滚子链简易拆装工具

链传动的优点是：没有滑动;工况相同时,传动尺寸比较紧凑;不需要很大的张紧力,作用在轴上的载荷较小;效率较高,可达98％;能在较恶劣的环境下使用;可用于轴距较大的场合。     

Residual pattern of fenhexamid on pepper fruits grown under greenhouse conditions using HPLC and confirmation via tandem mass spectrometry

Fenhexamid (25%, SC) was sprayed on pepper fruits grown under greenhouse conditions at the recommended dose rate of 20 g/20 L water. Fruit samples were collected randomly at 0 (2 h after application), 1, 2, 4, 6, 8, 11, and 14 days post-application. The samples were extracted with acetonitrile, partitioned with water, passed through a cleanup procedure, and analysed via HPLC. Residues were confirmed via LC–tandem mass spectrometry (LC–MS/MS) in positive-ion electrospray ionisation (ESI+) mode. The rate of disappearance of fenhexamid on pepper fruits was described as first-order kinetics (r² = 0.992) with a half-life of 4.7-day. Based on the pattern of decline of the fungicide residues in relation to the estimated maximum residue limits (MRL = 5 mg/kg), a safety pre-harvest interval of 1 day is suggested for peppers at the recommended dosage.     

第四届欧洲建筑与城市设计研讨会

景观………… 在文化、生态以及社会领域中扮演着公共利益的重要角色。它是经济活动的有利资源,景观保护、管理及规划还创造了就业机会。……有助于地方文化的形成……是欧洲自然和文化遗产的基本元素,促进人类繁荣和欧洲特征的巩固……是人们生活质量的重要组成部分：城市和乡村,没落地区或高尚地区,或者是隐匿的佳境,甚至是每天的必经之地。     

Formation of electrospun nylon-6/methoxy poly(ethylene glycol) oligomer spider-wave nanofibers

A methoxy poly(ethylene glycol) (MPEG) oligomer with a viscous nylon-6 supporting solution was fabricated and polymerized simultaneously to form a nanofiber network structure via electrospinning. This network consisted of thin MPEG nanofibers and thick nylon-6 nanofibers, which were arranged in a spider-web like structure. These two different nanofibers were separated from the electrospun mat by extraction of MPEG using water. This result showed that the hybrid nanocomposite mat consisted of two different interconnecting polymeric nanofibers. We propose that this interconnection is due to the formation of hydrogen bonds between MPEG and nylon-6 molecules. This spider-web structure formed by electrospinning was responsible for increasing the mechanical strength and the wetability of nylon-6 mat in the presence of small amounts of MPEG.     

ICI Reduction in OFDM System Using IMBH Pulse Shapes

In this paper, the Improved Modified Bartlett-Hanning (IMBH) window family is used in an OFDM system to reduce the ICI. It is found that the IMBH pulse shape gives better results than the PMSP, ISP, BTRC, RC, Bartlett and rectangular pulse shapes in terms of both ICI and BER. The optimization of SIR in terms of window parameters has also been obtained. This analysis provides a better insight to control ICI or BER with proposed pulse shape. The IMBH pulse shapes give an improvement of 2–3 dB in ICI with different frequency offsets and roll-off factors. Similarly, with proposed pulse shapes the BER level can be obtained at lower SNR of approximately 5 dB. Therefore, the IMBH pulse shapes outperform other reported pulse shapes in both the dimensions, i.e., ICI and BER.