The influences of canopy temperature measuring on the derived crop water stress index

Crop water stress index(CWSI)is widely used for efficient irrigation management.Precise canopy temperature(T_(c))measurement is necessary to derive a reliable CWSI.The objective of this research was to investigate the influences of atmospheric conditions,settled height,view angle of infrared thermography,and investigating time of temperature measuring on the performance of the CWSI.Three irrigation treatments were used to create different soil water conditions during the 2020-2021 and 2021-2022 winter wheat-growing seasons.The CWSI was calculated using the CWSI-E(an empirical approach)and CWSI-T(a theoretical approach)based on the T_(c).Weather conditions were recorded continuously throughout the experimental period.The results showed that atmospheric conditions influenced the estimation of the CWSI;when the vapor pressure deficit(VPD)was>2000 Pa,the estimated CWSI was related to soil water conditions.The height of the installed infrared thermograph influenced the T_(c)values,and the differences among the T_(c)values measured at height of 3,5,and 10 m was smaller in the afternoon than in the morning.However,the lens of the thermometer facing south recorded a higher T_(c)than those facing east or north,especially at a low height,indicating that the direction of the thermometer had a significant influence on T_(c).There was a large variation in CWSI derived at different times of the day,and the midday measurements(12:00-15:00)were the most reliable for estimating CWSI.Negative linear relationships were found between the transpiration rate and CWSI-E(R^(2)of 0.3646-0.5725)and CWSI-T(R^(2)of 0.5407-0.7213).The relations between fraction of available soil water(FASW)with CWSI-T was higher than that with CWSI-E,indicating CWSI-T was more accurate for predicting crop water status.In addition,The R^(2)between CWSI-T and FASW at 14:00 was higher than that at other times,indicating that 14:00 was the optimal time for using the CWSI for crop water status monitoring.Relative higher yield of winter wheat was obtained with average seasonal values of CWSI-E and CWSI-T around 0.23 and 0.25-0.26,respectively.The CWSI-E values were more easily influenced by meteorological factors and the timing of the measurements,and using the theoretical approach to derive the CWSI was recommended for precise irrigation water management.

Seasonal constraint of dynamic water temperature on riverine dissolved inorganic nitrogen transport in land surface modeling

水体温度变化对河流可溶性无机氮(DIN)输送有着强烈控制作用.然而,在全球尺度上河流DIN输送量对水温度变化的响应尚不清楚.因此,本文基于陆面过程模式,耦合河流水温估算和DIN传输方案,设定有,无动态水温情景,对比研究陆面模拟中水温变化对河流DIN通量变化的影响.结果表明:在考虑水温动态变化后,在30°N和30°S之间, DIN通量年振幅减小5%–25%.在中国东部地区,水温动态变化使河流DIN通量在夏季减少1%–3%,在冬季增加1%–5%,对DIN通量具有明显的季节性约束作用,表明动态水温的表达在河流DIN输送模拟中的重要性.

Temperature rise induced by an annular focused transducer with a wide aperture angle in multi-layer tissue

In order to improve the operability and accuracy of high-intensity focused ultrasound （HIFU）, an annular focused transducer, whereby a B-ultrasound probe is placed in its center, is used to realize the real time monitoring and control of the treatment. In this paper, the spheroidal beam equation （SBE） was used to calculate the sound lield by an annular focused transducer with a wide aperture angle to first derive the heat deposition and the Pennes equation was used to calculate the temperature field in multi-layer tissue. We studied the effect of different parameters on the temperature of the tissues. The result shows that the focal length has a significant influence on both maximum liver temperature rise and skin temperature rise, and both increase with the increase in the focal length. When the frequency increases, the temperature rise first undergoes a rapid increase before gradually reaching a maximum, and then finally decreasing. The temperature rise increases while the inner radius decreases or the sound pressure increases. By choosing suitable parameters, the proper temperature rise both on the target tissue and skin via an annular tbcused transducer with a wide aperture angle can be obtained.

Effects of soil temperature and soil water content on soil respiration in three forest types in Changbai Mountain

Soil incubation experiments were conducted in lab to delineate the effect of soil temperature and soil water content on soil respirations in broad-leaved/Korean pine forest (mountain dark brown forest soil), dark coniferous forest (mountain brown coniferous forest soil) and erman's birch forest (mountain soddy forest soil) in Changbai Mountain in September 2001. The soil water content was adjusted to five different levels (9%, 21%, 30%, and 43%) by adding certain amount of water into the soil cylinders, and the soil sample was incubated at 0, 5, 15, 25 and 35°C for 24 h. The results indicated that in broad-leaved/Korean pine forest the soil respiration rate was positively correlated to soil temperature from 0 to 35°C. Soil respiration rate increased with increase of soil water content within the limits of 21% to 37%, while it decreased with soil water content when water content was over the range. The result suggested the interactive effects of temperature and water content on soil respiration. There were significant differences in soil respiration among the various forest types. The soil respiration rate was highest in broad-leaved/Korean pine forest, middle in erman's birch forest and the lowest in dark coniferous forest. The optimal soil temperature and soil water content for soil respiration was 35°C and 37% in broad-leaved/Korean pine forest, 25°C and 21% in dark coniferous forest, and 35°C and 37% in erman's birch forest. Because the forests of broad-leaved/Korean pine, dark coniferous and erman's birch are distributed at different altitudes, the soil temperature had 4–5°C variation in different forest types during the same period. Thus, the soil respiration rates measured in brown pine mountain soil were lower than those in dark brown forest and those measured in mountain grass forest soil were higher than those in brown pine mountain soil. Key words Soil temperature - Soil water content - Soil respiration - The typical forest ecosystem in Changbai Mountain CLC number S7118.51 Document code A Foundation item: This study was supported by grant from the National Natural Science Foundation of China (No. 30271068), the grant of the Knowledge Innovation Program of Chinese Academy of Sciences (KZ-CX-SW-01-01B-12) and the grant from Advanced Programs of Institute of Applied Ecology Chinese Academy of Sciences.Biography: WANG Miao (1964-), male, associate professor in Institute of Applied Ecology, Chinese Academy of Science, Shenyang 110016, P. R. China.Responsible editor: Song Funan

Changes of Water Temperature and Harmful Algal Bloom in the Daya Bay in the Northern South China Sea

Economic development around the Daya Bay, China has profoundly affected the marine environment in the bay area in recent years, particularly since the operation of Daya Bay Nuclear Power Station （DNPS） in 1994. This study analyzed the changes of water temperature and harmful algal blooms （HABs） for two periods： 1983-1993 and 1994-2004, using in situ and satellite data. Results showed that yearly mean surface water temperature （SWT） and Chl-a concentration （Chl-a） increased by 1.1 ℃ and 1.9 mg/m^3, respectively, after 1994. The monthly occurrence of HAB was found to have increased also. HABs appeared only in spring and autumn before 1994, but occurred all the year round after 1994. SWT, Chl-a and HABs all increased significantly in May. Those changes were associated with environmental changes in this area, such as thermal discharge from the DNPS and enhancement of eutrophication from human activities around the Daya Bay.

Mechanism of Nutrient Silicon and Water Temperature Influences on Phytoplankton Growth

This paper analyzed how nutrient silicon and water temperature influenced the variation of phytoplankton growth and the change of its assemblage structure, and probed the different characteristics of the variation of phytoplankton growth and the different profiles of the change of its assemblage structure influenced by nutrient silicon and water temperature. Taking Jiaozhou Bay for example, this paper showed the process of both the variation of phytoplankton growth and the change of its assemblage structure, unveiled the mechanism of nutrient silicon and water temperature influencing the variation of phytoplankton growth and the change of its assemblage structure, and determined that nutrient silicon and water temperature were the motive power for the healthy running of the marine ecosystem.

Characteristics and Trend Variation of Light,Temperature and Water Resources in Dongling District of Shenyang Province in Recent 49 Years

The meteorological data of light,temperature and water during 1961-2009 were selected to analyze the trend variation of climatic resources and provide the basis for developing and utilizing local climate resources.The results indicated that light resource presented the decreasing tendency in Dongling District,annual radiation reduced by 528 MJ/m2,and annual sunshine duration decreased by 333 h.The heat resource presented the increasing tendency,the average annual temperature increased by 1.04 ℃,and active accumulated temperature increased by 228 ℃.The general trend of annual precipitation declined slightly,precipitation resource during every age changed slightly and would tend to be stable.

Evaluation of spatial-temporal dynamics in surface water temperature of Qinghai Lake from 2001 to 2010 by using MODIS data

Lake surface water temperature （SWT） is an important indicator of lake state relative to its water chemistry and aquatic ecosystem,in addition to being an important regional climate indicator.However,few literatures involving spatial-temporal changes of lake SWT in the Qinghai-Tibet Plateau,including Qinghai Lake,are available.Our objective is to study the spatial-temporal changes in SWT of Qinghai Lake from 2001 to 2010,using Moderate-resolution Imaging Spectroradiometer （MODIS） data.Based on each pixel,we calculated the temporal SWT variations and long-term trends,compared the spatial patterns of annual average SWT in different years,and mapped and analyzed the seasonal cycles of the spatial patterns of SWT.The results revealed that the differences between the average daily SWT and air temperature during the temperature decreasing phase were relatively larger than those during the temperature increasing phase.The increasing rate of the annual average SWT during the study period was about 0.01℃/a,followed by an increasing rate of about 0.05℃/a in annual average air temperature.The annual average SWT from 2001 to 2010 showed similar spatial patterns,while the SWT spatial changes from January to December demonstrated an interesting seasonal reversion pattern.The high-temperature area transformed stepwise from the south to the north regions and then back to the south region from January to December,whereas the low-temperature area demonstrated a reversed annual cyclical trace.The spatial-temporal patterns of SWTs were shaped by the topography of the lake basin and the distribution of drainages.

Alternate row mulching optimizes soil temperature and water conditions and improves wheat yield in dryland farming

Straw mulching allows for effective water storage in dryland wheat production. Finding a suitable straw mulching model that facilitates wheat growth was the objective of this study. A 2-year field experiment was conducted to investigate the effects of two straw mulching patterns （FM, full coverage within all the rows; HM, half coverage within alternate rows） and two mulching rates （4.5 and 9.0 t ha^-1） on soil moisture, soil temperature, grain yield, and water use efficiency （WUE） of winter wheat in northern China, with no mulching （M0） as the control. Results showed that mulching increased the soil water storage in all growth stages under high mulching rates, with a stronger effect in later growth stages. Water storage under the HM model was greater in later stages than under the FM model. Soil water content of HM groups was higher than that of FM groups, especially in surface soil layers. Evapotranspiration decreased in mulched groups and was higher under high mulching rates. Aboveground biomass during each growth stage under the HM model was higher than that under M0 and FM models with the same mulched rate, leading to a relatively higher grain yield under the HM model. Mulching increased WUE, a trend that was more obvious under HM9.0 treatment. Warming effect of soil temperature under the HM pattern persisted longer than under the FM model with the same mulching rates. Accumulated soil temperature under mulched treatments increased, and the period of negative soil temperature decreased by 9-12 days under FM and by 10-20 days under HM. Thus, the HM pattern with 9.0 t ha^-1 mulching rate is beneficial for both soil temperature and water content management and can contribute to high yields and high WUE for wheat production in China.

Relationship Between Canopy Temperature at Flowering Stage and Soil Water Content,Yield Components in Rice

The canopy temperature of rice at the flowering stage and the soil water content were investigated under different soil water treatments （the soil water contents were 24%, 55%, 90% and 175% at the flowering stage）. The canopy temperature was lower than air temperature, and the soil water content significantly influenced the canopy temperature. The lower the soil water content, the higher the canopy temperature, the less the accumulative absolute value of canopy-air temperature difference. Moreover, the maximum difference between treatments and CK in the accumulative absolute value of canopy-air temperature difference appeared at 13：00 μm. in a day, thus, it could be considered as a suitable measuring time. Under the lowest water content treatment, the peak flowering occurred in the first three days （about 70% of panicles flowered）, resulting in shortened and lightened panicle of rice. As to the CK and the high water content treatments, the peak flowering appeared in the middle of flowering duration, with longer panicle length and higher panicle weight. Results indicated the lower the soil water content, the less the filled grain number and grain yield.

Kinetics of Non-catalyzed Decomposition of D-xylose in High Temperature Liquid Water

The kinetics of non-catalyzed decompositions of xylose and its decomposition product furfural in high temperature liquid water （HTLW） was studied for temperature from 180 to 220℃ and under pressure of 10MPa. The main products of xylose decomposition were furfural and formic acid, and furfural further degraded to formic acid under HTLW condition. With the assumption of first order kinetics e.quation, the evaluated activation energy of xylose and furfural decomposition was 123.27kJ·mol^-1 and 58.84kJ·mol^-1, respectively.

Tomato Leaf Photosynthetic Responses to Humidity andTemperature Under Salinity and Water Deficit

Greenhouse tomato plants (Lycopersicon esculentum Mill cv. Capello) were grown on peat-based substrate and treated with high (4.5 mS cm-1) and low (2.3 mS cm-1) nutrient solution electric conductivity(EC) under high and low substrate water contents. FOur weeks after the beginning of the treatments, photosynthesis (Th) was measured under different humidity and temperatures to examine the interactive effectswith rhizosphere salinity and water deficit. A rectangular hyperbolic model fitted the light-photosynthesiscurve. Photosynthetic capacity (PC) was decreased but quantum yield (YQ) was increased by rhizospheresalinity caused by high EC. PN was decreased by low humidity only in high EC- and/or water-stressed plants.Under high photosynthetic photon flux (PPF), low humidity induced PC decline in water-stressed plants andPN oscillation in high-EC-treated plants. PN increased steadily as the leaf temperature changed from 18 Cto 23 and then decreased steadily from 23 to 38 . At 34 , PN decreased significantly in waterstressed plants. Dark respiration (RD) increased in an exponential manner as the leaf temperature changedfrom 18 to 38 to an extent about ten times higher under 38 than under 18 . Our data suggestedthat PN decrease under high temperature was attributed, st least in part, to the increased RD. RD in highEC- and/or water-stressed plants was higher than that in the plants of control under lower temperature butlower than that in the plants of control under high temperature. The analysis of stomatal and mesophyllconductance showed that low humidity effect was mainly through stomatal response while temperature effectwas mainly through biochemical functions. The result showed that environmental stresses affected PN in anadditive or synergistic manner.

Effects of Temperature and Water Saturation on CO_2 Production and Nitrogen Mineralization in Alpine Wetland Soils

Relationships between carbon (C) production and nitrogen (N) mineralization were investigated in two alpine wetland soils of the Tibetan Plateau using laboratory incubation under different temperatures (5, 15, 25, and 35 ℃) and water saturation (noninundation and inundation). A significant positive relationship was found between CO2 production and N mineralization under increasing temperatures from 5 to 35 ℃ with the same water saturation condition in the marsh soil (r2 > 0.49, P < 0.0001) and the peat soil (r2 > 0.38, P < 0.002), and a negative relationship with water saturation increasing at the same temperature, especially 25 and 35 ℃, in the marsh soil (r2 > 0.70, P < 0.009) and the peat soil (r2 > 0.61, P < 0.013). In conclusion, temperatures and water saturation could regulate the relationship between CO2 production and net N mineralization in the Tibetan alpine marsh and peat soils.

Impact of Increasing Stratospheric Water Vapor on Ozone Depletion and Temperature Change

Using a detailed, fully coupled chemistry climate model （CCM）, the effect of increasing stratospheric H20 on ozone and temperature is investigated. Different CCM time-slice runs have been performed to investigate the chemical and radiative impacts of an assumed 2 ppmv increase in H20. The chemical effects of this H20 increase lead to an overall decrease of the total column ozone （TCO） by ～1% in the tropics and by a maximum of 12% at southern high latitudes. At northern high latitudes, the TCO is increased by only up to 5% due to stronger transport in the Arctic. A 2-ppmv H2O increase in the model＇s radiation scheme causes a cooling of the tropical stratosphere of no more than 2 K, but a cooling of more than 4 K at high latitudes. Consequently, the TCO is increased by about 2%-6%. Increasing stratospheric H2O, therefore, cools the stratosphere both directly and indirectly, except in the polar regions where the temperature responds differently due to feedbacks between ozone and H2O changes. The combined chemical and radiative effects of increasing H2O may give rise to more cooling in the tropics and middle latitudes but less cooling in the polar stratosphere. The combined effects of H2O increases on ozone tend to offset each other, except in the Arctic stratosphere where both the radiative and chemical impacts give rise to increased ozone. The chemical and radiative effects of increasing H2O cause dynamical responses in the stratosphere with an evident hemispheric asymmetry. In terms of ozone recovery, increasing the stratospheric H2O is likely to accelerate the recovery in the northern high latitudes and delay it in the southern high latitudes. The modeled ozone recovery is more significant between 2000 ～2050 than between 2050～2100, driven mainly by the larger relative change in chlorine in the earlier period.

Effect of water temperature on digestive enzyme activity and gut mass in sea cucumber Apostichopus japonicus (Selenka),with special reference to aestivation

The effect of water temperature on gut mass and digestive enzyme activity in sea cucumber Apostichopusjaponicus, including relative gut mass （RGM）, amylase, lipase, pepsin and trypsin activities were studied at temperatures of 7, 14, 21, and 28℃ over a period of 40 days. Results show that RGM significantly decreased after 40 days at 21 ℃ and markedly decreased over the whole experiment period at 28℃; however, no significant effect of duration was observed at 7 or 14℃. At 14℃, trypsin activity significantly decreased over 10 and 20 days, then increased; amylase and trypsin activity significantly decreased after 40 days at 28℃. However, no significant effect of duration was found on amylase, pepsin or trypsin activities in the other temperature treatment groups. At 28℃, lipase activity peaked in 20 days and then markedly decreased to a minimum at the end of the experiment. On the other hand, pepsin activity at 28℃ continuously increased over the whole experimental period. Principle component analysis showed that sea cucumbers on day 40 in the 21℃ group and in the previous 20 days in the 28℃ group were in the prophase of aestivation. At 28℃, sea cucumbers aestivated at 30-40 days after the start of the experiment. It is concluded that the effect of temperature on the digestion ofA. japonicus is comparatively weak within a specific range of water temperatures and aestivation behavior is accompanied by significant changes in RGM and digestive enzyme activities.

Temperature Dependency of Water Vapor Permeability of Shape Memory Polyurethane

Solution-cast films of shape memory polyurethane have been investigated.Differential scanning calorimetry, DMA, tensile test, water vapor permeability and the shape memory effect were carried out to characterize these polyurethane membranes. Samples cast at higher temperatures contained more hard segment in the crystalline state than a sample cast at lower temperature. The change in the water vapor permeability (WVP) of SMPU films with respect to the temperature follows an S-shaped curve, and increases abruptly at T m of the soft segment for the fractional free volume (FFV, the ratio of free volume and specific volume in polymers) increased linearly with temperature. The water vapor permeability dependency of the temperature and humidity contribute to the result of the change of diffusion and solubility with the surrounding air condition. The diffusion coefficient (D) are the function of temperature and show good fit the Arrhenius form but show different parameter values when above and below T g. The crystalline state hard-segment is necessary for the good shape memory

Effect of temperature on soil-water characteristics and hysteresis of compacted Gaomiaozi bentonite

Laboratory tests under different constraint conditions were carried out to obtain the soil-water retention curves(SWRCs) of highly-compacted confined/unconfined Gaomiaozi(GMZ) bentonite at 20,40 and 80 ℃,respectively. The effect of temperature on the soil-water characteristics of the highly-compacted GMZ bentonite was analyzed. The results show that the water retention capacity of the highly-compacted GMZ bentonite decreases as the temperature increases under unconfined and confined conditions. At a certain temperature,the constraint conditions have little influence on the water retention capacity of the compacted bentonite at high suction,but the water retention capacity of the confined specimen is lower than that of the unconfined specimen at low suction. Under unconfined conditions,the hysteretic behaviour of the compacted bentonite decreases with increasing temperature. At high suction(>4 MPa) ,the hysteretic behaviour of the unconfined bentonite tends to increase with the decrease of the suction. In summary,the hysteretic behaviour of the compacted bentonite is not significant.

The effects of water flow and temperature on thermal regime around a culvert built on permafrost

Temperature and water flow through a culvert beneath the Alaska Highway near Beaver Creek,Yukon,were measured at hourly intervals between June and October 2013.These data were used to simulate the effect of the culvert on the thermal regime of the road embankment and subjacent permafrost.A 2-D thermal model of the embankment and permafrost was developed with TEMP/W and calibrated using field observations.Empirical relations were obtained between water temperatures at the entrance to the culvert,flow into the culvert,and water temperatures inside the structure.Water temperatures at the entrance and inside the culvert had a linear relation,while water temperatures inside the culvert and water flow were associated by a logarithmic relation.A multiple linear regression was used to summarize these relations.From this relationship,changes in the flow rate and water temperatures at the entrance of the culvert were simulated to obtain predicted water temperatures in the culvert.The temperatures in the culvert were used in the thermal model to determine their effects on the ground thermal regime near the culvert.Variation of ±10% in water flow rate had no impact on the thermal regime underneath the culvert.Variation of water temperature at the entrance of the culvert had a noticeable influence on the thermal regime.A final simulation was conducted without insulation beneath the culvert.The thaw depth was 30 cm with insulation,and 120 cm without insulation,illustrating the importance of insulation to the ground thermal regime.

Effect of temperature, chloride ions and sulfide ions on the electrochemical properties of 316L stainless steel in simulated cooling water

The influence of temperature, chloride ions and sulfide ions on the anticorrosion behavior of 316L stainless steel in simulated cooling water was studied by electrochemical impedance spectroscopy and anodic polarization curves. The results show that the film resistance increases with the solution temperature but decreases after 8 days’ immersion, which indicates that the film formed at higher temperature has inferior anticorrosion behavior; Chloride ions and sulfide ions have remarkable effects on the electrochemical property of 316L stainless steel in simulated cooling water and the pitting potential declines with the concentration of chloride ions; the passivation current has no obvious effect; the rise of the concentration of sulfide ions obviously increases the passivation current, but the pitting potential changes little, which indicates that the two types of ions may have different effects on destructing passive film of stainless steel. The critical concentration of chloride ions causing anodic potential curve’s change in simulated cooling water is 250 mg/L for 316 L stainless. The effect of sulfide ions on the corrosion resistance behavior of stainless steel is increasing the passivation current density Ip. The addition of 6 mg/L sulfide ions to the solution makes Ip of 316 L increase by 0.5 times.

New acoustic system for continuous measurement of river discharge and water temperature

In many cases, river discharge is indirectly estimated from water level or streamflow velocity near the water surface. However, these methods have limited applicability. In this study, an innovative system, the fluvial acoustic tomography system （FATS）, was used for continuous discharge measurement. Transducers with a central frequency of 30 kHz were installed diagonally across the river. The system＇s significant functions include accurate measurement of the travel time of the transmission signal using a GPS clock and the attainment of a high signal-to-noise ratio as a result of modulation of the signal by the 10th order M-sequence. In addition, FATS is small and lightweight, and its power consumption is low. Operating in unsteady streamflow, FATS successfully measured the cross-sectional average velocity. The agreement between FATS and acoustic Doppler current profilers （ADCPs） on water discharge was satisfactory. Moreover, the temporal variation of the cross-sectional average temperature deduced from the sound speed of FATS was similar to that measured by a temperature sensor near the bank.