GM(1,N)模型在城市道路交通噪声预测中的精度分析

根据武汉市1998～2002年城市道路交通噪声检测数据以及相关的数据,分析相关因素的选取对GM(1,N)灰色模型的预测精度的影响.结果表明选取相关因素会降低GM(1,N)灰色模型的精度,而GM(1,1)模型则有较好的预测精度;利用GM(1,1)模型对武汉市2008年前的道路交通噪声进行了预测.     

广西灌阳县观音阁响水洞的形成环境及1号石笋的古气候信息

本文根据灌阳县响水洞的成洞地质条件、生态环境以及洞穴的组成等 ,论述了洞穴的形成、发育过程。通过对响水洞 1号石笋的铀系测年 ,碳氧同位素及沉积 (间断 )纹层分析 ,获得了距今 4 4.0～ 3 .1ka高分辨率古气候演变信息。反映 4 4.0ka以来区内经历了严寒 (晚大理冰期 )、冰期后干冷和温热 (间夹短暂的冷期 )等气候变化 ,为确定响水洞的形成时代和环境提供了科学依据。     

地质学野外教学基地建设的几点思考

综合考虑地质学实践课的特点及野外地质实习基地应具备的功能,根据目前我校地质学野外实习基地的现状,提出了合理选择及建设地质学野外教学基地的几点思考.依照吉林大学地球科学院野外地质实习基地建设经验,制定了我校地质野外实习基地的建设原则和初步构想.     

高校学生干部应具备的能力及培养途径与方法

高校学生干部在党团组织、老师和广大同学中起着桥梁纽带与助手作用,他们所具备的意识和能力,直接关系到学校及各项学生活动的开展.本篇文章首先列举了学生干部应具备的六个基本意识和基本能力,进而结合实践经验从选拔、培训、实践、总结四个方面提出学生干部的培养途径和方法.     

Virus Particle Detection by Convolutional Neural Network in Transmission Electron Microscopy Images

A new computational method for the detection of virus particles in transmission electron microscopy (TEM) images is presented. Our approach is to use a convolutional neural network that transforms a TEM image to a probabilistic map that indicates where virus particles exist in the image. Our proposed approach automatically and simultaneously learns both discriminative features and classifier for virus particle detection by machine learning, in contrast to existing methods that are based on handcrafted features that yield many false positives and require several postprocessing steps. The detection performance of the proposed method was assessed against a dataset of TEM images containing feline calicivirus particles and compared with several existing detection methods, and the state-of-the-art performance of the developed method for detecting virus was demonstrated. Since our method is based on supervised learning that requires both the input images and their corresponding annotations, it is basically used for detection of already-known viruses. However, the method is highly flexible, and the convolutional networks can adapt themselves to any virus particles by learning automatically from an annotated dataset.     

Reproductive disturbance of Japanese bumblebees by the introduced European bumblebee Bombus terrestris

The European bumblebee, Bombus terrestris, is an invasive eusocial species whose distribution is expanding greatly beyond its native range because numerous colonies are imported to or locally produced in non-native countries for pollination of agricultural crops. Closely related species exist in Japan where the unrestricted import and use of B. terrestris has resulted in the establishment of wild colonies. Laboratory studies previously showed that B. terrestris and Japanese native species can copulate and produce fertilized eggs. Although these eggs do not hatch, the interspecific mating can cause a serious reproductive disturbance to native bumblebees. In this study, we determined the frequencies of interspecies mating between B. terrestris males and native bumblebee queens in the wild on the islands of Hokkaido and Honshu by analyzing the DNA sequences of spermatozoa stored in spermathecae of native queens. We found that 20.2% of B. hypocrita hypocrita queens and 30.2% of B. hypocrita sapporoensis queens had spermatozoa of B. terrestris males in their spermathecae. Given that a Bombus queen generally mates only once in her life, such high frequencies of interspecific mating with B. terrestris pose serious threats to the populations of native bumblebees in Japan.     

An overlooked side effect of nest-scattering behavior to decrease predation risk (Acari: Tetranychidae,Stigmaeidae)

The number of nests containing egg masses a female makes over her lifetime and the pattern of scattering nests vary among species in a genus of nest-weaving spider mites (Stigmaeopsis). We hypothesized that the scattered nests of small nest builders have a previously overlooked indirect effect in that the void nests created after predation take on a new role as hindering devices that effectively decrease predator searching efficiency. First, we demonstrated that the experimental design used in this study is a good reflection of the nest distribution pattern of Stigmaeopsis takahashii (an intermediate-sized nest builder) in the field. Using this species as a model, we tested how different nest-scattering patterns affect the predator to examine how scattering may indirectly provide an anti-predation strategy by increasing a predators searching time. Next, we observed how artificially arranged void nests disturb predatory behavior in both starved and fully fed predator females and showed that void nests have a strong hindering effect on predators. Thus, we concluded that the nesting behavior of this mite species not only has anti-predator effects but must also have a stabilizing effect on predator–prey interaction systems at the population level.     

Chlorine promotes antimony volatilization in municipal waste incineration

Antimony volatilization in municipal waste incineration was studied. Two municipal waste samples and antimony(III) oxide (Sb₄O₆) were heated to 500°C and 700°C in an air stream in a quartz furnace. The volatilization of Sb₄O₆ occurred more at 700°C that at 500°C. Conversely, antimony volatilization form municipal waste was stronger at 500°C than at 700°C. This implies that antimony from municipal waste is volatilized as chloride instead of oxide. The chlorine sources for antimony chlorination, a gas-phase reaction involving hydrochloric acid and a solid-phase reaction of inorganic chlorine, e.g., CaCl₂, were compared. Only the solid-phase reaction could offer enough active chlorine to induce chlorination of antimony oxide. Received: July 2, 1998 / Accepted: January 28, 1999     

Adsorptive removal and photocatalytic decomposition of sulfamethazine in secondary effluent using TiO2–zeolite composites

We investigated the adsorption and decomposition of sulfamethazine (SMT), which is used as a synthetic antibacterial agent and discharged into environmental water, using high-silica Y-type zeolite (HSZ-385), titanium dioxide (TiO₂), and TiO₂–zeolite composites. By using ultrapure water and secondary effluent as solvents, we prepared SMT solutions (10 μg/L and 10 mg/L) and used them for adsorption and photocatalytic decomposition experiments. When HSZ-385 was used as an adsorbent, rapid adsorption of SMT in the secondary effluent was confirmed, and the adsorption reached equilibrium within 10 min. The photocatalytic decomposition rate using TiO₂ in the secondary effluent was lower than that in ultrapure water, and we clarified the inhibitory effect of ions and organic matter contained in the secondary effluent on the reaction. We synthesized TiO₂–zeolite composites and applied them to the removal of SMT. During the treatment of 10 μg/L SMT in the secondary effluent using the composites, 76 % and more than 99 % of the SMT were decomposed within 2 and 4 h by photocatalysis. The SMT was selectively adsorbed onto high-silica Y-type zeolite in the composites. Resultantly, the inhibitory effect of the coexisting materials was reduced, and the composites could remove SMT more effectively compared with TiO₂ alone in the secondary effluent.