ANALYSIS AND DESIGN OF LOAD-UNIFORMING MANGLE ROLLERS WITH AXIALLY-STAGGERED CONTACT

It is desirable to get a uniform load distribution for the pressure rollers of the mangle.In thispaper,the load uniforming principle of the axially-staggered pressure rollers and the rules for theroller design have been analysed by the theory of bending of beams.The ratio of maximum tominimum value of the distributed load in the nip being taken as a useful index to describe the uni-formity of the load distribution,the performance of the so-called load-uniforming pressure rollerswith rubber covering,under various operation conditions,has been evaluated.As a result,it isproved that the load-uniforming pressure rollers with axially-staggered contact is a pratically use-ful means of uniformizing the load distribution,which ensures that the mangle will squeeze the ma-terial to be processed uniformly over its whole width under any technological load,and needs onlysome simple regulations.The conclusions obtained in this paper can easily be extended to the pressure rollers with anysupport conditions.

基于linux防火墙netfilter的配电终端通信报文预处理hook模块设计与实现

本文讨论并分析了Netfilter的功能框架、工作原理及数据包处理的实现机制，设计了在Netfilter框架中实现配电终端报文预处理的hook模块，实现去除通讯遥控报文数字签名的功能，为配网自动化的二次安防提供帮助，同时为其他通信应用中修改tep包数据提供借鉴参考。

Estimation of the carbon pool in soil and above-ground biomass within mangrove forests in Southeast Mexico using allometric equations

We report the results of carbon stored in soil and aboveground biomass from the most important area of mangroves in Mexico, with dominant vegetation of Red mangrove （Rhizophora mangle L.）, Black mangrove （Avicennia germinans L.）, white mangrove （Laguncularia racemosa Gaertn.） and button mangrove （Conocarpus erectus L.）. We sampled soils with high fertility during the dry season in 2009 and 2010 at three sites on Atasta Peninsula, Campeche. We used allometric equations to estimate above ground biomass （AGB） of trees. AGB was higher in C. erectus （253.18±32.17 t？ha-1）, lower in A. germinans （161.93±12.63 t？ha-1）, and intermediate in R. mangle （181.70±16.58 t？ha-1） and L. racemosa （206.07±19.12 t？ha-1）. Of the three studied sites, the highest absolute value for AGB was 279.72 t？ha-1 in button mangrove forest at any single site. Carbon stored in soil at the three sites ranged from 36.80±10.27 to 235.77±66.11 t？ha-1. The Tukey test （p 〈0.05） made for AGB was higher for black mangrove showed significant differences in soil carbon content between black mangrove and button mangrove. C. erectus had higher AGB compared with the other species. A. germinans trees had lower AGB because they grew in hypersaline environments, which reduced their development. C. erectus grew on higher ground where soils were richer in nutrients. AGB tended to be low in areas near the sea and increased with distance from the coast. A. germinans usually grew on recently deposited sediments. We assumed that all sites have the same potential to store carbon in soil, and then we found that there were no significant differences in carbon content between the three samples sites： all sites had potential to store carbon for long periods. Carbon storage at the three sampling sites in the state of Campeche, Mexico, was higher than that reported for other locations.

Update in combined musculoskeletal and vascular injuries of the extremities

Combined musculoskeletal and vascular injuries of the extremities are conditions in which a multidisciplinary approach is a sine qua non to ensure life initially and limb viability secondarily.Vascular injuries as part of musculoskeletal trauma are usually the result of the release of a high energy load in the wound site so that the prognosis is determined by the degree of soft-tissue damage,duration of limb ischemia,patient’s medical status and presence of associated injuries.The management of these injuries is challenging and requires a specific algorithm of action,because they are usually characterized by increased morbidity,amputation rate,infection,neurological and functional deficits,and they could be life threatening.Although vascular injuries are rare and occur either isolated or in the context of major combined musculoskeletal trauma,the high index of suspicion,imaging control,and timely referral of the patient to organized trauma centers ensure the best functional outcome of the extremity in such challenging cases.Even after a successful initial treatment of a combined trauma pattern,long-term follow-up is crucial to prevent and detect early possible complications.The purpose of this manuscript is to provide an update on diagnosis and treatment of combined musculoskeletal and vascular injuries of the extremities,from an orthopedic point of view.

Principle of Mangling Correction of Plate-welding Section Steel and its Application

Thanks to the fantastic development of power, transportation, chemical engineering, architecture and other fields, there has been an increasing demand for new type of section steel with large sections used for construction frame, such as type-H, type-T, and type-C section steel. New types of section steel usually are long and with large cross section. Therefore, for the sake of the cost, steel plate welding structure is used home and abroad. During the welding process, welding distortion seems unavoidable. Presently, proper welding machinery, technique and standards are adopted to minimize the distortion. Angular distortion is corrected with oil press and angular distortion corrector, while horizontal distortions like sickle curve and arch are mainly done with flame. Flame correction is of great labor intensity and is also time and material consuming. Besides, the correction is affected by the operators’ skill and mood, which, to some extent, limits the productivity. In this paper, a new technique of section steel distortion correction with high efficiency and adaptability and yet low investment and cost will be proposed for the development of new-type section steel. The correction principles and capability calculation should be done some research on, which will be introduced. The practice done on section steel with a wing edge of 40～60 mm, proves satisfactory: compared with oil-press correction, continual mangling correction saves equipment investment by three quarters, installed capacity by three quarters and investment by three quarters and with a much higher efficiency. Particularly in the distortion correction of heavy welding structures, mangling correction stands out from the crowd. Mangling correction proves to be the best solution to the continual horizontal distortion correction of welding section steel.

Upper extremity vascular injuries:Etiology,management and outcome

BACKGROUND Vascular injuries of the upper extremities are considered relatively rare injuries affecting mostly the young population.They often are complex injuries accompanied by other musculoskeletal trauma or trauma in other anatomic locations.Their management is challenging since they can lead to disabilities with major socioeconomic effects.AIM To analyze data about the mechanism of injury,the management algorithm and functional outcomes of vascular injuries of the upper extremity.METHODS One hundred and fifteen patients(96 males and 19 females)with arterial injuries of the upper extremity treated in a tertiary trauma center from January 2003 to December 2022 was conducted.Mean patients’age was 33.7 years and the mean follow up time was 7.4 years.Patients with Mangled Extremity Severity Score≥7 and Injury Severity Score≥20,previous upper limb surgery or major trauma and any neuromuscular or psychiatric disease were excluded,from the study.RESULTS A penetrating trauma was the most common cause of injury.The radial artery was the artery injured in most of the cases(37.4%)followed by the ulnar(29.5%),the brachial(12.1%)and the axillary(6%).A simultaneous injury of both of the forearm’s arteries was in 15.6%of the cases.In 93%of the cases there were other concomitant musculoskeletal injuries of the extremity.Tendon lacerations were the most common,followed by nerve injuries.The postoperative functional scores(full Disabilities of the Arm,Shoulder,and Hand and VAS)had very satisfactory values.CONCLUSION Although vascular injuries of the upper extremity are rare,they may occur in the context of major combined musculoskeletal trauma.Although a multidisciplinary approach is essential to optimize outcome,the ability of trained hand surgeons to repair all injuries in combined vascular and musculoskeletal upper extremity trauma,excluding isolated vascular injuries,ensures shorter operative times and better functional outcomes.