专家：中国急需自建根域名服务器

2014年1月22日,国家互联网应急中心发布消息称,1月21日15时20分,大量互联网用户无法正常访问域名以“．com”、“．net”等结尾的网站。事件发生后,国家互联网应急中心,第一时间启动应急响应机制,协调组织部分技术支撑单位进行调查和应急处置,16时50分左右,用户访问基本恢复正常。     

打破提供云服务的障碍

正今天,云备份即服务仍然是一个热门的话题,托管服务提供商(MSP)现在正向越来越多的客户提供云服务。根据ESG最近一项对云的分析指出,60%的终端用户受访者目前正在使用云或者是在部署云战略。备份和灾难恢复即服务是云领域发展速度较快的一个细分市场,托管服务提供商及其客户正     

网站优化过程中哪些因素会影响用户体验?

正众所周知,网站优化过程中我们一直倡导的优化方式就是正规的白帽手法,随着百度算法的升级,白帽方式笔者仅仅是我们优化网站的前提,要更加深入细致的做好网站优化笔者认为我们必须从深层次的角度去分析和提升网站的用户体验,下面笔者以自己对于网站优化过程中用户体验提升的细节方面和大家进行详细的探讨,好,闲话短续咱们进入今天主     

Seoer如何摆脱排名的误区

正Seo是为了什么?为了大把的流量,为了足够的成交,为了大把的获利。如,要是现在我们的中心词排名并不靠前,但是流量可大把大把的抓,或者流量并不多,但是成交不错,那么比那些排名好没流量,流量多但没成交的网站又如何呢?其实刚做seo的时候大家都知道这个问题,但做着做着就迷失到排名里面了,做个好的计划,搞好方向非常重要,最起码不迷失。那么具体我们如何不要计较那些排名利用seo来     

运动发酵单胞原生质球的形成和再生

运动发酵单胞(Zymomonas mobilis)ATCC29191菌株在含1～3g/L甘氨酸的液体培育12小时的菌体,用含20g/L的溶菌酶溶液处理12小时,可以稳定得到80％～90％的原生质球。原生质球稀释后在底层再生培养基上涂布,上面复盖一层半固体培养基,30℃培养5～7小时,再生率可达10~(-2)水平。     

纤维素酶的固体发酵

从来自国内外11株菌株的初步比较,筛选出酶活较高的康氏木霉N_2—78和瑞热埃木霉QM6a。对康氏木霉P_2和土曲霉3.3935所作的纤维素碳源试验中,发现木质纤维素较纯纤维素好,未经处理的木质纤维素比经处理的好。麸皮和稀土对康氏木霉P_2产酶作用影响较大,而对土曲霉3.3935则无明显的影响。     

Possible Energy Network with polygeneration system and CCS for China

On basis of adopting polygeneration systems for power and alternative fuels,capturing CO2 with near zero energy penalties,and storing CO2 on sites,a new kind of Energy Network can integrate energy utilization,CO2 capture,transportation and storage synthetically.Techno-economic analysis of this solution focusing on Inner Mongolia and the Yangtze River Delta districts had been carried with comparison to the chain method for energy utilization and CO2 sequestration.This solution can save 21.5% of energy,and re...     

Analysis of junction temperatures in high-power GaN-based LEDs

We presented the analysis of the incomplete conduction in bonding medium in high power GaN-based light-emitting diode (LED) packages. A numerical study was carried out with parametric model to understand the junction temperature variation due to bonding medium defects. Transient thermal measurement was performed to evaluate LED’s junction temperature. Thermal resistance from chip to lead frame was 20 K/W in our sample LED. It was suggested that only 60% of the surface area of the bonding medium was involved...     

Preparation of micro-patterned surfaces of Si-N-O films and their influence on adhesion behavior of endothelial cells

Microgrooves were prepared on Si(100) surface by photolithography and wet etching.Subsequently,Si-N-O films were deposited on the microgrooves by unbalanced magnetron sputtering(UBMS) and micro-patterned surfaces of Si-N-O films were obtained.The size of the micropatterns was measured by surface profilometer.The chemical composition of Si-N-O films were characterized by X-ray photoelectron spectrometry(XPS) and the wettability of the micropatterned surfaces was evaluated by contact angle measurement.The beh...     

A novel shaft-less double suction mini pump

A novel double suction shaft-less mini pump was developed for heat control of small energy systems in this study.The mini pump impeller with an exit diameter of 40 mm was combined with the motor rotor supported by the hybrid dynamic bearing.The specific speed of the pump was 125 min-1 m3 min-1 m.The hydraulic performance of the pump was investigated experimen-tally under four rotational speeds.From the test results,it was recognized that the pump could provide a flow discharge of 5 L/min and head of 1.5 m,w...