Seasonal Changes in Photosynthetic Characteristics of Ammopiptanthus mongolicus

Seasonal changes in the photosynthetic characteristics of Ammopiptantus mongolicus (Maxim. )Chen f. were studied. When the net photosynthetic rate decreased with the elevation of air temperature, thestomatal conductance and stomatal limitation value tended to decline simultaneously, while the interoellularCO2 concentration was increased. According to the two criteria discriminating the stomatal limitation of Photosynthesis suggeSted by Fmrquhar and Sharkey, the seasonal changes in these parameters indicated that the decrease in Pn may not be due to stomatal factor. These studies proved that the relative contents of the large subunit of Rubisco and the photochemical activities correlated with the seasonal changes in the net photosyntheticrate, whieh may show that these two factors contribute primarily to the seasonal changeS in CO2 assimilation.

A change of phenolic acids content in poplar leaves induced by methyl sali-cylate and methyl jasmonate

The contents of seven different phenolic acids such as gallic acid, catechinic acid, pyrocatechol, caffeic acid, coumaric acid, ferulic acid and benzoic acid in the poplar leaves （Populus Simonii×Populus Pyramibalis c.v and Populus deltoids） suffocated by Methyl jasmonate （MeJA） and Methyl salicylate （MeSA） were monitored for analyzing their functions in interplant communications by using high-pressure liquid chromatography （HPLC）.The results showed that the contents of phenolic acids had obviously difference in leaves exposed to either MeSA or MeJA.When P.deltoides leaves exposed to MeJA or MeSA, the level of gallic acid, coumaric acid, caffeic acid, ferulic acid and benzoic acid was increased, gallic acid in leaves treated with MeJA comes to a peak at 24 h while to a peak at 12-d having leaves treated with MeSA.When P.Simonii ×P.Pyramibalis c.v leaves were exposed to MeJA or MeSA, the level of gallic acid, pyrocatechol and ferulic acid was increased; The catechinic acid and benzoic acid had a little drop; The caffeic acid and coumaric acid were undetected in both suffocated and control leaves.This changed pattern indicated that MeJA and MeSA can act as airborne signals to induce defense response of plants.

Relationship Between Ecophysiological Features and Grain Yield in Different Soybean Varieties

Photosynthetic rate ( P n ), transpiration rate ( E ), stomatal conductance ( g s ), water use efficiency ( WUE ), intercellular CO 2( C i ) and leaf water potential ( Ψ ) in varieties of soybean ( Glycine max (L.) Merr.) measured in the past three decades (1970s, 1980s and 1990s) and their inter_relationships were analyzed. These parameters of soybean changed with development stages. It is shown that there was a strongly positive relationship between the yield of soybean and its net photosynthetic rate. Soybean varieties with high yield potential had higher P n , g s and Ψ than those with low yield potential. Their values of C i were remarkably lower. Such relationship was especially remarkable at the critical stage of pod_bearing. P n of soybean of high yield was obviously higher than that of low yield. Of the different stages, the highest P n was found in the pod_bearing stage and other values were higher, too. P n and Ψ of modern soybean varieties were higher and such was continuing. Increased partitioning of carbon to seed and the size of sink may also be important for yield formation when P n values were remarkably higher in the pod_bearing stage.

Ionic Conduction and Fuel Cell Performance of Ba0.98Ce0.8Tm0.2O3-α Ceramic

The perovskite-type oxide solid solution Ba0.98Ce0.8Tm0.2O3-α was prepared by high temperature solid-state reaction and its single phase character was confirmed by X-ray diffraction. The conduction property of the sample was investigated by alternating current impedance spectroscopy and gas concentration cell methods under different gases atmospheres in the temperature range of 500-900 ℃. The performance of the hydrogen-air fuel cell using the sample as solid electrolyte was measured. In wet hydrogen, the sample is a pure protonic conductor with the protonic transport number of 1 in the range of 500-600 ℃, a mixed conductor of proton and electron with the protonic transport number of 0.945-0.933 above 600 ℃. In wet air, the sample is a mixed conductor of proton, oxide ion, and electronic hole. The protonic transport numbers are 0.010-0.021, and the oxide ionic transport numbers are 0.471-0.382. In hydrogen-air fuel cell, the sample is a mixed conductor of proton, oxide ion and electron, the ionic transport numbers are 0.942 0.885. The fuel cell using Ba0.98Ce0.8Tm0.2O3-α as solid electrolyte can work stably. At 900 ℃, the maximum power output density is 110,2 mW/cm2, which is higher than that of our previous cell using Ba0.98Ce0.8Tm0.2O3-α （x〈≤1, RE=Y, Eu, Ho） as solid electrolyte.

助听器产品电磁兼容性影响因素的研究

助听器作为气导性听力损失患者的重要康复设备,随着技术的不断创新和功能的不断丰富,其电子组件的复杂性也在不断提升。文章旨在探讨可能影响多功能助听器电磁兼容性的各种因素,以确保助听器产品能够在复杂的电磁环境下稳定、安全地运行。通过对助听器的不同配置、功能和外观结构等电磁兼容试验分析,识别对助听器电磁兼容性可能产生潜在影响的因素。

Ionic Conduction and Fuel Cell Performance of Ba0.97Ce0.8Ho0.2O3-α Ceramic

The perovskite-type-oxide solid solution Ba0.97Ce0.8Ho0.2O3-α was prepared by high temperature solidstate reaction and its single-phase character was confirmed by X-ray diffraction. The ionic conduction of the sample was investigated using electrical methods at elevated temperatures, and the performance of the hydrogen-air fuel cell using the sample as solid electrolyte was measured, which were compared with those of BaCe0.8Ho0.2O3-α. In wet hydrogen, BaCe0.8Ho0.2O3-α almost exhibits pure protonic conduction at 600-1000℃, and its protonic transport number is 1 at 600-900 ℃ and 0.99 at 1000 ℃. Similarly, Ba0.97Ce9.8Ho0.2O3-α exhibits pure protonic conduction with the protonic transport number of 1 at 600- 700℃, but its protonic conduction is slightly lower than that of BaCe0.8Ho0.2O3-α, and the protonic transport number are 0.99-0.96 at 800-1000 ℃. In wet air, the two samples both show low protonic and oxide ionic conduction. For Ba0.97Ce0.8Ho0.2O3-α, the protonic and oxide ionic transport numbers are 0.01-0.11 and 0.30-0.31 respectively, and for BaCe0.8Ho0.2O3-α, 0.01-0.09 and 0.27-0.33 respectively. Ionic conductivities of Ba0.97Ce0.8Ho0.2O3-α are higher than those of BaCe0.8Ho0.2O3-α under wet hydrogen and wet air. The performance of the fuel cell using Ba0.97Ce0.8Ho0.2O3-α as solid electrolyte is better than that of BaCe0.8Ho0.2O3-α. At 1000 ℃, its maximum short-circuit current density and power output density are 465 mA/cm^2 and 112 mW/cm^2, respectively.

Trichosanthin functions as Th2-type adjuvant in induction of allergic airway inflammation

It is important to understand the pathogenesis of asthma induced by natural allergens, which could exclude the interference of artificial adjuvant and provide insights of natural immune response in the disease. In the present study, we show that Trichosanthin （TCS） could induce airway inflammation even without the help of alum. Furthermore, TCS appeared capable of replacing alum to promote OVA-specific airway inflammation. TCS induced accumulation of IL-4-producing eosinophils in peritoneum at an early stage and the adjuvant function of TCS was eliminated by blockage of IL-4 at this stage. Finally, the eosinophils triggered by TCS from WT mice, but not from IL-4- deficient mice were shown to function as adjuvant for the induction of OVA-specific Th2 responses. Our data indicate that TCS is not only an allergen, but also a Th2-typc adjuvant modulating the switching of immune responses to a Th2 pathway. This chain of events results from IL-4 production by eosinophils at an early stage of TCS-priming. In conclusion, TCS may be useful as a Th2 adjuvant, and innate immune cells, such as eosinophils, may be a good target to study the initiation of Th2 response.

Self-magnetism and Persistent Photoconductivity

Persistent photoconductivity has been investigated by various models, among which the Macroscopic Barrier model, Large-Lattice-Relaxation model, and Random Local Potential Fluctuations model are mostly well known. Although the three well-known models have played important roles in describing the persistent photoconductivity, they are not the principal cause of persistent photoconductivity. In this paper a classical model originated from ＂selfmagnetism of electron gas＂ is proposed to illustrate the persistent photoconductivity phenomenon. This classical model is based on electron gas pulsation, which depends on the charge density. Different concentrations of current carriers create different frequencies in the system, and thus the system is sensitive to different wave lengths of incident light. Then the construction of different detectors can be possible for different wave lengths of incident light.

Optical and Electrical Properties of Sensitized Polyaniline by Electrochemical Polymerization

To sensitize polyaniline with dyes by electrochemical polymerization, HClO 4 is employed as the dopant and oxidant, and the polyaniline with different sensitive properties is synthesized. The effect of sensitized emeraldine salt on the absorption spectrum is discussed in details. The maximum conductivity of sensitized films reaches 1.22 S/cm, and investigation on dye sensitizing of the polymer reveals that C.I. Direct Blue 71, C.I. Direct Blue 84, C.I. Direct Black 19 and CuPc-(COOH) 4 may enhance the photoconductivity of polyaniline greatly.

Effect of surfactant Tween on induction time of gas hydrate formation

Acceleration of gas hydrate formation is important in preventing coal and gas outbursts and is based on a hydration mechanism. It becomes therefore necessary to investigate the effect of surfactants, acting as accelerants for hydrate formation, on induction time. We experimented with three types of a Tween solution with equal concentrations of 0.001 mol/L (T40, T40/T80 (1:1), T40/T80 (4:1)). By means of visual experimental equipment, developed by us, we measured generalized induction time using a Direct Observation Method. The experimental data were analyzed combined with a mass transfer model and a hydrate crystal nuclei growth model. Our major conclusions are as follows: 1) solubilization of surfactants produces supersaturated gas molecules, which promotes the mass transfer from a bulk phase to hydrates and provides the driving force for the complexation between host molecules (water) and guest molecules in a gas hydrate formation process; 2) when the solution of the surfactant concentration exceeds the critical micelle concentration (CMC), the surfactant in an aqueous solution will transform to micelles. Most of the gas molecules are bound to form clusters with water molecules, which promotes the formation of crystal nuclei of gas hydrates; 3) the surfactant T40 proved to have more notable effects on the promotion of crystal nuclei formation and on shortening the induction time, compared with T40/T80 (1:1) and T40/T80 (4:1).

Impacts of salinity parameterizations on temperature simulation over and in a hypersaline lake

In this paper,we introduced parameterizations of the salinity effects(on heat capacity,thermal conductivity,freezing point and saturated vapor pressure) in a lake scheme integrated in the Weather Research and Forecasting model coupled with the Community Land Model(WRF-CLM). This was done to improve temperature simulation over and in a saline lake and to test the contributions of salinity effects on various water properties via sensitivity experiments. The modified lake scheme consists of the lake module in the CLM model,which is the land component of the WRF-CLM model. The Great Salt Lake(GSL) in the USA was selected as the study area. The simulation was performed from September 3,2001 to September 30,2002. Our results show that the modif ied WRF-CLM model that includes the lake scheme considering salinity effects can reasonably simulate temperature over and in the GSL. This model had much greater accuracy than neglecting salinity effects,particularly in a very cold event when that effect alters the freezing point. The salinity effect on saturated vapor pressure can reduce latent heat flux over the lake and make it slightly warmer. The salinity effect on heat capacity can also make lake temperature prone to changes. However,the salinity effect on thermal conductivity was found insignificant in our simulations.

Mixed Conduction in BaCe0.8Pr0.2O3-α Ceramic

BaCe0.8Pr0.2O3-α ceramic was synthesized by high temperature solid-state reaction. The structural characteristics and the phase purity of the crystal were determined using powder X-ray diffraction analysis. By using the methods of AC impedance spectroscopy, gas concentration cell and electrochemical pumping of hydrogen, the conductivity and ionic transport number of BaCe0.8Pr0.2O3-α were measured, and the electrical conduction behavior of the material was investigated in different gases in the temperature range of 500-900℃. The results indicate that the material was of a single perovskite-type orthorhombic phase. From 500℃ to 900 ℃, electronic-hole conduction was dominant in dry and wet oxygen, air or nitrogen, and the total conductivity of the material increased slightly with increasing oxygen partial pressure in the oxygen partial pressure range studied. Ionic conduction was dominant in wet hydrogen, and the total conductivity was about one or two orders of magnitude higher than that in hydrogen-free atmosphere （oxygen, air or nitrogen）

REFLUX ESOPHAGITIS AND AIRWAY HYPERRESPONSIVENESS

Objectives’ To observe the effects of reflux esophagitis(RE) on the lung function and alrway reactivity,and study the mechanism of airway hyperresponsiveness(AHR) in patients with RE.Methods. Lung function measurements and airway provocation tests were performed in 31 RE patientsand 35 control subjects’ TXB, and PGF,. were determined in 20 cases of each group.Results. In RE patients the lung function was lower and the rate of AHR was higher than control sub-jects (P<0. 05). Among RE patients 25 % had higher airway sensitivity (Dminr 3u ). The TXB2 of REpatients with AHR was higher than those without AHR’ Dmin correlated significantly with TXB2 (r=0. 653, P<0. 05).Concluswhs’ RE could damage the lung function. The rate of AHR was 61 %, the high airway sensltivity was probably potential asthma, and TXB2 may play a role in the pathogenesis of AHR.

The Method for Inferring a Buried Fault from Resistivity Tomograms and Its Typical Electrical Features

Electrical resistivity tomography (ERT) has been used to experimentally detect shallow buried faults in urban areas in the past a few years, with some progress and experience obtained. According to the results from Olympic Park, Beijing, Shandong Province, Gansu Province and Shanxi Province, we have generalized the method and procedure for inferring the discontinuity of electrical structures (DES) indicating a buried fault in urban areas from resistivity tomograms and its typical electrical features. In general, the layered feature of the electrical structure is first analyzed to preliminarily define whether or not a DES exists in the target area. Resistivity contours in resistivity tomograms are then analyzed from the deep to the shallow. If they extend upward from the deep to the shallow and shape into an integral dislocation, sharp flexure (convergence) or gradient zone, it is inferred that the DES exists, indicating a buried fault. Finally, horizontal tracing is be carried out to define the trend of the DES. The DES can be divided into three types-type AB, ABA and AC. In the present paper, the Zhangdian-Renhe fault system in Zibo city is used as an example to illustrate how to use the method to infer the location and spatial extension of a target fault. Geologic drilling holes are placed based on our research results, and the drilling logs testify that our results are correct. However, the method of this paper is not exclusive and inflexible. It is expected to provide reference and assistance for inferring the shallow buried faults in urban areas from resistivity tomograms in the future.

Effective stress in soils under different saturation conditions

BISHOP’s effective stress or two state stress variables are unsatisfactory for unsaturated soils where one of fluid phases is discontinuous, so new expressions of effective stress should be founded. The approach for derivation was according to the principle of equilibrium of forces (i.e., the stress-sharing principle), and it was firstly validated by demonstrating TERZAGHI’s principle of effective stress. And then, the derivations were subdivided into four parts according to different pore air states: 1) air bubbles were spherical and suspended in pore water; 2) air bubbles were bound on soil skeleton; 3) air bubbles held almost the single section of pore; 4) air phase was continuous. The different formulae of effective stress were presented. Conclusions are drawn as follows: 1) For nearly-saturated soils, the "real" effective stress would be a little smaller than TERZAGHI’s effective stress; 2) For soils in which air phase is discontinuous in the form of bubbles, a new concept of pore air elastic pressure is put forward, and the total stress can be constituted by effective stress, pore water pressure and pore air elastic pressure; 3) For soils in which air phase is continuous, effective stress is equal to the value of the total stress plus suction; 4) Suction can be divided into two parts: one is the effect caused by additional pressure, and the other is the contract action by the "skin".

Structure and Oxygen Sensing Properties of TiO_2 Porous Semiconductor Thin Films

Semiconductor-type TiO2 oxygen sensing thin films were synthesized using tetrabutyl titanate （Ti （OBu）4） as precursor and diethanolamine （DEA） as complexing agent by the sol-get process. The porous and oxygen sensing TiO2 films were obtained by the addition of polyethylene glycol （PEG）. The micrographs of scanning electron microscope （SEM） show that the pores of the sample about 400-600 nm in size with PEG（2 000 g/mol） are larger than those about 300 nm in size with PEG（ 1 000 g/mol）, while the density of pores is lower. The results also indicate that increasing the content of PEG properly is beneficial to the formation of porous structure. With the increasing content of PEG from 0 g to 2.5 g, the oxygen sensitivity increases from 330 to more than 1 000 at 800 ℃, from 170 to more than 1 000 at 900℃, and the response time to O2 and H2 are about 1.5 s and less than 1s, respectively.

Control of combustion area using electrical resistivity method for underground coal gasification

Underground coal gasification （UCG） is one of the clean technologies to collect heat energy and gases （hydrogen, methane, etc.） in an underground coal seam. It is necessary to further developing environ- mentally friendly UCG system construction. One of the most important UCG＇s problems is underground control of combustion area for efficient gas production, estimation of subsidence and gas leakage to the surface. For this objective, laboratory experiments were conducted according to the UCG model to iden- ti[y the process of combustion cavity development by monitoring the electrical resistivity activity on the coal samples to setup fundamental data for the technology engineering to evaluate combustion area. While burning coal specimens, that had been sampled from various coal deposits, electrical resistivity was monitored. Symmetric four electrodes system （ABMN） of direct and low-frequency current electric resistance method was used for laboratory resistivity measurement of rock samples. Made research and the results suggest that front-end of electro conductivity activity during heating and combusting of coal specimen depended on heating temperature. Combusting coal electro conductivity has compli- cated multistage type of change. Electrical resistivity method is expected to be a useful geophysical tool to for evaluation of combustion volume and its migration in the coal seam.

IR, 1H NMR, Electronic Properties and Conductivity Studies of N1 ,N4-Bis（Diphme）Benzene-l,4-Diamine Chloride Zirconium （IV） [{（Ar）2NC6H5N（Ar）2}ZrCl4] （Ar = C6H5）

A range of new compounds such as N1,N4-bis（diphenylmethlene）benzene-l,4-diamine zirconium （IV） chloride [{（Ar）2NC6HsN（Ar）z}ZrCl4] （Ar = C6H5） complex counting the chelating amine and chloride in position trans have been prepared. Well-defined NI,N4-bis（diphenylmethlene）benzene-l,4-diamine zirconium （IV） chloride [{（Ar）2NC6H5N（Ar）2}ZrCl4] （Ar = C6H5） was obtained by stoichiometric addition of {（Ar）2NC6H5N（Ar）2} （Ar = C6H5） and {ZrC14} in ethanol at reflex temperature. IR, 1H NMR, electronic properties using hyperchem program study has been improved for this compound such as bond distance, and this compound was also defined as electric conductivity which proves to be useful for conductively compound.

Superposability of unsteady aerodynamic loads on bridge deck sections

The 2-dimensional unsteady aerodynamic forces,in the context of both a thin airfoil where theory of potential flow is always applicable and a bluff bridge-deck section where separated flow is typically induced,are investigated from a point of view of whether or not they conform to the principle of linear superposition in situations of various structural motions and wind gusts.It is shown that some basic preconditions that lead to the linear superposability of the unsteady aerodynamic forces in cases of thin airfoil sections are no longer valid for a bluff section.Theoretical models of bridge aerodynamics such as the one related to flutter-buffeting analysis and those concerning aerodynamic admittance(AA)functions,however,necessitate implicitly this superposability.The contradiction revealed in this work may throw light on the perplexing problem of AA functions pertaining to the description of buffeting loads of bridge decks.Some existing theoretical AA models derived from flutter derivatives according to interrelations valid only for thin airfoil theories,which have been employed rather extensively in bridge aerodynamics,are demonstrated to be illogical.Finally,with full understanding of the preconditions of the applicability of linear superposability of the unsteady aerodynamic forces,suggestions in regard to experiment-based AA functions are presented.

Neck-controlled sensitivity study on nano-grain SnO_2 gas sensors

The electrical potential inside a cylinder with a space charge layer is used to express the neck potential barrier of nano-SnO2 gas elements, and the neck-controlled sensitivity and the grain size effect are studied. It is shown that the sensing properties are influenced by the microstructural features, such as the grain size, the geometry and connectivity between grains, and that the neck controlled sensitivity alone is higher than the neck-grain controlled sensitivity and the difference between the neck controlled sensitivity and the neck-grain controlled sensitivity is large in the high sensitivity range for nano-SnO2 gas elements, which suggests a possible approach to the improvement of the sensitivity of a sensor by decreasing the number of necks of a nano-grain SnO2 gas element.