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Locked segment of rock-like material specimens with different brittleness index were prepared by combining materials in different ratios. Compression-shear tests of rock-like material specimens with different brittleness degree were carried out by acoustic emission and Laser Doppler Vibrometer measurement. The fracture evolution process of the specimen was divided into three stages through the displacement-time curve: compaction stage and elastic deformation stage, constant deformation stage and accelerated deformation stage. The natural frequency responded obviously at the boundary point of the constant deformation stage and accelerated deformation stage, the point of natural frequency steeply dropped corresponds to the starting point of constant deformation stage, which is defined as the damage point. The point of substantial increase in the natural frequency corresponds to the starting point of accelerated deformation stage, which is defined as expansion point. There were obvious critical instability information before the failure of specimens: The natural frequency showed rise, steep drop and stable jitter; The ringing count rate and energy rate increased near the critical instability point; The b-value continued to decrease at a low level before the peak strength. Tensile failure was the main failure mode of the three specimens with different brittleness degree, the tensile failure degree increased with the increase of brittleness degree. The energy released by the specimen at failure moment increased with the increase of brittleness degree, and the b-value decreased with the increase of brittleness degree. The degree of brittleness is one of the important indexes to study the locked segment.

The structural health state of liquefied natural gas (LNG) wharf is important for the docking and operation of LNG ships. Based on the finite element modal analysis (FEMA) and evidential reasoning (ER) rule, a new health assessment model for the LNG wharf is proposed in this paper, where structural weak areas are considered. Firstly, combining the structural mechanism and FEMA, the LNG wharf is simulated and modeled. The weak areas of the wharf in common working modes are analyzed and obtained. Secondly, based on the analysis results, the sensor deployment is guided and the wharf health information is collected. Finally, based on the ER rule, the sensor monitoring information is fused to realize the health assessment of the wharf. This paper takes an LNG wharf in the Hainan Yangpu area of China as an example. The experimental results show that the proposed method can accurately and effectively assess the health state of the wharf.

Traffic congestion and car pollution are becoming serious plagues nowadays. High travel cost brings a great burden to people and society. A ridesharing system mitigates traffic congestion and car pollution by allowing passengers to share their travel costs with others. Traditional ridesharing platforms usually require passengers to submit their plans in advance and then design schedules for the drivers who would like to offer a ride. Nowadays, with the development of the smartphone technology, dynamic ridesharing systems enable passengers request a car anytime and anywhere. This paper mainly considers the problems of how to allocate passengers to drivers, how to charge the passengers and how to design feasible schedules for the driver in such online environment. The allocation problem is modeled as an online weighted matching problem with the graph changing over time. Firstly, we give a fair pricing method which is easy to be understood and accepted by the passengers. We develop a greedy algorithm called LiqMax_Gre for the purpose of maximizing liquidity and an algorithm called UtiMax for the purpose of maximizing utility. LiqMax_Gre achieves a competitive ratio of 1 λ + 1 , where λ is the maximal number of passengers a car can take. In general, we prove that no online algorithm can have a good guarantee for the design goal of maximizing utility. Innovatively, UtiMax considers not only the current maximal utility, but also the opportunity cost, which is the utility contributed by occupying a seat. It reflects the utility in the future and thus can be used to handle the difficulty in online design. We prove that, our algorithm has a competitive ratio of 1/3 in a special case. The schedule problem is NP-hard and we design a heuristic nearest neighbor algorithm to solve it.

Ridesharing, as an emerging efficient solution for transportation congestion, has achieved great business success in recent years. A critical issue in the ridesharing system is to determine a group of passengers to share a ride and the corresponding payments to charge them to cover the cost of drivers. We present the desired properties of a cost-sharing mechanism in ridesharing systems, namely economic efficiency, incentive compatibility, individual rationality and budget balance. However, the existing classic mechanisms do not achieve these properties even in a simple case. In this work, we formulate a cost-sharing model for ridesharing systems, and design two VCG-based mechanisms for the simple case and the general case, respectively. The simple case can capture the ridesharing problem with a symmetric cost function, while the general case describes a more general ridesharing problem with a submodular cost function. We theoretically demonstrate that these two mechanisms are approximately economic efficient with other desirable properties guaranteed. Finally, we evaluate the proposed mechanisms on a real-world dataset. The evaluation results show that our mechanism could increase the user experience of passengers as well as the efficiency of the ridesharing system.

The concentration-mass (c-M) relation encodes the key information of the assembly history of the dark matter halos, however its behavior at the high mass end has not been measured precisely in observations yet. In this paper, we report the measurement of halo c-M relation with galaxy-galaxy lensing method, using shear catalog of the Dark Energy Camera Legacy Survey (DECaLS) Data Release 8, which covers a sky area of 9500 deg^2. The foreground lenses are selected from redMaPPer, LOWZ, and CMASS catalogs, with halo mass range from 10^{13} to 10^{15} M_sun and redshift range from z=0.08 to z=0.65. We find that the concentration decreases with the halo mass from 10^{13} to 10^{14} M_sun, but shows a trend of upturn after the pivot point of ~10^{14} M_sun. We fit the measured c-M relation with the concentration model c(M)=C_0 (M/(10^{12} M_sun/h)^{-��} [1+(M/M_0)^{0.4}], and get the values (C_0, ��, log(M_0) = (5.119_{-0.185}^{0.183}, 0.205_{-0.010}^{0.010}, 14.083_{-0.133}^{0.130}), and (4.875_{-0.208}^{0.209}, 0.221_{-0.010}^{0.010}, 13.750_{-0.141}^{0.142}) for halos with 0.08, 12 pages, 5 figures, accepted by ApJ

To achieve an accurate structural health assessment, data collected by multiple sensors needs to be fused effectively. When the number of sensors is limited, it is necessary to determine the reasonable position of sensors and adopt the adequate fusion method. Therefore, a structural health assessment method based on evidential reasoning (ER) rule considering the optimal sensor placement (OSP) is proposed in this paper. In particularly, the discrete integer coding covariance matrix adaptive evolution strategy (D-CMAES) algorithm is developed to determine the scheme of OSP based on the finite element modal analysis (FEMA). Furthermore, in order to select adequate sensors whose data will be fused by the ER rule, a strategy for determining the weight of the ER rule is proposed according to the perception probability. The effectiveness of the proposed method is verified by a case study about the health assessment of the LNG wharf in Hainan, China.

With the development of 60 GHz technology, data centers are going to be wireless. A fundamental challenge in wireless data center networking is how to efficiently use 60 GHz wireless technology to improve the performance. Many existing works have been proposed for this, but most of them do not perform well in connectivity or may not be flexible for different environments in data centers. This paper presents Graphite, a novel network structure that has many desirable features for wireless data centers. The whole architecture can be suitable for several different deployments of data centers. In Graphite, the problem of link blockage can be properly solved. Graphite makes best use of the propagation distance of 60 GHz and allows one server to communicate with as many other servers as possible. Graphite also improves the average node degree, which is more than any other existing wireless topologies on the same condition. Furthermore, Graphite can be suitable for data center with different deployments. We build a small testbed of Graphite to demonstrate its ability to solve the problem of link blockage. Results from theoretical analysis and extensive evaluations show that Graphite is a viable wireless topology for data center networks.

This paper studies flow and heat transfer of nanofluids over a rotating disk with uniform stretching rate. Three types of nanoparticles-Cu, Al2O3 and CuO-with water-based nanofluids are considered. The governing equations are reduced by Von Karman transformation and then solved by the homotopy analysis method (HAM), which is in close agreement with numerical results. Results indicate that with increasing in stretching strength parameter, the skin friction and the local Nusselt number, the velocity in radial and axial directions increase, whereas the velocity in tangential direction and the thermal boundary layer thickness decrease, respectively. Moreover, the effects of volume fraction and types of nanofluids on velocity and temperature fields are also analyzed.

This paper presents an investigation for bioconvection heat transfer of a nanofluid containing gyrotactic microorganisms over a stretching sheet, in which the effects of radiation, velocity slip and temperature jump are taken into account. The nonlinear governing equations are reduced into four ordinary differential equations by similarity transformations and solved by Homotopy Analysis Method (HAM), which is verified with numerical results in good agree. Results indicate that the density of motile microorganisms and gyrotactic microorganisms increase with bioconvection Rayleigh number, while decrease with increasing in bioconvection Peclet number and bioconvection Lewis number. It is also found that the Nusselt number, Sherwood number and gyrotactic microorganisms density depend strongly on the buoyancy, nanofluids and bioconvection parameters.

Background The emphasis on gynecologic cancer prognosis has been on clinicopathological features and molecular markers, and few studies to date have investigated the relationship between the nonbiological factors (NBFs) and the entire gynecologic cancer patients. The objective of this study is to evaluate the impact of race, marital status, insurance type, socioeconomic status, and education degree on the stage of diagnosis and the risk of cancer-specific mortality for gynecologic cancer patients.Methods Data was obtained from the Surveillance, Epidemiology and End Results database between 2007 and 2014. Survival time between different groups was compared using Kaplan-Meier analysis and log-rank tests. A multivariate logistic regression model was utilized to identify NBFs associated with stage at diagnosis. Fine and Gray competing risk regression models were used to identify NBFs associated with cancer-specific survival.Results 35,854 patients were included in this analysis. After adjusting for age and malignancy site, gynecologic cancer patients who were single, divorced, black, any-Medicaid insured were more likely to present with metastatic disease at diagnosis. For both metastatic and non-metastatic gynecologic cancer, being single, divorced, widowed, black, any-Medicaid insured, uninsured, and having lower socioeconomic status were all significant predictors of poor cancer-specific survival.Conclusions The characteristics of being unmarried, black, any-Medicaid insured, and having lower socioeconomic status have a significant impact on the early diagnosis and survival of gynecologic cancer patients. Future improvements in cancer care and adequate social support is imperative and would play a vital role in the prognosis of this disadvantaged group.

In this study, the generalised velocity slip and the generalised temperature jump of nanofluid in the flow over a stretching sheet with variable thickness are investigated. Because of the non-adherence of the fluid to a solid boundary, the velocity slip and the temperature jump between fluid and moving sheet may happen in industrial process, so taking velocity slip and temperature jump into account is indispensable. It is worth mentioning that the analysis of the velocity v, which has not been seen in the previous references related to the variable thickness sheet, is presented. The thermophoresis and the Brownian motion, which are the two very important physical parameters, are fully studied. The governing equations are simplified into ordinary differential equations by the proper transformations. The homotopy analysis method (HAM) is applied to solve the reduced equations for general conditions. In addition, the effects of involved parameters such as velocity slip parameter, temperature jump parameter, Prandtl number, magnetic field parameter, permeable parameter, Lewis number, thermophoresis parameter, and Brownian motion parameter are investigated and analysed graphically.

A facile synthetic route was employed to prepare double-shell PtRu/TiO 2 catalyst successfully without any stabilizer, in which Ru precursor was reduced by microwave and Pt precursor was in-situ reduced on Ru/TiO 2 using l -ascorbic acid as the soft reductant. The morphology, structure and composition of as-prepared catalysts were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive analysis of X-ray (EDX), transmission electron microscope (TEM) and X-ray photoelectron spectroscopy (XPS). Cyclic voltammetry and chronoamperometry demonstrate the enhancement of electrocatalytic activity and stability towards the methanol electrooxidation of PtRu/TiO 2 in comparison with Pt/TiO 2 , Pt/C (JM) and PtRu/C (JM). Furthermore, the activity for methanol oxidation reaction (MOR) is much higher in alkaline media than that in acidic media. The improved activity and stability could be attributed to the synergetic effects of Pt–Ru and the electrochemically stable TiO 2 .

The first massive galaxy groups in the Universe are predicted to have formed at redshifts well beyond two. Baryonic physics, like stellar and active galactic nuclei (AGN) feedback in this very active epoch, are expected to have left a strong imprint on the thermo-dynamic properties of these early galaxy groups. Therefore, observations of these groups are key to constrain the relative importance of these physical processes. However, current instruments are not sensitive enough to detect them easily and characterize their hot gas content. In this work, we quantify the observing power of the Advanced Telescope for High ENergy Astrophysics (Athena), the future large X-ray observatory of the European Space Agency (ESA), for discovering and characterizing early galaxy groups at high redshifts. We used the SImulation of X-ray TElescopes (SIXTE) simulator to mimic Athena observations, and a custom-made wavelet-based algorithm to detect galaxy groups and clusters in the redshift range $0.5 \le z \le 4$. We performed extensive X-ray spectral fitting in order to characterize their gas temperature and X-ray luminosity. We also investigate how well Athena will constrain different feedback mechanisms. In the deep Wide Field Imager (WFI) survey expected to be carried out during part of Athena's first four years (the nominal mission lifetime) more than 10,000 galaxy groups and clusters at $z\ge 0.5$ will be discovered. We find that Athena can detect $\sim20$ high-redshift galaxy groups with masses of $M_{500}\geq$ $5\times 10^{13}$ $M_{\odot}$ and $z\geq2$, and almost half of them will have a gas temperature determined to a precision of $\Delta T/T \le 25\%$. We demonstrate that high-redshift galaxy groups can be detected very efficiently as extended sources by Athena and that a key parameter determining the total number of such newly discovered sources is the area on the sky surveyed by Athena., Comment: 24 pages, 18 figures, accepted for publication in A&A

Background The optimal timing of radiotherapy (RT) with respect to surgery remains controversial for locally advanced non-small cell lung cancer (LA NSCLC) undergoing surgery and the long-term effect of neoadjuvant RT, adjuvant RT, and chemotherapy-only on survival is unknown. Methods A retrospective study with Greedy 5 → 1 Digit propensity score matching technique was performed for locally advanced NSCLC patients identified from the Surveillance, Epidemiology, and End Results (SEER) database during 2004 to 2012. Kaplan-Meier and the log-rank test were conducted to compare NSCLC-specific survival. Cox proportional hazards multivariable regression was performed to assess the impact of different treatment regimens on cancer-specific mortality after adjustment for demographic factors, histology type, tumor grade, tumor size, nodal stage, and extent of resection. Results One thousand, two hundred and seventy-eight locally advanced NSCLC patients undergoing surgery were identified after propensity matching. Cox regression analyses showed the risk of cancer-specific mortality is not significantly different among neoadjuvant RT, adjuvant RT, and chemotherapy-only. Subgroup analyses showed that for patients with T1/2 & N2/3, the surgery plus chemotherapy-only group showed markedly higher mortality risk (HR = 1.42, 95%CI:1.10–1.83) than the neoadjuvant RT group. Other risk factors include older age, higher tumor grade, larger tumor size, and greater lymph node involvement. Conclusions The findings of this study suggest that the benefit of additional neoadjuvant or adjuvant RT to chemotherapy may be linked to a proper selection of LA NSCLC patients who undergo surgery. The timing of radiotherapy should be decided on the premise of fully considering patients’ condition and the quality of life after treatment. Electronic supplementary material The online version of this article (10.1186/s12885-018-4900-x) contains supplementary material, which is available to authorized users.

The present study, we prepared polysaccharides from Rosa rugosa petals (RRPS) using hot-water extraction and purified the polysaccharides by chromatography to obtain RRPS-1 and RRPS-2. Preliminary structural features of RRPS were characterized by different instrumental methods, such as HPGPC, FT-IR, and GC analysis. The average molecular weights of RRPS-1 and RRPS-2 were 8.8 kDa and 443.8 kDa, respectively. Then, antioxidant and moisture-preserving activities of RRPS were determined in vitro. The analysis of antioxidant activities suggested that RRPS-2 had good potential for scavenging activity of radicals. We also found that the RRPS-2 has strong moisture-preserving activity in vitro. These results clearly indicated that RRPS-2 might have a good potential to be utilized in pharmaceutical, food and cosmetics industries.

Table S1. Baseline characteristics of the unmatched cohorts. Table S2. Multivariable Cox regression for unmatched dataset. (DOCX 20 kb)

We study the unsteady natural convection of nanofluid between the outer and inner surfaces of a concentric annulus. The inner surface is heated sinusoidally with time about a fixed mean temperature but the outer boundary is kept at a constant temperature. The effects of Brownian motion and thermophoresis are taken into account. Numerical solutions are presented using the continuous finite-element method. Results indicate that the heat and mass transfer rates are significantly influenced by inner wall temperature oscillation, which presents periodic triangle fluctuation for the considered parameters of amplitude A, inner circle radius R, and frequency F.

Thioglycoside-containing trimannose analogs were designed and prepared to mimic the natural N-glycan core trisaccharide α-d-Man-(1→3)-[α-d-Man-(1→6)]-d-Man. (1→6)-S-Linked trimannoside 1 and its trivalent cluster 2 were synthesized in 11 and 15 steps, respectively, taking advantages of the armed mannopyranosyl trichloroacetimidate as glycosyl donor. Hemagglutination inhibition of the two new thiomannotriose analogs was preliminarily examined. Comparing to the parent trimannoside α-d-Man-(1→3)-[α-d-Man-(1→6)]-d-Man-OMe, the cluster mannotrioside 2 presented a comparable binding affinity to Con A, while the monomer 6-S-trimannoside 1 exhibited a slightly lower inhibition ability.

In this article, we discuss the flow and heat transfer of nanofluids over a rotating porous disk with velocity slip and temperature jump. Three types of nanoparticles – Cu, Al2O3, and CuO – are considered with water as the base fluid. The nonlinear governing equations are reduced into ordinary differential equations by Von Karman transformations and solved using homotopy analysis method (HAM), which is verified in good agreement with numerical ones. The effects of involved parameters such as porous parameter, velocity slip, temperature jump, as well as the types of nanofluids on velocity and temperature fields are presented graphically and analysed.

This paper studies MHD flow and radiation heat transfer of nanofluids against a flat plate in porous medium with the effects of variable surface heat flux and first-order chemical reaction. Three types of nanoparticles Cu, Al2O3 and Ag are investigated. Similarity transformations are applied to reduce the governing partial differential equations with boundary conditions into a system of ordinary differential equations over a semi-infinite interval. An efficient analytical approach based on differential transformation base functions method (DTM-BF) for unbounded domains is performed to give approximate solutions which are verified by numerical ones, showing close agreement. The effects of the solid volume fraction, types of nanoparticles, permeability, magnetic field, chemical reaction, Schmidt number, radiation and suction/blowing on velocity, temperature and concentration fields are graphically illustrated and analyzed in detail.

National Natural Science Foundation of China [21107089]; Nature Science Foundation of Fujian Province of China [2011J01055]; research fund for the Doctoral Program of Higher Education [20110121120041]

A new type of glyco-nanoparticle has been accomplished through Cu(I)-catalyzed 1,3-dipolar cycloaddition of 6-azidohexyl Neu5Ac-alpha-C-galactoside and N-propargyl derivative, which was attached on a silica-wrapping magnetic nanoparticle. Neu5Ac-alpha-C-galactoside was stereo-selectively synthesized in 11 steps from isopropyl thiogalactopyranoside and per-acetylated Neu5Ac phenylsulfone using samarium-mediated reductive desulfonylation as the key step. Magnetic nanoparticles were prepared with one-step hydrothermal method and a subsequent coating with (N,N'-di-propargyl-3-aminopropyol) triethoxysilane derivative. (C) 2013 Elsevier Ltd. All rights reserved.

Our experiment reported here adopts water, alcohol (100 %), carboxymethyl cellulose (CMC) aqueous solution with different concentrations as the base-fluid of nano-fluids. We show diffusion, aggregation and precipitation of nano-size particles in the optical quartz glass Petri dishes filled with nano-fluids flat with the help of a rotating cone. The experimental results illustrate that nanoparticles are preferably suspended in CMC aqueous solution than in water or alcohol, which means the effective Hamaker constant of water- or alcohol-particle suspensions is bigger than that of CMC-particle suspension. In the experiment with CMC as the base solution, increasing the viscosity of the solution can alleviate the settling velocity of particles and make the suspension better. The experiment also discovers that in static condition, the mutual attractive force between nanoparticles plays an important role in the suspension; however, if external forces, which are higher than the attraction, exist, they are decisive parts. In addition, Al2O3 solution is much more sensitive than the Cu solution with the varying concentration and status in the experiment because the density of Al2O3 particles is smaller than that of Cu-nanoparticles.

The first total synthesis of natural product ribisin A has been achieved in 11 steps from commercially available methyl α- d -glucopyranoside with 21.6% overall yield. The highly oxygenated benzofuran skeleton of this natural product was constructed, taking advantages of the inherent chirality of d -glucose, through the key reactions of Ferrier carbocyclization, Johnson iodination, Suzuki cross-coupling, and Wacker oxidative cyclization.

Build a large-scale 3D shape retrieval benchmark that supports multi-modal queries.Evaluate the 26 3D shape retrieval methods using 3 types of metrics.Solicit and identify state-of-the-art methods and promising related techniques.Perform detailed analysis on diverse methods w.r.t accuracy and efficiency.Make benchmark and evaluation tools freely available to the community. Large-scale 3D shape retrieval has become an important research direction in content-based 3D shape retrieval. To promote this research area, two Shape Retrieval Contest (SHREC) tracks on large scale comprehensive and sketch-based 3D model retrieval have been organized by us in 2014. Both tracks were based on a unified large-scale benchmark that supports multimodal queries (3D models and sketches). This benchmark contains 13680 sketches and 8987 3D models, divided into 171 distinct classes. It was compiled to be a superset of existing benchmarks and presents a new challenge to retrieval methods as it comprises generic models as well as domain-specific model types. Twelve and six distinct 3D shape retrieval methods have competed with each other in these two contests, respectively. To measure and compare the performance of the participating and other promising Query-by-Model or Query-by-Sketch 3D shape retrieval methods and to solicit state-of-the-art approaches, we perform a more comprehensive comparison of twenty-six (eighteen originally participating algorithms and eight additional state-of-the-art or new) retrieval methods by evaluating them on the common benchmark. The benchmark, results, and evaluation tools are publicly available at our websites (http://www.itl.nist.gov/iad/vug/sharp/contest/2014/Generic3D/, 2014, http://www.itl.nist.gov/iad/vug/sharp/contest/2014/SBR/, 2014).