Search

Background: Soybean is the most important oil crop globally; however, droughts are expected to seriously affect the growth and development of soybean in the context of climate change. Methods: In this study, polyethylene glycol (PEG) was used to simulate drought to explore the regulation of proline metabolism in soybean leaves under different degrees of drought stress at the seedling stage. Result: The results showed that the activities of ornithine aminotransferase and D1-pyrroline-5-carboxylate synthetase increased while the activities of proline dehydrogenase decreased with an increase in drought stress. During the same number of treatment days, the higher the degree of drought stress, the greater the increase or decrease in enzyme activity. The content of leaf proline increased gradually with an extension in stress time at PEG concentrations of 5% and 10%, first increased and then decreased at PEG concentrations of 15% and 20% and the peak value appeared on the 7th and 9th day, respectively.

Dairy products are the major source of odd- and branched-chain fatty acids (OBCFAs), a group of nutrients with emerging health benefits. The animal diet is known to influence milk fat OBCFAs of dairy cows; however, little is known about the effects of physiological factors. The objective of this study was to investigate the effects of parity and lactation stage on OBCFAs in milk fat of dairy cows. Holstein dairy cows (n = 157) were selected according to parity (first, second, third, or greater) and days in milk (DIM) (≤21 DIM, 21 DIM ≤ 100, 100 DIM ≤ 200,200 DIM). All cows were fed the same total mixed ration for three weeks. Milk samples were collected during the last three days of each lactation stage for fatty acid (FA) analyses via gas chromatography. Results showed that first- and second-parity cows displayed significantly higher proportions and yields of iso-14:0, iso-15:0, iso-16:0, total iso-FA, and total branched-chain FA (P 0.05) compared with other parities. The proportions of C17:0 and C17:1 cis-9 were also greater in first-parity cows (P 0.05), while the yields of C17:0 and C17:1 cis-9 were similar among different parities (P 0.05). The proportions of total OBCFAs were greater in first- and second-parity cows (P 0.05), whereas the highest yield was observed in second-parity cows. Lactation dairy cows in ≤ 21 DIM group displayed lower proportions of iso-13:0, anteiso-13:0, C13:0, iso-14:0, C15:0, iso-16:0, total iso-FA, and total OBCFAs compared with that of the other groups (P 0.05), and also lower yields of iso-14:0 and iso-16:0 (P 0.05). In contrast, C17:0 and C17:1 cis-9 proportions and yields were higher in dairy cows with ≤ 21 DIM (P 0.05). Iso-17:0 and anteiso-17:0 were not affected by lactation stage (P 0.05). Taken together, our data showed that both parity and lactation stage have considerable effects on milk fat OBCFAs of dairy cows. In summary, first- and second-parity cows had higher milk OBCFAs compared with later parity cows, and OBCFAs with medium chain lengths were lower in dairy cows with ≤ 21 DIM, while C17:0 and C17:1 cis-9 were higher. These findings show that milk OBCFA contents are differentially modulated by physiological state. They will be useful in future studies that seek to alter OBCFA composition of Holstein dairy cow milk fats.

The characteristics of shear bands in cold-rolled Ta-2.5W alloy are systematically investigated at different mechanical reduction levels. With increasing strain, the shear bands can appear as in-grain shear bands, trans-granular shear bands and wavy bands. At low strain the crystallographic planar in-grain shear bands are aligned close to the highly stressed slip planes at low strain. As strain increases, the shear bands rotate around the or direction to smaller inclination angles with respect to the rolling direction (RD). Meanwhile, new groups of shear bands are developed. Two groups of in-grain shear bands with a specific fishbone structure appear in the orientations with larger Taylor factor at medium strain. The trans-granular shear bands are formed when the adjacent grains get the continuity of slip planes. Therefore, the frequency of trans-granular shear bands increases with the enhancing of local texture. The wavy bands appear to be a result of sequential necking in the harder γ-fiber and a cooperative flow in the softer α-fiber. Meanwhile, the formation model of the wavy bands is also proposed based on the laminar composites.

Elongated lamellar bands parallel to rolling plane are usually formed in γ-fiber of Ta W alloys at high strains. However, in this study, a type of lamellar bands oriented with α-fiber is formed in Ta 10 W alloy cold-rolled to 5%. Meanwhile, island equiaxed grains with special orientations can be seen in the lamellar bands. Furthermore, the lamellar bands are not homogenously distributed in the whole samples and concentrated in some elongated-grain bands. Although the lamellar bands are composed of extending planar dislocation boundaries with one or two dislocation cells across, they cannot result from incremental rotation of microbands or microshear bands, since no shear bands appear in these lamellar bands at such low strain. Therefore, the lamellar bands can be initiated by the retained elongated lamellar boundaries after annealing. They show a persistent microstructural feature as the ratio of reduction increases. As the hardness and dislocation density of the persistent lamellar bands is quite different from that of other deformed microstructures, these bands are bad for plastic deformation process. Meanwhile, protrusions at high-angle lamellar boundaries migrating to the recovered lamellar bands are observed during annealing because of the inhomogeneous dislocation microstructure. The lamellar bands can be fully eliminated when the annealing temperature reaches 1500 °C.

Glasses and vitroceramics in the xMoO 3 ·(100 − x)[4PbO 2 ·Pb] system with x = 5-50 mol% MoO 3 were prepared by melt quenching method. The influence of MoO 3 content on optical properties and structure of the 4PbO 2 ·Pb host network was investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman, photofluorescence and X-ray photoelectron (XPS) spectroscopies. The X-ray patterns show the presence of a small amount of Pb 2 MoO 5 crystalline phase in the sample with x = 40 mol% MoO 3 . By increasing of MoO 3 content up to 50 mol% MoO 3 , Pb 2 MoO 5 and tetragonal PbO crystalline phases were detected. Raman data show the bending modes of the O Pb O linkages which allow the intercalation of [PbO 4 ] structural units, isolated [MoO 4 ] and deformed [MoO 6 ] structural units as basic structural units formed by lead and molybdenum atoms. The photofluorescence spectroscopy data shows the transitions of Mo + 5 and Pb 2 + ions. According to the XPS data, the vitroceramic network contains mainly [MoO 4 ] tetrahedral units and small amounts of [MoO 6 ] octahedral units.

Lithium–lead–germanate glasses in the xLi 2 O·(100-x)[7GeO 2 ·3PbO] system, where 0 ≤ x ≤ 40 mol% Li 2 CO 3 exhibit a “germanate anomaly”, which is a maximum in their density profiles with the addition of Li 2 CO 3 up to 20 mol%. The structural characterization of the samples was performed by investigations of Raman spectroscopy and X-ray scattering analysis. An EXAFS analysis of the spectra collected at the germanium K-edge for series of lithium–lead–germanate glasses is also presented. With the EXAFS-extracted structural parameters were reconstructed to the local neighborhood of Ge atoms and were verified current opinions on the germanate anomaly in the considered glasses. The formation of higher-coordinated Ge species in the glassy network can be correlated with the density anomaly. Several structural mechanisms can be summarized by increasing of lithium carbonate in the lead–germanate glassy: i) depolymerization of germanate network; ii) conversion of 3- to 4-membered [GeO 4 ] rings; iii) transformation of connected [GeO 6 ] structural units into isolated [GeO 6 ] structural units and a conversion part of higher to lower coordination number of germanium atoms.

The effect of tungsten content on deformation texture and microstructure of Ta-W alloy is studied. It is found that the increase of tungsten content results in the strengthening of α-fiber and the weakening of γ-fiber in Ta-W alloys. The volume fraction of γ-fiber developed in Ta-10W alloy is lower than that in Ta-2.5W alloys. Meanwhile, a more significant through-thickness texture gradient is formed in Ta-10W alloy. The addition of tungsten has an important effect on the ability cross-slip of dislocations. Therefore, more dislocation loops and activated slip systems can be seen in Ta-2.5W alloy. The size of the dislocation cells in Ta-2.5W alloy is larger than that in Ta-10W alloy. As shear bands tends to appear in γ-fiber, the density of shear bands in the Ta-2.5W alloy is much higher than that of Ta-10W alloy at the same reduction strain. Meanwhile, the wavelength of the wavy shear bands in Ta-10W alloy is smaller than that in Ta-2.5W alloy. In Ta-10W alloy, new grains with Goss orientation can be seen in periodic shear bands developed in {111} orientations, which is different from that in Ta-2.5W alloy.

[EN] Apricot pretreated with RF and then dried with convective hot air at 65℃, 3.0m/s in this research. RF pretreatment time of 20, 30, 40 and 50min were chosen. Results showed that, there is only falling rate period during apricot hot air drying, and the drying rate of apricot is improved significantly; Herdenson and Pabis model is suitable for apricot hot air drying; retentions of flavonoids, polyphenols and Vc in dried apricot were higher than those of fresh apricot; when RF treating time was chosen 30mins, nutrients retentions of Vc, flavonoid and polyphenols were 0.9543mg/100g, 5.4089mg/100g and 7.3382mg/100g, separately., The work was financially supported by the Fundamental Research Funds for the Central Universities of China (NO. GK201503072 and GK201601007).

[EN] In this paper, hot air drying (HAD) was applied when moisture content of apple slices range from 50% to 86%, and then vacuum-filling nitrogen drying (VFND) was used till moisture content reaching 7%. Results showed that, the drying rate of apple slice during VFND period increased with temperature increment and decreased with increment of slice thickness; compared to freezing dried samples, samples dried in this research were owned lower Vc and higher flavonoid; when HAD (70℃,3.0m/s)+VFND(relative pressure 0.08MPa, 50℃) and thickness of 6.0mm, nutrients reached better levels: retentions of Vc, total phenolics and flavonoid were 1.63mg/100g, 4.07mg/100g and 2.10mg/100g, respectively., The work was financially supported by the Fundamental Research Funds for the Central Universities of China (NO. GK201503072 and GK201601007).

Aims To perform a systematic evaluation of the applicability, validity and reliability of the long PCR-RFLP of 16S-ITS-23S rRNA genes for bacterial genotyping using both sequences retrieved from public genome databases and the experimental data obtained on bacterial cultures. Methods and Results 3301 Full-length sequences of 16S-ITS-23S rRNA genes were retrieved from 885 published bacterial genomes. Copy numbers of the whole set of 16S-ITS-23S rRNA genes per genome ranged from 1 (n = 161) to 14 (n = 4) with an average of 3·71. Their length varied greatly, from 4319 to 6568 bp with an average of 4952 bp. Computer-simulated RFLP analyses of the 16S-ITS-23S fragments flanked by the conserved primers 27F and 2241R suggested MspI, RsaI, HhaI and TaqI as the most appropriate enzymes for long PCR-RFLP analysis of the 16S-ITS-23S sequence. MspI was used to screen over 900 bacterial cultures isolated from the Huguangyan Maar Lake in southern China. An experimental sequencing of 16S rRNA genes of the isolates possessing a unique RFLP band pattern proved the broad applicability and high resolution of this approach. Conclusions These results indicate that long PCR-RFLP of 16S-ITS-23S rRNA genes is a potentially universal and reliable bacterial genotyping tool with a high resolution. Significance and Impact of the Study The methodology of long PCR-RFLP of 16S-ITS-23S rRNA genes will facilitate the exploration and tracing of cultivable microbial diversity in natural environments.

The influence of DC current on the resistivity and phase transition of polycrystalline La 0.7 Ca 0.3 MnO 3 has been investigated. The specific heat measurement found that charge carriers and ferromagnetic spin-wave contributions were changed after applied DC current. Applying high electric fields leads to the formation of ferromagnetic regions. The resistivity drops abruptly once the percolating current path is established. As current through the sample disappears, the larger ferromagnetic (FM) clusters, however, remain and are frozen in giving a measurable contribution to the specific heat of the system. The larger clusters should give rise to the value of spin-wave stiffness constant ( D ), as it is expected to increase the strength of the ferromagnetic coupling. The metallic ferromagnetic regions would make the charge carrier delocalization and attribute to specific heat linear term γ .

To investigate the economic performance of applying the ground source heat pump system in swine farms in Beijing China, initial investment and operating cost of ground source heat pump (GSHP) heating and cooling system, coal fired heating system (CFH), wet curtain fan cooling system (WCFC), air conditioner heating and cooling system (AC) were analyzed and compared. The results showed that the initial investment of GSHP heating and cooling system was higher than that of the CFH system integrated with WCFC system, the relative operating cost of the heating systems of GSHP, CFH and AC was 0.94, 1.00 and 0.98, respectively. The relative operating cost of the cooling system of the GSHP, WCFC and AC system was 4.50, 1.00 and 6.38, respectively.

The 5-hydroxytryptamine (5-HT)-7 receptor began to be cloned and pharmacologically characterized close to 20 years ago. It couples positively via G-proteins to adenylyl cyclase and activation of this receptor increases neuronal excitability, and several studies have shown that degeneration of the nigrostriatal pathway leads to an impairment of 5-HT system. Here we reported that systemic and local administration of 5-HT₇ receptor agonist AS 19 produced excitation, inhibition and no change in the firing rate of pyramidal neurons in medial prefrontal cortex (mPFC) of normal and 6-hydroxydopamine-lesioned rats. In normal rats, the mean response of the pyramidal neurons to AS 19 by systemic and local administration in mPFC was excitatory. The inhibitory effect by systemic administration of AS 19 was reversed by GABA(A) receptor antagonist picrotoxinin. Systemic administration of picrotoxinin excited all the neurons examined in normal rats, and after treatment with picrotoxinin, the local administration of AS 19 further increased the firing rate of the neurons. In the lesioned rats, systemic administration of AS 19, at the same doses, also increased the mean firing rate of the pyramidal neurons. However, cumulative dose producing excitation in the lesioned rats was higher than that of normal rats. Systemic administration of AS 19 produced inhibitory effect in the lesioned rats, which was partially reversed by picrotoxinin. The local administration of AS 19, at the same dose, did not change the firing rate of the neurons in the lesioned rats. Systemic administration of picrotoxinin and the local administration of AS 19 did not affect the firing rate of the neurons in the lesioned rats. These results indicate that activity of mPFC pyramidal neurons is regulated through activation of 5-HT₇ receptor by direct or indirect action, and degeneration of the nigrostriatal pathway leads to decreased response of these neurons to AS 19, suggesting dysfunction and/or down-regulation of 5-HT₇ receptor on the pyramidal neurons and GABA interneurons in the lesioned rats.

With the improvement of the wiring density and the signal frequency, electrical interconnection based on the copper wire connection could not meet the need of Electrical interconnection. Board-level photoelectric interconnection is a new way of interconnection to solve the problems existing in the pure electrical interconnection. This paper introduced the definition of board-level optoelectronic interconnection technology, summarized the characteristics and basic principle and classification of board-level optoelectronic interconnection technology analyzed the board level photoelectric interconnection technology research status at home and abroad, points out that the board level photoelectric interconnection problems existing in the development, and prospected the future of board-level photoelectric technology development trend.

A new high-temperature thermal sensor based on large-grain polysilicon film formed by metal-induced lateral crystallization (MILC) is proposed. The sensor demonstrates a positive temperature coefficient (PTC) characteristic from 130 °C to high temperatures above 600 °C. Its fabrication process is more cost-effective than its silicon on insulator (SOI) counterpart, and its performance is better than the sensor based on small-grain polysilicon formed by solid-phase crystallization (SPC). Therefore, the proposed sensor is more suitable to be integrated into single-chip CMOS-MEMS gas-sensor system for monitoring the high temperature of sensing membranes.

La0.67Ca0.33MnO3 (LCMO)/YBa2Cu3Oy (YBCO)/Ni trilayers were fabricated with varying thickness of the mid-superconducting YBCO layer. Two different deposition systems were used to avoid oxidation of the magnetic metal Ni and contamination of the deposition systems. Transport properties show that the temperature dependence of resistance goes from a metallic-to-metal-insulator transition (manganite-like behavior) to a superconducting behavior (M-M-S) with increase of the thickness of the YBCO layer. The magnetoresistance (MR) ratio is very small in comparison with LCMO/YBCO bilayers at low temperature. Such phenomenon may depend on the charge transfer and the magnetic spin interaction between the bottom and cap magnetic layers. (c) 2005 Elsevier B.V. All rights reserved.

An analytical two-dimensional model is developed to explain the minority-carrier exclusion effect in circular spreading-resistance temperature (SRT) sensor fabricated on thin silicon film. The model can be used to show the relation between minority-carrier exclusion length and maximum operating temperature of the sensor under different bias currents and different doping levels. Comparison is made between the proposed model and the conventional one-dimensional model used for similar sensors with rectangular shape. Experimental results show that the new model is more accurate than the one-dimensional model for predicting the characteristics of the circular SRT sensor.

A thermal sensor built from a silicon resistor with a simple rectangular layout structure on thin-film (0.1 μm) silicon-on-insulator (SOI) substrate is studied and compared with those on thick-film (10 μm) SOI and bulk (450 μm) Si. Besides supporting the theory of minority-carrier exclusion effect through one-dimensional highly confined carrier transport in the ultra-thin rectangular silicon film, the thin-film SOI device demonstrates the effect of silicon-film thickness on the maximum operating temperature ( T max ) of the sensor: thinner Si film results in higher T max due to higher current density and hence stronger exclusion effect. Measurements and simulations both show that the SOI structure can indeed have the silicon-film thickness as an additional degree of freedom for increasing T max . More importantly, the thin-film SOI thermal resistor can achieve a T max beyond 400 °C even under a very low operating current of 0.1 μA, which is about 1000 times smaller than that of the thick-film SOI counterpart with the same T max . In conclusion, silicon resistor on SOI is a promising low-cost thermal sensor for a broad scope of low-power high-temperature applications.

This study was performed to compare the effects of recombinant human growth hormone (rhGH), glutamine (Gln) and simultaneous treatment with rhGH and Gln in rats subjected to 75% intestinal resection and maintained with parenteral nutrition (PN) for 6 days. Morphological changes including mucosal thickness, villus height, crypt depths and villus surface area of the residue jejunum were measured under a light microscope; expression of PCNA as an index of cell proliferation and apoptotic cells were observed using immunohistochemical staining; Ileal IGF-1 mRNA was determined by Northern blot analysis. The morphological parameters of the jejunal mucosa in rats treated with PN alone were only about 52-62% of those in reference group (P

Specific heats and magnetic moments of La 0.5 Ca 0.5 + x MnO 3 − y + Δ y polycrystalline ceramics were measured under different resistance states induced by electric pulses. Experimental results revealed that the specific heat associated with ferromagnetic spin waves had a larger value at a low resistance state compared to that at a high state, indicating the growth of ferromagnetic regions as the resistance changed from a high state to a lower one. The charge ordering temperature ( T CO ) at a low resistance state was higher than that at a high state, in contrast to the prediction based on the traditional double exchange model. We proposed that the ferromagnetic clusters at a low resistance state would cause a reduction of the collective Jahn–Teller distortion in the ferromagnetic phase, thus leading to an increase in T CO .

We report experimental observation of the edge enhancement of ligh emission from Au particles, which is not expected in the framework of the decay of localized plasmons. It is proposed to be due to the excitation of surface plasmons by the tunneling electrons through the Cherenkov effect.

Substitution of Pb for Hg was performed in the Hg based 1223 phase HgBa2Ca2Cu3O8+delta a (T-c similar to 135 K), resulting in an increase of the superconducting transition temperature to T-c(dia) = 143 K for samples with a nominal composition of Hg0.7Pb0.3Ba2Ca2Cu3O8+delta. The crystal structure of this solid solution has been investigated by neutron powder diffraction (NPD) and synchrotron X-ray diffraction (SXRD) techniques at room temperature (RT). The compound has the same crystal structure as Hg-1223 with the space group P4/mmm and lattice parameters a = 3.8457(1) Angstrom and c = 15.8252(7) Angstrom. Rietveld analysis results indicate that Hg is partially replaced by Pb, and the oxygen content, delta, is 0.450(2). The lattice parameter changes resulting from the Pb substitution are too small to account for the T-c change mimicking the effect of pressure.

We present the aggregation of silver perchlorate molecules in Langmuir-Blodgett films, which are generated from the reaction of silver arachidate multilayers with perchloric acid gas. Salt-acid conversion and structural variation of the films are investigated. The morphology of silver perchlorate clusters is visualized using atomic force microscopy. Plate-like clusters with diameters of several nanometres are presumed to result from the assembly of neighbouring smaller particles.

5-Hydroxytryptamine(1A) (5-HT(1A)) receptors are expressed in the prefrontal cortical interneurons. Among these interneurons, calcium-binding protein parvalbumin (PV)-positive fast spiking (FS) interneurons play an important role in regulatory function of the prefrontal cortex. In the present study, the response of medial prefrontal cortex (mPFC) FS interneurons to the selective 5-HT(1A) receptor agonist 8-OH-DPAT and change in expression of 5-HT(1A) receptor on PV-positive neurons were examined in rats with 6-hydroxydopamine (6-OHDA) lesions of the substantia nigra pars compacta (SNc) by using extracellular recording and double-labeling immunofluorescence histochemistry. Systemic administration of 8-OH-DPAT (1-243 μg/kg, i.v.) dose-dependently inhibited the mean firing rate of the FS interneurons in sham-operated and the lesioned rats, respectively. The cumulative doses producing inhibition in the lesioned rats (243 μg/kg) was significantly higher than that of sham-operated rats (27 μg/kg). Furthermore, the local application of 8-OH-DPAT (0.01 μg) in the mPFC inhibited the FS interneurons in sham-operated rats, while having no effect on firing rate of the FS interneurons in the lesioned rats. In contrast to sham-operated rats, the lesion of the SNc in rats did not cause the change of PV-positive neurons in the prelimbic prefrontal cortex, a subregion of the mPFC, whereas the lesion of the SNc markedly reduced in percentage of PV-positive neurons expressing 5-HT(1A) receptors. Our results indicate that degeneration of the nigrostriatal pathway results in the decreased response of FS interneurons in the mPFC to 5-HT(1A) receptor stimulation, which attributes to down-regulation of 5-HT(1A) receptor expression in these interneurons.

Dextrose, lipid emulsion, amino-acids, electrolytes, vitamins and trace elements were mixed in a well defined order to prepare 10 different total nutrient admixture solutions. The pH and osmolality of these solutions did not change significantly during 14 days of storage at 4 degrees C. Mean diameters of lipid particles on different occasions for the different solutions varied from 0.31 +/- 0.10 mum to 0.48 +/- 19 mum with 95% of particles less than 0.6 mum. Particles greater than 6 mum were not observed. Cultures were all negative. 243 patients received 5101 infusions of the admixture fluids. Patients on treatment for more than 1 week showed improved nitrogen balance. Serum transferrin and albumin were increased when treatment was ongoing for more than 2 weeks. No adverse reactions or abnormal laboratory findings were observed. One patient, with only duodenum and a part the colon left, has been maintained in good health for more than 55 months using this kind of nutritional support.

A high-gain and broadband printed antenna together with its feed network is developed, which consists of seven hexagonal sub-arrays as cells, each one is a hexagonal compound air-fed array (CAFA), arranged in a beehive-like shape. After choosing an optimal feeding-voltage ratio of the central cell to the circumjacent cells as 0.42, the corresponding feed network is carefully designed. The measured results of a fabricated prototype are of common bandwidth (for VSWR ⩽ 2.0÷1 & gain-drop ⩽ −3 dB & SLL ⩽ −15 dB) 8.28 % and maximal gain 22.51 dBi, while the simulation results are 9.63 % and 22.87 dBi.

Based on the minority-carrier exclusion theory, an analytical model is developed to explain the operating principle of thermal sensors fabricated on silicon-on-insulator in terms of the carrier-concentration distribution and the temperature dependence of the sensor resistance. The effects of temperature and carrier concentrations on carrier mobilities are included in the model. A two-region model is proposed to improve the resistance model at low bias current. The effect of self-heating on the sensor model is also considered.

The agricultural non-point source pollution by nitrogen (N) and phosphorus (P) loss from typical paddy soil (whitish soil, Bai Tu in Chinese) in the Taihu Lake region was investigated through a case study. Results shown that the net load of nutrients from white soil is 34.1 kg ha(-1) for total nitrogen (TN), distributed as 19.4 kg ha(-1), in the rice season and 14.7 kg ha(-1) in the wheat season, and for total phosphorus (TP) 1.75 kg ha(-1), distributed as 1.16 kg ha(-1) in the rice season and 0.58 kg ha(-1) in the wheat season. The major chemical species of N loss is different in the two seasons. NH4-N is main the form in the rice season (53% of TN). NO3-N is the main form in wheat season (46% of TN). Particle-P is the main form in both seasons, (about 56% of TP). The nutrient loss varied with time of the year. The main loss of nutrients happened in the 10 days after planting, 64% of TN and 42% of TP loss, respectively. Rainfall and fertilizer application are the key factors which influence nitrogen and phosphorus loss from arable land, especially rainfall events shortly after fertilizer application. So it is very important to improve the field management of the nutrients and water during the early days of planting.

A two-dimensional model is developed to explain the minority-carrier exclusion effect in circular Spreading-Resistance Temperature (SRT) sensor fabricated on thin silicon film. The model can be used to show the relation between minority-carrier exclusion length and maximum operating temperature of the sensor under different bias currents and different doping levels. Comparison is made between the proposed model and the conventional one-dimensional model used for similar sensors with rectangular shape. Experimental results show that the new model is more accurate than the one-dimensional model for predicting the characteristics of the circular SRT sensor.

A high-current injection phenomenon was found in Spreading-Resistance Temperature (SRT) sensor on SOI. Simulation and experiment of the sensor with different silicon-film thicknesses and doping concentrations were conducted to demonstrate this phenomenon, which can be explained by the conductivity modulation model normally used in LIGBT. This study is very helpful for designing the operating current of SRT sensor on SOI.

In this work, thermal resistors based on a simple rectangular structure are fabricated on three kinds of substrates thin-film (0.1 /spl mu/m) silicon-on-insulator (SOI), thick-film (10 /spl mu/m) SOI and bulk Si, and their characteristics are investigated. Measurements verify that SOI can indeed have additional freedom for increasing the maximum operating temperature (T/sub max/). More importantly, the thin-film SOI thermal resistor not only achieves a T/sub max/ as high as 420/spl deg/C, but also a low operating current of 1 /spl mu/A, which is about 1,000 times smaller than that of the thick-film SOI counterpart for the same T/sub max/. In conclusion, silicon resistor on SOI is a promising low-cost thermal sensor for a broad scope of low-power high-temperature applications.

This paper shows some technique about fabrication and analysis of electret back-plates in a kind of special microphones, which are used in measurement of sound wave. The sample of Teflon-FEP film (25 um thick) is deposited on the surface of the back-electrode of metal. Based on experimental results of the surface potential decay of electret samples, we use the method of high temperature extrapolation to calculate the active energy of trapped electrons. The result of experiments of surface potential decay is coincident with the theoretical analysis.

The effects of interlayer polarization in the preparation of electret are studied in this paper. We have deeply discussed several different samples by different ways, which is meaningful for the research of mini electret devices.

When a super-thin film electret is evaporated with metal electrodes on two sides, the electrons in electrodes have the possibility of crossing potential area in film. Suppose the electrons obey Fermi-distribution, it is found that the tunnel current across the film depends on both exerted voltage between the film and the thickness of the film. The temperature and work function of electrode-metal also have significant effects on the current. If exerted electrical field is very large, the result of calculation shows that the current can be proportional to exerted voltage in certain conditions.

A case of normal gestation after 5 years on HPN is reported. The patient had her entire jejunum and ileum and right colon resected because of gangrene and has subsisted normally on HPN ever since. From the second trimester on, her HPN formula was supplemented to meet the requirement for growth and development of the foetus. Anaemia, hypoalbuminaemia, low plasma zinc levels and jaundice became manifest in the final trimester. These responded readily to readjustment of her HPN formula. A normal baby weighing 2020 g was delivered by Caesarean section at 36 weeks. Long-term HPN, final trimester abnormalities and HPN formula adjustments are discussed.