Numerical Investigation of Flow and Heat Transfer Characteristics in Plate with Multiple Incline Stage Holes

In this paper, the effects of impingement and film composite cooling on the design of combustion chamber cooling structure are simulated by numerical simulation. The focus of the investigation was on increased film cooling efficiency and enhanced heat transfer between the coolant and the hole wall. The five-stage shaped hole model and one cylindrical hole design have the same equivalent flow area. The flow and heat transfer characteristics of cylindrical hole and stage-shaped hole were numerically investigated under same blowing ratio, and compared at the same blowing ratio. The results showed the stage-shaped hole resulted in higher cooling effectiveness, especially in rear part, and the mechanisms of which were studied in details. The consequences of the phase parameters in the flow have very clearly dependedt on the internal shape of the corresponding hole. Stage-shaped holes formed impact inside the wall, tapped the coolant potential in cooling, and increased the heat transfer inside the solid wall. Further, stage-shaped hole resulted in unstabilized flow inside hole, gave an enhancement of lateral spreading ability, and brought a significant increase of the film lateral effectiveness. Further, the affection of area ratio and height ratio has been studied by five models. The results show that the increasing of area ratio leads to an increase in cooling efficiency, which also indicates the increasing of height ratio showed slight affection

Life fingerprints of nuclear reactions in the body of animals

Nuclear reactions are a very important natural phenomenon in the universe. On the earth, cosmic rays constantly cause nuclear reactions. High energy beams created by medical devices also induce nuclear reactions in the human body. The biological role of these nuclear reactions is unknown. Here we show that the in vivo biological systems are exquisite and sophisticated by nature in influence on nuclear reactions and in resistance to radical damage in the body of live animals. In this study, photonuclear reactions in the body of live or dead animals were induced with 50-MeV irradiation. Tissue nuclear reactions were detected by positron emission tomography (PET) imaging of the induced beta+ activity. We found the unique tissue "fingerprints" of beta+ (the tremendous difference in beta+ activities and tissue distribution patterns among the individuals) are imprinted in all live animals. Within any individual, the tissue "fingerprints" of 15O and 11C are also very different. When the animal dies, the tissue "fingerprints" are lost. The biochemical, rather than physical, mechanisms could play a critical role in the phenomenon of tissue "fingerprints". Radiolytic radical attack caused millions-fold increases in 15O and 11C activities via different biochemical mechanisms, i.e. radical-mediated hydroxylation and peroxidation respectively, and more importantly the bio-molecular functions (such as the chemical reactivity and the solvent accessibility to radicals). In practice biologically for example, radical attack can therefore be imaged in vivo in live animals and humans using PET for life science research, disease prevention, and personalized radiation therapy based on an individual's bio-molecular response to ionizing radiation

CycleAlign: Iterative Distillation from Black-box LLM to White-box Models for Better Human Alignment

Language models trained on large-scale corpus often generate content that is harmful, toxic, or contrary to human preferences, making their alignment with human values a critical concern. Reinforcement learning from human feedback (RLHF) with algorithms like PPO is a prevalent approach for alignment but is often complex, unstable, and resource-intensive. Recently, ranking-based alignment methods have emerged, offering stability and effectiveness by replacing the RL framework with supervised fine-tuning, but they are costly due to the need for annotated data. Considering that existing large language models (LLMs) like ChatGPT are already relatively well-aligned and cost-friendly, researchers have begun to align the language model with human preference from AI feedback. The common practices, which unidirectionally distill the instruction-following responses from LLMs, are constrained by their bottleneck. Thus we introduce CycleAlign to distill alignment capabilities from parameter-invisible LLMs (black-box) to a parameter-visible model (white-box) in an iterative manner. With in-context learning (ICL) as the core of the cycle, the black-box models are able to rank the model-generated responses guided by human-craft instruction and demonstrations about their preferences. During iterative interaction, the white-box models also have a judgment about responses generated by them. Consequently, the agreement ranking could be viewed as a pseudo label to dynamically update the in-context demonstrations and improve the preference ranking ability of black-box models. Through multiple interactions, the CycleAlign framework could align the white-box model with the black-box model effectively in a low-resource way. Empirical results illustrate that the model fine-tuned by CycleAlign remarkably exceeds existing methods, and achieves the state-of-the-art performance in alignment with human value

Tracking differentiator based back-stepping control for valve-controlled hydraulic actuator system

Back-stepping design method is widely used in high-performance tracking control tasks As is known to all, the controller based on back-stepping design will become complex as the model order increases, which is the so called “explosion of terms” problem. In this paper, a tracking differentiator (TD) based back-stepping controller is proposed to handle the “explosion of terms” problem. Instead of calculating the derivatives of intermediate control variables through tedious analytical expressions, for the proposed method, the tracking differentiator is embedded into each recursive procedure to generate the substitute derivative signal for every intermediate control variable. As a result, the complexity of implementation procedure of back-stepping controller is significantly reduced. The discrepancies between the derivative substitutes and the real derivatives are considered. And the effects on control performances caused by the discrepancies are analyzed. In addition to giving the theoretical results and the stability proofs with Lyapunov methods, the developed controller design method is evaluated through a series of experiments with a hydraulic robot arm position serve system. The control performance of the proposed controller is verified by the experiments results.</p

MicroRNA-101 Exerts Tumor-Suppressive Functions in Non-small Cell Lung Cancer through Directly Targeting Enhancer of Zeste Homolog 2

Introduction:Overexpression of the enhancer of zeste homolog 2 (EZH2) protein has been found in broad range of cancer types, including non-small cell lung cancer (NSCLC). Nevertheless, the mechanisms by which EZH2 becomes overexpressed in NSCLC remain unclear. MicroRNAs (miRNAs) can regulate target gene expression through translational control. In this study, we investigate whether miRNA (miR-101) regulates EZH2 expression in NSCLC.Methods:We evaluated the expression of miR-101 and EZH2 in 20 matched NSCLC and adjacent nontumor lung tissues by reverse-transcriptase polymerase chain reaction and immunohistochemistry, respectively. Luciferase reporter assay was used to determine whether miR-101 directly targets EZH2. To assess the effect of miR-101 on NSCLC biological behavior, cell proliferation, invasion, and response to chemotherapy were analyzed using NSCLC cells transfected with miR-101 mimics or transfected with specific small interfering RNA to deplete EZH2 (small interfering RNA-EZH2).Results:Reduced expression of miR-101 was associated with overexpression of EZH2 in NSCLC tumor tissues. Transfection of miR-101 mimics significantly suppressed the activity of the luciferase reporter containing wild type but not mutant EZH2 3′-UTR and decreased EZH2 expression in NSCLC cell lines. Furthermore, enforced expression of miR-101 or knockdown of EZH2 led to reduced NSCLC cell proliferation and invasion and sensitized cancer cells to paclitaxel-mediated apoptosis through inducing expression of the proapoptotic protein Bim.Conclusions:miR-101 inhibits cell proliferation and invasion and enhances paclitaxel-induced apoptosis in NSCLC cells, at least in part, by directly repressing EZH2 expression. Therapeutic strategies to rescue miR-101 expression or silence EZH2 may be beneficial to patients with NSCLC in the future

Seroprevalence and Risk Factors of Chlamydia abortus

Chlamydia abortus, an important pathogen in a variety of animals, is associated with abortion in sheep. In the present study, 1732 blood samples, collected from Tibetan sheep between June 2013 and April 2014, were examined by the indirect hemagglutination (IHA) test, aiming to evaluate the seroprevalence and risk factors of C. abortus infection in Tibetan sheep. 323 of 1732 (18.65%) samples were seropositive for C. abortus antibodies at the cut-off of 1 : 16. A multivariate logistic regression analysis was used to evaluate the risk factors associated with seroprevalence, which could provide foundation to prevent and control C. abortus infection in Tibetan sheep. Gender of Tibetan sheep was left out of the final model because it is not significant in the logistic regression analysis (P>0.05). Region, season, and age were considered as major risk factors associated with C. abortus infection in Tibetan sheep. Our study revealed a widespread and high prevalence of C. abortus infection in Tibetan sheep in Gansu province, northwest China, with higher exposure risk in different seasons and ages and distinct geographical distribution

Heat statistics in the relaxation process of the Edwards-Wilkinson elastic manifold

The stochastic thermodynamics of systems with a few degrees of freedom has been studied extensively so far. We would like to extend the study to systems with more degrees of freedom and even further-continuous fields with infinite degrees of freedom. The simplest case for a continuous stochastic field is the Edwards-Wilkinson elastic manifold. It is an exactly solvable model of which the heat statistics in the relaxation process can be calculated analytically. The cumulants require a cutoff spacing to avoid ultra-violet divergence. The scaling behavior of the heat cumulants with time and the system size as well as the large deviation rate function of the heat statistics in the large size limit is obtained

Experimental investigation of flow and heat transfer characteristics on matrix ribbed channel

The effect of the rib width to height ratio t/e and width to pitch ratio t/p on the local heat transfer distribution in a rectangular matrix ribbed channel with two opposite in line o 45 ribs are experimentally investigated for Reynolds Numbers from 54000 to 150000. The rib height to channel height ratio e/H is 0.5, t/p and t/e both varies in range of 0.3-0.5. And to simulate the actually situation in turbine blades, and provide useful direct results for turbine blade designers, the parameters are same with the blade. The experiments results show that, in comparison to fully developed flow in a smooth pipe of equivalent hydraulic diameter, the Nusselt number inside the matrix-ribbed rectangular channel is increased up to 5 to 9 times higher, while total pressure drop is enlarged by up to significant magnitude. The Nusselt number ratio increases with t/p and t/e increased. Semi-empirical heat transfer is developed for designing of cooling channel