测绘工程专业毕业设计（论文）选题质量控制

＂指导学生撰写毕业设计（论文）是实现培养目标的重要教学环节,具有不可替代的作用,‘决不能降低要求,更不能放任自流’＂[1]。毕业设计（论文）一般经过选题、过程控制和答辩等几个环节,文章结合我院测绘工程专业多年毕业设计（论文）实际,着手研究选题环节的质量控制,对提高毕业设计（论文）的质量,适应我校应用创新型学生培养方案,...     

贡山独龙江地区锡钨矿找矿前景

贡山县独龙江地区,基础地质工作已发现多处物化探异常,认为该区具有形成和赋存锡钨矿床的地质条件,而与南段腾冲、梁河等地相似,极具寻找锡钨多金属矿潜力。     

Differences in habitat selection of male and female megrim (Lepidorhombus whiffiagonis, Walbaum) to the west of Ireland. A result of differences in life-history strategies between the sexes?

The sex ratio in the catches of megrim (Lepidorhombus whiffiagonis, Walbaum) varied systematically with depth on three independent trawl survey series off the west coast of Ireland. Female megrim dominated the shallow catches, while males were more common in catches from deeper waters. The size difference between the sexes alone cannot explain this pattern because it remained evident when fish length was taken into account. Therefore size-specific habitat preferences or size-selective fishing mortality cannot fully explain the observed trend in the sex ratio of megrim. Female megrim grow to a larger size, at a faster rate than males and it is likely that their differences in habitat preferences are related to this. Shallower waters are warmer during the growing season and are likely to provide better conditions for fast growth. An understanding of the mechanisms behind these patterns is an important consideration in the management and conservation of this fish stock, which might be particularly vulnerable because the commercial landings are to a large extent dominated by female megrim.     

A GIS modelling framework to evaluate marine spatial planning scenarios: Co-location of offshore wind farms and aquaculture in the German EEZ

The concept of co-location of marine areas receives an increased significance in the light of sustainable development in the already heavily used offshore marine realm. Within this study, different spatial co-location scenarios for the coupling of offshore aquacultures and wind farms are evaluated in order to support efficient and sustainable marine spatial management strategies. A Geographic Information System (GIS) and multi-criteria evaluation (MCE) techniques were combined to index suitable co-sites in the German exclusive economic zone of the North Sea. The MCE was based on criteria such as temperature, salinity or oxygen. In total, 13 possible aquaculture candidates (seaweed, bivalves, fish and crustaceans) were selected for the scenario configuration. The GIS modelling framework proved to be powerful in defining potential co-location sites. The aquaculture candidate oarweed (Laminaria digitata) revealed the highest suitability scores at 10–20 m depth from April to June, followed by haddock (Melanogrammus aeglefinus) at 20–30 m depth and dulse (Palmaria palmata) and Sea belt (Saccharina latissima) at 0–10 m depth between April and June. In summary, results showed several wind farms were de facto suitable sites for aquaculture since they exhibited high suitability scores for Integrated Multi-Trophic Aquaculture (IMTA) systems combining fish species, bivalves and seaweeds. The present results illustrate how synergies may be realised between competing needs of both offshore wind energy and offshore IMTA in the German EEZ of the North Sea. This might offer guidance to stakeholders and assist decision-makers in determining the most suitable sites for pilot projects using IMTA techniques.     

基于克隆选择算法的冲压工艺机器人结构优化研究

冲压上下料机器人的结构优化设计,通常涉及多个优化参数,采用传统的优化方法往往由于优化目标函数的复杂性不能得到理想的效果。提出基于克隆选择算法的机器人本体结构优化方法,依托有限元ANSYS Workbench平台得到上下料机器人关键零部件的全局最优本体结构。通过与ANSYS Workbench自带优化算法的比较可知:在不增加结构质量的情况下,能获得更高的刚度和强度,从而有效提高机器人的机械性能。实验测试证明了该方法有效可行。     

Constraining water age dynamics in a south-eastern Australian catchment using an age-ranked storage and stable isotope approach

Improving our knowledge of the travel times of water through catchments is critical for the management and protection of water resources and to improve our understanding of fundamental catchment behaviour. In this study we use the age-ranked storage framework StorAge Selection (SAS) to investigate travel times in the Corin catchment, a headwater catchment in the south-east of Australia covered by native Eucalyptus species. Few studies have applied the SAS framework globally and in energy-intensive areas where catchment losses are heavily in favour of evapotranspiration relative to streamflow. A combination of observed and modelled values of oxygen-18 (δ¹⁸O ), the stable isotope in water, are used to constrain storage selection preferences of streamflow and evapotranspiration and the size of the catchment active storage. The highest performing parameter combinations that could reproduce δ¹⁸O in streamflow were dependent on a strong preference for young water in evapotranspiration, and a mixture of weak young and old water preference in streamflow. The mean travel time of streamflow over the study period 2007–2019, weighted by the flow rate, is limited to within a probable range of 2.81–9.77 years. The size of the active storage, a key parameter in the SAS framework, was poorly identified, and in combination with the isotopic inputs into the model, contributed to the uncertainty of the results. We discuss the implications of the results with respect to the study area, as well as within the context of SAS research globally and identify ways to improve the modelling process.     

Probability of correct selection from lognormal and convective diffusion models based on the likelihood ratio

The objective of the paper is to show that the use of a discrimination procedure for selecting a flood frequency model without the knowledge of its performance for the considered underlying distributions may lead to erroneous conclusions. The problem considered is one of choosing between lognormal (LN) and convective diffusion (CD) distributions for a given random sample of flood observations. The probability density functions of these distributions are similarly shaped in the range of the main probability mass and the discrepancies grow with the increase in the value of the coefficient of variation (C _V ). This problem was addressed using the likelihood ratio (LR) procedure. Simulation experiments were performed to determine the probability of correct selection (PCS) for the LR method. Pseudo-random samples were generated for several combinations of sample sizes and the coefficient of variation values from each of the two distributions. Surprisingly, the PCS of the LN model was twice smaller than that of the CD model, rarely exceeding 50%. The results obtained from simulation were analyzed and compared both with those obtained using real data and with the results obtained from another selection procedure known as the QK method. The results from the QK are just the opposite to that of the LR procedure.     

论计算机不间断电源系统

本文讨论了计算机不间断电源系统的原理、性能及其发展趋势,并对计算机不间断电源系统的选型和维护作了探讨。     

测氡仪器工作状态选取浅析

在仪器标定检查工作中,常常会涉及到工作状态的选取问题。工作状态选取是否合适,将直接影响着观测数据的准确性。本文仅介绍笔者在工作中遇到的几种异常情况及通过实验识别仪器正常与否的方法。笔者深感在台站仪器老化日异严重的今天,认真识别仪器性能是否正常的重要性。     

琅玡山抽水蓄能电站厂房位置及轴线方向的优化选择

地下厂房位置及轴线方向的选择是一项重要的地质工作,本文在分析琅山抽水蓄能电站厂房区工程地质条件的基础上,就厂房位置及其轴线方向的优化选择,进行了分析和研究。