误差方差的非齐次估计的可容许的充要条件

研究误差方差的非齐次二次估计的可容许性．在平方损失下,给出了一个非齐次二次估计在非齐次二次估计类中是误差方差的容许估计的充要条件．     

毛细管电泳法手性拆分14种二肽

以咔唑-9-乙基氯甲酸酯(CEOC)作为柱前衍生试剂,采用毛细管电泳对14种二肽进行了手性拆分。以5种二肽为代表,考察了缓冲液种类、浓度、pH值、二元手性选择剂的组合配比等因素对二肽的拆分效果,优化了实验条件。在各自的优化条件下,14种二肽手性拆分的分离度均在3.63以上,最高分离度可达43.14(Gly-Ala)。     

Moderate deviations for a risk model based on the customer-arrival process

In this paper, we investigate the moderate deviations for a customer-arrival-based insurance risk model, in which customer’s actual claim sizes are described as independent and identically distributed heavy-tailed random variables multiplying a shot function, and the model can be treated as a Poisson shot noise process.     

Unsupervised person re-identification based on removal of camera bias and dynamic updating of the memory bank

In recent years, unsupervised person reidentification technology has made great strides. The technology retrieves images of interested persons under different cameras from massive repositories of unlabeled images. However, in the current research, there are some existing problems, such as the influence of pedestrians appearing across cameras and pseudo-label noise. To solve these problems, we conduct research in two ways: removing the camera bias and dynamically updating the memory model. In removing the camera bias, based on a learnable channel attention module, the features that are only related to cameras can be extracted from the feature map, thereby removing the camera bias in the global features and obtaining the features that can represent the pedestrians. In regards to dynamically updating the memory model, since the instance features do not necessarily belong to the identity represented by the pseudo-label, we adopt a method to update the memory dynamically according to the distance between the instance features and the category features so that the category features tend to be true. We combine the removal of the camera bias and the dynamic updating of the memory model to better solve problems in this field. Extensive experimentation demonstrates the superiority of our method over the state-of-the-art approaches on fully unsupervised Re-ID tasks.     

蒙特卡罗法在堤防边坡可靠度分析中的应用

以堤防边坡为研究对象,运用可靠度分析方法中的蒙特卡罗法,通过建立边坡状态函数,生成随机变量,对边坡的稳定性进行可靠性模拟,求出失效概率和可靠指标,并附有实例,具有实用性和可操作性。     

Palladium-Catalyzed Desulfitative Cross-Coupling of Sodium Arylsulfinates with Aryl Bromides and Chlorides： An Alternative Convenient Synthesis of Biaryls

An alternative method for synthesis of biaryls has been developed through the Pd catalyzed desulfitative coupling reaction of sodium arylsulfinates with aryl bromides and chlorides. The procedure tolerates a variety of functional groups, such as cyano, formyl, acetyl, chloro, methoxy, trifluoromethyl and heteroaromatic unit. The desired products were obtained in moderate to excellent yields under relatively mild reaction conditions without additives, base or co-catalyst.     

超快光电导开关的传输特性分析及优化方案

超快光电导开关输出的是超宽带的电脉冲信号,因此开关至负载的传输线路设计优劣对输出波形影响很大。本研究分析了光电导开关典型的同轴-微带传输结构,计算了线性工作模式下开关电阻瞬态变化在传输线路阻抗不连续处引起的电磁波反射,及其对输出脉冲波形和电压传输率产生的影响,然后与实测脉冲波形进行了对比,解释了肩峰现象。最后根据仿真结果提出了提高光电导开关传输特性的三种优化方案。     

太空探测与地球环境保护

了解太阳系的现状、起源和演化，通过对太阳系天体的比较研究，了解那些过程在过去和现在对地球和人类环境有那些影响；了解太阳系的化学史以及何处具有生命发生和发展的化学环境。     

用于CH4/CO2重整反应Ni/ZrO2-Al2O3催化剂的结构和抗积炭性能

在表面活性剂P123作用下,通过无机盐的双水解反应制备了介孔ZrO2-Al2O3复合氧化物.研究发现,所得样品具有较大的比表面积和可调变的孔结构.ZrO2可嵌入到Al2O3骨架中形成固溶体,因而热稳定性增加;与Al2O3相比,适量ZrO2加入使ZrO2-Al2O3的酸密度和酸强度增加.在CH4/CO2干气重整反应中,N...     

The Expected Values for the Gutman Index and Schultz Index in the Random Regular Polygonal Chains

Two famous topological indices, the Gutman index and Schultz index, are studied in this article. We mainly calculate the exact analytical formulae for the expected values of the Gutman index and Schultz index of a random regular polygonal chain with n regular polygons. Moreover, we determine the average values and the extremal values of the indices in regard to the set of all these regular polygonal chains.