不同菜地土壤的铁氨氧化脱氮过程探究

采集了不同菜地的土壤，分析其理化性质.采用同位素示踪技术测定了铁氨氧化、反硝化和厌氧氨氧化的速率，运用Miseq高通量测序技术探究了菜地土壤的群落组成.结果表明，铁氨氧化速率在种植蔬菜的土壤显著高于裸地的土壤，并且铁氨氧化速率与土壤Fe（III）（r = 0.736， P < 0.05）和总有机碳（r = 0.575， P < 0.05）均有显著的正相关.另外，在不同菜地中5种主要的铁还原菌（芽孢杆菌属，假单胞菌属，嗜酸菌属，脂环酸芽孢杆菌属，梭状芽胞杆菌属）被检测到，并且铁还原菌的相对丰度在种植蔬菜的土壤（1.38%~2.19%）比在裸地的土壤（0.75%）高.在脱氮贡献方面铁氨氧化， 反硝化和厌氧氨氧化分别贡献了7.3%~12.4%， 53.1%~72.3%和18.9%~36.4%的氮气产生，说明铁氨氧化是菜地中重要的微生物脱氮路径.     

A lagrangian dispersion model for calculating concentration distribution within a built-up domain

A Lagrangian model to study the dispersion of pollutants between urban buildings is described. The flow field is supplied by an objective analysis (Rockle (1990) Ph.D. thesis, Vom Fachbereich Mechanik, der Technischen Hochschule Darmstadt, Germany) and is adjusted to satisfy the continuity equation. From the resulting; mass consistent field the Lagrangian diffusion parameters are eliminated. A 3-D Lagrangian diffusion model in a nonhomogeneous field is applied to calculate the pollutant distribution between the buildings. Several examples are studied and compared to wind tunnel measurements.     

从废印制电路板元器件中分离电容器的方法

以典型废印制电路板湿法剥离得到的元器件为研究对象,通过筛分和磁选相结合的物理方法,分离其中的电容器。研究发现,筛分后电容器分布在9.5-19 mm和4.0-9.5 mm范围内,并且50%以上的元器件与电容器得到分离。9.5-19 mm范围内的元器件经过磁选,可以将强磁性的铜线绕阻类元器件分离出来,剩余元器件采用8 mm宽的条形筛进行筛分,筛上物主要为电容器,筛下物主要为芯片和引脚;4.0-9.5 mm范围内的元器件经过磁选,可以将92.93%的电容器分离出来。     

Electromagnetic field dosimetry for clinical application

The 21st century medicine is characterized with increasing variety of diagnostic and therapeutic devices that implement magnetic and electromagnetic fields most of which utilize time varying signals. In many cases, however, these devices are used without proper knowledge of the physical parameters of the applied signals. In an attempt to facilitate the use of magnetotherapeutic devices, the basic principles of physical and biophysical dosimetry in clinical settings are discussed in this article.     

Measurements of human exposure from emerging wireless technologies

The rapid development of wireless technologies leads to increased human exposure to electromagnetic fields from new devices. Most of these technologies communicate in short to medium range. Communication devices, such as mobile phones (GSM, UMTS, LTE) and wireless computer networks (WLAN, HSDPA, WIMAX) usually work at distances up to some 10 km. Other techniques like Bluetooth, RFID, and wireless USB work at distances up to a few meters. RFID systems can use several frequency bands from low frequencies up to microwaves. The other technologies are mainly using microwave frequencies. Most of these technologies have a rather low-output power, typically <1 W average power, except for fixed transmitters like base stations. This means that the exposure from distant sources is low. If the devices are kept close to the body, the local exposure can be in the range of the levels in the ICNIRP recommendation; this is the case, for example, for mobile phones and WLAN transmitters in laptops. For distant sources, there exist several measurement techniques such as spectrum analysers, measurement receivers, and broadband meters. For sources used close to the body, the local SAR levels have to be determined. For this purpose, instruments measuring the local electric field inside body phantoms have been developed. An alternative to measurements is numerical simulations. If one has knowledge of the signal characteristics of the different technologies then it is possible to find a suitable measurement technique to assess the human exposure.     

胺基化磁性壳聚糖微球固定化Candida tropicalis处理含酚废水研究

通过戊二醛将Candida tropicalis固定在胺基化磁性壳聚糖微球（NH2-M-CSm）上，探讨了游离Ct、磁性壳聚糖微球（M-CSm）固定化Ct和NH2-M-CSm固定化Ct除酚的最适条件。结果表明，游离Ct最适pH为5.5，M-CSm和NH2-M-CSm固定化Ct均在4-6之间；游离Ct最适温度为35℃，M-CSm和NH2-M-CSm固定化Ct均为30℃；NH2-M-CSm固定化Ct的热稳定性〉M-CSm固定化Ct〉游离Ct；离子强度对固定化Ct无影响，而对游离Ct有一定的影响；一价态离子对游离Ct和固定化Ct影响不大；二价态离子对游离Ct起抑制作用，而对固定化Ct起促进作用；三价态离子对游离Ct和固定化Ct均起抑制作用。通过实验还得知，固定化Ct可以通过再培养恢复酶活力，其半衰期至少为90 d。最后，在实际废水处理中，经3 h反应后，NH2-M-CSm固定化Ct除酚几乎达100%，而游离Ct只达到80%左右。     

漏磁探伤设备在油田油管杆修复检测中的应用

介绍了漏磁探伤设备在孤东采油厂管、杆修复检测中的应用现状,针对探伤检测中存在的问题,提出了相应的对策,提高了探伤检测效果。