A Prediction Method Based on Monte Carlo Simulations for Finite Element Analysis of Soil Medium considering Spatial Variability in Soil Parameters

With the Stochastic Finite Element Method (SFEM), the spatial variability of soil properties can be incorporated into the analysis of geotechnical structures. Although this method is significantly superior in principle to the homogeneous analysis of soil parameters, generalizing the method in engineering practice is difficult due to its computational inefficiency. In this paper, we propose a new method for the fast calculation of convergence results. The proposed method introduces a distance space to the Monte Carlo Method (MCM) random field instances and, considering the importance of a safety margin in structures, uses selected spatial interpolation to predict the MCM instances to be solved. Two case study simulations are presented. The results show that compared to the full Monte Carlo Simulation, the fast calculation method proposed in this paper can achieve very accurate convergence results while substantially reducing the computational cost, and the simulation errors for the structure are on the safer side

A comparison between algal bloom frequency in Hong Kong's eastern and western waters

The Pearl River estuary is a paradox. From 1980 to 1997 there were a total of over 481 algal blooms reported for Hong Kong waters and less 6 % of these were from the Pearl River estuary. Why should so few algal blooms occur in an area so rich in nutrients? The purpose of this study was to determine why the nutrient-rich waters of the Pearl River estuary supported so few algal blooms. Sewage discharges to the Pearl River have increased quite substantially over the last thirty years, as has private industry and mariculture activities. By the year 2001 it is expected that 3,200 million tones of domestic sewage will annually be discharged to the Pearl River. Agricultural activity gives rise to pollution from fertilizers and pesticides. In only 3 years between 1986 and 1989 the reliance on chemical fertilizers in the Pearl River Delta increased by 40%. With these enormous discharges of nutrient-rich water from sewage and farmland runoff we expected to find frequent algal blooms in the Pearl River estuary. The fact that we did not gave rise to the paradox examined in this study. The presence of large amounts of dissolved and particulate organic matter makes the Pearl River estuary an ideal location for heterotrophs to multiply. During the peak of the wet season, over 200 million bacterial cells per litre were observed in plankton samples taken from near the center of the Peal River estuary. These bacteria were the basis of a food web that was dominated by ciliates and colourless microflagellates. Autotrophs were relatively rare in the center of the Pearl River estuary at this time. In 1998 during the peak of the wet season (June and July) 26 sites were sampled in the east and west of Hong Kong. About half of these were in the Pearl River estuary. It was not possible to monitor all 26 stations on a weekly basis but two sites, one in the western part of Hong Kong (Lamma Channel) and one in the eastern part of Hong Kong (Port Shelter) were chosen as representative of eastern and western Hong Kong waters. Each of these two sites was sampled at weekly intervals in 1998. Brackish water tolerant diatoms dominated the phytoplankton in the western waters while the plankton in the eastern waters was much more diverse and abundant with both diatoms and dinoflagellates reaching high densities at various times over the year. To determine why autotrophs bloom so infrequently in the Peal River Estuary we carried out an incubation study. A station located near the center of the Pearl River Estuary was chosen for study. This was the first time an incubation experiment was carried out to determine the effects of retention time, turbidity and salinity on the plankton living near the center of Pearl River Estuary. The results indicated that low salinity, poor light penetration and short water retention time in the estuary combine to limit the productivity of phytoplankton there. In summer, sewage bacteria, ciliates and colourless microflagellates characterized the plankton near the center of the Pearl River estuary. In winter (dry season) flows from the Pearl River are much smaller and the plankton at the center of the estuary was dominated by autotrophs similar to those observed in the East Lamma Channel

A Multi-Objective q-Rung Orthopair Fuzzy Programming Approach to Heterogeneous Group Decision Making

In allusion to heterogeneous multi-criteria group decision making (MCGDM) problems with incomplete weights and q-rung orthopair fuzzy (q-ROF) truth degrees, where many kinds of criteria values, i.e., crisp values, intervals, trapezoidal fuzzy values, hesitant fuzzy values and q-ROF values (q-ROFVs), and multiple types of interactions exist, i.e., positive synergetic interactions, negative synergetic interactions and independence, a novel multi-objective q-ROF programming approach is proposed. In particular, in order to globally capture the interactions among criteria, Choquet-based relative closeness degrees are developed based on the technique for order performance by similarity to ideal solution (TOPSIS) and the Choquet integral. Then, the q-ROF Choquet-based group consistency index (q-ROFCGCI) and the q-ROF Choquet-based group inconsistency index (q-ROFCGII) are defined. Next, to derive optimal 2-additive fuzzy measures on the criteria set and optimal experts' weights, a new multi-objective q-ROF mathematical programming model is established by minimizing the q-ROFCGII and maximizing the q-ROFCGCI. Subsequently, an algorithm based on the adaptive non-dominated sorting genetic algorithm III (A-NSGA-III) is designed to solve the established model. Afterwards, the Choquet-based overall relative closeness degrees of the alternatives is used to obtain their preferred ordering. Finally, the effectiveness and advantage of the proposed approach is verified using four real cases concerning the evaluation of social commerce

Hypothetical model for host searching and selection processes of fall armyworm females and larvae (neonate and older), based on literature sources and this study’s results (see Discussion for literature sources).

<p>This study’s findings are pertinent to various stages of the searching and selection processes, so were incorporated into the model as hypotheses for further study, and are indicated by filled boxes containing italicized text.</p

Electron cooling of a bunched ion beam in a storage ring

A combination of electron cooling and rf system is an effective method to compress the beam bunch length in storage rings. A simulation code based on multiparticle tracking was developed to calculate the bunched ion beam cooling process, in which the electron cooling, intrabeam scattering (IBS), ion beam space-charge field, transverse and synchrotron motion are considered. Meanwhile, bunched ion beam cooling experiments have been carried out in the main cooling storage ring (CSRm) of the Heavy Ion Research Facility in Lanzhou, to investigate the minimum bunch length obtained by the cooling method, and study the dependence of the minimum bunch length on beam and machine parameters. The experiments show comparable results to those from simulation. Based on these simulations and experiments, we established an analytical model to describe the limitation of the bunch length of the cooled ion beam. It is observed that the IBS effect is dominant for low intensity beams, and the space-charge effect is much more important for high intensity beams. Moreover, the particles will not be bunched for much higher intensity beam. The experimental results in CSRm show a good agreement with the analytical model in the IBS dominated regime. The simulation work offers us comparable results to those from the analytical model both in IBS dominated and space-charge dominated regimes

Establishment and Characterization of 7 Novel Hepatocellular Carcinoma Cell Lines from Patient-Derived Tumor Xenografts

<div><p>Hepatocellular carcinoma (HCC) is a common cancer with poor prognosis worldwide and the molecular mechanism is not well understood. This study aimed to establish a collection of human HCC cell lines from patient-derived xenograft (PDX) models. From the 20 surgical HCC sample collections, 7 tumors were successfully developed in immunodeficient mice and further established 7 novel HCC cell lines (LIXC002, LIXC003, LIXC004, LIXC006, LIXC011, LIXC012 and CPL0903) by primary culture. The characterization of cell lines was defined by morphology, growth kinetics, cell cycle, chromosome analysis, short tandem repeat (STR) analysis, molecular profile, and tumorigenicity. Additionally, response to clinical chemotherapeutics was validated both <i>in vitro</i> and <i>in vivo</i>. STR analysis indicated that all cell lines were unique cells different from known cell lines and free of contamination by bacteria or mycoplasma. The other findings were quite heterogeneous between individual lines. Chromosome aberration could be found in all cell lines. Alpha-fetoprotein was overexpressed only in 3 out of 7 cell lines. 4 cell lines expressed high level of vimentin. Ki67 was strongly stained in all cell lines. mRNA level of <i>retinoic acid induced protein 3 (RAI3)</i> was decreased in all cell lines. The 7 novel cell lines showed variable sensitivity to 8 tested compounds. LIXC011 and CPL0903 possessed multiple drug resistance property. Sorafenib inhibited xenograft tumor growth of LIXC006, but not of LIXC012. Our results indicated that the 7 novel cell lines with low passage maintaining their clinical and pathological characters could be good tools for further exploring the molecular mechanism of HCC and anti-cancer drug screening.</p></div

Introduction of Research Work on Laser Proton Acceleration and Its Application Carried out on Compact Laser–Plasma Accelerator at Peking University

Laser plasma acceleration has made remarkable progress in the last few decades, but it also faces many challenges. Although the high gradient is a great potential advantage, the beam quality of the laser accelerator has a certain gap, or it is different from that of traditional accelerators. Therefore, it is important to explore and utilize its own features. In this article, some recent research progress on laser proton acceleration and its irradiation application, which was carried out on the compact laser plasma accelerator (CLAPA) platform at Peking University, have been introduced. By combining a TW laser accelerator and a monoenergetic beamline, proton beams with energies of less than 10 MeV, an energy spread of less than 1%, and with several to tens of pC charge, have been stably produced and transported in CLAPA. The beamline is an object–image point analyzing system, which ensures the transmission efficiency and the energy selection accuracy for proton beams with large initial divergence angle and energy spread. A spread-out Bragg peak (SOBP) is produced with high precision beam control, which preliminarily proved the feasibility of the laser accelerator for radiotherapy. Some application experiments based on laser-accelerated proton beams have also been carried out, such as proton radiograph, preparation of graphene on SiC, ultra-high dose FLASH radiation of cancer cells, and ion-beam trace probes for plasma diagnosis. The above applications take advantage of the unique characteristics of laser-driven protons, such as a micron scale point source, an ultra-short pulse duration, a wide energy spectrum, etc. A new laser-driven proton therapy facility (CLAPA II) is being designed and is under construction at Peking University. The 100 MeV proton beams will be produced via laser–plasma interaction by using a 2-PW laser, which may promote the real-world applications of laser accelerators in malignant tumor treatment soon