最后一次电话(外一首)

最后一次电话（外一首）沈念梓再见的话已说过千遍万遍伤感的气息已逼紧心间握紧话筒的手谁也不忍先放下那么你说———一二三一齐挂———挂断那丝丝缕缕的牵念挂掉那一世的情缘却挂不住我泪落满面说是几个世纪的轮回说是几个世纪的守候亲爱的慢慢靠近你的时候怎么那一根...

Infrared radiation method for measuring ice segregation temperature of artificially frozen soils

In order to study the evolution of the freezing fringe and final lenses of frost susceptible soils and advance the understanding of frost heave and mechanism of frost heave control, we used an open one-dimensional frost heave test system of infrared radiation technology, instead of a traditional thermistor method. Temperatures of the freezing fringe and segregated ice were measured in a non-contact mode. The results show that accurate and precise temperatures of ice segregation can be obtained by infrared thermal imaging systems. A self-developed inversion program inverted the temperature field of frozen soils. Based on our analysis of temperature variation in segregated ice and our study of the relationship between temperature and rate of ice segregation in cooling and warming processes during intermittent freezing, the mechanism of decreasing frost heave of frozen soils by controlling the growth of final lenses with an intermittent freezing mode, can be explained properly.

Thermal state of soils in the active layer and underlain permafrost at the kilometer post 304 site along the China-Russia Crude Oil Pipeline

On-site monitoring is very important for understanding formation mechanisms of frost hazards frequently occurring in pipeline foundation soils and for designing and deploying according mitigative measures in permafrost regions.Significant thaw subsidence of ground surfaces along the ChinaRussia Crude Oil Pipeline(CRCOP) from Mo'he to Daqing,Heilongjiang Province,Northeast China have been observed at some segments underlain by ice-rich warm(>1.0°C) permafrost since the official operation in January 2011.Recent monitoring results of the thermal states of foundation soils at the kilometer post(KP) 304 site along the CRCOP are presented in this paper.The results indicate that during the period from 2012 to 2014,shallow soils(at the depths from0.8 to 4.0 m from ground surface) has warmed by approximately 1.0°C in the lateral range of 1.2 to 2.1 maway from the pipeline axis,and deeper permafrost(such as at the depth of 15 m,or the depth of zero annual amplitude of ground temperatures) by 0.08°C per year 4 m away from the pipe axis,and 0.07°C per year 5 m away from the pipeline axis.The results indicate an all-season talik has developed around and along the CRCOP.The thaw bulb,with a faster lateral expansion(compared with the vertical growth),enlarges in summer and shrinks in winter.This research will provide important references and bases for evaluating thermal influences of warm pipeline on permafrost and for design,construction,operation and maintenance of pipelines in permafrost regions.

Long-Term Frozen Storage Impact on the Antioxidant Capacity and Chemical Composition of Sardinian Myrtle （Myrtus communis L,） Berries

The effects of frozen storage at -18 ℃ up to 6 months, on the antioxidant properties, chemical composition and other physicochemical properties of myrtle berries （Myrtus comrnunis L.） has been evaluated. Berries showed a good resistance to storage decay, and weight loss remained after six months in the 15% range. Results showed that frozen storage up to 6 months affect individual antocyanins content in different ways. Nevertheless the total anthocyanins content was at the end of storage higher than in fresh fruits. The antioxidant capacity calculated with 2,2-diphenyl-l-picrylhidrazyl （DPPH） and 2,2＇-Azino-bis （3-ethylbenzothiazoline-6-sulfonic acid） （ABTS） increased during storage and the calculated r2 showed a positive correlation with the total anthocyanins content. Gluconic and fumaric acid did not changed, quinic acid decreased while malic and shikimic acid increased. The total organic acid content during storage was higher than in fresh fruits causing a slight decrease in pH. Fructose and glucose increased with the same rate and the ratio fructose/glucose remained unchanged （1.06 ± 0.01）, CIE L^＊a^＊b^＊ coordinates showed a shift of the colour to tawny brown after six months storage.

Nanospike surface-modified bionic porous titanium implant and in vitro osteogenic performance

This work aimed to prepare the nanospike surface-modified bionic porous titanium implants that feature favorableosteointegration performance and anti-bacterial functions.The implant was prepared using freeze casting,and nanospikesurface-modification of the implant was performed using thermal oxidation.The pore morphology and size,mechanical properties,and osteogenic performance of the implants were analyzed and discussed.The results showed that when the volume ratio of titaniumpowder in slurry was set to be10%,the porosity,pore diameter,compressive strength,and elastic modulus of the porous sampleswere(58.32±1.08)%,(126.17±18.64)μm,(58.51±20.38)MPa and(1.70±0.52)GPa,respectively.When the porous sample wassintered at a temperature of1200°C for1h,these values were(58.24±1.50)%,(124.16±13.64)μm,(54.77±27.55)MPa and(1.63±0.30)GPa,respectively.The nanospike surface-modified bionic porous titanium implants had favorable pore morphology andsize,mechanical properties and osteointegration performance through technology optimization,and showed significant clinicalapplication prospect.

The Degradation and Pollution of Soils on the Territory of the Kovykta Gas Condensate Field

In this paper, research results from the time interval 2002-2012 are used to give an account of the chemical composition of soils on the territory of the Kovykta gas condensate field. The findings presented provide a better understanding of the ecological state of soil cover, its resilience to anthropogenic impacts, and its possible disturbance caused by the drilling pad construction activity, and by the laying of geophysical profiles. An analysis of soil pollution for the study territory generally showed that the soils are polluted with chemical elements which refer to toxicity classes： Pb, Cu, Ni, Cr, Ba and Mn. High levels ofoil products were detected near boreholes. Strong mineralization was recorded in the soil near borehole. It has a chloride-sodium chemical composition. As a result of the construction of foundation pits, recesses, ditches and earth embankments, the soil is totally destroyed, and rock outcrops show up. Disturbances of the sod cover due to road construction or even by all-terrain vehicles in these extreme conditions entail an accelerated development of linear erosion to form scours and gullies. Elimination of the canopy layer leads to an increase in surface heating, and to an acceleration of permafrost thawing. Swamping is accelerated on negative relief forms due to the increased entry of melt waters.

Research status of soil frost-heave theory and frost-heave prediction models

Soil frost heaving is a complex physical, mechanical, and chemical synthesis process. This paper summarizes the frost-heaving theory over half a century, including the capillary theory, the frozen-fringe theory, and those achievements recently made by scholars. In this paper, we also discus researching achievements of the soil-prediction model during the past 40 years, including the water-dynamics model, the rigid-ice model, the segregation-potential model, and the thermo-dynamic model. This summary and discussion will enable readers to understand the latest direction of research; it also summarizes the development of frost-heave prediction models and their advantages and shortcomings.

Research on soil salt transfer under freeze-thawing condition

Soil salt transformation plays an important role in the freeze-thawing process,which is also one of basic problems of cryopedology. The very special law is made up of the two time salt-moisture transfer under freeze-thawing condition. Based on the latest research at home and abroad,through the investigation of soil moisture-salt change in the freeze-thawing process,the conclusion is made that the soil water potential gradient is the main driving force of soil salt movement and the factors are of quantities. The research shows that,when freezing,temperature drops,salt and moisture move towards frozen layer. All make the salinity content of the frozen layer increase significantly. In the thawing process,salinity and moisture in the soil move up again with evaporation and makes the salt second migration.

Freezing Desalination

The solidification of a binary mixture causes allowed thermosolutal convection. Under certain conditions, the separation of its components gives rise to a preferential movement of migration of solutes. The quantity and the concentration of the obtained products depend on the mechanisms of sepa＇,ration which depend on different parameters and the applied boundary conditions. In this way, the freezing of H20-NaC1 mixture makes it possible to obtain a liquid phase which is charged in solute and is called brine and a solid phase which is composed of ice being able to become fresh water, and so it can works as a desalination process. In this paper, a series of experiments of seawater freezing on cold surface is carried out at the laboratory under different operating conditions. During these experiments, the role of each parameter （temperature of crystallization, duration of crystallizat on...） which is able to impact the final composition is focused on. After a preliminary series of experiment, the yield is： improved to reach rates of salt and make it possible to regard the water produced as drinkable according to the standards of WHO （World Health Organization）.

Effect of Butylated Hydroxytoluene on Survival of Frozen-TIhawed Fighting Bull Spermatozoa

The aim of the present study was to evaluate effect of 3 levels of butylated hydroxytoluene （BHT） supplemented in extender for fighting bull semen. Ejaculates were obtained from 10 healthy fighting bulls by artificial vagina. Semen with motility of more than 70% was included in the experiment. Tris-fructose-glycerol-egg yolk extender containing 0, 1, 3 and 7 mM BHT was used to dilute semen to final concentration of 200 × 10^6 cells/ml. Diluted semen was frozen in 0.25 mL straws and frozen semen was thawed in a 37 ℃ water bath for 15 sec before being evaluated at 0 and 1 hour. Sperm motility at 0 and 1 hour after thawing did not differ among groups tested （ranged 47.86-53.57 and 21.79-24.29 respectively）. At 0 hour after thawing, percentage of live sperm of 3 mM BHT （37.39% ± 2.91%） was lower than those of 0 and 1 mM BHT （43.71%± 2.76% and 41.46% ±2.59% respectively, P 〈 0.05） but not different from 7 mM BHT （40.89%± 2.50%）. The effect was more significant at 1 hour after thawing and 3 mM BHT （32.07% ± 2.45%） suppressed live cells more than other concentrations （ranged 35.07%-37.46%, P 〈 0.05）. At 0 hour after thawing, percentage of membrane integrity （hypo-osmotic swelling test） was not affected by BHT concentration （ranged 23.89%-28.54%）. However, at 1 hour after thawing, percentage of membrane integrity of 3 mM BHT （19.75% ± 1.41%） was lower that of 7 mM BHT （23.29% ± 1.88%, P 〈 0.05） but not different from those of 0 and 1 mM BHT （20.32% ±1.81% and 22.07% ± 2.27% respectively）. No significant effect was found on percentage of abnormal sperm. There was no effect of BHT supplementation in extender on most of the Hamilton-thorn motility analyser parameters. It may be concluded that 3 mM BHT can be harmful to fighting bull spermatozoa and lower concentrmion can be used without detrimental effect. Further study may be needed to verify use of BHT in lower range of concentrations.

一九七五:那个冰冷的春节

过年啦!过年啦!五六岁的我和姐姐穿着新衣服,手举着风车,花灯笼,糖葫芦,在清晨的雪地上跑来跑去,脚上红花的灯芯绒小棉鞋踏着洁白的雪地,一红一白的十分好看。鞭炮声,欢笑声撒满了各个角落。外婆在喊我回家吃年糕,一个雪球飞来打在我的肩头,我肩头绽开了晶莹的雪花,我傻笑着、胡噜着……

Correlation between high-resolution climate records from a Nanjing stalagmite and GRIP ice core during the last glaciation

A 400-mm-long stalagmite from Tangshan Cave, Nanjing has beenanalyzed by a high-precision TIMS-U series dating method and also determined for oxygen and carbon stable isotopic compositions. The results provided a high-resolution paleoclimate record for eastern China during a time interval (from 54 000 to 19 000 aBP) of the last glaciation. The continuous record of oxygen-18 variations in the stalagmite, indicating a precipitation history of the East Asian monsoon, shows not only signals of the Heinrich events, but also the Dansgaard-Oeschger cycles which are first found in the last glacial climate record of the East Asian monsoon area. Although the stalagmite-based climatic signals match well with the GRIP ice core record, some differences between the two re-cords can be recognized: (1) The last glacial climate changes in eastern China exhibited a long-term remarkably cooling trend, superimposed on which were four successive Bond’s cycles illus-trated by the δ18O curve. This strong cooling tendency may be an effect of the strong summer mon-soon event during the MIS 3 over the Tibetan Plateau. (2) There exist some phase differences of 1000—2000 years between the cooling events in the stalagmite-based climate signal and the GRIP ice core record. Such differences should be further verified by calibrations of multiple dating meth-ods.

Physiographic and geological characteristics of shelves in north and west of Taiwan

In north of Taiwan the East China Sea Shelf extends from the coastline of China's Mainland to the southern Okinawa Trough, showing a shelf-slope-basin bathymetric profile. Sea floor of the East China Sea Shelf is generally smooth and flat. It is wide (230 km) and relatively shallow with an average shelf-break depth of 120 m, reflecting the effect of Quaternary glaciation about 15000 years ago. The Pliocene-Quaternary East China Sea Shelf is underlain by thin sequences of about 1000 m thick shallow marine sediments mainly derived from China, forming an eastward dipping sedimentary wedge due to regional tilting and subsidence and representing the youngest part of the Cenozoic rift margin in southeastern China. The Taiwan Strait Shelf has two phases in development: one is the early phase of the Paleo-cene-Miocene rift margin and the other is the late stage of the Pliocene-Quaternary foreland sedi-mentation. It is a foreland shelf and its present morphology results from the combined effects of tectonic subsidence and sedimentation overprinting that of the Late Pleistocene glaciation about 15000 years ago.Southeast of the Taiwan Strait Shelf lies the very narrow Kaoping Shelf along the southwest-ern Taiwan coast. The island shelf is a short, narrow and shallow shelf (100 km long, 20 km wide and 80 m deep). Progradation of Quaternary orogenic sediments from the Taiwan orogen forms the present island shelf off southwest Taiwan. The shelf represents the early stage of foreland basin sedimentation.The transition from a passive margin shelf (East China Sea Shelf), a foreland shelf (Taiwan Strait Shelf) to an island shelf (Kaoping Shelf) along the strike of the fold-and-thrust belt of Taiwan mainly reflects the oblique collision between the Luzon Arc and the Chinese margin from Pliocene to the present. The accompanying uplift of Taiwan orogen, foreland-basin sedimentation, and sea level changes contribute to the formation of these three different shelves adjacent to Taiwan.

Effect of Pore Size on the Nucleate Pool Boiling of Structured Enhanced Tubes

In this study, pool boiling test results are provided for the structured enhanced tubes having pores with connecting gaps. The surface geometly of the present tube is similar to that of Turbo-B. Three tubes with different pore size (0.20 mm, 0.23 mm and 0.27 mm) were manufactured and tested using R-11, R-123 and R-134a. The pore size which yields the maximum heat transfer coefficient varied depending on the refrigerant. For R-134a, the maximum heat transfer coefficient was obtained for the tube having 0.27 nun pore size. For R-11 and R- 123, the optimum pore size was 0.23 mm. One novel feature of the present tubes is that their boiling curves do not show a cross-over characteristic, which existing pored tubes do. The connecting gaps of the present tube are believed to serve an additional route for the liquid supply and delay the dry-out of the tunnel. The present tubes yield the heat transfer coefficients approximately equal to those of the existing pored enhanced tubes. At the heat flux 40 kW/m2 and saturation temperature 4.4° C, the heat transfer coefficients of the present tubes are 6.5 times larger for R-11, 6.0 times larger for R-123 and 5.0 times larger for R-134a than that of the smooth tube

Reconstruction of Soil Particle Composition During Freeze-Thaw Cycling： A Review

Studies conducted over several decades have shown that the freeze-thaw cycles are a process of energy input and output in soil, which help drive the formation of soil structure, through water expansion by crystallization and the movement of water and salts by thermal gradients. However, most of these studies are published in Russian or Chinese and are less accessible to international researchers. This review brought together a wide range of studies on the effects of freezing and thawing on soil structure. The following findings are summarized： i） soil structure after freeze-thaw cycles changes considerably and the changes are due to the mechanical fragmentation of soil coarse mineral particles and the aggregation of soil fine particles; ii） the particle size of soil becomes homogeneous and the variation in soil structure weakens as the number of freeze-thaw cycles increases; iii） in the freezing process of soil, an important principle in the variation of soil particle bonding is presented as： condensation →aggregation→ crystallization; iv） the freeze-thaw cycling process has a strong effect on soil structure by changing the granulometric composition of mineral particles and structures within the soil. The freeze-thaw cycling process strengthens particle bonding, which causes an overall increase in aggregate stability of soil, showing a process from destruction to reconstruction.

Geochemistry and genesis of authigenic pyrite from gas hydrate accumulation system in the Qilian Mountain permafrost, Qinghai, northwest China

A type of authigenic pyrites that fully fill or semi-fill the rock fractures of drillholes with gas hydrate anomalies are found in the Qilian Mountain permafrost; this type of pyrite is known as ＂fracture-filling＂ pyrite. The occurrence of ＂fracture-filling＂ pyrite has a certain similarity with that of the hydrate found in this region, and the pyrite is generally concentrated in the lower part of the hydrate layer or the hydrate anomaly layer. The morphology, trace elements, rare earth elements, and sulfur isotope analyses of samples from drillhole DK-6 indicate that the ＂fracture-filling＂ pyrites are dominated by cubic ones mainly aligned in a step-like fashion along the surfaces of rock fractures and are associated with a circular structure, lower Co/Ni and Sr/Ba, lower ZREE, higher LREE, significant Eu negative anomalies, and 634ScDT positive bias. In terms of the pyrites＇ unique crys- tal morphology and geochemical characteristics and their relationship with the hydrate layers or abnormal layers, they are closely related with the accumulation system of the gas hydrate in the Qilian Mountain permafrost. As climate change is an important factor in affecting the stability of the gas hydrate, formation of fracture-filling pyrites is most likely closely related to the secondary change of the metastable gas hydrate under the regional climate warming. The distribution intensity of these py- rites indicates that when the gas hydrate stability zone （GHSZ） is narrowing, the hydrate decomposition at the bottom of the GHSZ is stronger than that at the top of the GHSZ, whereas the hydrate decomposition within the GHSZ is relatively weak. Thus, the zone between the shallowest and the deepest distribution of the fracture-filling pyrite recorded the largest possible original GHSZ.