Performance of Concrete Subjected to Severe Multiple Actions of Composite Salts Solution under Wet-Dry Cycles and Flexural Loading in Lab

Several action regimes were employed, namely, those exposed to solutions containing single and/or composite chloride and sulfate salts, and under wet-dry cycles and/or flexural loading. The variations in dynamic modulus of elasticity（Erd values） were monitored, as well as the key factor impacting on the chloride ingress when concrete subjected to multiple action regimes was identified by the method of Grey Relation Analysis（GRA）. The changes in micro-structures and mineral products of interior concrete after different action regimes were investigated by means of X-ray diffraction（XRD）, mercury intrusion technique（MIP）, and scanning electron microscopy（SEM）. The test results showed that the cyclic wet-dry accelerated the deterioration of OPC concrete more than the action of 35% flexural loading based on the results of Erd values and the GEA. The analyses from micro-structures could give certain explanations to the change in Erd values under different action regimes.

Multiple cycles of magnetic activity in the Sun and Sun-like stars and their evolution

The wavelet transform method for high-quality time-frequency analysis is applied to sets of observations of relative sunspot numbers and stellar chromosphere fluxes of 10 Sun-like stars. Wavelet analysis of solar data shows that in a certain interval of time there are several cycles of activity with pe- riods of duration which vary considerably from each other： from quasi-biennial cycles to lO0-yr cycles. Cyclic activity was detected in almost all Sun-like stars that we examined, even those that previously were not considered as stars with cyclic activity according to analysis using a Scargle periodogram. The durations of solar and stellar cycles significantly change during the observation period.

Durability of concrete beams reinforced with CFRP sheet under wet-dry cycles and loading

The test results of eight concrete beams reinforced with carbon fiber reinforced polymer （CFRP） sheets subjected to an aggressive environment under a sustained load are presented. The beams are 1 700 mm long with a rectangular cross-section of 120- mm width and 200-mm depth. The beams are precracked with a four-point flexural load, bonded CFRP sheets, and placed into wet-dry saline water（ NaCl） either in an unstressed state or loaded to about 30% or 60% of the initial ultimate load. The individual and coupled effects of wet-dry saline water and sustained bending stresses on the long term behaviour of concrete beams reinforced with the CFRP are investigated. The test results show that the coupled action of wet-dry saline water and sustained bending stresses appears to significantly affect the load capacity and the failure mode of beam strengthened with CFRP, mainly due to the degradation of the bond between CFRP and concrete. However, the stiffness is not affected by the coupled action of wet-dry cycles and a sustained load.

Cycle Multiplicity of Total Graph of Complete Bipartite Graph

Cycle multiplicity of a graph G is the maximum number of edge disjoint cycles in G. In this paper, we determine the cycle multiplicity of and then obtain the formula of cycle multiplicity of total graph of complete bipartite graph, this generalizes the result for, which is given by M.M. Akbar Ali in [1].

Degradation of Pore Structure and Microstructures in Hardened Cement Paste Subjected to Flexural Loading and Wet-dry Cycles in Sea Water

Hardened cement paste was subjected to the flexural loading and wet-dry cycles in sea water. The degradation of microstructures was obtained using scanning electron microscope （SEM）, and the energy dispersive spectrum （EDS） analysis was carried to analyze the local composition. Mercury intrusion porosimetry （Poremaster GT-60） was used to analyze the degradation of pore structures. The experimental results show that the synergistic action of the flexural loading, wet-dry cycles and sea water leads to significant deterioration of hardened cement paste. The degradation of microstructures in the tensile region is more serious than that in the compressive region. The flexural loading and wet-dry cycles accelerate the chemical attack of sea water.

Combined Life Cycle Assessment and Costing Analysis Optimization Model Using Multiple Criteria Decision Making in Earth-Resource Systems

Life Cycle Assessment (LCA) is a comprehensive method to evaluate all attributes or aspects of potential environmental impact throughout a product’s lifecycle. Financial impacts are often added to the systemic evaluation process to reflect both environmental and economic assessment. For the specific application of LCA informing design of new technologies, when numerous variables are undecided or under defined, the process of forming an inventory of complete dataset is very difficult. Accumulating the early data consumes time, and limits application of LCA to new technologies and projects. As such, LCA may not normally be associated with forecasting or guiding a design/production process with an incomplete data set. Here, a life cycle assessment optimization model (LCAO) is described for incomplete data sets, based on the life cycle inventory (LCI) hybrid method and a modified multiple criteria decision making (MCDM) approach. The approach requires data, but can proceed in the given an incomplete or uncertain data set. The model of the algorithm also shows promising results to reveal previously unknown key variables within the dataset, which can then facilitate the minimization of environmental impact while maximizing economic benefits in product design.

Triptolide Inhibits Cell Growth and Induces G0-G1 Arrest by Regulating P21wap1/cip1 and P27 kip1 in Human Multiple Myeloma RPMI-8226 Cells

Objective： To investigate the effects of triptolide（TPL） on cell growth, cell cycle and the expressions of p21wapl/cipl and p27kipl. Methods： MTT assay was used to determine the cell viability after triptolide treatment in human multiple myeloma RPMI-8226 cells. The effect on cell cycle distribution was determined by flow cytometry. Semi-quantitative reverse transcription-PCR was used to examine the mRNA expressions of p21wapl/cipl and p27kipl. The protein expressions of p21 wapl/cipl and p27kipl were determined by Western blot. Results： Triptolide of varying concentrations induced cell viability inhibition in dose- and time-related fashion and caused Go- G1 phase arrest of cell cycle progression in RPMI-8226 cells. These effects accompanied with up-modulation of the expressions of p21 wapl/cipl and p27kipl. Conclusion： These results suggest that triptolide inhibit cell proliferation and cell cycle progression via up-regulating p21wapl/cipl and p27kipl and triptolide may exert its anti-cancer activity through this pathway.

Damage characteristics and new constitutive model of sandstone under wet–dry cycles

The mechanical properties of rock deteriorate under repeated wet-dry(WD)cycles,causing the deformation and failure of the rock mass.A reasonable damage constitutive model can truly reflect the whole process of rock deformation and failure.Therefore,it is of great significance to study the damage characteristics and constitutive behaviour of rock subjected to numerous WD cycles.First,sandstone from Tingliang tunnel was sampled for the WD cycle experiment,and uniaxial and triaxial tests were carried out on the rock samples after various numbers of WD cycles to analyze their macroscale damage characteristics.Then,the damage mechanisms of the rock samples under the action of WD cycling were identified by X-ray diffraction(XRD)and scanning electron microscopy(SEM).Finally,based on the test data,the WD cycle-induced damage variable,Weibull distribution function,damage threshold,Drucker-Prager(D-P)yield criterion and residual strength correction coefficient were introduced,a wet-dry loading(WDL)constitutive damage model that considers the cracking stress of rock masses was established,and the expressions of the corresponding parameters were given.The results show that an increasing number of WD cycles induces considerable variations in the macroscopic physical and mechanical parameters(such as the rock sample mass,saturated water content,longitudinal-wave velocity,compressive strength and elastic modulus),and the rate of change presents two stages,the inflection point of their rate of change is the 15th WD cycle.Microscopically,the rock sample structure changes from intact and dense to fragmented and unconsolidated;additionally,the surface roughness increases,and the mineral composition changes.The established constitutive damage model exhibited good agreement with the experimental data;thus,this model can reflect the deformation and failure of rocks under WDL conditions,and the physical meaning of each parameter is clear.

A NEW ANALYZING APPROACH TO MODELING SLOTTED MULTIPLE ACCESS SYSTEMS

In this paper, the analyzing approaches proposed by Zhao Dongfeng, et al.(1997) have been extensively studied. The average cyclic times of the slotted multiple access systems are analyzed by using the average cycle method. Analytic formulae for mean values of a successful period and a colliding period and an idle period are derived. The upper bounds of the system throughput with capture effect and collision resolution are provided. Finally, the simulation results of the slotted multiple access channels are given.

Effect of incubation temperature and wet-dry cycle on the availabilities of Cd,Pb and Zn in soil

The effect of incubation temperature and wet-dry cycle on the availabilities of Cd, Pb and Zn was studied. Three soils with pH ranging from 3.8 to 7.3, organic carbon （OC） from 0.7% to 2.4%, and clay from 12.3% to 35.6% were selected. Soils were spiked with reagent grade Cd（NO3）2, Pb（NO3）2, and Zn（NO3）2 at concentrations of 30 mg Cd/kg soil, 300 mg Zn/kg soil and 2000 mg Pb/kg soil. The soils were incubated at 35, 60, 105℃, respectively and went through four wet-dry cycles. Metal availability in soils was estimated by soil extraction with 0.1 mol/L Ca（NO3）2. According to this study, the effect of the spiking temperature on the metal availabilities was different among the metals, soils and wet-dry cycles. Mostly, 35 ~C was the first recommended spiking temperature for Cd and Pb while no spiking temperature was obviously better than others for Zn. Three wet-dry cycles was recommended regardless of the type of metals and incubation temperature.

Research on the Pitting Mechanism of Dispersion-Strengthened High-Strength Steel Under Wet-Dry Cycling in a Marine Environment

Due to the wet-dry cycling in the ocean tidal zone,the supply of dissolved oxygen and salt-containing particles were sufficient,so the corrosion was serious.Pitting corrosion was a common form of localized corrosion.This paper studied the pitting corrosion mechanism of dispersion-strengthened high-strength steel under different wet-dry ratio environments.Electrochemical Impedance Spectroscopy was used to study the changes of corrosion rate and electric double layer structure of the dispersionstrengthened high-strength steel.Scanning electron microscope,Raman spectroscopy,electron probe microanalysis and laser confocal scanning microscope were used to observe the corrosion product morphologies,analyze the corrosion product compositions,analyze the secondary distribution of alloy elements in the corrosion products and analyze the pitting information of the steel after the corrosion products were removed.The results showed that the degree of the steel corrosion was slight when the wetting time was longer,the size and depth of the corrosion pits on the surface were smaller.This was because the environment with longer wetting time made the corrosion products denser.In this environment,the conversion ofγ-FeOOH to Fe3O4 was promoted.In addition,it could also promote the alloying elements to be more concentrated in the rust layer.The above phenomena hindered the further corrosion of the matrix by dissolved oxygen and Cl−in the seawater.

Multiple transition metals modulated hierarchical networks for high performance of metal-ion batteries

Searching anodes with excellent electrochemical performance has been in great demand for rechargeable metal ion batteries. In this contribution, Fe/Co co-doped Ni S with N-based carbon(Fe Co-NiS@NC) derived from trimetallic Prussian blue analogue is designed and synthesized. The composition can be easily adjusted and modulated by multi-metals. In addition, the well-designed carbon nanocubes effectively promote electronic conductivity and buffer the volume change upon charge and discharge cycling, resulting in good capacity and long-term cycle life for both lithium-ion batteries and sodium-ion batteries, with capacities of 1018 m Ah g^(-1)(vs. Li/Li^(+)) and 454 m Ah g^(-1)(vs. Na/Na^(+)), respectively, after 100 cycles.Kinetics studies indicate that the electrochemical behaviors are manipulated by both diffusion and pseudocapacitance processes. These strategies would open new opportunities and potention for novel energy storage.

卵巢功能减退患者多周期累积与非累积胚胎移植临床结局比较

目的探讨卵巢功能减退(DOR)患者多周期累积与非累积胚胎移植体外受精-胚胎移植(IVF-ET)临床结局的差异。方法回顾性分析2019-01至2022-12于首都医科大学附属北京妇产医院生殖医学科进行IVF-ET治疗的卵巢储备功能减退的不孕患者174例的临床资料,纳入患者均已完成所有胚胎移植及最终随访。收集患者的基础内分泌、抗苗勒管激素水平及窦卵泡计数,记录促排卵治疗后的卵巢反应参数及妊娠结局等相关临床资料,比较多周期累积胚胎移植(累积组)与非累积胚胎移植(非累积组)两种IVF-ET治疗的临床结局。结果DOR患者多周期累积胚胎移植与非累积胚胎移植两组间的累积妊娠率(35.24%vs.27.54%)、早期流产率(32.43%vs.26.32%)及累积活产率(21.90%vs.18.84%)差异无统计学意义(P>0.05);纳入移植策略、BMI、首次取卵年龄、AMH、胚胎移植数、优质胚胎移植数、累积获卵数等多个因素后进行logistic回归分析,两种不同的胚胎移植策略(OR=1.522,95%CI 0.608~3.814)对活产无明显影响(P>0.05)。结论对于DOR患者,进行多周期重复取卵后的累积胚胎移植并不能提高患者的累积妊娠率及活产率。

基于混合维修机制的动车组多设备系统维修策略优化

为降低动车组多设备系统一个寿命周期内的维修总成本,以动车组某设备系统为研究对象,采用混合式故障率演化规则描述其故障率变化,以预防性维修成本和故障维修成本为主要成本考量,对其一个寿命周期内的维修经济性进行优化研究,并结合我国动车组维修实际,分别建立等周期预防性维修策略和基于可靠性的预防性维修策略模型。通过分析动车组系统中各单设备在两种维修策略下的维修总成本,选择使维修总成本最低的维修策略作为该设备一个寿命周期内的最终维修策略,进而提出一种动车组多设备系统混合维修策略。算例结果表明,混合维修策略下动车组多设备系统的维修总成本相较于等周期预防性维修策略降低了19.3%,相较于基于可靠性的预防性维修策略降低了16.7%。

含Ag@Ni核壳结构粉体镍基复合涂层的多循环高温摩擦学性能

为了抑制Ag的扩散,采用化学镀方法制备Ag@Ni核壳结构粉体,并利用大气等离子喷涂技术制备NiCrAlY-Mo-Ag@Ni涂层,详细研究核壳结构设计对涂层在高温循环工况下的力学及摩擦学性能的影响。研究结果表明:Ag的核壳结构设计可以提高镍基涂层中Ag与NiCrAlY的界面结合强度,进而显著提高复合涂层的硬度。Ni覆层有效地抑制了Ag在高温摩擦过程中的扩散与耗散。800℃时NiCrAlY-Mo-Ag@Ni涂层的摩擦因数仅为0.25,磨损率仅为1×10^(-5)mm^(3)/(N·m),显著低于NiCrAlY-Mo-Ag涂层。同时,Ag的核壳结构设计使得涂层在高温多循环工况下始终保持良好的自润滑性和耐磨性。

采用组织芯片技术检测大肠癌组织中p16和cyclinD1的表达

目的 :研究大肠癌组织中多肿瘤抑制蛋白 (P16 )和细胞周期蛋白 (cyclinD1)的表达及其意义。 方法 :采用组织芯片技术制作 80例大肠癌组织芯片 ,同时用S P免疫组织化学方法检测大肠癌组织芯片中P16和cyclinD1的表达。 结果 :80例大肠癌中P16和cyclinD1的阳性率分别为 4 0 0 %、5 7 5 %。P16低表达、cyclinD1高表达与大肠癌的浸润程度密切相关 ,大肠癌中P16低表达与cyclinD1的高表达密切相关。 结论 :P16和cyclinD1的表达水平可以作为评估大肠癌预后的参考指标 ,P16低表达影响cyclinD1的高表达。应用组织芯片大规模高效检测临床组织样本是可行的 ,具有快速、方便、经济、准确的特点。

圈与路的点被多重集可区别的E-全染色

图G的E-全染色是指使得相邻顶点染以不同色,每条边与它的端点染以不同的颜色的全染色.设f是图G的E-全染色,图G的一个顶点x在f下的多重色集合C˜(x)是指点x的颜色以及与x关联的边的颜色构成的多重集.若图G的任意两个不同顶点在f下的多重色集合不同,则f称为图G的点被多重集可区别的E-全染色.对图G进行点被多重集可区别的E-全染色所需用的最少的颜色的数目叫做G的点被多重集可区别的E-全色数.利用反证法和构造具体染色的方法,讨论了圈与路的点被多重集可区别的E-全染色问题,给出了圈与路的最优的点被多重集可区别的E-全染色方案,并确定了圈与路的点被多重集可区别的E-全色数.

无纺结构麻纤维复合材料疲劳性能及失效机理

近年来,以可持续性为特征的麻纤维因其在环境可接受性和商业可行性方面的优势而备受关注。以麻纤维代表之一的洋麻毡为增强材料,不饱和聚酯(UP)为基体,采用手工叠层和模压成型的方法制备了洋麻/UP复合材料。设计低周疲劳(低速低循环疲劳)和高周疲劳(高速多循环疲劳测试)来探讨其疲劳性能和疲劳极限,重点观察不同疲劳测试条件下麻纤维的断裂形态和失效机理。

采用组织芯片技术探讨p16和cyclin D1在胆囊癌中的表达及临床意义

目的探讨多肿瘤抑制蛋白(p16)和细胞周期蛋白(cyclin D1)的表达在胆囊癌发生发展中的作用及其对预后的影响,研究应用组织芯片在大规模高效检测临床组织样本的可行性。方法取40例胆囊癌、24例胆囊良性病变和16例癌旁黏膜标本,采用组织芯片技术制作成组织芯片,同时用S-P免疫组织化学方法检测组织芯片中p16和cyclinD1的表达。结果p16和cyclin D1在胆囊癌中的阳性表达率分别为40.0(和57.5(,与胆囊良性病变(75.0(,29.2()和癌旁黏膜(93.8(,12.5()相比有显著性差异(P<0.005)。p16的低表达和cyclin D1的高表达与胆囊癌的分化程度(P(0.025,P<0.01)、浸润深度(P<0.01,P<0.025)、淋巴结转移(P<0.01,P<0.01)以及患者的5年生存率(P<0.025,P<0.05)密切相关。p16和cyclinD1在胆囊癌中的表达呈负相关(r=-0.54)。结论p16和cyclin D1的异常表达在胆囊癌的发生、发展过程中起重要作用。p16和cyclin D1的表达水平可以作为评估胆囊癌预后的参考指标。应用组织芯片大规模高效检测临床组织样本是可行的,具有快速、方便、经济、准确的特点。

Evaluation of red soil-bentonite mixtures for compacted clay liners

Compacted clay liners are an integral part of the waste landfills,which are provided to contain the leachate within the landfills and protect the surrounding environment.Generally,locally available natural soils are used for the construction of compacted clay liners if they satisfy the design criteria.However,not all soils in their natural state satisfy all the design criteria for the liner materials.Thus,there is a definite need to modify the locally available natural soils by blending with bentonite to meet the required design criteria for the liners.In view of this,the present study evaluates the suitability of an Indian red soil enhanced with bentonite as a liner material.To achieve this,a series of experiments were carried out using locally available red soil and bentonite.First,the suitability of the red soil was evaluated as a liner material.The experimental results showed that the red soil met all the selection criteria stipulated by the Environmental Protection Agencies(EPAs)for the liners except the hydraulic conductivity criterion.Therefore,the red soil was mixed with bentonite contents of 10%,20%and 30%,and the red soil-bentonite mixtures were evaluated for their suitability for liners in their compacted state.Further,as the liners in the arid and semi-arid regions are subjected to moisture variations due to seasonal moisture fluctuations and other factors,the red soil-bentonite mixtures were subjected to wetdry cycles,and their suitability was evaluated after wet-dry cycles.The experimental results revealed that all the red soil-bentonite mixtures met the stipulated EPA criteria for the liners in the as-compacted state.However,the red soil-bentonite mixtures with 20%and 30%bentonite contents only satisfied the hydraulic conductivity requirement even after wet-dry cycles.The experimental findings were supplemented with the microstructural insights captured through digital camera images,scanning electron microscopy(SEM),and mercury intrusion porosimetry(MIP)studies.