mlsa-iai-msu-lab/ru_sci_bench_zho_cite_reranking huggingface dataset:
Response of a Grassland Ecosystem to Climate Change in a Theoretical Model

The response of a grassland ecosystem to climate change is discussed within the context of a theoretical model. An optimization approach, a conditional nonlinear optimal perturbation related to parameter (CNOP-P) approach, was employed in this study. The CNOP-P, a perturbation of moisture index in the theoretical model, represents a nonlinear climate perturbation. Two kinds of linear climate perturbations were also used to study the response of the grassland ecosystem to different types of climate changes. The results show that the extent of grassland ecosystem variation caused by the CNOP-P-type climate change is greater than that caused by the two linear types of climate change. In addition, the grassland ecosystem affected by the CNOP-P-type climate change evolved into a desert ecosystem, and the two linear types of climate changes failed within a specific amplitude range when the moisture index recovered to its reference state. Therefore, the grassland ecosystem response to climate change was nonlinear. This study yielded similar results for a desert ecosystem seeded with both living and wilted biomass litter. The quantitative analysis performed in this study also accounted for the role of soil moisture in the root zone and the shading effect of wilted biomass on the grassland ecosystem through nonlinear interactions between soil and vegetation. The results of this study imply that the CNOP-P approach is a potentially effective tool for assessing the impact of nonlinear climate change on grassland ecosystems.
Evaluation of Heavy Rainfall Model Forecasts over the Korean Peninsula Using Different Physical Parameterization Schemes and Horizontal Resolution

In this study, the accuracy of a Pennsylvania State University-National Center for Atmospheric Research mesoscale model (PSU/NCAR MM5) for predicting heavy summer precipitation over the Korean Peninsula was investigated. A total of 1800 simulations were performed using this model for 30 heavy rainfall events employing four cumulus parameterization schemes (CPS), two grid-scale resolvable precipitation schemes (GRS), and two planetary boundary layer (PBL) schemes in three model resolutions (90 km, 30 km, and 10 km). The heavy rainfall events were mesoscale convective systems developed under the influence of mid-latitude baroclinic systems with low-level moisture transport from the ocean. The predictive accuracy for maximum rainfall was approximately 80% for 10-km resolution and was 60% for 30-km resolution. The predictive accuracy for rainfall position extended to -150 km from the observed position for both resolutions. Simulated rainfall was most sensitive to CPS, then to PBL schemes, and then to GRS. In general, the Grell (GR) scheme and the Anthes and Kuo (AK) scheme showed a better prediction capability for heavy rainfall than did the Betts-Miller (BM) scheme and the Kain-Fritsch (KF) scheme. The GR scheme also performed well in the 24-h and 12-h precipitation predictions: the parameterized convective rainfall in GR is directly related to synoptic-scale forcing. The models without CPS performed better for rainfall amounts but worse for rainfall position than those with CPS. The MM5 model demonstrated substantial predictive capacity using synoptic-scale initial conditions and lateral boundary data because heavy summer rainfall in Korea occurs in a strong synoptic-scale environment.
A Study of Structure and Mechanism of a Meso-beta-scale Convective Vortex and Associated Heavy Rainfall in the Dabie Mountain Area Part I:Diagnostic Analysis of the Structure

An analysis was conducted on the evolutional process of a mesoscale convective vortex(MCV)and associated heavy rainfall in the Dabie Mountain area on 21-22 June 2008,as well as their structural characteristics in different stages,by using the mesoscale reanalysis data with 3 km and 1 h resolution generated by the Local Analysis and Prediction System(LAPS)in the Southern China Heavy Rainfall Experiment.The results showed that the latent heat released by convection in the midtroposphere was the main energy source for the development of a low-level vortex.There was a positive feedback interaction between the convection and the vortex,and the evolution of the MCV was closely related to the strength of the positive interaction.The most typical characteristics of the thermal structure in different stages were that,there was a relatively thin diabatic heating layer in the midtroposphere in the formative stage;the thickness of diabatic heating layer significantly increased in the mature stage;and it almost disappeared in the decay stage.The characteristics of the dynamic structure were that,in the formative stage,there was no anticyclonic circulation at the high level;in the mature stage,an anticyclonic circulation with strong divergence was formed at the high level;in the decay stage,the anticyclonic circulation was damaged and the high-level atmosphere was in a disordered state of turbulence.Finally,the structural schematics of the MCV in the formative and mature stage were established respectively.
Coupling a Terrestrial Biogeochemical Model to the Common Land Model

A terrestrial biogeochemical model(CASACNP)was coupled to a land surface model(the Common Land Model,CoLM)to simulate the dynamics of carbon substrate in soil and its limitation on soil respiration. The combined model,CoLM CASACNP,was able to predict long-term carbon sources and sinks that CoLM alone could not.The coupled model was tested using measurements of belowground respiration and surface fluxes from two forest ecosystems.The combined model simulated reasonably well the diurnal and seasonal variations of net ecosystem carbon exchange,as well as seasonal variation in the soil respiration rate of both the forest sites chosen for this study.However,the agreement between model simulations and actual measurements was poorer under dry conditions.The model should be tested against more measurements before being applied globally to investigate the feedbacks between the carbon cycle and climate change.
Impacts of Land Process on the Onset and Evolution of Asian Summer Monsoon in the NCEP Climate Forecast System

Impacts of land models and initial land conditions (ICs) on the Asian summer monsoon, especially its Onset, were investigated using the NCEP Climate Forecast System (CFS). Two land models, the Oregon State University (OSU) land model and the NCEP, OSU, Air Force, and Hydrologic Research Laboratory (Noah) land model, were used to get parallel experiments. The experiments also used land ICs from the NCEP/Department of Energy (DOE) Global Reanalysis 2 (GR2) and the Global Land Data Assimilation System (GLDAS). Previous studies have demonstrated that, a systematic weak bias appears in the modeled monsoon, and this bias may be related to a cold bias over the Asian land mass. Results of the current study show that replacement of the OSU land model by the Noah land model improved the model's cold bias and produced improved monsoon precipitation and circulation patterns. The CFS predicted monsoon with greater proficiency in El Nino years, compared to La Nina years, and the Noah model performed better than the OSU model in monsoon predictions for individual years. These improvements occurred not only in relation to monsoon onset in late spring but also to monsoon intensity in summer. Our analysis of the monsoon features over the India peninsula, the Indo-China peninsula, and the South Chinese Sea indicates different degrees of improvement. Furthermore, a change in the land models led to more remarkable improvement in monsoon prediction than did a change from the GR2 land ICs to the GLDAS land ICs.
Accumulation over the Greenland Ice Sheet as Represented in Reanalysis Data

Annual precipitation,evaporation,and calculated accumulation from reanalysis model outputs have been investigated for the Greenland Ice Sheet(GrIS),based on the common period of 1989-2001.The ERA-40 and ERA-interim reanalysis data showed better agreement with observations than do NCEP-1 and NCEP-2 reanalyses.Further,ERA-interim showed the closest spatial distribution of accumulation to the observation.Concerning temporal variations,ERA-interim showed the best correlation with precipitation observations at five synoptic stations,and the best correlation with in situ measurements of accumulation at nine ice core sites.The mean annual precipitation averaged over the whole GrIS from ERA-interim (363 mm yr·~(-1))and mean annual accumulation(319 mm yr·~(-1))are very close to the observations.The validation of accumulation calculated from reanalysis data against ice-core measurements suggests that further improvements to reanalysis models are needed.
Relationship Between East Asian Winter Monsoon and Summer Monsoon

Using National Centers for Environmental Prediction/National Centre for Atmospheric Research (NCEP/ NCAR) reanalysis data and monthly Hadley Center sea surface temperature (SST) data, and selecting a representative East Asian winter monsoon (EAWM) index, this study investigated the relationship between EAWM and East Asian summer monsoon (EASM) using statistical analyses and numerical simulations. Some possible mechanisms regarding this relationship were also explored. Results indicate a close relationship between EAWM and EASM: a strong EAWM led to a strong EASM in the following summer, and a weak EAWM led to a weak EASM in the following summer. Anomalous EAWM has persistent impacts on the variation of SST in the tropical Indian Ocean and the South China Sea, and on the equatorial atmospheric thermal anomalies at both lower and upper levels. Through these impacts, the EAWM influences the land-sea thermal contrast in summer and the low-level atmospheric divergence and convergence over the Indo-Pacific region. It further affects the meridional monsoon circulation and other features of the EASM. Numerical simulations support the results of diagnostic analysis. The study provides useful information for predicting the EASM by analyzing the variations of preceding EAWM and tropical SST.
Assessment of Dynamic Downscaling of the Extreme Rainfallover East Asia Using a Regional Climate Model

This study investigates the capability of the dynamic downscaling method(DDM)in an East Asian climate study for June 1998 using the fifth-generation Pennsylvania State University-National Center for Atmospheric Research non-hydrostatic Mesoscale Model(MM5).Sensitivity experiments show that MM5 results at upper atmospheric levels cannot match reanalyses data,but the results show consistent improvement in simulating moisture transport at low levels.The downscaling ability for precipitation is regionally dependent.During the monsoon season over the Yangtze River basin and the pre-monsoon season over North China,the DDM cannot match observed precipitation.Over Northwest China and the Tibetan Plateau (TP),where there is high topography,the DDM shows better performance than reanalyses.Simulated monsoon evolution processes over East Asia,however,are much closer to observational data than reanalyses. The convection scheme has a substantial impact on extreme rainfall over the Yangtze River basin and the pre-monsoon over North China,but only a marginal contribution for Northwest China and the TP.Land surface parameterizations affect the locations and pattern of rainfall bands.The 10-day re-initialization in this study shows some improvement in simulated precipitation over some sub-regions but with no obvious improvement in circulation.The setting of the location of lateral boundaries(LLB)westward improves performance of the DDM.Including the entire TP in the western model domain improves the DDM performance in simulating precipitation in most sub-regions.In addition,a seasonal simulation demonstrates that the DDM can also obtain consistent results,as in the June case,even when another two months consist of no strong climate/weather events.
Temporal and Spatial Characteristics of Extreme Hourly Precipitation over Eastern China in the Warm Season

Based on hourly precipitation data in eastern China in the warm season during 1961-2000,spatial distributions of frequency for 20 mm h~(-1)and 50 mm h~(-1)precipitation were analyzed,and the criteria of short-duration rainfall events and severe rainfall events are discussed.Furthermore,the percentile method was used to define local hourly extreme precipitation;based on this,diurnal variations and trends in extreme precipitation were further studied. The results of this study show that,over Yunnan,South China,North China,and Northeast China,the most frequent extreme precipitation events occur most frequently in late afternoon and/or early evening.In the Guizhou Plateau and the Sichuan Basin,the maximum frequency of extreme precipitation events occurs in the late night and/or early morning.And in the western Sichuan Plateau,the maximum frequency occurs in the middle of the night. The frequency of extreme precipitation(based on hourly rainfall measurements)has increased in most parts of eastern China,especially in Northeast China and the middle and lower reaches of the Yangtze River, but precipitation has decreased significantly in North China in the past 50 years.In addition,stations in the Guizhou Plateau and the middle and lower reaches of the Yangtze River exhibit significant increasing trends in hourly precipitation extremes during the nighttime more than during the daytime.
Radiative Forcing and Climate Response Due to Black Carbon in Snow and Ice

The radiative forcing and climate response due to black carbon (BC) in snow and/or ice were investigated by integrating observed effects of BC on snow/ice albedo into an atmospheric general circulation model (BCC AGCM2.0.1) developed by the National Climate Center (NCC) of the China Meteorological Administration (CMA). The results show that the global annual mean surface radiative forcing due to BC in snow/ice is +0.042 W m~(-2), with maximum forcing found over the Tibetan Plateau and regional mean forcing exceeding +2.8 W m~(-2). The global annual mean surface temperature increased 0.071℃ due to BC in snow/ice. Positive surface radiative forcing was clearly shown in winter and spring and increased the surface temperature of snow/ice in the Northern Hemisphere. The surface temperatures of snow-covered areas of Eurasia and North America in winter (spring) increased by 0.83℃ (0.6℃) and 0.83℃ (0.46℃), respectively. Snowmelt rates also increased greatly, leading to earlier snowmelt and peak runoff times. With the rise of surface temperatures in the Arctic, more water vapor could be released into the atmosphere, allowing easier cloud formation, which could lead to higher thermal emittance in the Arctic. However, the total cloud forcing could decrease due to increasing cloud cover, which will offset some of the positive feedback mechanism of the clouds.
FINITE ELEMENT ANALYSIS OF OPTIMAL CONTROL PROBLEM GOVERNED BY STOKES EQUATIONS WITH L2-NORM STATE-CONSTRAINTS

An optimal control problem governed by the Stokes equations with L2-norm state constraints is studied. Finite element approximation is constructed. The optimality conditions of both the exact and discretized problems are discussed, and the a priori error estimates of the optimal order accuracy in L2-norm and H1-norm are given. Some numerical experiments are presented to verify the theoretical results. Mathematics subject classification: 49J20, 65N30
乌梁素海沉积物分布特征

乌梁素海,地理坐标为40°36'—41°03'N,108°43'—108°57'E,形似一瓣桔,被芦苇和香蒲分割成大小不一的几个水域;湖区呈南北长,东西窄的狭长形态,南北长50 km,东西宽20 km,水域平均水深为1．5 m左右,最大水深2．5 m左右,是中国八大淡水湖之一,现有水域面积285．38 km~2．近年来,乌梁素海富营养化和外源污染源的研究已有较多的报道,但对其内源污染问题涉及的较少．乌梁素海是黄河遗迹湖,位于内蒙古高原中部黄河沿岸的河套平原的最东端,其开发历史悠久,由于受到人类活动的强烈影响,其湖底沉积物淤积在时空分布上有较大的差异．由于湖泊沉积物常被视作湖泊环境的重要信息库,特别是湖底的现代沉积部分可反映湖泊的污染程度及其演变过程,因此研究湖底沉积物的分布特征,对于控制湖泊的内源污染和富营养化有着重要意义．[取自正文]
百年一遇大旱后城市雨水及降雨径流重金属污染调查

从2009年入秋至2010年春,我国西南地区发生了百年一遇的秋冬春连旱的严重干旱[1]．目前国内外鲜见长时间干旱等异常气候气象条件的雨水和降雨径流污染研究,在昆明,相关研究尚属空白．本文以昆明城区典型集水区雨水、路面与屋面径流为研究对象,调查了百年一遇大旱后的昆明城区雨水和降雨径流重金属污染状况,以期为长期干旱之后的城市降雨径流重金属污染调控与治理提供科学依据．[取自正文]
大冶铜绿山矿区周围土壤重金属分布特征及污染状况评价

综上所述,研究区土壤中重金属元素的富集程度都比较高,通过不同时间跨度上3个批次的数据对比,可以发现铜绿山周边土壤中重金属含量的变化呈逐步增加的趋势．土壤中重金属的相关性较差,污染来源可能不同．矿山开采以及铁路运输等都有可能对该区土壤造成污染．土壤环境质量评价表明,重金属的单项污染指数与综合污染指数已有明显提高,采样点中有77%的土壤重金属综合污染指数超过1．且通过不同时间跨度上3组数据的对比显示出污染越来越严重,单项污染指数变化较明显的是Cd与Zn元素,由原来的未污染级别到污染级别．其中Cd的污染已经相当严重．[取自正文]
珠江口大襟岛中华白海豚保护区水质评价及影响因素分析

中华白海豚(Sousa chinensis)是国家一级重点保护的濒危野生动物,在我国主要分布在广东珠江口、福建九龙江口和广西钦州海域．大襟岛中华白海豚自然保护区位于珠江口大襟岛近海,区内共有10余种珍稀濒危物种,也是至今为止我国海域已知的第二大中华白海豚集中分布区域,不仅数量集中,而且拥有完整的世代结构．[取自正文]
离子色谱法测定砷酸根、亚砷酸根、溴酸根、氯酸根及常见阴离子

砷酸盐、亚砷酸盐以及溴酸盐等因具有较大的毒性,对人类健康和生态环境构成了巨大的威胁,日益受到人们的关注． 美国疾病控制中心(CDC) 和癌症研究机构(LARC) 将砷定为第一类致癌物,国际癌症研究机构将溴酸根定为2B 级潜在致癌物,氯酸盐定为中等毒性化合物,世界卫生组织(WHO) 及《生活饮用水卫生标准》规定砷、氯酸盐、溴酸盐在饮用水中的限量分别为 0． 01、0． 7、0． 01 mg·L~(-1),因此准确测定水和环境中的这些化合物愈显重要．[取自正文]
口服三氯丙烷致肝功能衰竭死亡

TCP主要用于制造某些合成橡胶,也可用作溶剂、油漆和清漆的清除剂、脱脂剂、农药杀虫剂的中间体,是人类致癌物。近年来,由于精细化工、建筑涂料等行业快速发展,接触TCP机会增加。有研究用F344兔和 B6C3Fl鼠做急性口服毒性试验发现,其吸收、代谢、排泄很快,60 h就可排泄口服剂量的50%～65%;代谢物主要集中在肝、心和胃~([1])。本组口服含TCP成分的“稀料”后,主要损害的靶器官为肝脏,与动物试验中的靶器官一致。口服中毒后,早期出现恶心、呕吐,右上腹痛等症状并不明显。血液浓度较高者1～3 d内即出现肝脏酶谱急剧升高、凝血机制障碍,表现为黄疸、皮下黏膜出血点、便血、血尿,进一步可出现肝性脑病、昏迷、多脏器功能衰竭死亡。国内资料观察可见,其中毒方式多为涂料喷漆后经呼吸道吸收和误服后经消化道吸收,经消化道吸收者病情较呼吸道吸收者凶险,血液中毒物成分浓度较高,预后很差~([2-4])。本组2例患者误服后很快因肝功能衰竭而死亡,符合TCP发病特点。TCP被肝细胞线粒体内P450酶催化后,生成活性极强的代谢产物,直接诱导肝细胞坏死。此外,TCP在肝细胞内导致内源性谷胱甘肽、N-乙酰半胱氨酸耗竭,氧自由基堆积,导致肝细胞迅速坏死。TCP慢性接触对人体的危害主要是致癌性和刺激作用。[取自正文]
个体化免疫抑制治疗的理论与实践

新型免疫抑制剂在降低急性排斥反应发生率的同时,也因其狭窄的治疗指数以及药代动力学、药效动力学的个体差异而导致的药物毒性,很大程度上影响了移植物以及受者的长期存活。[取自正文]
穴位注射配合微波治疗咽异感症

咽异感症中医学称为“梅核气”，患者常因咽喉如物梗喉感觉很痛苦、焦噪，中年女性患者居多，不适感尤重。现代研究发现，产生咽异感症的常见原因有:①咽及咽邻近器官的因素，凡病变累及咽腔或咽壁的任何一层组织，使咽部的感觉神经受到刺激，神经兴奋性发生变化，甚至咽肌痉挛或强直，或使吞咽功能受到影响，均可产生咽异感症；②远离器官和全身性因素，迷走神经在胸腔和腹腔诸器官中有着广泛的分布，这些器官罹病时可在咽部产生各种异常感觉。这种咽部异常感觉的产生，可能通过迷走神经的反射作用而引起，也可能迷走神经受刺激后，使环咽肌发生痉挛；③精神因素，精神因素对咽异感症的发生和症状的轻重起伏有着明显的影响[1]。临床上常用注射、服药的方法治疗此病症，但效果往往不佳。[取自正文]
脉冲Nd：YAG激光治疗糖尿病性牙周炎的疗效观察

糖尿病患者由于血糖水平、牙周组织温度、pH值等均较高，有利于牙周细菌生长；而且在长期高血糖环境下，机体牙周组织结构、抗感染能力、致病微生物种类、数量及构成等均发生明显变化；另外高血糖环境还容易造成机体微循环障碍及牙周袋内氧化还原电势进一步降低，更有利于厌氧菌繁殖，从而加重牙周炎病情。基于上述原因。临床治疗糖尿病性牙周炎的疗效往往不尽如人意，迫切希望借助新的手段提高疗效。[取自正文]
骨保护素与冠状动脉疾病的研究进展

冠状动脉(冠脉)疾病主要指冠状动脉粥样硬化性心脏病,其发生的病理生理基础是冠脉血管钙化和粥样硬化。新近研究发现血管钙化是一种类似于骨和软骨形成的主动调节过程,是活跃的血管结构的骨化。动脉粥样硬化 (atherosclerosis,AS)是心血管系统最常见的表现形式,病变主要累及大中动脉,表现为内膜的脂质沉积和钙化。血管钙化与动脉硬化密切相关,是动脉硬化的重要标志。血管钙化和动脉硬化所致冠心病的发生机制及检测标志物一直是研究的热点和难点。[取自正文]
新辅助化疗期乳癌患者心理护理

乳腺癌新辅助化疗是指对于乳腺癌患者在局部治疗之前所给予的全身化疗。现已成为局部进展期乳腺癌的标准治疗方式,并逐渐应用于可手术的早期乳癌患者。乳腺癌新辅助治疗的兴起,使许多以前只能姑息治疗的局部晚期乳腺癌患者,获得了手术机会,降低了死亡率,延长了生存时间。其中有部分患者通过术前新辅助化疗获得了保乳手术的机会〔1〕。
Elevated levels of serum antibodies against alpha-1, 6-glucan in patients with systemic lupus erythematosus or rheumatoid arthritis

This study was undertaken to investigate whether levels of anti-alpha-1, 6-glucan antibodies in human sera correlate with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). Serum samples were collected from patients with SLE (n = 30), RA (n = 30) and healthy adult volunteers. IgG, IgA and IgM levels against alpha-1, 6-glucan were measured using enzyme linked immunosorbent assays. Anti-alpha-1, 6-glucan IgG prevalence was raised in patients with active SLE (73.3%) and RA (60%) compared with healthy controls (13.3%). Strong correlation between anti-alpha-1,6-glucan-lgG levels and anti-perinuclear factor (r = 0.642; p<0.05) in RA patients or anti-nuclear antibodies (r = 0.675; p < 0.05) in SLE patients was observed. No significant differences in anti-alpha-1,6-glucan-lgA or-lgM levels were noted between different groups. We conclude that anti-alpha-1,6-glucan-lgG levels were significantly elevated in patients with SLE or RA and positively correlated with disease activity.
Molecular regulation of telomerase activity in aging

The process of aging is mitigated by the maintenance and repair of chromosome ends (telomeres), resulting in extended lifespan. This review examines the molecular mechanisms underlying the actions and regulation of the enzyme telomerase reverse transcriptase (TERT), which functions as the primary mechanism of telomere maintenance and regulates cellular life expectancy. Underpinning increased cell proliferation, telomerase is also a key factor in facilitating cancer cell immortalization. The review focuses on aspects of hormonal regulations of telomerase, and the intracellular pathways that converge to regulate telomerase activity with an emphasis on molecular interactions at protein and gene levels. In addition, the basic structure and function of two key telomerase enzyme components-the catalytic subunit TERT and the template RNA (TERC) are discussed briefly.
AMPD3 is involved in anthrax LeTx-induced macrophage cell death

The responses of macrophages to Bacillus anthracis infection are important for the survival of the host, since macrophages are required for the germination of B. anthracis spores in lymph nodes, and macrophage death exacerbates anthrax lethal toxin (LeTx)-induced organ collapse. To elucidate the mechanism of macrophage cell death induced by LeTx, we performed a genetic screen to search for genes associated with LeTx-induced macrophage cell death. RAW 264.7 cells, a macrophage-like cell line sensitive to LeTx-induced death, were randomly mutated and LeTx-resistant mutant clones were selected. AMP deaminase 3 (AMPD3), an enzyme that converts AMP to IMP, was identified to be mutated in one of the resistant clones. The requirement of AMPD3 in LeTxinduced cell death of RAW 264.7 cells was confirmed by the restoration of LeTx sensitivity with ectopic reconstitution of AMPD3 expression. AMPD3 deficiency does not affect LeTx entering cells and the cleavage of mitogen-activated protein kinase kinase (MKK) by lethal factor inside cells, but does impair an unknown downstream event that is linked to cell death. Our data provides new information regarding LeTx-induced macrophage death and suggests that there is a key regulatory site downstream of or parallel to MKK cleavage that controls the cell death in LeTx-treated macrophages.
Land Resources of Cryolithozone and Possible Transformations under Globle Change

Issues about land resources of cryolithozone and their possible transformation under global change conditions we will consider on example of the large region of the Russian Federation-the Republic of Sakha(Yakutia),which is considered as the center of the underground continental glaciation of earth in present conditions.The Republic of Sakha(Yakutia)extends between 77°00′and 55°40′of northern latitude and 105°30′and 162°40′of eastern longitude.It stretches from north to south 2000 km and from west to east 2300 km.The area of largest subject in Russia is 3 103 200 km2,which is equal to 2/3 of the Western Europe and exceeds the area of France 6 times,England, almost 13 times,and covers three time zones and three latitudinal climatic zones:arctic,tundra and taiga.The sum of active temperatures(>10℃) in the tundra zone is less than 500℃, in the subzone of northern taiga,800-1200℃and the warmest places in Central and Southern Yakutia reach 1400-1700℃.The whole territory of the republic is situated in the wide distribution of permafrost.On the plains which occupy the area about 1/3 of republic the ice complex is developed(Fig.1)which contains the underground ice up to 50%-90%of ground volume(Fig.2).[取自正文]