改性环氧带锈涂料的研究

研究了以改性环氧树脂和聚乙烯醇缩丁醛为基料的钢铁带锈涂料 ,通过对成膜物质、转化剂、渗透剂、颜料等的研究 ,得到了集稳定、转化、渗透为一体的多功能涂料。经过实验测试 ,该涂料的各项性能指标均达到了设计要求 ,并且本工艺方案简单易行、省时高效 ,具有较高的实用价值。     

基于节点加权和边加权的重分形研究

目前对于网络重分形的研究,在网络权重性质方面主要是原始网络、节点加权网络、边加权网络,每一个都是单独进行研究,论文主要对同时包含节点权重和边权重的网络进行分析,研究网络广义分形维数的变化情况。首先对已有的沙箱算法进行改进,并利用分形布朗运动时间序列进行改进算法的验证,然后利用改进的沙箱算法对由分形布朗运动时间序列生成的同时包含节点权重和边权重的可视复杂网络进行计算,接着同时单独改变边权重和节点权重,进一步研究广义分形维数随边权重和节点权重改变的变化情况。结果表明改进沙箱算法在保持了传统沙箱算法计算精度的前提下,大大地提高了计算的速度。对于同时单独改变节点权重和边权重,对复杂网络的广义分形维数的影响是截然不同的,节点权重的变化基本不影响网络广义分形维数的变化,而边权重则大大的影响且不同权重指数下的影响情况各不相同。     

NH3·H2O对桂林地区红黏土工程特性的影响试验研究

为研究氮肥污染对桂林红黏土物理力学性质的影响,使用氨水(NH₃·H₂O)溶液对具有代表性的桂林雁山红黏土进行浸泡,考虑氨水质量分数(0,4.5%,9.0%,13.5%,18.0%)和养护时间(1,7,14 d)双因子因素,通过室内试验,分析氨水污染对桂林雁山红黏土物理力学性质的影响规律。试验结果表明:随着氨水质量分数及养护时间的增加,桂林雁山红黏土的质量、含水率、相对密度和液塑限均增大,压缩模量减小,土体压缩性增强;碱-土作用是引起红黏土物理力学性质发生变化的主要原因,其相互作用导致红黏土颗粒间的胶结物被溶解后又重新生成絮状物,使其原本稳定的结构状态发生改变。     

利用废旧胶粉改善红黏土工程性质试验研究

随着废旧轮胎的日益剧增,回收利用率较低带来了严重的环保问题。利用废旧轮胎胶粉对红黏土进行改良,形成混合土。通过标准轻型击实试验、等效击实试验、直剪试验以及渗透试验,研究了不同胶粉掺量(0%,3%,8%,15%,25%)和不同含水量对混合土的击实特性、抗剪强度特性以及渗透性的影响。研究结果表明:①混合土的最大干密度比原状红黏土低,且胶粉的掺量越大,最大干密度越小;②胶粉掺量增大,标准击实试验的最优含水率增大,等效击实试验的最优含水率有减小趋势;③胶粉掺量不超过15%时,随着胶粉掺量增大,混合土的抗剪强度增大,内摩擦角增大,且出现应变硬化现象:④标准击实下,胶粉掺量为8%时,混合土的渗透速率变化不明显;但胶粉掺量增加到15%时,混合土的渗透速率显著提高,提升幅度达到97.3%。研究成果可为贵州地区今后废旧胶粉的循环利用和胶粉改良红黏土的工程运用提供参考。     

Successive cancellation multibit-flipping decoding algorithm for polar codes

The investigation of the probability of error bits in a codeword shows that single-bit errors and 2-bit errors are main reasons that influence the decoding performance of polar codes with a short or moderate blocklength. Based on the statistical analysis of the error bits, a successive cancellation(SC) multibit-flipping decoding algorithm is proposed. Compared with the SC single-bit-flipping decoding, the proposed scheme can obtain better performance gains for polar codes with a short blocklength. Compared with the SC list decoding by exploring multiple paths simultaneously, the proposed scheme has a lower space complexity. Moreover, the decoding complexity of the proposed decoding algorithm decreases as the signal to noise ratio(SNR) increases. Simulation shows that for polar codes with a short or moderate blocklength, the performance of the proposed decoder can approach that of the SC list decoding with lower decoding complexity in high SNR regions.     

高均匀性长波红外远心照明系统设计

基于数字微镜器件(DMD)的红外景象模拟器可在室内环境下模拟真实景物及其环境的红外辐射,实现对红外成像系统性能的准确测试与评估。照明系统作为红外景象模拟器的重要组成部分,为其提供红外辐射能。为使光束均匀照射在DMD器件表面,通过分析研究黑体特性及朗伯定律,确定采用像方远心光路作为照明系统的结构形式。以拉氏不变量为依据研究确定的照明系统特性参数,能够实现与投影系统完美衔接。根据设计参数完成对照明系统初始结构的计算,利用ZEMAX进行调制、优化,并完成像质评价。设计结果表明,以此方式设计的照明系统均匀性高、球差小,可进一步提高模拟仿真效果。     

Analysis of the impact of coal mining on the ecological environment of the nature reserve

With the gradual attention of the state to the protection of natural ecological environment, the planning and layout of the nature reserve will overlap with some coal mine areas. In order to strengthen the construction of ecological civilization, it is necessary to study the impact of mining on the ecological environment of the nature reserve. Through the methods of GIS and RS, and evaluation o f ecological protection index system, the differences and impacts of ecological environment changes before and after the planning of the nature reserve are analyzed. The results show that since 2002, the effect of water collection and artificial soil and water conservation measures on improving the ecological environment of vegetation are obvious, the dominant species of vegetation type in the overlapping area of coal mine and nature reserve have changed from grass vegetation to shrub vegetation, inwhich the area of arbor forest land has increased significantly, the veetationcoverage in the overlapping area has also increased considerably . The intensity of soil erosion has decreased year by year after mining the coal resources. Postharvest hydraulic erosion intensity is mainly below mild, and the area of artificial soil and water conservation has increased significantly. T he negative impact of the ground subsidence caused by coal mining on the ecological environment is less than the positive effect brought by artificial soil and waterconservation measures, and it is generally developing in a more stable direction. The ecological protection status index increased fr om 32. 98 to 45.94, and the change degree of ecological protection status in nature reserves is 12.9 ≥10. T he ecological protection status of the nature reserve improved significantly. On the basis of ecological environment protection and restoration measures in the nature reserve, coal mines need to further study the comprehensive impact of human activitieson the ecological environment of the nature reserve.     

橡胶弹性元件低温刚度预测方法

在20,0,-10,-20,-30,-40℃下,对橡胶材料进行单轴拉伸试验,采用4种常用类型本构模型拟合试验数据,得出不同温度下的模型参数,并利用拟合优度对模型拟合效果进行评估,结果表明Ogden3和4阶模型拟合效果最好。分别考虑环境温度以及温度场的改变(从室温20℃逐步降低至-40℃)对橡胶力学性能的影响,对锥形橡胶弹簧在各试验温度下施加垂向载荷的刚度进行预测,并对产品进行相应的刚度试验。试验结果表明,仿真分析中若考虑温度场的改变对橡胶力学性能的影响,刚度预测精度显著提高;在环境温度低于-20℃时,仿真分析有必要考虑温度场的变化而产生的热应力对橡胶弹性元件刚度的影响。     

一种改进Papoulis-Gerchberg的多幅超分辨重构方法

为进一步提高拍摄图像的分辨率,提出一种改进的Papoulis-Gerchberg超分辨算法.新算法提出边缘检测方法,可以改善传统方法空间复杂度和重构图像边缘模糊的问题.新算法在原有的算法基础上融于边缘检测,针对多幅同一场景输入图像,在每次Papoulis-Gerchberg迭代过程加入坎尼检测,同时将每步的重构误差投影到下一步重构过程,降低了算法空间复杂度,能有效恢复丢失的边缘高频信息.MATLAB实验结果表明,与现有的经典超分辨重构方法相比,本算法反映图像质量的峰值信噪比和灰度标准差更高,信噪比和灰度标准差比改进前算法分别提高0.5 d B和2.5.从视觉感官上对比,重构图像整体效果也更加清楚,去除了原始重构方法图像边缘叠影现象,有效提高了原始输入图像的分辨率.     

钢筋混凝土桥梁抗力模型的建立及应用

对在役钢筋混凝土桥梁进行可靠度评估和寿命预测中,抗力是可靠度计算的重要因素,建立抗力模型至关重要。针对建立在役钢筋混凝土桥梁抗力模型的这一问题,分析了混凝土强度变化、钢筋锈蚀、混凝土与钢筋的粘结能力变化3大因素及其时变规律。考虑了锈蚀引起的钢筋力学性能降低,引入了基于纤维模型的计算模式不定性参数,采用数学方法建立了钢筋混凝土桥梁抗力随时间衰减模型。引入某钢筋混凝土简支T梁桥进行了抗力模型的计算,验证了模型的可靠性。抗力衰减模型的建立为结构可靠性评估打下了基础。