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Absorptive root-multidimension strategy links air temperature and species distribution in a montane forest
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作者 Zuhua Wang Min Liu +5 位作者 Long Li Jianwei Hou Xiaodong Zhang Haibo Li Chuandong Yang Lilin Yang 《Forest Ecosystems》 SCIE CSCD 2023年第3期307-315,共9页
Background: Air temperature affects absorptive root traits, which are closely related to species distribution.However, it is still unclear how air temperature regulates species distribution through changes in absorpti... Background: Air temperature affects absorptive root traits, which are closely related to species distribution.However, it is still unclear how air temperature regulates species distribution through changes in absorptive root traits. Seven functional traits of the absorptive roots of 240 individuals of 52 species, soil properties and air temperature were measured along an elevational gradient on Mt. Fanjingshan, Tongren City, Guizhou, and then the direct and indirect effects of these controls on species distribution were detected.Results: Absorptive roots adapted to air temperature with two strategies. The first strategy was positively associated with the specific root area(SRA) and specific root length(SRL) and was negatively associated with the root tissue density(RTD), representing the classic root economics spectrum(RES). The second strategy was represented by the trade-off between root diameter, mycorrhizal fungi colonization(MF) and SRL, representing the collaboration gradient with “do it yourself” resource uptake ranging from “outsourcing” to mycorrhizal resource uptake. Air temperature regulated species distribution in six ways: directly reducing species importance value;indirectly increasing the species importance value by reducing soil nitrogen content or increasing soil pH by reducing soil moisture inducing absorptive roots to change from “do it yourself” resource absorption to “outsourcing” resource absorption;indirectly decreasing the species importance value by decreasing soil moisture to change from“outsourcing”resource absorption to “do it yourself” resource absorption;indirectly increasing the species importance value with increasing soil pH by reducing soil moisture resulting in absorptive root traits turning into nutrient foraging traits;and indirectly decreasing the species importance value by promoting absorptive root traits to nutrient conservation traits.Conclusions: Absorptive root traits play a crucial role in the regulation of species distribution through multiapproaches of air temperature. 展开更多
关键词 Air temperature absorptive roots Functional traits Structural equation models Mt.Fanjingshan
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Gastrointestinal motility and absorptive disorders in patients with inflammatory bowel diseases: Prevalence, diagnosis and treatment 被引量:8
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作者 Luísa Leite Barros Alberto Queiroz Farias Ali Rezaie 《World Journal of Gastroenterology》 SCIE CAS 2019年第31期4414-4426,共13页
Inflammatory bowel diseases(IBD),Crohns disease and ulcerative colitis,are chronic conditions associated with high morbidity and healthcare costs.The natural history of IBD is variable and marked by alternating period... Inflammatory bowel diseases(IBD),Crohns disease and ulcerative colitis,are chronic conditions associated with high morbidity and healthcare costs.The natural history of IBD is variable and marked by alternating periods of flare and remission.Even though the use of newer therapeutic targets has been associated with higher rates of mucosal healing,a great proportion of IBD patients remain symptomatic despite effective control of inflammation.These symptoms may include but not limited to abdominal pain,dyspepsia,diarrhea,urgency,fecal incontinence,constipation or bloating.In this setting,commonly there is an overlap with gastrointestinal(GI)motility and absorptive disorders.Early recognition of these conditions greatly improves patient care and may decrease the risk of mistreatment.Therefore,in this review we describe the prevalence,diagnosis and treatment of GI motility and absorptive disorders that commonly affect patients with IBD. 展开更多
关键词 Inflammatory BOWEL diseases Crohn’s disease Ulcerative colitis Gastrointestinal motility and absorptive DISORDERS Irritable BOWEL syndrome SMALL INTESTINAL bacterial OVERGROWTH SMALL INTESTINAL fungal OVERGROWTH Dyssynergic defecation Fecal incontinence Chronic INTESTINAL PSEUDO-OBSTRUCTION
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Absorptive Fabry–Pérot Interference in a Metallic Nanostructure
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作者 王瑞 吴艳玲 +4 位作者 余博晗 胡立立 顾长志 李俊杰 赵继民 《Chinese Physics Letters》 SCIE CAS CSCD 2019年第2期64-70,共7页
In conventional optics, the Fabry–Pérot(FP) effect is only considered for transparent materials at a macroscopic dimension. Down to the nanometer scale, for absorptive metallic structures, the FP effect has not ... In conventional optics, the Fabry–Pérot(FP) effect is only considered for transparent materials at a macroscopic dimension. Down to the nanometer scale, for absorptive metallic structures, the FP effect has not been directly observed so far. It is unclear whether such a macroscopic effect still holds for a subwavelength metallic nanostructure. Here, we demonstrate the probing of FP interference in a series of nanometer-thick Au films with subwavelength hole arrays. The evidence from both linear and second harmonic generation signals, together with angle-resolved investigations, exhibit features of a FP effect. We also derive an absorptive FP interference equation, which well explains our experimental results. Our results for the first time experimentally confirm the long-persisting hypothesis that the FP effect holds ubiquitously in a metallic nanostructure. 展开更多
关键词 absorptive FABRY ROT INTERFERENCE METALLIC NANOSTRUCTURE
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Absorptive reduction and width narrowing in Λ-type atoms confined between two dielectric walls
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作者 李院院 侯洵 +3 位作者 白晋涛 闫军锋 甘琛利 张彦鹏 《Chinese Physics B》 SCIE EI CAS CSCD 2008年第8期2885-2889,共5页
This paper investigates the absorptive reduction and the width narrowing of electromagnetically induced transparency (EIT) in a thin vapour film of A-type atoms confined between two dielectric walls whose thickness ... This paper investigates the absorptive reduction and the width narrowing of electromagnetically induced transparency (EIT) in a thin vapour film of A-type atoms confined between two dielectric walls whose thickness is comparable with the wavelength of the probe field. The absorptive lines of the weak probe field exhibit strong reductions and very narrow EIT dips, which mainly results from the velocity slow-down effects and transient behaviour of atoms in a confined system. It is also shown that the lines are modified by the strength of the coupling field and the ratio of L/λ, with L the film thickness and λthe wavelength of the probe field. A simple robust recipe for EIT in a thin medium is achievable in experiment. 展开更多
关键词 absorptive reduction width narrowing electromagnetically induced transparency
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Nonlinear Intestinal Absorption of Fluorescein Isothiocyanate Dextran 4, 000 Caused by Absorptive and Secretory Transporting System
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作者 Mikio Tomita Rie Ohkubo +2 位作者 Shohei Ouchi Chise Kawahata Masahiro Hayashi 《Pharmacology & Pharmacy》 2011年第3期173-179,共7页
The mechanism of the nonlinear concentration dependence of the intestinal absorption of fluorescein isothiocyanate dextran 4,000 (FD-4) was studied using in situ rat intestinal loops and the in vitro Ussing-type chamb... The mechanism of the nonlinear concentration dependence of the intestinal absorption of fluorescein isothiocyanate dextran 4,000 (FD-4) was studied using in situ rat intestinal loops and the in vitro Ussing-type chamber method. The intestinal absorption rate constant of FD-4, as evaluated by the intestinal loop method, increased significantly in a nonlinear fashion as the FD-4 concentration increased up to 0.2 mM and tended to decrease at concentrations higher than 0.2 mM. The mucosal-to-serosal permeation of FD-4 across rat ileal sheets, as evaluated by the in vitro Ussing-type chamber method, also increased in a nonlinear fashion in the low concentration range (0.01 - 0.02 mM), before decreasing as the concentration increased further, whereas serosal-to-mucosal permeation decreased in a concentration-dependent manner. In addition, mucosal-to-serosal flux and serosal-to-mucosal flux were increased and reduced in the presence of the metabolic inhibitor 2, 4-dinitrophenol, respectively. These results suggest that FD-4 is predominantly secreted into the intestinal lumen by an efflux transport system. 展开更多
关键词 FLUORESCEIN ISOTHIOCYANATE DEXTRAN 4 000 NONLINEAR absorptive TRANSPORT NONLINEAR SECRETORY TRANSPORT Rat Ileal Intestine
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Quantization of electromagnetic field in quadratic continuous nonlinear absorptive dielectrics
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作者 李维 刘世炳 +1 位作者 于承新 杨巍 《Chinese Physics B》 SCIE EI CAS CSCD 2010年第2期290-295,共6页
This paper reports that in the quantization of electromagnetic field in the dielectrics, the wave equation with regard to the Green function is analytically solved by a direct integral method for a quadratic continuou... This paper reports that in the quantization of electromagnetic field in the dielectrics, the wave equation with regard to the Green function is analytically solved by a direct integral method for a quadratic continuous nonlinear absorptive dielectric medium. The quantization of the electromagnetic field in such a nonlinear absorptive dielectric is carried out for which the material dielectric function is assumed as a separable variable about the frequency and the space coordinate. The vacuum field fluctuations for different spatial continuous variations of dielectric function are numerically calculated, which shows that the present result is self-consistent. 展开更多
关键词 nonlinear absorptive dielectric noise current operator Green function
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Xylose: absorption, fermentation, and post-absorptive metabolism in the pig 被引量:3
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作者 Nichole F.Huntley John F.Patience 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2018年第1期1-9,共9页
Xylose, as β-1,4-linked xylan, makes up much of the hemicel ulose in cel wal s of cereal carbohydrates fed to pigs. As inclusion of fibrous ingredients in swine diets continues to increase, supplementation of carbohy... Xylose, as β-1,4-linked xylan, makes up much of the hemicel ulose in cel wal s of cereal carbohydrates fed to pigs. As inclusion of fibrous ingredients in swine diets continues to increase, supplementation of carbohydrases, such as xylanase,is of interest. However, much progress is warranted to achieve consistent enzyme efficacy, including an improved understanding of the utilization and energetic contribution of xylanase hydrolysis product(i.e. xylooligosaccharides or monomeric xylose). This review examines reports on xylose absorption and metabolism in the pig and identifies gaps in this knowledge that are essential to understanding the value of carbohydrase hydrolysis products in the nutrition of the pig. Xylose research in pigs was first reported in 1954, with only sporadic contributions since. Therefore, this review also discusses relevant xylose research in other monogastric species, including humans. In both pigs and poultry, increasing purified D-xylose inclusion general y results in linear decreases in performance, efficiency, and diet digestibility. However,supplementation levels studied thus far have ranged from 5% to 40%, while theoretical xylose release due to xylanase supplementation would be less than 4%. More than 95% of ingested D-xylose disappears before the terminal ileum but mechanisms of absorption have yet to be ful y elucidated. Some data support the hypothesis that mechanisms exist to handle low xylose concentrations but become overwhelmed as luminal concentrations increase. Very little is known about xylose metabolic utilization in vertebrates but it is wel recognized that a large proportion of dietary xylose appears in the urine and significantly decreases the metabolizable energy available from the diet. Nevertheless, evidence of labeled D-xylose-1-^(14)C appearing as expired^(14)CO_2 in both humans and guinea pigs suggests that there is potential,although small, for xylose oxidation. It is yet to be determined if pigs develop increased xylose metabolic capacity with increased adaptation time to diets supplemented with xylose or xylanase. Overall, xylose appears to be poorly utilized by the pig, but it is important to consider that only one study has been reported which supplemented D-xylose dietary concentrations lower than 5%. Thus, more comprehensive studies testing xylose metabolic effects at dietary concentrations more relevant to swine nutrition are warranted. 展开更多
关键词 Pentose utilization SWINE Threitol Xylose absorption Xylose metabolism
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Absorptive process of ~3H-5-hydroxytryptamine in the intestinal lumen
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作者 黄威权 李维民 王文超 《Journal of Medical Colleges of PLA(China)》 CAS 1992年第3期242-245,共4页
Absorptive process of ~3H-5-hydroxytryptamine(~3H-5-HT)in the intestinal lumenwas studied by radiochemical method and autoradiography.The results indicated that ~3H-5-HTinjected into the intestinal lumen was rapidly a... Absorptive process of ~3H-5-hydroxytryptamine(~3H-5-HT)in the intestinal lumenwas studied by radiochemical method and autoradiography.The results indicated that ~3H-5-HTinjected into the intestinal lumen was rapidly absorbed.The absorptive peak appeared at 1 h af-ter ~3H-5-HT injection.Part of the absorbed ~3H-5-HT might enter the blood circulation,andthe other part was located specifically in the submucous plexus,myenteric plexus and some ep-ithelial cells.Whether these neurones and epithelial cells are 5-HT containing cells or are cellswith specific binding sites awaits further studies. 展开更多
关键词 SEROTONIN INTESTINAL absorption AUTORADIOGRAPHY RADIOCHEMISTRY rats
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Absorptive Nonlinearity in Er-Doped Optical Fiber
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作者 Song, Qian Li, Ji-xing Zhang, Yuan-cheng 《Wuhan University Journal of Natural Sciences》 EI CAS 1999年第2期56-59,共4页
Optical absorptive nonlinearity in Er doped optical fiber has been discussed and measured at the window wavelength 1.55 μm for optical communications firstly. It is proposed that the mechanism of this absorptive... Optical absorptive nonlinearity in Er doped optical fiber has been discussed and measured at the window wavelength 1.55 μm for optical communications firstly. It is proposed that the mechanism of this absorptive nonlinearity is the induced absorption. The first order nonlinear absorptive coefficient and the imaginary part and the complex value of the third order susceptibility at that wavelength are obtained from the measured absorptive nonlinearity. 展开更多
关键词 optical nonlinearity Er doped fiber optical absorption
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Wideband radar cross section reduction based on absorptive coding metasurface with compound stealth mechanism
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作者 杨歆汨 刘昌荣 +1 位作者 侯波 周小阳 《Chinese Physics B》 SCIE EI CAS CSCD 2021年第10期274-282,共9页
A scheme of combing wave absorption and phase cancellation mechanisms for widening radar cross section(RCS)reduction band is proposed.An absorptive coding metasurface implementing this scheme is derived from tradition... A scheme of combing wave absorption and phase cancellation mechanisms for widening radar cross section(RCS)reduction band is proposed.An absorptive coding metasurface implementing this scheme is derived from traditional circuit analog absorber(CAA)composed of resistive ring elements which characterize dual resonances behavior.It is constructed by replacing some of the CAA elements by another kind of resistive ring elements which is singly resonant in between the original two resonant bands and has reflection phase opposite to that of the original elements at resonance.Hence the developed metasurface achieves an improved low-RCS band over which the lower and higher sub-bands are mainly contributed by wave absorption mainly while the middle sub-band is formed by joint effect of wave absorption and antiphase cancellation mechanisms.The polarization-independent wideband RCS reduction property of the metasurface is validated by full-wave simulation results of a preliminary and an advanced design examples which employ the same element configuration but different element layout schemes as partitioned distribution and random coding.The advanced design also exhibits broadband bistatic low-RCS property and keeps a stable specular RCS reduction performance with regard to incident elevation angle up to 35◦.The advanced design is fabricated and the experimental results of the sample agrees qualitatively well with their simulated counterparts.The measured figure of merit(i.e.,low-RCS bandwidth ratio versus electrical thickness)of the sample is 40.572,which is superior to or comparable with those for most of other existing metasurface with compound RCS reduction mechanism.The proposed compound metasurface technique also features simple structure,light weight,low cost and easy fabrication compared with other techniques.This makes it promising in applications such as radar stealth and electromagnetic compatibility. 展开更多
关键词 radar cross section(RCS)reduction coding metasurface wave absorption anti-phase cancellation
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The Changes in Representatives of Specific Social Sectors of the CPPCC——A Perspective from the Political Absorptive Capacity of the CPC
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作者 Li Houqiang Guo Dan +1 位作者 Chen Lanxin Guo Li(译) 《Contemporary Social Sciences》 2018年第3期126-142,共17页
The establishment of the representatives of special social sectors of the CPPCC has to a greater degree guaranteed broad and in-depth participation for the people from all walks of life in the national political activ... The establishment of the representatives of special social sectors of the CPPCC has to a greater degree guaranteed broad and in-depth participation for the people from all walks of life in the national political activities,providing an institutionalized platform for various social strata and social groups to systematically give their advice and suggestions.The establishment,adjustment,and changes in the sectors are of vital political significance not only in ensuring to the greatest extent that people from all walks of life widely participate in national political activities,and providing an institutionalized platform for people of all social strata and communities to systematically express their opinions and offer their advice,but also in manifesting the democratic absorption mechanism for the CPC to conduct democratic consultation and governance on the platform of democratic consultation.The more industries involved in the sectors,the more representative the sectors are,and the more reasonable the proportions of the sectors,the more likely it is to guarantee the level and quality of the democratic consultation and to solve more practical problems.This is why the establishment and changes of the CPPCC sectors are an important manifestation of the CPC's political absorptive capacity.The CPPCC is an effective organizing form for the CPC to integrate society and an important platform for the governing party and society to maintain a social pattern of diversified interests and political stability,while the CPPCC sectors are the basic units for the governing party to promote the idea of participatory democracy. 展开更多
关键词 the CPPCC SECTORS the CPC POLITICAL ABSORPTION
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Research on EM pulse protection property of plasma-microwave absorptive material-plasma sandwich structure 被引量:6
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作者 YUAN ZhongCai & SHI JiaMing State Key Laboratory of Pulse Power Laser Technology, Key Lab of Infrared and Low Temperature Plasma of Anhui Province, Hefei Electronic Engineering Institute, Hefei 230037, China 《Science China(Technological Sciences)》 SCIE EI CAS 2010年第12期3221-3224,共4页
A plasma-microwave absorptive material (MAM)-plasma sandwich structure is presented to protect the electronic device against high power electromagnetic pulse. The model of electromagnetic wave reflected by and transmi... A plasma-microwave absorptive material (MAM)-plasma sandwich structure is presented to protect the electronic device against high power electromagnetic pulse. The model of electromagnetic wave reflected by and transmitting through the structure is established. Based on the characteristic parameters of plasma generated by discharge and usual MAM, the electromagnetic transmissive properties of the sandwich structure are investigated by the method of finite difference in time domain. The results indicate that in a rather broad frequency range, the electromagnetic attenuations by the structure are obviously better than the sum of attenuations resulted from plasma and MAM respectively. The models and results presented are instructive for electromagnetic pulse protection. 展开更多
关键词 PLASMA MICROWAVE absorptive MATERIAL (MAM) SANDWICH structure electromagnetic PULSE finite difference time domain
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A SEMI-ANALYTICAL SOLUTION FOR CHARACTERISTICS OF A DAMRESERVOIR SYSTEM WITH ABSORPTIVE RESERVOIR BOTTOM 被引量:6
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作者 LI Shang-ming LIANG Hong LI Ai-min 《Journal of Hydrodynamics》 SCIE EI CSCD 2008年第6期727-734,共8页
In this study, a semi-analytical formulation based on the Scaled Boundary Finite Element Method (SBFEM) was proposed and used to obtain the solution for the characteristics of a two-dimensional dam-reservoir system ... In this study, a semi-analytical formulation based on the Scaled Boundary Finite Element Method (SBFEM) was proposed and used to obtain the solution for the characteristics of a two-dimensional dam-reservoir system with absorptive reservoir bottom in the frequency domain. For simplicity, the dam with arbitrary upstream faces was assumed to be rigid and was subjected to a horizontal ground acceleration, while the reservoir with absorptive bottom was assumed to be semi-infinite. The reservoir was divided into two sub-domains: a near-field sub-domain and a far-field sub-domain. The near-field sub-domain with arbitrary geometry was modelled by the Finite Element Method (FEM), while the effects of the far-field sub-domain which was assumed to be horizontal were described by a semi-analytical formation. The semi-analytical formulation involved the effect of absorptive reservoir bottom, as well as the radiation damping effect of a semi-infinite reservoir. A FEM/SBFEM coupling formulation was presented to solve dam-reservoir coupled problems. The accuracy and efficiency of the coupling formulation were demonstrated by computing some benchmark examples. Highly accurate results are produced even if the near-field sub-domain is very small. 展开更多
关键词 dam-reservoir interaction absorptive bottom SBFEM Hydraulic pressure FEM/SBFEM coupling formulation
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Absorptive Capacity of Information Technology and Its Conceptual Model 被引量:4
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作者 毕新华 余翠玲 《Tsinghua Science and Technology》 SCIE EI CAS 2008年第3期337-343,共7页
In order to examine the problem of how to improve the use of information technology (IT) in enterprises, this paper makes an exploration from the perspective of organizational absorptive capacity. We propose the con... In order to examine the problem of how to improve the use of information technology (IT) in enterprises, this paper makes an exploration from the perspective of organizational absorptive capacity. We propose the concept of IT absorptive capacity from an organizational level. A dynamic process model is developed to further analyze IT absorption. IT absorptive capacity of this process is embodied as six forms: identification, adoption, adaptation, acceptance, infusion, and knowledge management. By means of questionnaire surveys of 76 Chinese enterprises, the main factors that favor or disable the capacity of each stage are discovered. Using the method of system dynamics, a conceptual model of IT absorptive capacity is developed to analyze the action mechanism of the factors in detail. The model indicates that the critical factors are embodied in the aspect of management. Furthermore, it demonstrates that IT absorption is a spiral process, during which IT absorptive capacity evolves dynamically and, consequently, promotes IT use. 展开更多
关键词 information technology (IT) IT absorption absorptive capacity conceptual model
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Fabrication of cellulose aerogel from wheat straw with strong absorptive capacity 被引量:1
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作者 Jian LI Caichao WAN +1 位作者 Yun LU Qingfeng SUN 《Frontiers of Agricultural Science and Engineering》 2014年第1期39-45,共7页
An effectively mild solvent solution containing NaOH/PEG was employed to dissolve the cellulose extracted from the wheat straw.With further combined regeneration process and freeze-drying,the cellulose aerogel was suc... An effectively mild solvent solution containing NaOH/PEG was employed to dissolve the cellulose extracted from the wheat straw.With further combined regeneration process and freeze-drying,the cellulose aerogel was successfully obtained.Scanning electron microscope,X-ray diffraction technique,Fourier transform infrared spectroscopy,and Brunauer-Emmett-Teller were used to characterize this cellulose aerogel of low density(about 40 mg·cm^(–3))and three-dimensional network with large specific surface area(about 101 m2·g^(–1)).Additionally,with a hydrophobic modification by trimethylchlorosilane,the cellulose aerogel showed a strong absorptive capacity for oil and dye solutions. 展开更多
关键词 cellulose aerogel absorptive capacity waste wheat straw FREEZE-DRYING
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Effects of gravel on the water absorption characteristics and hydraulic parameters of stony soil
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作者 MA Yan WANG Youqi +2 位作者 MA Chengfeng YUAN Cheng BAI Yiru 《Journal of Arid Land》 SCIE CSCD 2024年第7期895-909,共15页
The eastern foothills of the Helan Mountains in China are a typical mountainous region of soil and gravel,where gravel could affect the water movement process in the soil.This study focused on the effects of different... The eastern foothills of the Helan Mountains in China are a typical mountainous region of soil and gravel,where gravel could affect the water movement process in the soil.This study focused on the effects of different gravel contents on the water absorption characteristics and hydraulic parameters of stony soil.The stony soil samples were collected from the eastern foothills of the Helan Mountains in April 2023 and used as the experimental materials to conduct a one-dimensional horizontal soil column absorption experiment.Six experimental groups with gravel contents of 0%,10%,20%,30%,40%,and 50%were established to determine the saturated hydraulic conductivity(K_(s)),saturated water content(θ_(s)),initial water content(θ_(i)),and retention water content(θ_(r)),and explore the changes in the wetting front depth and cumulative absorption volume during the absorption experiment.The Philip model was used to fit the soil absorption process and determine the soil water absorption rate.Then the length of the characteristic wetting front depth,shape coefficient,empirical parameter,inverse intake suction and soil water suction were derived from the van Genuchten model.Finally,the hydraulic parameters mentioned above were used to fit the soil water characteristic curves,unsaturated hydraulic conductivity(K_(θ))and specific water capacity(C(h)).The results showed that the wetting front depth and cumulative absorption volume of each treatment gradually decreased with increasing gravel content.Compared with control check treatment with gravel content of 0%,soil water absorption rates in the treatments with gravel contents of 10%,20%,30%,40%,and 50%decreased by 11.47%,17.97%,25.24%,29.83%,and 42.45%,respectively.As the gravel content increased,inverse intake suction gradually increased,and shape coefficient,K_(s),θ_(s),andθ_(r)gradually decreased.For the same soil water content,soil water suction and K_(θ)gradually decreased with increasing gravel content.At the same soil water suction,C(h)decreased with increasing gravel content,and the water use efficiency worsened.Overall,the water holding capacity,hydraulic conductivity,and water use efficiency of stony soil in the eastern foothills of the Helan Mountains decreased with increasing gravel content.This study could provide data support for improving soil water use efficiency in the eastern foothills of the Helan Mountains and other similar rocky mountainous areas. 展开更多
关键词 stony soil gravel content water absorption characteristics hydraulic parameters one-dimensional horizontal soil column absorption experiment van Genuchten model eastern foothills of Helan Mountains
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Cascade equilibrium stage relaxation method by introducing equilibrium efficiency parameter
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作者 Xuepu Cao Shengkun Jia +2 位作者 Xing Qian Yiqing Luo Xigang Yuan 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第2期145-156,共12页
Optimizing multistage processes,such as distillation or absorption,is a complex mixed-integer nonlinear programming(MINLP)problem.Relaxing integer into continuous variables and solving the easier nonlinear programming... Optimizing multistage processes,such as distillation or absorption,is a complex mixed-integer nonlinear programming(MINLP)problem.Relaxing integer into continuous variables and solving the easier nonlinear programming(NLP)problem is an optimization idea for the multistage process.In this article,we propose a relaxation method based on the efficiency parameter.When the efficiency parameter is 1or 0,the proposed model is equivalent to the complete existence or inexistence of the equilibrium stage.And non-integer efficiency represents partial existence.A multi-component absorption case shows a natural penalty for non-integer efficiency,which can assist the efficiency parameter converging to 0 or 1.However,its penalty is weaker than the existing relaxation models,such as the bypass efficiency model.In a simple distillation case,we show that this property can weaken the nonconvexity of the optimization problem and increase the probability of obtaining better optimization results. 展开更多
关键词 Mathematical modeling ABSORPTION DISTILLATION Optimization
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Simultaneous removal of sulfur dioxide and nitrogen oxide from flue gas by phosphorus sludge:The performance and absorption mechanism
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作者 Yuanyuan Yin Xujun Wang +3 位作者 Lei Xu Binbin He Yunxiang Nie Yi Mei 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第1期212-221,共10页
Developing low-cost and green simultaneous desulfurization and denitrification technologies is of great significance for sulfur dioxide(SO_(2))and nitrogen oxide(NO_(x))emission control at low temperatures,especially ... Developing low-cost and green simultaneous desulfurization and denitrification technologies is of great significance for sulfur dioxide(SO_(2))and nitrogen oxide(NO_(x))emission control at low temperatures,especially for small and medium-sized coal-fired boilers and furnaces.Herein,phosphorus sludge,an industrial waste from the production process of yellow phosphorus,has been developed to simultaneously eliminate SO_(2)and NO_(x)from coal-fired flue gas.The key factors affecting the experimental results indicate that desulfurization and denitrification efficiency of over 95%can be achieved at a low temperature of 55℃.Further,the absorption mechanism was investigated by characterizing the solid and liquid phases of the phosphorus sludge during the absorption process.The efficient removal of SO_(2)is attributed to the abundance of iron(Fe^(3+))and manganese(Mn^(2+))in the absorbent.SO_(2)can be rapidly catalyzed and converted to SO_(4)^(2-)by them.The key to NOx removal is the oxidation of NO toward watersoluble high-valent nitrogen oxides by oxidizing reactive substances induced via yellow phosphorus,which are then absorbed by water and converted to NO_(3)^(-).Meanwhile,yellow phosphorus is oxidized to phosphoric acid(H_(3)PO_(4)).The spent absorption slurry can be reused through wet process phosphoric acid production,as it contains sulfuric acid(H_(2)SO_(4)),nitric acid(HNO_(3)),and H_(3)PO_(4).Accordingly,this is a technology with broad application prospects. 展开更多
关键词 ABSORPTION OXIDATION Multiphase reaction Phosphorus sludge Yellow phosphorus Low temperature
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A shield of defense:Developing ballistic composite panels with effective electromagnetic interference shielding absorption
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作者 Nisrin Rizek Abdelal 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第5期123-136,共14页
The primary goal of this study is to develop cost-effective shield materials that offer effective protection against high-velocity ballistic impact and electromagnetic interference(EMI)shielding capabilities through a... The primary goal of this study is to develop cost-effective shield materials that offer effective protection against high-velocity ballistic impact and electromagnetic interference(EMI)shielding capabilities through absorption.Six fiber-reinforced epoxy composite panels,each with a different fabric material and stacking sequence,have been fabricated using a hand-layup vacuum bagging process.Two panels made of Kevlar and glass fibers,referred to as(K-NIJ)and(G-NIJ),have been tested according to the National Institute of Justice ballistic resistance protective materials test NIJ 0108.01 Standard-Level IIIA(9 mm×19 mm FMJ 124 g)test.Three panels,namely,a hybrid of Kevlar and glass(H-S),glass with ceramic particles(C-S),and glass with recycled rubber(R-S)have been impacted by the bullet at the center,while the fourth panel made of glass fiber(G-S)has been impacted at the side.EMI shielding properties have been measured in the X-band frequency range via the reflection-transmission method.Results indicate that four panels(K-NIJ,G-NIJ,H-S,and G-S)are capable of withstanding high-velocity impact by stopping the bullet from penetrating through the panels while maintaining their structural integrity.However,under such conditions,these panels may experience localized delamination with variable severity.The EMI measurements reveal that the highest absorptivity observed is 88% for the KNIJ panel at 10.8 GHz,while all panels maintain an average absorptivity above 65%.All panels act as a lossy medium with a peak absorptivity at different frequencies,with K-NIJ and H-S panels demonstrating the highest absorptivity.In summary,the study results in the development of a novel,costeffective,multifunctional glass fiber epoxy composite that combines ballistic and electromagnetic interference shielding properties.The material has been developed using a simple manufacturing method and exhibits remarkable ballistic protection that outperforms Kevlar in terms of shielding efficiency;no bullet penetration or back face signature is observed,and it also demonstrates high EMI shielding absorption.Overall,the materials developed show great promise for various applications,including the military and defense. 展开更多
关键词 BALLISTIC FRP composite EMI shielding ABSORPTIVITY CT-SCAN NIJ test BULLET DEFENSE
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MXene Hollow Spheres Supported by a C–Co Exoskeleton Grow MWCNTs for Efficient Microwave Absorption
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作者 Ze Wu Xiuli Tan +4 位作者 Jianqiao Wang Youqiang Xing Peng Huang Bingjue Li Lei Liu 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第6期76-94,共19页
High-performance microwave absorption(MA) materials must be studied immediately since electromagnetic pollution has become a problem that cannot be disregarded. A straightforward composite material, comprising hollow ... High-performance microwave absorption(MA) materials must be studied immediately since electromagnetic pollution has become a problem that cannot be disregarded. A straightforward composite material, comprising hollow MXene spheres loaded with C–Co frameworks, was prepared to develop multiwalled carbon nanotubes(MWCNTs). A high impedance and suitable morphology were guaranteed by the C–Co exoskeleton, the attenuation ability was provided by the MWCNTs endoskeleton, and the material performance was greatly enhanced by the layered core–shell structure. When the thickness was only 2.04 mm, the effective absorption bandwidth was 5.67 GHz, and the minimum reflection loss(RLmin) was-70.70 d B. At a thickness of 1.861 mm, the sample calcined at 700 ℃ had a RLmin of-63.25 d B. All samples performed well with a reduced filler ratio of 15 wt%. This paper provides a method for making lightweight core–shell composite MA materials with magnetoelectric synergy. 展开更多
关键词 MXene C-Co skeleton MWCNTS Microwave absorption
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