Results 81 to 90 of about 52,444 (177)

Anatomical study on the chalkiness formation of early indica rice(早籼垩白米形成的形态解剖学的研究)

open access: yesZhejiang Daxue xuebao. Lixue ban, 2002
以浙733(多垩白)和中优早5号(少垩白)两个品种为实验材料,利用人工气候箱控温手段,在植株开花后4天分别移入高(37℃)、中(30℃)、低温(24℃)的人工气候箱控温栽培.采用Spurr树脂半薄切片的方法对垩白部位的细胞结构和淀粉粒整体形态进行观察研究.实验结果表明,温度越高,腹背径向的细胞越扁,细胞数目越多,越易导致垩白的发生;不同温度处理下中优早5号的淀粉粒大多为多角形,但温度越高,淀粉粒排列越疏松,且大小不均一;低温处理下浙733的淀粉粒大多为多角形,排列较为紧密,但大小不均一,中 ...
JIANGWei-mei(姜维梅)   +2 more
doaj   +1 more source

Work Conditions for hot machining [PDF]

open access: yes, 1953
In turning steels by means of the hot machining technique, the machinability varies remarkably with the room temperature, and hence tool material, depth of cut, feed and cutting speed should be changed also with the temperature.
村中 利吉
core   +1 more source

A Stretchable Sandwich Composite Film With Ultra‐Broadband Electromagnetic Interference Shielding and High‐Performance Photothermal Conversion Capability

open access: yesRare Metals, Volume 45, Issue 3, March 2026.
ABSTRACT With the rapid growth demand for advanced integrated electronic systems, lightweight flexible electromagnetic interference (EMI) shielding films integrated with functional properties, such as excellent mechanical properties and self‐healing capability, are a research focus in high‐tech functional materials. Herein, a sandwich‐structured aramid
Dan Guo   +9 more
wiley   +1 more source

温度对MOA电阻片主要电气性能的影响

open access: yesDianci bileiqi, 2002
对 MOA电阻片在不同温度下几项主要电气特性试验结果进行了分析 ,阐述了温度对电阻片主要电气特性的影响 ,给出了详细的性能参数随温度的变化曲线 ,使人们对国产电阻片的温度特性有一个较全面的了解和掌握 ,以采取有效的措施大幅度地改善电阻片的固有温度特性 ,提高电阻片的综合电气性能 ,减少高压、超高压 MOA的损坏事故率 ,发展高性能特高压 MOA,提高 ...
郭洁, 朱跃
doaj  

Amphiphilic Block Copolymer‐Functionalized VO2 Nanocomposites for Smart Waterborne Polyurethane Coatings

open access: yesRare Metals, Volume 45, Issue 3, March 2026.
ABSTRACT Aqueous vanadium dioxide (VO2)‐based smart thermal insulation coatings represent a viable strategy to decrease building energy consumption and advance sustainable development goals. However, the inherent instability and limited compatibility with polymer matrices of VO2 hinder its widespread application.
Xiuxian Zhao   +9 more
wiley   +1 more source

运行与检修问答?

open access: yesGaoya dianqi, 1994
[问]高原环境条件有哪些特点?它对高压电器的运行性能有什么影响?[答]高原环境条件的特点主要是:气压低、气温低、气温日变化大、绝对湿度低和太阳辐射强度比较强烈.由于低气压时的低空气密度会降低空气的耐电压强度、空气的冷却效应以及弧隙的空气介质恢复强度,所以高压电器的空气绝缘耐压下降,由空气冷却的零部件温度增高,并且在空气中灭弧比较困难.气温的日变化大,可能引起高压电器的密封不易保持以及机械结构变形或开裂.低气温对高压电器因气压或空气密度降低而引起的温度增高有补偿作用 ...
涟生
doaj   +2 more sources

考虑冰层下移的输电线路高频融冰温升影响因素分析

open access: yesGaoya dianqi, 2023
高频融冰热效率高,具有实现输电线路在线融冰的发展前景,揭示融冰过程中温升与环境等因素的变化规律对于实际应用具有重要意义。文中建立了覆冰线路高频融冰模型,重点考虑了冰层下移时环境温度、风速和覆冰厚度等因素对冰层内表面温升的影响。研究结果表明:在融冰过程中,对流换热强度影响冰层内表面温升速率,风速降低、环境温度升高,对流换热强度减弱,温升速率均增大,但温升速率随覆冰厚度增大而减小。因而选择合适的环境条件和覆冰厚度时机进行融冰能有效提高温升速率和缩短融冰时间。
曾薇, 周羽生, 黄欣超, 周文晴
doaj  

Clinical study for the evaluation of hemodynamic effects of varicocele on scrotal scintigraphy and infrared-thermography [PDF]

open access: yes, 1998
精索静脈瘤の血行動態と陰嚢部の皮膚温度との関連性を陰嚢シンチグラフィと赤外線サーモグラフィを用いて検討した。対象は男子不妊を主訴とし臨床的に精索静脈瘤と診断された患者93例である。シンチグラフィ動態像では陰嚢部における時間-放射能曲線 (TAC) を作成し, TACの形状より早期に急上昇するもの (Type 1) と緩徐に上昇するもの (Type 2) に分類し, 内精静脈からの逆流血液量の評価とした。静態像では陰嚢部における異常集積の程度により重症度分類を行い ...
田中, 豊
core  

Synergistic Effect of MOF@CMC‐Derived Magnetic Nanocomposites: Enhancing Electromagnetic Interference Shielding and Joule Heating

open access: yesRare Metals, Volume 45, Issue 3, March 2026.
ABSTRACT Emerging as attractive alternatives for sustainable, low‐cost, and high‐performance electromagnetic interference (EMI) shielding, biomass‐derived carbon is nonetheless constrained by a limited repertoire of shielding mechanisms. Herein, a straightforward method was employed to synthesize self‐supporting Co nanoparticles embedded in porous N ...
Yingjie Xu   +6 more
wiley   +1 more source

252 kV GIS隔离开关温度场仿真及触头温度的预测方法研究

open access: yesGaoya dianqi, 2023
为了实现对气体绝缘开关GIS(gas insulator switchgear)触头温升的预测,文中建立了252 kV三相分箱型GIS隔离开关的三维电磁—传热—流场的多场耦合模型并采用有限元方法进行了求解。通过一段电阻率可变导体来模拟隔离开关触头存在接触电阻的情况,首先通过电磁场计算出各部分损耗,再将损耗作为热源带入传热-流场中,最后计算得到GIS的温度分布。对环境温度在-10~30℃、载流量在1 000~3 150 A、接触电阻在0~100μΩ的条件下,基于该模型计算出了不同情况下GIS的温度场分布 ...
郭一帆   +3 more
doaj  

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