The Interdependence of Deformational and Thermal Processes in Mountain Belts

Crustal temperatures within collisional orogens are anomalously high compared with temperatures at comparable depths in stable continents, which is evidence of thermal processes that are fundamental to orogenesis. These temperatures can be explained by the redistribution of crust enriched in heat-producing elements through the accretion of crust from the down-going plate to the upper plate and surface erosion. With the use of geologically reasonable rates, the model results predict high temperatures (over 600°C) and inverted upper-plate geotherms (about 100°C over 20 kilometers) at shallow depths (20 to 40 kilometers) by 25 to 35 million years after collision. This study emphasizes the interdependence of deformational, surficial, and thermal processes.     

Evaluation of a wireless infrared thermometer with a narrow field of view

Many agricultural studies rely on infrared sensors for remote measurement of surface temperatures for crop status monitoring and estimating sensible and latent heat fluxes. Historically, applications for these non-contact thermometers employed the use of hand-held or stationary industrial infrared thermometers (IRTs) wired to data loggers. Wireless sensors in agricultural applications are a practical alternative, but the availability of low cost wireless IRTs is limited. In this study, we designed prototype narrow (10°) field of view wireless infrared sensor modules and evaluated the performance of the IRT sensor by comparing temperature readings of an object (T_obj) against a blackbody calibrator in a controlled temperature room at ambient temperatures of 15 °C, 25 °C, 35 °C, and 45 °C. Additional comparative readings were taken over plant and soil samples alongside a hand-held IRT and over an isothermal target in the outdoors next to a wired IRT. The average root mean square error (RMSE) and mean absolute error (MAE) between the collected IRT object temperature readings and the blackbody target ranged between 0.10 and 0.79 °C. The wireless IRT readings also compared well with the hand-held IRT and wired industrial IRT. Additional tests performed to investigate the influence of direct radiation on IRT measurements indicated that housing the sensor in white polyvinyl chloride provided ample shielding for the self-compensating circuitry of the IR detector. The relatively low cost of the wireless IRT modules and repeatable measurements against a blackbody calibrator and commercial IR thermometers demonstrated that these wireless prototypes have the potential to provide accurate surface radiometric temperature readings in outdoor applications. Further studies are needed to thoroughly test radio frequency communication and power consumption characteristics in an outdoor setting.     

Low-Temperature Nonoxidative Activation of Methane over H-Galloaluminosilicate (MFI) Zeolite

Conversion of methane to higher hydrocarbons by its low-temperature activation without forming undesirable carbon oxides is of great scientific and practical importance. Methane can be highly activated, yielding high rates of conversion to higher hydrocarbons and aromatics (10 to 45 percent) at low temperatures (400° to 600°C), by its reaction over H-galloaluminosilicate ZSM-5 type (MFI) zeolite in the presence of alkenes or higher alkanes. The methane activation results from its hydrogen-transfer reaction with alkenes.     

High-pressure creep of serpentine, interseismic deformation, and initiation of subduction

The supposed low viscosity of serpentine may strongly influence subduction-zone dynamics at all time scales, but until now its role could not be quantified because measurements relevant to intermediate-depth settings were lacking. Deformation experiments on the serpentine antigorite at high pressures and temperatures (1 to 4 gigapascals, 200 degrees to 500 degrees C) showed that the viscosity of serpentine is much lower than that of the major mantle-forming minerals. Regardless of the temperature, low-viscosity serpentinized mantle at the slab surface can localize deformation, impede stress buildup, and limit the downdip propagation of large earthquakes at subduction zones. Antigorite enables viscous relaxation with characteristic times comparable to those of long-term postseismic deformations after large earthquakes and slow earthquakes. Antigorite viscosity is sufficiently low to make serpentinized faults in the oceanic lithosphere a site for subduction initiation.     

Borehole Temperatures and a Baseline for 20th-Century Global Warming Estimates

Lack of a 19th-century baseline temperature against which 20th-century warming can be referenced constitutes a deficiency in understanding recent climate change. Combination of borehole temperature profiles, which contain a memory of surface temperature changes in previous centuries, with the meteorological archive of surface air temperatures can provide a 19th-century baseline temperature tied to the current observational record. A test case in Utah, where boreholes are interspersed with meteorological stations belonging to the Historical Climatological Network, yields a noise reduction in estimates of 20th-century warming and a baseline temperature that is 0.6° ± 0.1°C below the 1951 to 1970 mean temperature for the region.     

Direct pH Measurement of NaCl-Bearing Fluid with an in Situ Sensor at 400°C and 40 Megapascals

The pH of concentrated NaCl-HCl fluids (0.57 mole of NaCl per kilogram of water) has been measured at supercritical conditions of water with a yttria-stabilized zirconia sensor in a titanium flow reactor. At 400°C and 40 megapascals, the in situ pH of the fluids, ranging from 3.3 to 6.2, differs greatly from its original value of 1.9 to 7.6 at ambient conditions. The measurements agree well with theoretical predictions, showing strong associations of HCl° and NaOH° complexes in high-temperature fluids. The pH sensor provides a powerful tool to investigate unambiguously the distribution of species in aqueous fluids at elevated temperatures and pressures.     

Weakening of dunite by serpentine dehydration

A shear press has been used to determine the mechanical behavior of serpentinized dunite and forsterite at normal pressures to 50 kilobars, temperatures to 900 degrees C; and strain rates from 10(-1) to 10(-4) per second. The shear strength of dunite, containing less than 5 percent by volume of serpentine, is reduced by at least 30 percent as the temperature is raised from 300 degrees to 520 degrees C. Abundant kink bands develop at normal pressures above 35 kilobars at 27 degrees C and at lower pressures as the temperature is increased.     

改性蛇纹石对Pb2+的吸附机理及吸附条件优化

为提升蛇纹石对污染物Pb²⁺的去除效果,实现废水中Pb²⁺的高效去除,本研究将天然蛇纹石矿物高温改性,探究改性后蛇纹石对Pb²⁺的吸附机理、解吸情况及蛇纹石用量、溶液的初始pH、蛇纹石粒径大小和吸附时间对吸附量和Pb²⁺去除率的影响,并通过Box-Behnken响应面法优化改性蛇纹石吸附Pb²⁺的实验条件。结果表明：改性蛇纹石吸附性能明显提升,理论最大饱和吸附容量更高,二者吸附过程均更符合Freundlich等温吸附模型和准二级动力学模型,且吸附过程为自发吸热进行的。改性蛇纹石吸附Pb²⁺的机理主要为蛇纹石裂解产生的Mg²⁺与溶液中溶解的CO₂结合形成MgCO₃,MgCO₃与溶液中的Pb²⁺发生溶积置换生成PbCO₃沉淀;Pb²⁺与改性后蛇纹石表面形成的高能键结合,以Pb（NO₃）₂·Si-O、PbO·O-Si-O配合物的形式吸附在蛇纹石表面。改性蛇纹石在溶液中Pb²⁺的解吸量及解吸率均较低,改性蛇纹石对Pb²⁺的吸附情况较为稳定,Pb²⁺不易被解吸出来。改性蛇纹石对溶液中Pb²⁺最佳吸附条件为固液比为1∶200（m∶V）,pH=5.5,粒径为140目,吸附时间为36 h,此时吸附量及Pb²⁺去除率分别为15.26 mg·g^-1、79.89%。研究表明,改性蛇纹石对Pb²⁺吸附性能明显提升,具有较高吸附容量且吸附较为稳定不易解吸,对去除废水中Pb²⁺具有潜在应用价值。     

晚霜冻胁迫后冬小麦株高降低及其与籽粒产量关系

【目的】探究晚霜冻胁迫对冬小麦株高及其构成因素的影响,阐明株高降低特性及其与节间长、穗长和籽粒产量的内在关系,为晚霜冻害评估指标的建立提供依据。【方法】基于低温室和田间可移动式霜箱2种模拟霜冻手段,分别以冬小麦幼穗发育阶段(小花原基分化、雌雄蕊原基分化、药隔形成、四分体形成和抽穗期)和零下处理温度(-1℃、-3℃、-5℃、-7℃、-9℃和-11℃)为梯度,共开展6期盆栽试验和3期小区试验;在考察植株茎部冻害、测定株高与其构成因素、统计籽粒产量要素的基础上,运用方差分析、回归函数拟合、以及突变检验等方法研究晚霜冻胁迫下株高降低特性,分析各构成因素对株高的贡献、以及株高与籽粒产量的回归关系。【结果】(1)在雌雄蕊原基分化至药隔形成后期,株高随处理温度降低而呈突变性降低特征,处理温度低于-5℃左右时突变开始,且不同植株个体、品种间有一定差异;在同一处理温度下,株高最大降幅出现在药隔形成后期。(2)在雌雄蕊原基分化期、药隔形成前期和药隔形成后期,对株高贡献排前两位的节间分别为倒四节间和倒三节间、倒三节间和倒二节间、倒二节间和倒四节间,其长度均因冻害胁迫而显著缩短,且与株高呈极强显著相关性(P0.001),此时株高亦呈显著降低趋势。(3)株高与穗粒数、千粒重、单株产量之间的回归模型符合幂函数曲线特征,其中,单株产量的降幅随株高降低而呈现先快后慢的变化态势;当单株产量因冻害胁迫降低至1.5 g以下时,其随株高继续降低而不再明显减少,此时穗粒数变化也已不大。【结论】在模拟晚霜冻胁迫条件下,正在伸长或待伸长的冬小麦节间长度与穗长显著缩短;当缩短节间与对株高起主要贡献的节间相一致时,株高显著降低。利用节间缩短特性、以及单株产量和株高降低之间的幂函数关系模型,可为冬小麦生长后期植株倒伏以及产量损失风险评估方法提供新的研究途径。     

中国不同气候区小麦产量及发育期持续时间对田间增温的响应

【目的】气候变暖对小麦生长发育有重要影响。然而,中国不同气候区小麦生长发育对温度升高的响应程度仍未系统量化。因此,急需阐明不同气候区增温及不同时段增温对小麦产量及发育期持续时间的影响程度,揭示小麦产量及发育期对增温的响应规律。【方法】本文搜集了1990-2017年间已发表的关于中国小麦全生育期田间持续增温条件下小麦产量变化的21篇文献,运用整合分析（Meta-analysis）量化田间不同增温幅度及不同时段增温对中国小麦产量及生育期的影响程度,系统阐明其在不同气候区的差异及规律。【结果】（1）亚热带季风区增温（0-3℃）显著增加小麦产量、千粒重和穗粒数,其平均增幅分别为8.2%、6.3%和4.7%;温带季风区增温（0-3℃）显著增加小麦产量、穗粒数和穗数,其平均增幅分别为6.8%、3.9%和5.5%,而温带大陆性气候区增温（0-3℃）显著降低小麦产量、千粒重和穗粒数,其平均降幅分别为10.2%、5.9%和8.3%。其中,亚热带季风区增温0-2℃,小麦产量显著提高了8.5%,而增温2-3℃时,小麦并未增产;温带季风气候区小麦增产愈为明显,当增温2-3℃时小麦的增产幅度达14.5%;相反,在温带大陆性气候区增温0-2℃和2-3℃时,小麦分别显著减产10.1%和15.9%。（2）亚热带季风区和温带大陆性气候区增温（0-3℃）小麦全生育期持续时间分别缩短了3.3%和7.1%,相反,在温带季风区,增温并未明显改变小麦全生育期持续时间;与此同时温带大陆性气候区和温带季风气候区的生殖期持续时间并无明显变化,而亚热带季风区小麦生殖生长持续时间却显著增加（8.7%）。（3）总体来看（季风气候区所有独立研究结果）夜间增温0-2℃和2-3℃对小麦产量有显著影响,小麦分别增产10.5%和15.0%。【结论】田间增温会显著影响中国粮食主产区小麦产量以及发育期持续时间,但不同气候区及不同时段增温对小麦生长和发育的影响不同。本研究结果可为未来气候变化新态势下中国粮食主产区种植制度优化与合理布局提供科学依据。     

Pore Fluid Constraints on the Temperature and Oxygen Isotopic Composition of the Glacial Ocean

Pore fluids from the upper 60 meters of sediment 3000 meters below the surface of the tropical Atlantic indicate that the oxygen isotopic composition (delta18O) of seawater at this site during the last glacial maximum was 0.8 ± 0.1 per mil higher than it is today. Combined with the delta18O change in benthic foraminifera from this region, the elevated ratio indicates that the temperature of deep water in the tropical Atlantic Ocean was 4°C colder during the last glacial maximum. Extrapolation from this site to a global average suggests that the ice volume contribution to the change in delta18O of foraminifera is 1.0 per mil, which partially reconciles the foraminiferal oxygen isotope record of tropical sea surface temperatures with estimates from Barbados corals and terrestrial climate proxies.     

Direct Radiometric Observations of the Water Vapor Greenhouse Effect Over the Equatorial Pacific Ocean

Airborne radiometric measurements were used to determine tropospheric profiles of the clear sky greenhouse effect. At sea surface temperatures (SSTs) larger than 300 kelvin, the clear sky water vapor greenhouse effect was found to increase with SST at a rate of 13 to 15 watts per square meter per kelvin. Satellite measurements of infrared radiances and SSTs indicate that almost 52 percent of the tropical oceans between 20°N and 20°S are affected during all seasons. Current general circulation models suggest that the increase in the clear sky water vapor greenhouse effect with SST may have climatic effects on a planetary scale.     

Chemical Solution Routes to Single-Crystal Thin Films

Epitaxial thin films of inorganic single crystals can be grown on single-crystal substrates with a variety of different solution chemistries. This review emphasizes chemical solution deposition, in which a solution is used to deposit a layer of precursor molecules that decompose to low-density, polycrystalline films during heating. Ways to control film cracking during deposition and heat treatment and why many precursors synthesize metastable crystalline structures are discussed, and the different mechanisms that convert the polycrystalline film into a single crystal are reviewed. Hydrothermal epitaxy, in which single crystal thin films are directly synthesized on templating substrates in an aqueous solution at temperatures <150°C, is also discussed.     

A low-cost microcontroller-based system to monitor crop temperature and water status

A prototype system was developed and constructed for automating the measurement and recording of canopy-, soil-, and air temperature, and soil moisture status in cropped fields. The system consists of a microcontroller-based circuit with solid-state components for handling clock/calendar, sensor power, and data storage and retrieval functions. Sensors, including an analog soil moisture sensor, analog and digital temperature sensors, and a digital infrared thermometer, are widely available and inexpensive. The circuit board and sensor assemblies require approximately 4 h to construct and test, and material costs totaled approximately US$84. Systems were built and tested during the 2009 growing season in a corn field to evaluate performance and suitability under local conditions. The sensors performed according to manufacturers’ specifications, with accuracies of ±0.4 °C, ±1.4 °C, and ±0.3 °C for air-, soil-, and canopy-temperature measurements, respectively. Soil moisture sensors were calibrated and provided measurements within ±2 kPa of the manufacturer's values. Reliability of data collection and storage averaged 91%, with most bad or missing data occurring during periods of inclement weather and electrostatic interference.     

Biomimetic Pathways for Assembling Inorganic Thin Films

Living organisms construct various forms of laminated nanocomposites through directed nucleation and growth of inorganics at self-assembled organic templates at temperatures below 100°C and in aqueous solutions. Recent research has focused on the use of functionalized organic surfaces to form continuous thin films of single-phase ceramics. Continuous thin films of mesostructured silicates have also been formed on hydrophobic and hydrophilic surfaces through a two-step mechanism. First, under acidic conditions, surfactant micellar structures are self-assembled at the solid/liquid interface, and second, inorganic precursors condense to form an inorganic-organic nanocomposite. Epitaxial coordination of adsorbed surfactant tubules is observed on mica and graphite substrates, whereas a random arrangement is observed on amorphous silica. The ability to process ceramic-organic nanocomposite films by these methods provides new technological opportunities.     

High temperatures do not decrease biocontrol potential for the host-killing parasitoid Neochrysocharis formosa (Hymenoptera: Eulophidae) on agromyzid leafminers

Temperature, as a critical abiotic factor, might influence the effectiveness of biological control by parasitoids in host-parasitoid systems. In this study, Neochrysocharis formosa (Westwood), a larval endoparasitoid, is used to investigate the efficacy of biological control on a vegetable agriculture pest, Liriomyza sativae Blanchard, reared on kidney bean (Phaseolus vulgaris L.), at four constant temperatures (26, 29, 32, and 35°C) under laboratory conditions. Our results show that high temperatures (29, 32, and 35°C) do not significantly affect lifetime host-killing events of female adults by increased daily host-killing events compared to temperature of 26°C, although their lifespans decrease with an increase in temperatures. Each life-history trait of female adults (lifespan, parasitism, stinging, or non-reproductive host-killing events) present a linear relation with temperatures and host-feeding events, respectively. Our findings contribute to a better understanding of biocontrol efficacy of parasitoid N. formosa against agromyzid leafminers at high-temperature seasons or environments.     

彩叶芋2个品种抗寒性的比较

以彩叶芋Caladium bicolor 2个品种的组培苗为试验材料,通过人工低温处理(0～20℃),研究彩叶芋叶片中的相对电导率、可溶性蛋白质量分数、可溶性糖质量分数、游离脯氨酸质量分数、超氧化物歧化酶(SOD)活性的变化,进行方差分析和多重比较分析,计算其半致死温度。2种彩叶芋品种叶片的半致死温度均较高。相对电导率与抗寒性呈负相关,可溶性蛋白、可溶性糖、游离脯氨酸、SOD活性与抗寒性呈正相关。研究分析表明:各个指标在不同温度和不同品种间的差异都达到了极显著水平(P<0.01)。其中相对电导率、可溶性蛋白、可溶性糖量、SOD活性可以更好地反应彩叶芋在低温下的生理变化及不同品种之间的抗寒性差异,可定为彩叶芋品种抗寒鉴定的初步指标。游离脯氨酸与彩叶芋抗寒性的关系还有待进一步研究。彩叶芋抗寒性的强弱为漆斑彩叶芋Caladium bicolor‘Wightii’>红艳彩叶芋‘Postman Joyner’。     

荧光猝灭法研究8-烷基黄连碱衍生物对溶菌酶的作用机制

通过测定不同温度(12、24、36℃)下8-烷基黄连碱衍生物(Cop-C8-n,n=4、6、8)对溶菌酶的荧光猝灭常数,并计算热力学参数,研究8-烷基黄连碱衍生物对溶菌酶的作用机制.结果表明:8-烷基黄连碱衍生物对溶菌酶的内源性荧光可产生极强的猝灭作用,猝灭作用过程既有静态猝灭又有动态猝灭;热力学参数证明,黄连碱衍生物...     

不同砧木对‘87-1’葡萄光合特性及荧光特性的影响

【目的】评价贝达、1103P、3309C、140Ru、5C、SO4、华葡1号、抗砧1等8种不同砧木对‘87-1’葡萄光合特性和叶绿素荧光特性的影响,为筛选适宜设施栽培的砧木提供理论基础。【方法】通过Li-6400光合仪测定光响应曲线(设定CO2浓度为400μmol·mol-1,温度为25℃,气体流速为500 mmol·s~(-1)。设定光合有效辐射按照由强到弱的顺序分别为2 000、1 800、1 500、1 200、800、400、200、100、50、20、0μmol·m~(-2)·s~(-1))、CO2响应曲线(设定光合有效辐射为1 200μmol·m~(-2)·s~(-1),温度和气体流速分别设为25℃和500 mmol·s~(-1)。CO2浓度按照400、200、100、50、20、400、400、800、1 200、1 500、1 800、2 000μmol·mol-1的顺序进行测定)、温度响应曲线(设定光合有效辐射为1 200μmol·m~(-2)·s~(-1),CO2浓度控制为400μmol·mol-1,气体流速为500 mmol·s~(-1)。温度按照由小到大的顺序设定为25、27、30、32、35和37℃),通过3条曲线分别求光补偿点、表观量子效率、暗呼吸效率、羧化效率、CO2补偿点、不同温度下净光合速率等参数,通过FMS-2型便携脉冲调制式荧光仪测定叶绿素荧光F0、Fm、Fv、Fv/F0、Fv/Fm等参数,比较不同砧木对‘87-1’各光合参数的影响,并通过Topsis综合评价法进行排名。【结果】‘87-1’/3309C、‘87-1’/1103P组合表观量子效率高,光补偿点低,暗呼吸速率较低,Topsis综合排名位于前2名,两者耐弱光能力较强。‘87-1’/3309C、‘87-1’/华葡1号羧化效率较高,CO2补偿点低,Topsis综合排名位于前2名,两者耐低浓度CO2能力较强。‘87-1’/SO4、‘87-1’/华葡1号不同温度下净光合变化值较小,高温下净光合速率较大,Topsis综合排名位于前2名,说明两者耐高温能力较强。通过方差分析发现‘87-1’/140Ru和‘87-1’/SO4组合F0最高,‘87-1’/1103P组合Fv最高,‘87-1’/1103P和‘87-1’/3309C的Fv/F0值最高,8个砧穗组合的Fm和Fv/Fm无显著性差异。【结论】3309C、1103P两种砧木可以有效提高‘87-1’耐弱光能力及原初光能转化效率,3309C、华葡1号两种砧木可以提高‘87-1’的耐低浓度CO2能力,SO4、华葡1号2种砧木可以提高‘87-1’的耐高温能力。     

High-pressure reactions and shear strength of serpentinized dunite

The recently reported Pronounced decrease in shear strength of serpentine-bearing rocks at 30 to 40 kilobars in the temperature range 300 degrees to 520 degrees C may be attributed to the transformation of serpentine to a Pressure-dependent, 10-angstrom,2: 1 layer silicate plus brucite and periclase. This reaction increases density by about 8.5 percent.