中-低-低变换工艺和准零汽耗技术

论述了变换反应的零汽耗概念,并据此分析了降低变换反应过程蒸汽消耗的有效途径。分别介绍了中-低-低变换工艺的设计思想、使用效果以及中-低-低工艺与JR型合成塔内件相结合实现变换准零汽耗的实践。

变换工段中-低-低改造工作总结

介绍了小型合成氨变换系统采用中-低-低工艺改造中串低工艺的技术要点.提出了使用中变段间喷水、减少系统设备对变换工艺降低能耗、减少阻力的重要性.通过对原变换系统改造工作的总结.为同行扩产改造提供了新的思路.

“中-低-低”变换工艺和“准零汽耗”技术

论述了变换反应的“零汽耗”概念,并据此分析了降低变换反应过程蒸汽消耗的有效途径。介绍了“中-低-低”变换工艺的设计思想,具有节能高效的特点、使用效果以及“中-低-低”工艺若与JR型合成塔内件相结合可以实现“准零汽耗”。

高-中危险度与低-极低危险度组胃间质瘤的影像诊断

目的高-中危险度与低-极低危险度组胃间质瘤的影像诊断。方法回顾性分析2015年4月—2017年12月期间该院50例经手术病理证实的胃间质瘤患者的CT影像及病理资料,根据危险度不同,分为高-中危险组(24例)与低-极低危险组(26例),观察两组患者是否在CT特征上有差异。结果高-中级别组胃间质瘤钙化10例、坏死23例、形态(分叶)18例、最大径>4 cm 20例;低-极低级别组钙化3例、坏死10例、形态(分叶)7例、最大径>4 cm 8例,(P=0.035、0.000、0.001、0.001),高-中级别组溃疡13例、混合生长9例、年龄(56.95±14.22)岁、平扫CT值(31.95±8.57)、动脉期CT值(61.79±20.76)、门静脉期CT值(70.50±19.34);低-极低级别组溃疡11例、混合生长6例、年龄(55.50±11.11)、平扫CT值(34.69±7.44)、动脉期CT值(62.15±21.13)、门静脉期CT值(73.03±26.16),(P=0.402、0.266、0.687、0.237、0.952、0.700,χ~2=0.703,1.236,0.406,-1.199,-0.061,-0.387)。结论高-中危险度与低-极低危险度组胃间质瘤CT影像征象,对胃间质瘤危险度的分级具有重要的参考价值。

加压中—低—低变换工艺的应用

介绍了上海吴泾化工有限公司合成氨装置中加压中—低—低变换工艺 ,分析了变换工艺改造前常压三段中变和改造后加压中—低—低变换工艺生产情况。加压中—低—低变换工艺运行后 ,变换出口 CO含量降到 1 %以下 ,吨氨蒸汽消耗只有 0 .1 2 4 t。

Simultaneous hydraulic fracturing of ultra-low permeability sandstone reservoirs in China: Mechanism and its field test

Based on the impact of the stress perturbation effect created by simultaneous propagation of multiple fractures in the process of simultaneous hydraulic fracturing, a thorough research on the mechanism and adaptation of simultaneous fracturing of double horizontal wells in ultra-low permeability sandstone reservoirs was conducted by taking two adjacent horizontal wells(well Yangping-1 and well Yangping-2 located in Longdong area of China Changqing Oilfield) as field test wells. And simultaneous fracturing optimal design of two adjacent horizontal wells was finished and employed in field test. Micro-seismic monitoring analysis of fracture propagation during the stimulation treatment shows that hydraulic fractures present a pattern of complicated network expansion, and the well test data after fracturing show that the daily production of well Yangping-1 and well Yangping-2 reach105.8 t/d and 87.6 t/d, which are approximately 9.4 times and 7.8 times the daily production of a fractured vertical well in the same area, respectively. Field test reflects that simultaneous hydraulic fracturing of two adjacent horizontal wells can enlarge the expansion area of hydraulic fractures to obtain a lager drainage area and realize the full stimulation of ultra-low permeability sandstone reservoirs in China Changqing oilfield. Therefore, simultaneous fracturing of two adjacent horizontal wells provides a good opportunity in stimulation techniques for the efficient development of ultra-low permeability reservoirs in China Changqing oilfield,and it has great popularization value and can provide a new avenue for the application of stimulation techniques in ultra-low permeability reservoirs in China.

Supportive Technologies and Roadmap for China’s Carbon Neutrality

The vision of carbon neutrality is a climate ambition of milestone significance for China and a key step for China’s transition from industrial civilization to ecological civilization.The realization of carbon neutrality requires profound changes in China’s technological and socioeconomic systems involving zero-carbon electric power,lowcarbon and zero-carbon end-use energy consumption,and negative emission technologies.Achievement of carbon neutrality is subject to the choice of pathways for various sectors,especially the electric power,industrial,transportation and construction sectors with significant carbon emissions and decarbonization difficulties.The goal of carbon neutrality will influence China’s economic and industry systems,resource and industrial layout,technological innovation and ecological environment in profound ways.Hence,China’s future policymaking on carbon neutrality needs to consider environmental,technological,economic and social impacts,establish a correlation between carbon peak and carbon neutrality,identify climate-friendly clean technology innovations in real earnest,and put carbon neutrality into the overall plan for ecological civilization.

Changes in Low Energy Neutron Counts Rate near Ground Level Associated to Steady Rain

Measurements of neutron count rate （0.025 eV to 10 MeV） at ground level were performed with a single free （He-3） tube detectorthat is located near ground level in Aeronautical Institute of Technology （ITA） Silo Jos6 dos Campos, SP, Brazil. The data were collected uninterruptedly since February 28, 2016 to March 11, 2016. Based on the analysis of data obtained in this period, was possible to observe the occurrence of events, backscattering for example,with significant increases in the neutron count rate during about 3 days of steady rain for all nearby regions. These events seem to be correlated with changes in local weather conditions such as cloud coverage or rain-precipitation of weak intensity. It was reported that the non-observation of a single event seems to be an indicative of the production of a burst of neutrons by a lightning discharge near the detector. Some explanations about the increasing of low energy neutrons are suggested in this article.

二网络热回收技术在合成氨装置中的应用

通过对变换能量平衡的分析可知,若不考虑热损失,变换系统理论上可以热量平衡,在实际生产中为了弥补变换系统热损失,采用"中-低-低"变焕技术和JR型氨合成塔内件的有机结合,合理利用氨合成的富余反应热,满足变换热量平衡,使"变换-合成"的综合能耗达到了新的水平,提高了以煤为原料的合成氨技术的竞争力。

Indications of stratospheric anomalies in the freezing rain and snow disaster in South China,2008

NCEP/NCAR reanalysis data were used to characterize stratospheric temperature and water-vapor anomalies before and after the freezing rain and snow disaster of South China in 2008,and the influence of stratospheric circulation anomalies on the troposphere.Stratospheric temperature and water-vapor anomalies provided good leading indicators of this weather event.The period from December 1st 2007 to February 28th 2008 was divided into 18 pentads.During the 6th pentad,temperature decreased significantly at 10 hPa in the near-polar stratospheric region,and the decreasing trend strengthened and extended downward and southward to middle and lower latitudes.During the 14th-18th pentads,the temperature decrease reached its maximum and extended to 30°N.This coincided with the widespread freezing rain and snow event.By the end of January 2008,the temperature decrease ended in the near-polar stratospheric region,but continued in the mid-latitude area of the troposphere as the freezing rain and snow weather persisted.Similar to the temperature variations,positive anomalies of relative humidity in the stratospheric near-polar region also strengthened and extended downward and southward,coinciding with the freezing rain and snow event.Along with the significant relationship between the freezing rain and snow disaster and stratospheric circulation anomalies,the stratospheric polar vortex changed its shape in late December,intensifying and spreading downward from the top of the stratosphere and southward to the Asian continent,resulting in a deepening of the East Asian Trough and a strengthening of meridional circulation.Before the occurrence of the freezing rain and snow event,temperature and vapor increases in the stratosphere transferred downward to the troposphere,along with a stratospheric flow in the near-polar region southward to lower latitudes.

Nighttime electron density enhancements at middle and low latitudes in East Asia

Nighttime enhancements in ionospheric electron density at mid- and low-latitudes are investigated by using the critical frequency of the F2-1ayer （foF2） data measured from ionosonde stations at Okinawa （26.3°N, 127.8°E, Geomagnetic 15.3°N）, Yamagawa （31.2°N, 130.6°E, Geomagnetic 20.4°N）, Kokubunji （35.7°N, 139.5°E, Geomagnetic 25.5°N）, and Wakkanai （45.4°N, 141.7°E, Geomagnetic 35.4°N） in East Asia during several solar cycles. The results show that there are obvious seasonal and solar activity dependencies of the nighttime electron density enhancements. The enhancements are termed pre-midnight enhancement and post-midnight enhancement, according to the local time when the enhancement appeared. The former has a higher occurrence probability in summer months than in winter months. In contrast, the latter has a larger occurrence probability in winter months than in summer months. Moreover, the nighttime enhancements in electron density are more likely to occur at lower solar activity. These seasonal and solar activity variations of the nighttime enhancements in electron density can be explained in terms of the combined effects of downward plasma flux from the plasmasphere and the neutral winds.