is realized in the semi-discrete finite-volume framework and is based on fifth-order weighted essentially non-oscillatory(WENO)interpolations in(multidimensional)random space combined with second-order piecewise linear reconstruction in physical space.Compared with spectral approximations in the random space,the presented methods are essentially non-oscillatory as they do not suffer from the Gibbs phenomenon while still achieving high-order accuracy.The new methods are tested on a number of numerical examples for both the Euler equations of gas dynamics and the Saint-Venant system of shallow-water equations.In the latter case,the methods are also proven to be well-balanced and positivity-preserving. 展开更多
关键词 Hyperbolic conservation and balance laws with uncertainties Finite-volume methods Central-upwind schemes Weighted essentially non-oscillatory(WENO)interpolations
下载PDF
Spatiotemporal variations of ecosystem services and driving factors in the Tianchi Bogda Peak Natural Reserve of Xinjiang,China
14
作者 ZHU Haiqiang WANG Jinlong +2 位作者 TANG Junhu DING Zhaolong GONG Lu 《Journal of Arid Land》 SCIE CSCD 2024年第6期816-833,共18页
Nature reserves play a significant role in providing ecosystem services and are key sites for biodiversity conservation.The Tianchi Bogda Peak Natural Reserve(TBPNR),located in Xinjiang Uygur Autonomous Region,China,i... Nature reserves play a significant role in providing ecosystem services and are key sites for biodiversity conservation.The Tianchi Bogda Peak Natural Reserve(TBPNR),located in Xinjiang Uygur Autonomous Region,China,is an important ecological barrier area in the temperate arid zone.The evaluation of its important ecosystem services is of great significance to improve the management level and ecological protection efficiency of the reserve.In the present study,we assessed the spatiotemporal variations of four ecosystem services(including net primary productivity(NPP),water yield,soil conservation,and habitat quality)in the TBPNR from 2000 to 2020 based on the environmental and social data using the Integrated Valuation of Ecosystem Services and Trade-offs(InVEST)model.In addition,the coldspot and hotspot areas of ecosystem services were identified by hotspot analysis,and the trade-off and synergistic relationships between ecosystem services were analyzed using factor analysis in a geographic detector.During the study period,NPP and soil conservation values in the reserve increased by 48.20%and 25.56%,respectively;conversely,water yield decreased by 16.56%,and there was no significant change in habitat quality.Spatially,both NPP and habitat quality values were higher in the northern part and lower in the southern part,whereas water yield showed an opposite trend.Correlation analysis revealed that NPP showed a synergistic relationship with habitat quality and soil conservation,and exhibited a trade-off relationship with water yield.Water yield and habitat quality also had a trade-off relationship.NPP and habitat quality were affected by annual average temperature and Normalized Difference Vegetation Index(NDVI),respectively,while water yield and soil conservation were more affected by digital elevation model(DEM).Therefore,attention should be paid to the spatial distribution and dynamics of trade-off and synergistic relationships between ecosystem services in future ecological management.The findings of the present study provide a reference that could facilitate the sustainable utilization of ecosystem services in the typical fragile areas of Northwest China. 展开更多
关键词 net primary productivity(NPP) water yield soil conservation habitat quality Integrated Valuation of Ecosystem Services and Trade-offs(InVEST)model geographic detector Tianchi Bogda Peak Natural Reserve
下载PDF
Entropy‑Conservative Discontinuous Galerkin Methods for the Shallow Water Equations with Uncertainty
15
作者 Janina Bender PhilippÖffner 《Communications on Applied Mathematics and Computation》 EI 2024年第3期1978-2010,共33页
In this paper,we develop an entropy-conservative discontinuous Galerkin(DG)method for the shallow water(SW)equation with random inputs.One of the most popular methods for uncertainty quantifcation is the generalized P... In this paper,we develop an entropy-conservative discontinuous Galerkin(DG)method for the shallow water(SW)equation with random inputs.One of the most popular methods for uncertainty quantifcation is the generalized Polynomial Chaos(gPC)approach which we consider in the following manuscript.We apply the stochastic Galerkin(SG)method to the stochastic SW equations.Using the SG approach in the stochastic hyperbolic SW system yields a purely deterministic system that is not necessarily hyperbolic anymore.The lack of the hyperbolicity leads to ill-posedness and stability issues in numerical simulations.By transforming the system using Roe variables,the hyperbolicity can be ensured and an entropy-entropy fux pair is known from a recent investigation by Gerster and Herty(Commun.Comput.Phys.27(3):639–671,2020).We use this pair and determine a corresponding entropy fux potential.Then,we construct entropy conservative numerical twopoint fuxes for this augmented system.By applying these new numerical fuxes in a nodal DG spectral element method(DGSEM)with fux diferencing ansatz,we obtain a provable entropy conservative(dissipative)scheme.In numerical experiments,we validate our theoretical fndings. 展开更多
关键词 Shallow water(SW)equations Entropy conservation/dissipation Uncertainty quantifcation Discontinuous Galerkin(DG) Generalized Polynomial Chaos(gPC)
下载PDF
Secondary Hyperparathyroidism in Dialysis Patients: Short- and Long-Term Outcomes of Conservative Parathyroidectomy
16
作者 Imane Saidi Sara Elmaakoul +1 位作者 Naima Ouzeddoun Loubna Benamar 《Open Journal of Nephrology》 2024年第2期147-156,共10页
Secondary hyperparathyroidism (HPT) is frequent in dialysis patients. Parathyroidectomy (PTX) is indicated for patients who failed medical therapy. We reviewed the data from 184 dialysis patients who underwent PTX bet... Secondary hyperparathyroidism (HPT) is frequent in dialysis patients. Parathyroidectomy (PTX) is indicated for patients who failed medical therapy. We reviewed the data from 184 dialysis patients who underwent PTX between January 2015 and January 2023. We aimed to evaluate the short and long term outcomes of PTX in dialysis patients, comparing the conservative 3/4 versus 7/8 techniques in this population.166 dialysis patients with secondary HPT were included. A conservative subtotal PTX (sPTX) 7/8 was performed in 72% of patients and sPTX 3/4 in 28% of them. Severe postoperative hypocalcaemiaocurred in 45 patients (27%). Hypocalcaemia was significantly more frequent in the sPTX 7/8 group (p = 0.012). One case of persistent HPT (0.6%) and 20 cases of recurrence (12%) were diagnosed. Recurrence was more frequent in the sPTX 3/4 group (15%). No deaths were reported during the perioperative period. 展开更多
关键词 Secondary Hyperparathyroidism DIALYSIS Chronic Kidney Disease conservative Subtotal Parathyroidectomy
下载PDF
Bilateral Congenital Upper Eyelid Eversion (Ectropion): A Rare Presentation Responded Well to Conservative Treatment at Temeke Regional Referral Hospital-Tanzania
17
作者 Husna Msangi Annamary Stanslaus +2 位作者 Hussein Msuma Salha Omary Milka Mafwiri 《Open Journal of Ophthalmology》 2024年第3期204-207,共4页
Congenital eversion of the upper eyelids is a rare condition, the exact cause of which remains unknown. It is more frequently associated with Down’s syndrome and black babies. If diagnosed early and treated properly,... Congenital eversion of the upper eyelids is a rare condition, the exact cause of which remains unknown. It is more frequently associated with Down’s syndrome and black babies. If diagnosed early and treated properly, the condition can be managed without surgery. We report a case of non syndromic congenital bilateral severe upper eyelid eversion in otherwise normal 3 days old neonate of African descent (Tanzanian), born by vaginal delivery. The case was conservatively managed by lubricants, antibiotics and eyelid patching. We report this case because from the best of our knowledge it has never been documented here at our hospital and Tanzania before. 展开更多
关键词 Upper Eyelid Eversion Congenital Ectropion conservative Management
下载PDF
Fertilization and Soil Ploughing Practices under Changing Physical Environment Lead to Soil Organic Carbon Dynamics under Conservation Agriculture in Rice-Wheat Cropping System: A Scoping Review
18
作者 Salwinder Singh Dhaliwal Arvind Kumar Shukla +8 位作者 Sanjib Kumar Behera Sarwan Kumar Dubey Agniva Mandal Mehakpreet Kaur Randhawa Sharanjit Kaur Brar Gagandeep Kaur Amardeep Singh Toor Sohan Singh Walia Priyadarshani Arun Khambalkar 《Agricultural Sciences》 2024年第1期82-113,共32页
Ploughing and fertilization practices in rice-wheat system have deteriorated the soil carbon (C) pools. Conservation agriculture (CA) based management approaches have proven to enhance C sequestration and reverse the ... Ploughing and fertilization practices in rice-wheat system have deteriorated the soil carbon (C) pools. Conservation agriculture (CA) based management approaches have proven to enhance C sequestration and reverse the loss of soil-organic-carbon (SOC), which further enhances soil fertility. Different fractions of SOC pools react to the alterations in management practices and indicate changes in SOC dynamics as compared to total C in the soil. Higher SOC levels in soil have been observed in case of reduced/no-till (NT) practices than conventional tillage (CT). However, between CT and zero tillage/NT, total SOC stocks diminished with an increase in soil depth, which demonstrated that the benefits of SOC are more pronounced in the topsoil under NT. Soil aggregation provides physical protection to C associated with different-sized particles, thus, the improvement in soil aggregation through CA is an effective way to mitigate soil C loss. Along with less soil disturbance, residual management, suitable crop rotation, rational application of manures and fertilizers, and integrated nutrient management have been found to be effective in not only improving soil C stock but also enhancing the soil health and productivity. Thus, CA can be considered as a potential method in the build-up of SOC of soil in rice-wheat system. 展开更多
关键词 TILLAGE Conservation Agriculture Soil Organic Carbon Carbon Fractions Rice-Wheat system Organic Amendments
下载PDF
Research Progress on Conservative Treatment of Lumbar Disc Herniation
19
作者 Yingsong Xiao Nida Wan 《Expert Review of Chinese Medical》 2024年第2期54-58,共5页
Lumbar disc herniation(LDH)is a common orthopedic disease in clinical practice,with main symptoms of varying degrees of pain and functional impairment,seriously affecting the quality of work and life of patients,and a... Lumbar disc herniation(LDH)is a common orthopedic disease in clinical practice,with main symptoms of varying degrees of pain and functional impairment,seriously affecting the quality of work and life of patients,and also causing a certain degree of economic burden to the patient's family and society.At present,there are various conservative treatment methods for LDH in clinical practice.Conservative treatment has the characteristics of small trauma and high safety,which can achieve symptom relief and cure for most patients in clinical practice.This article aims to provide a scientific reference for the selection of treatment plans for LDH patients by reviewing relevant literature on conservative treatment of LDH that has been publicly reported both domestically and internationally in recent years. 展开更多
关键词 lumbar disc herniation conservative treatment research progress
下载PDF
Exploration and Application Practice of Energy Conservation Theory and Method in Steel Manufacturing Process System
20
作者 Jiaxiang Hao Yuanyuan Wu 《Frontiers of Metallurgical Industry》 2024年第2期37-42,共6页
This article briefly discusses the theoretical basis and overall goals of energy conservation in the steel manufacturing process system.It is proposed that in the process of implementing system energy conservation,it ... This article briefly discusses the theoretical basis and overall goals of energy conservation in the steel manufacturing process system.It is proposed that in the process of implementing system energy conservation,it is necessary to fully recognize and utilize the characteristics and functional advantages of the steel manufacturing process,pay more attention to energy quality,firmly grasp the overall goal of system optimization,focus on the integrated optimization of gas,steam,and waste heat systems,and propose the idea of constructing a"steel chemi-cal gas electricity heating cooling multi generation system".Based on practice,the main principles,models,and effects of implementing systematic energy conservation in steel enterprises have been proposed. 展开更多
关键词 steel manufacturing process system energy-saving system optimization energy conservation and emis-sion reduction waste heat and energy generation POLYGENERATION
下载PDF
上一页 1 2 161 下一页 到第
使用帮助 返回顶部