用乐泰厌氧胶粘补变送器长漂内漏

介绍了使用乐泰厌氧胶粘补变送器长漂内漏的实用技术、操作工艺及应用效果。

金沙水拍云崖暖——攀枝花国际长漂节

1999年，美国《国家地理》列出21世纪最为惊险的25项探险活动，中国的长江漂流排名第二。自上世纪八十年代始，一批又一批热血男儿在这条中华母亲河上披波斩浪，他们在波峰浪谷间完成回归，以意志和勇气达成自我……时至今日，漂流这项充满探险精神的活动已大步走向民众，在倡导“运动、健康、休闲“的今天，漂流已不再仅是探险者和专业人士的领地，它正被越来越多的热衷户外运动的人们所青睐。

An Ant Colony Algorithm Based on Cross-Layer Design for Routing and Wavelength Assignment in Optical Satellite Networks

This paper introduces an ant colony routing and wavelength assignment algorithm based on cross-layer design(CL-ACRWA),which can overcome the adverse effects of Doppler wavelength shift on data transmission in optical satellite networks. Firstly, a cross-layer optimization model is built, which considers the Doppler wavelength shift, the transmission delay as well as wavelength-continuity constraint. Then an ant colony algorithm is utilized to solve the cross-layer optimization model, resulting in finding an optimal light path satisfying the above constraints for every connection request. The performance of CL-ACRWA is measured by the communication success probability, the convergence property and the transmission delay. Simulation results show that CL-ACRWA performs well in communication success probability and has good global search ability as well as fast convergence speed. Meanwhile, the transmission delay can meet the basic requirement of real-time transmission of business.

Dynamic routing and wavelength assignment algorithm of optical satellite networks based on cross-layer design

In order to overcome the adverse effects of Doppler wavelength shift on data transmission in the optical satellite networks,a dynamic routing and wavelength assignment algorithm based on crosslayer design( CL-DRWA) is introduced which can improve robustness of the network. Above all,a cross-layer optimization model is designed,which considers transmission delay and wavelength-continuity constraint,as well as Doppler wavelength shift. Then CL-DRWA is applied to solve this model,resulting in finding an optimal light path satisfying the above constraints for every connection request. In CL-DRWA,Bellman-Ford method is used to find an optimal route and a distributed relative capacity loss method is implemented to get an optimal wavelength assignment result on the optimal route. Moreover,compared with the dynamic routing and wavelength assignment algorithm based on minimum delay strategy( MD-DRWA),CL-DRWA can make an improvement of 5. 3% on the communication success probability. Meanwhile,CL-DRWA can meet the requirement of transmission delay for real-time services.

Genetic Analysis of Floating Enteromorpha prolifera in the Yellow Sea with AFLP Marker

Extremely large accumulation of green algae Enteromorpha prolifera floated along China'coastal region of the Yellow Sea ever since the summer of 2008.Amplified Fragment Length Polymorphism (AFLP) analysis was applied to assess the genetic diversity and relationships among E. prolifera samples collected from 9 affected areas of the Yellow Sea.Two hundred reproducible fragments were generated with 8 AFLP primer combinations,of which 194 (97%) were polymorphic. The average Nei's genetic diversity, the coefficiency of genetic differentiation (Gst), and the average gene flow estimated from Gst in the 9 populations were 0.4018, 0.6404 and 0.2807 respectively. Cluster analysis based on the unweighed pair group method with arithmetic averages (UPGMA) showed that the genetic relationships within one population or among different populations were all related to their collecting locations and sampling time. Large genetic differentiation was detected among the populations.The E. prolifera originated from different areas and were undergoing a course of mixing.

Drifting Sand Endangering Gezira Irrigation Scheme in Central Sudan, History and Impact

This study was carried out at Gezira area in Central Sudan that lies between longitude 32° and 32° 50＇ and latitude 14° and 14°15＇. It dealt with the history of the sand, its source and rate of movement towards Gezira scheme and monitored the trend of blowing sand over 10 years. To find out the origin of drifting sand, sand samples were collected from the sandy area west to the White Nile and from the study area. Heavy minerals analysis was carried out on these samples and its mineral assemblage was matched with the mineral of both sand at western bank of the White Nile and the Blue Nile. To picture the trend of moving sand, Multispectral Scanning System （MSS, 1975）, and Thematic Map （TM, 1985） were used to delineate the sandy areas and their trend with time. The rate of the blowing sand was quantified using Bottemane sand catcher. The heavy mineral results showed that the mineral of the drifting sand in the study area are quite similar to the sand of sand dune west to the White Nile indicating the same origin. The sand was transported by southern and southwestern winds through a corridor across the White Nile to its eastern bank, where the most likely water transported sediment was reworked by wind and transported further to the northeast. Between 1972 and 1985, the sand invaded the area at an average rate of about 30 km2 per year and map of 1985 demonstrated a corridor across the White Nile for sand movement. The area was subject to 7 days sand storm with an average of 35 kg/m.d and in summer time, the average amount of moving sand was about 28 kg/m.d. These results demonstrated the future hazard of drifting sand and its impact, which has to be tackled immediately to protect Gezira scheme.

Improved YOLOv7 Algorithm for Floating Waste Detection Based on GFPN and Long-Range Attention Mechanism

Floating wastes in rivers have specific characteristics such as small scale,low pixel density and complex backgrounds.These characteristics make it prone to false and missed detection during image analysis,thus resulting in a degradation of detection performance.In order to tackle these challenges,a floating waste detection algorithm based on YOLOv7 is proposed,which combines the improved GFPN(Generalized Feature Pyramid Network)and a long-range attention mechanism.Firstly,we import the improved GFPN to replace the Neck of YOLOv7,thus providing more effective information transmission that can scale into deeper networks.Secondly,the convolution-based and hardware-friendly long-range attention mechanism is introduced,allowing the algorithm to rapidly generate an attention map with a global receptive field.Finally,the algorithm adopts the WiseIoU optimization loss function to achieve adaptive gradient gain allocation and alleviate the negative impact of low-quality samples on the gradient.The simulation results reveal that the proposed algorithm has achieved a favorable average accuracy of 86.3%in real-time scene detection tasks.This marks a significant enhancement of approximately 6.3%compared with the baseline,indicating the algorithm's good performance in floating waste detection.

用于激光锁频的低泵浦场饱和吸收光谱（英文）

目的:利用激光透过原子气室时的端面反射产生泵浦光,实现低泵浦场的饱和吸收光谱,提高饱和吸收光谱锁频方法对运动平台的适应性。创新点:1.在饱和吸收光谱中实现无需额外反射镜调节的泵浦光与探测光的重合方法;2.在饱和吸收光谱中实现强探测-弱泵浦的实验方式。方法:1.利用原子气室端面反射光作为泵浦光,实现低泵浦场的饱和吸收光谱装置(图1和2);2.研究实现低泵浦场的饱和吸收光谱所需的角度控制精度(图4);3.研究采用此方法的激光频率锁定效果(图5和6)。结论:1.低泵浦场的饱和吸收光谱方法可以满足激光频率锁定的要求;2.低泵浦场的饱和吸收光谱装置相比传统装置,没有多余的可调节的反射镜,装置更加简洁,锁频效果受环境影响更小,对运动平台的适应性更强。

泽雅山溪钓

周末假日,抛弃俗务,驱离尘嚣,三五结伴,到泽雅山溪游钓,一边饱览自然山水风光,一边享受溪钓旷野乐趣,健身怡情,逍遥自在。泽雅系浙江省省级风景名胜区,位于温州市瓯海区西部山区,距市区18公里。这里重嶂叠翠,山溪蜿蜒,瀑、潭、渊、涧、溪、滩、泊等水景瑰丽,不仅使“水泽之雅”的风景更具神奇魅力,而且为山溪游钓拓展旷野钓场。

Effect of non-uniform magnetic field on crystal growth by floating-zone method in microgravity

The magnetic damping effect of the non-uniform magnetic field on the floating-zone crystal growth process in microgravity is studied by numerical simulation. The results show that the non-uni-form magnetic field with designed configuration can effectively reduce the flow near the free surface and then in the melt zone. At the same time, the designed magnetic field can improve the impurity concen-tration non-uniformity along the solidification interface. The primary principles of the magnetic field con-figuration design are also discussed.