Range Of T3 Research Articles

不同覆盖方式对旱地果园水热特征的影响

PDF HTML阅读 XML下载 导出引用 引用提醒 不同覆盖方式对旱地果园水热特征的影响 DOI: 10.5846/stxb201211051543 作者: 作者单位: 甘肃省农业科学院林果花卉研究所,甘肃省农业科学院林果花卉研究所,静宁县林业局,甘肃省农业科学院林果花卉研究所,甘肃省农业科学院林果花卉研究所,静宁县康源果农协会 作者简介: 通讯作者: 中图分类号: 基金项目: 现代农业产业技术体系建设专项资金资助项目（CARS-29-41）；农业部西北作物抗旱栽培与耕作重点开放实验室和甘肃省旱作区水资源高效利用重点实验室开放基金课题资助项目（HNSJJ-201103） The effects of different mulching way on soil water thermal characteristics in pear orchard in the arid area Author: Affiliation: Institute of Fruit and Floriculture of Gansu Academy of Agricultural Sciences,Institute of Fruit and Floriculture of Gansu Academy of Agricultural Sciences,Jingning county Fruit Industry Bureau,Institute of Fruit and Floriculture of Gansu Academy of Agricultural Sciences,Institute of Fruit and Floriculture of Gansu Academy of Agricultural Sciences,Jingning county KangYuan Growers Association Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:采用垄膜覆盖（T1）、覆草（T2）和免耕无覆盖（T3）等方法，测定分析陇东旱地果园水热状况，结果表明，0-60 cm土壤温度全年T1最高，萌芽开花期至果实膨大期T2温度最低，新梢停止生长期至落叶期T3温度最低。T1地表和20 cm土壤最高温度出现在6月上旬，40 cm和60 cm出现在8月上旬，表现为浅层（0-40 cm）最高温度出现提前，而T2和T3不同土层最高温度均在8月上旬。0-25 cm不同处理土壤温度表现为晴天最高，雨天最低。除7月至8月土壤温差以T1最大外，其余时期均以T3最大，全年T2温差最小。梨树生长前期（4-6月），T3土壤含水量最小，7月以后，T3最高。梨年生长周期中，T1土壤含水量变化最小，T3最大。不同土层T1土壤容重最小，孔隙度最大，T3土壤容重最大，孔隙度最小；0-120 cm土层T1和T3土壤容重均表现为先升后降，T2为先降后稳定变化的特点。不同处理土壤营养元素含量随时间变化而降低，T3降幅最大。地面覆盖减缓了土壤养分的流失，同时增加了土壤铁、锌、硼等元素含量。 Abstract:By adopting the ridge film mulching (T1),wheatgrass mulching (T2) and zero tillage without cover (T3) method. To determine and analyze the soil temperature and moisture in a year changes in dry land pear orchard in eastern Gansu. The results show that the soil temperature of T1 is highest in 0-60cm soil horizon in a year. During bud sprouting and flowering to the growth stage of the fruit, the soil temperature of T2 is lowest,and T3 is lowest which new shoots stop growing period to leaf fall period.T1 treatment which The highest temperature of the surface and 20cm soil appears in early June, but 40 cm and 60cm appeared in early August. It was concluded that the highest temperature of the shallow layer (0-40 cm) of T1 appears in advance, while the highest temperature of different soil layer of T2 and T3 are in early August. In 0-25cm soil horizon, different treatment soil temperature performance for sunny is highest, lowest rainy day. The soil temperature difference of T1 from July to August is maximum, and T3 is maximum in the remaining time. In a year, the soil temperature difference of T2 is minimum. At growth prophase (4-6 months)of pear tree, the soil moisture content of T3 is minimum. After the July, the soil moisture content of T3 is highest. Annual growth cycle of pear tree, the soil moisture content change of T1 is minimum, and T3 is maximum. The soil bulk density of T1 with different soil horizon is minimum and its soil porosity is maximum. T3 is contrary. In 0-120 cm soil horizon, the soil bulk density of T1 and T3 treatment are performing first rises then falls, but T2 treatment is the first drop then stable change. The soil nutrient element contents of different treatment with the time change is reduced, the range of T3 is biggest. Mulching slow down loss speed of the soil nutrients, and also increase the soil trace element contents of iron, zinc, boron, etc. 参考文献 相似文献 引证文献

Histological evaluation of osseointegration aroundtitanium implants in thyroidectomized rabbits(experimental study).

Background: Thyroid hormones are essential for linear growth and peak bone mass acquisition. Hypothyroidism occurs when the thyroid gland produces less than the normal amount of thyroid hormones. The present study was carried out to evaluate the effect of hypothyroidism on osseointegration around the titanium implants screwed in rabbit's tibia. Materials and methods :Fifty four machined surface Iraqi implants were inserted in 27 male rabbits (2implants in each rabbit's tibia ).Eighteen of these rabbits were subjected to near total thyroidectomy to induce hypothyroidism three weeks before implantation surgery. While the remaining 9 rabbits were remain as a control group. Blood sample was taken from each animal at the beginning of this study in order to find the normal range of T3,T4,and TSH .And another blood sample was taken for experimental groups to find the levels of T3,T4,and TSH three weeks after thyroidectomy in order to assess the hypothyroidism status .After 2, 4, 6 weeks after implant surgery (6rabbits from experimental group and 3rabbits from the control group) were sacrificed. In the day of scarification, one of the screws was unscrewed with a torque meter, and the peak torque required to shear off the implant was recorded. Then the decalcified sections of the bone around the implants were studied histologically and histomorphometrically .The eye piece reticule was used for morphometrical studies, which were includes: number of osteocytes, number of osteoblasts, thickness and number of bone trabeculae, and thread width Results:The results showed that hypothyroid rabbits had delay in osseointegration, bone formation and maturation around implants in almost all rabbits in experimental groups. While the rabbits in the control groups showed improvement in osseointegration around titanium implant. Removal torque test illustrated higher torque test value in control animals than in experimental one. Moreover, there were increases in torque test values in both groups with time. Biochemical serum analysis revealed a decrease in T3, T4, and increase TSH levels in experimental animals. Conclusion: It can be concluded that there were low bone quality with a delay in bone healing around titanium implants in hypothyroidied rabbits compared with healthy one.

Discussion of “Thrust Restraint Design of Concrete Pressure Pipe” by Mehdi S. Zarghamee, Daniel W. Eggers, Rasko P. Ojdrovic, and Daniel P. Valentine

The authors are to be complimented on their development of a design procedure for restraint of pressure-induced thrust at bends in pipelines, using concrete pressure pipe, which includes the effects of soil resistance to lateral movement of tied-pipe. The authors’ procedure is a needed extension of a beam-on-elasticfoundation design procedure for thrust restraint of fiberglassreinforced plastic pipe and fittings developed in the late 1970s Ameron 1980 , but it is found to be lacking in some respects. Throughout this discussion, is substituted for the authors’ for compatibility with AWWA 1996 . In the authors’ Eq. 3 the third term, 2klb cos 2 /2 referred to herein as T3, represents passive soil-pressure forces that act on the bend to resist thrust T. The fourth term of Eq. 3 2fulb sin /2 referred to herein as T4, represents friction forces that act on the bend to resist thrust. Both terms are incorrect because they are not based on movement of the bend into the soil in the direction of the thrust force and because all bends are treated as having only a single mitered joint. The correct third term is T3 =k lk where lk is the effective length of the projection of the outer surface of the entire bend on a plane perpendicular to T. That projection is a rectangle of length 2lb cos /2 and width Do, with half ellipses appended to its ends. The major axis of the ellipses is Do and the minor axis is Do sin /2 . The effective projected length, which is equal to the projected area divided by Do, is lk=2lb cos /2 + /4 Do sin /2 . The correct fourth term is T4 = f l where l is the sum of the centerline lengths of each of the mitered sections of the bend. Using the guidelines for the design of mitered bends in AWWA 1996 , l =2 lb −R tan /2 + ns−1 R tan /2 , where lb is equal to L1 from Table 1 of AWWA 1996 , R is the radius of the bend, ns is the number of mitered sections and = / ns−1 . For Do=1,829 mm 72 in. values of T3 /T3 range from 0.9 to 1.4 for values of from 7.5° to 90° and R from 1.0Do to 2.5Do. Values of T4 /T4 range from 15.3 to 2.0 over the same ranges of and R. The differences represented by the ratios, especially T4 /T4, are significant. The authors’ depend upon axial friction forces on tied pipe from vertical loads We, Wp, and Wf to resist thrust force, but they neglect friction forces produced by lateral soil pressure against the pipe. The total lateral force producing friction along the springlines of pipe is equal to 2Vo, and, because lateral friction pressure is greatest near the bend, it could be significant in reducing the amount of longitudinal reinforcement of the first few tied pipe as well as the number of tied pipe. It seems overly conservative to neglect the effect of friction from lateral soil pressure.

Iodine deficiency induces thyroid autoimmune reactivity in Wistar rats.

The last 2 decades it has become clear that iodine deficiency has a modulating effect on the thyroid autoimmune response in humans. Also, in animals that spontaneously develop autoimmune thyroid disease, evidence is accumulating that a low iodine intake can modulate thyroid autoimmune reactivity. However, it is still not clear what the effect of a low iodine intake on thyroid autoimmune reactivity is in normal nonautoimmune animals. To study the relationship of a dietary low iodine intake on the thyroid autoimmune reactivity in nonautoimmune animals, normal Wistar rats (female) were kept on an enriched iodine diet (daily iodine intake of 100 micrograms iodine), a "for our area normal" (conventional) diet (COD; daily iodine intake of 7 micrograms iodine), a low iodine diet (LID; 2 days of 1% KCLO4, followed by iodine-deficient drinking water/pellets), or an extremely low iodine diet (LID+; 1% KCLO4 continuously in the drinking water and iodine-deficient pellets). The enriched iodine diet rats were euthyroid (T3, approximately 8 nM/liter: T4, approximately 50 nM/liter; TSH, approximately 2 ng/ml), had a normal thyroid weight (approximately 12.5 mg), and showed only minimal signs of local thyroid immune reactivity; low numbers of intrathyroidal dendritic cells (DC; approximately 35 DC/mm2), CD4+ cells (approximately 2 cells/mm2), and CD8+ cells (approximately 2.5 cells/mm2) were found in combination with low anticolloid antibody production (incidence of positive animals, 12.5%). The COD resulted in a normal thyroid function. The rats were euthyroid (range of T3, 1.6-1.2 nM/liter; T4, approximately 50 nM/liter; TSH, approximately 2 ng/ml) and had a normal thyroid weight (approximately 12.5 mg). However, some signs of thyroid autoimmune reactivity were found [number of intrathyroidal DC, approximately 40/mm2; approximately 3 CD4-positive (CD+) cells/mm2; approximately 3 CD8+ cells/mm2; together with a 30% incidence of anticolloid antibodies]. The LID and LID+ not only induced goiter formation [thyroid weight, 27.3 +/- 4.2 mg (mean +/- SD) after 12 weeks of LID and 38.4 +/- 5.3 mg after 4 weeks of LID+] and low production of T4 by the thyroid [28 +/- 3 nM/liter (mean +/- SD)] after 12 weeks of LID and 14 +/- 3 nM/liter after 2 weeks of LID+], but also induced various signs of thyroid autoimmune reactivity.(ABSTRACT TRUNCATED AT 400 WORDS)

Studies of the Binding of Thyroid Hormones and Their Short Loop Feedback Effects in Bovine Thyroid Tissue*

In vitro studies in bovine thyroid tissue have been conducted to explore the postulated short loop negative feedback of thyroid hormones on several thyroid functions and their responses to TSH. Initial experiments in thyroid plasma membranes provided no evidence that T4 or T3 in concentrations as high as 5 × 105 M and 4 × 105 M, respectively, could displace [125I]iodobovine TSH (bTSH) from its specific binding sites within the membranes. In addition, as judged from the lack of variation in the percentage binding of [125I]T3 and [125I]T4 to membranes over a wide range of T3 and T4 concentrations, no evidence of specific or saturable binding sites for either of the two hormones could be demonstrated up to concentrations of 2 X 105 M. Preincubation of thyroid slices for 3 h with T3 at concentrations of 105 and 10“4 M failed to alter basal cAMP concentrations or the pronounced stimulation of cAMP concentrationsproduced by incubation with bTSH. Basal and bTSHstimulated rates of generation of 14CO2 from uniform...