Design of One Dimensional Adjustment Platform Servo Control System Based on Neural Network

This paper designed a one dimensional adjustment of high precision servo control system, in order to provide individual comprehensive combat system high precision gun visual Angle. In servo control system hardware design based on DSP digital signal processing (DSP) chip as the CPU control circuit, in regard to algorithm, using the three layers BP neural network algorithm for PID integral gain and differential gain and intelligently adjusting proportion gain. On this basis, also analyzes the advantages and disadvantages of the traditional BP neural network algorithm, carries on the improvement. Vector using adaptive control, numerical optimization and introducing the steepness factor method, solve the contradiction between the stability and learning time, greatly improving the convergence speed and stability of the system performance, the static stability of the turntable accuracy is less than 3″, indicators reached the design requirements

The Study of Low-Light Sights Reliability Test System in High and Low Temperature Environment

In a certain period of time Products and system complete the required function under the condition of rules, the ability is called the reliability. Reliability is an important factor to reflect the quality of products, is the focus of the weapons and equipment quality. There is no guarantee reliability, even the most advanced equipment can not also play a role. In this paper, the design of test system is mainly used for small arms LOW-LIGHT SIGHTS sight reliability test. The shimmer sight reliability tests provide light stress, electrical stress, thermal stress and other stress environment. Detection shimmer sight working conditions, on failure of the automatic screening and recording

Methods to Improve the Teaching Effect of the Professional Course of the University

Aiming at the poor teaching effect of professional course in university, student interest is not high and show how to improve the important measures of the teaching effect of professional course in university and universities, starting from the view of teachers, effective preparation is the prerequisite to improve the professional teaching, effective classroom teaching is the effective guarantee to improve the teaching of professional course, advanced teaching methods is the fundamental guarantee to enhance the teaching of professional courses, starting from the perspective of students, learning interest is the basic power, improve the teaching of professional courses ability is the fundamental aim of improve the teaching of professional courses

Association between daily screen time and risk of stroke among middle-aged and elderly people: research based on China health and nutrition survey

BackgroundWe aimed to explore the independent associations between screen time and the risk of stroke among Chinese adults based on the China Health and Nutrition Survey (CHNS).MethodsData on Chinese adults aged older than 40 years from the CHNS in during 2004–2009 were selected. A total of 4,587 individuals were included in 2009, including screen time and the risk of stroke. Simultaneously, we traced the previous screen time to 2004 for those with outcome measures in 2009 (n = 2,100). Basic information, lifestyle, and screen behavior were obtained through face-to-face interviews and self-completed questionnaires. Anthropometric data collected included blood pressure, body weight, height, hip circumference, and waist circumference. Fasting blood was obtained for measurements of lipid and glucose levels. Cross-sectional analysis and cohort analysis were both performed using multivariate logistic regression.ResultsOf all participants, 3,004 (65.49%) participants spent more than 2 h per day on screen time. Taking the men who spent less than 2 h on screen per day as reference, the crude odds ratio (OR) of the high risk of stroke was 1.53 [95% confidence interval (CI), 1.20–1.95] for the men who spent 2–3 h per day on screen and 2.37 (95% CI, 1.78–3.16) for the men who spent more than 3 h per day on screen. This difference remained significant after adjusting for confounding factors. No association was observed among women. However, in the cohort analysis with screen time in 2006 as the independent variable, the association between screen time and stroke risk was found both in men [OR, 1.83 (95% CI, 1.19–2.82)] and women [OR, 1.48 (95% CI, 1.10–1.99)]).ConclusionWe found that the high screen time was associated with an increased stroke risk, which was pronounced in men, warranting a universal need to limit screen time in order to improve health

AgentBench: Evaluating LLMs as Agents

Large Language Models (LLMs) are becoming increasingly smart and autonomous, targeting real-world pragmatic missions beyond traditional NLP tasks. As a result, there has been an urgent need to evaluate LLMs as agents on challenging tasks in interactive environments. We present AgentBench, a multi-dimensional evolving benchmark that currently consists of 8 distinct environments to assess LLM-as-Agent's reasoning and decision-making abilities in a multi-turn open-ended generation setting. Our extensive test over 27 API-based and open-sourced (OSS) LLMs shows that, while top commercial LLMs present a strong ability of acting as agents in complex environments, there is a significant disparity in performance between them and OSS competitors. We identify the typical reasons of failures in environments and LLMs, showing that poor long-term reasoning, decision-making, and instruction following abilities are the main obstacles for developing usable LLM agents. Training on code and high quality multi-turn alignment data could improve agent performance. Datasets, environments, and an integrated evaluation package for AgentBench are released at \url{https://github.com/THUDM/AgentBench}.Comment: 55 page

Two-State Reactivity in Low-Valent Iron-Mediated C–H Activation and the Implications for Other First-Row Transition Metals

C–H bond activation/functionalization promoted by low-valent iron complexes has recently emerged as a promising approach for the utilization of earth-abundant first-row transition metals to carry out this difficult transformation. Herein we use extensive density functional theory and high-level ab initio coupled cluster calculations to shed light on the mechanism of these intriguing reactions. <i>Our key mechanistic discovery for C–H arylation reactions reveals a two-state reactivity (TSR) scenario in which the low-spin Fe­(II) singlet state, which is initially an excited state, crosses over the high-spin ground state and promotes C–H bond cleavage</i>. Subsequently, aryl transmetalation occurs, followed by oxidation of Fe­(II) to Fe­(III) in a single-electron transfer (SET) step in which dichloroalkane serves as an oxidant, thus promoting the final C–C coupling and finalizing the C–H functionalization. Regeneration of the Fe­(II) catalyst for the next round of C–H activation involves SET oxidation of the Fe­(I) species generated after the C–C bond coupling. <i>The ligand sphere of iron is found to play a crucial role in the TSR mechanism by stabilization of the reactive low-spin state that mediates the C–H activation</i>. This is the first time that the successful TSR concept conceived for high-valent iron chemistry is shown to successfully rationalize the reactivity for a reaction promoted by low-valent iron complexes. A comparative study involving other divalent middle and late first-row transition metals implicates iron as the optimum metal in this TSR mechanism for C–H activation. It is predicted that stabilization of low-spin Mn­(II) using an appropriate ligand sphere should produce another promising candidate for efficient C–H bond activation. This new TSR scenario therefore emerges as a new strategy for using low-valent first-row transition metals for C–H activation reactions

Functional Characterisation of Anticancer Activity in the Aqueous Extract of Helicteres angustifolia L. Roots.

Helicteres angustifolia L. is a shrub that forms a common ingredient of several cancer treatment recipes in traditional medicine system both in China and Laos. In order to investigate molecular mechanisms of its anticancer activity, we prepared aqueous extract of Helicteres angustifolia L. Roots (AQHAR) and performed several in vitro assays using human normal fibroblasts (TIG-3) and osteosarcoma (U2OS). We found that AQHAR caused growth arrest/apoptosis of U2OS cells in a dose-dependent manner. It showed no cytotoxicity to TIG-3 cells at doses up to 50 μg/ml. Biochemical, imaging and cell cycle analyses revealed that it induces ROS signaling and DNA damage response selectively in cancer cells. The latter showed upregulation of p53, p21 and downregulation of Cyclin B1 and phospho-Rb. Furthermore, AQHAR-induced apoptosis was mediated by increase in pro-apoptotic proteins including cleaved PARP, caspases and Bax. Anti-apoptotic protein Bcl-2 showed decrease in AQHAR-treated U2OS cells. In vivo xenograft tumor assays in nude mice revealed dose-dependent suppression of tumor growth and lung metastasis with no toxicity to the animals suggesting that AQHAR could be a potent and safe natural drug for cancer treatment

Effect of AQHAR on antioxidant enzyme activities and biochemical parameters in mice blood.

<p>Effect of AQHAR on antioxidant enzyme activities and biochemical parameters in mice blood.</p

Cell cycle analysis of control and AQHAR treated cancer and normal human cells.

<p>Cell cycle distribution of control and AQHAR-treated U2OS (A and C) and TIG-3 (B and D) cells are shown. Results from three independent experiments are represented as mean ± SD. *<i>p</i><0.05 denotes statistically significance difference between the control and treated groups.</p

Cytotoxicity of curcubitacin B on cancer and normal human cells.

<p>(A) Schematic representation showing the effect of AQHAR on cancer cells by induction of oxidative stress (ROS) and DNA-damage leading to activation of growth arrest and apoptosis signaling. (B) Effect of curcubitacin B on a variety of human cancer and normal cells, ***<i>p</i><0.001 denotes statistically significant difference between the control and treated groups. (C) Phase contrast images of control and curcubitacin B-treated human osteosarcoma (U2OS) and normal (TIG-3) cells showing the toxicity to both. (D) Cell cycle analysis showing the arrest of U2OS and TIG-3 cells in G2/M phase in response to curcubitacin B treatment. (E) Cucurbitacin B-treated U2OS cells show decrease in phosphorylated RB (pRB) and increase in p53 at doses as low as 0.025 μM. Similar effects were observed by immunostaining in both cancer (U2OS) and normal (TIG-3) cells (F).</p