首页 | 官方网站   微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   13篇
  免费   2篇
工业技术   15篇
  2016年   1篇
  2013年   2篇
  2012年   1篇
  1998年   1篇
  1997年   4篇
  1996年   1篇
  1990年   1篇
  1980年   2篇
  1974年   1篇
  1973年   1篇
排序方式: 共有15条查询结果,搜索用时 266 毫秒
1.
With Staphylococcus xylosus FAX-1, metmyoglobin in MRS broth (pH 5.8) was found to undergo conversion to hexacoordinate nitric oxide (NO) complex of Fe(II) myoglobin. When the pH of the MRS culture containing myoglobin changed from 5.8 to 4.0, it affected the conversion from hexacoordinate to pentacoordinate NO complex of Fe(II) myoglobin. This conversion process was reversible. Salami without nitrite or nitrate addition was prepared by inoculating S. xylosus FAX-1, and pentacoordinate NO complex of Fe(II) myoglobin (nitrosylmyoglobin formed in cured meat) was formed in the salami.  相似文献   
2.
A series of lead titanates containing lattice defects was prepared and characterized in terms of inhomogeneously distributed vacancies, □Pb and □O•. The tetragonal lattice strain and the Curie temperature varied as functions of the Pb or O deficiency in the crystals. The tetragonal strain for these crystals decreased slowly with increasing temperature as the Curie temperature was approached. The phase transition, which extends over a temperature interval, is interpreted according to a model in which microregions in the crystal differ in composition and therefore have different Curie temperatures.  相似文献   
3.
Red Pigment of Parma Ham and Bacterial Influence on its Formation   总被引:7,自引:0,他引:7  
The red pigment of Parma ham was compared with the myoglobin derivatives present in meat and meat products. Spectral patterns of 75% acetone extracts and electron spin resonance spectra from Parma ham differed from those of the myoglobin derivatives. Staphylococci isolated from Parma ham generated red myoglobin derivative from metmyoglobin. Model fermented sausage prepared by inoculation with the isolates developed a more desirable red color without nitrite or nitrate treatment. The red pigment of Parma ham and the model sausage appeared to be the same myoglobin derivative. The reddening of Parma ham is probably caused by the action of bacteria.  相似文献   
4.
Abstract

Causality in changing natural systems can be seen to involve all four Aristotelian causal categories—material, efficient, formal and final. Final causality of materialistic origin can be found in the need to maintain energy flow continuity within dissipative systems. Each interacting dissipative system acts finalistically so as to attract needed energy. In so acting, it continually disturbs its neighborhood by generating potential energy flow disruptions as results of its activities. Final causality based, in this way, on the energy requirements of dissipative systems will generate formal causes as well. In contrast, the emergence of formal causes in mechanistic systems driven solely by efficient causes is extremely unlikely. We suggest viewing the subordination of phenotypic dissipative systems by genotypic counterparts as an historical example of the emergence of formal causes out of the material necessity of maintaining flow continuity. Functional separation between genotypic and phenotypic dissipative systems can occur if the energies to be dissipated are localized, as is the chemical binding energy of molecules with respect to biological functions at a higher scalar level.  相似文献   
5.
The carcinogenicity of vicia, galanga, lathyrus and lycium, which are plants used as human food or in folk medicine, and of caffeic acid and prunasin, which are plant constituents, was examined in an inbred strain of ACI rats. Fresh plant materials were dried, milled and mixed with the rat basal diet in the ratio of 16% and 33% of the total. The plant constituents, caffeic acid and prunasin, were mixed with the basal diet in the ratio of 0.5% and 0.03%, respectively. These diets were administered to rats for periods ranging upward from 180 days. Carcinogenic activity was not observed with any of the plants or plant constituents.  相似文献   
6.
7.
The d.c. conductivity, σ, and the oxygen gas-sensing behaviour of V2O5–SnO–TeO2 glass prepared by press-quenching were studied in argon and oxygen gas atmospheres at temperatures ranging from 303–473 K. The glass of 50V2O5·20SnO·30TeO2 (mol %) was n-type semiconducting. The high-temperature conductivity was lower in oxygen and higher in argon than that in air. This was explained by the V4+ ions in the glass being oxidized by oxygen which had diffused into the glass, resulting in an increase in V5+ with time. The experimental relationship between σ and oxygen partial pressure, P O2, agreed quantitatively with the theoretical relation σ ∝ P O2 -1/4 . Changes in conductivity by switching the atmospheres between oxygen and argon gases were found to be reproducible. From the data of these dynamic changes, the oxygen gas sensitivity, S, at 473 K was obtained to be 1.3 in oxygen atmosphere. The dynamic changes could be quantitatively explained by an oxygen diffusion model. Throughout these discussions, the present tellurite glass was found to possess a potential applicability as an oxygen gas sensor. This revised version was published online in November 2006 with corrections to the Cover Date.  相似文献   
8.
为了从钢铁中提取各种夹杂物颗粒,考察了采用无水电解质的恒电位和恒电流的提取方法。结果认为,4%的MS[4 % (V/V)甲基水杨酸-1 % (m/V) 水杨酸-1 %( m/V) 四甲基氯化铵-甲醇)和10%AA(10 %(V/V)乙酰丙酮-1 % (m/V)四甲基氯化铵-甲醇]电解质溶液适用于提取钢铁中夹杂物TiOx和TiAl2O5。尽管这些电解提取法可以提取化学性能不稳定的夹杂物颗粒,然而,因为对夹杂物的观察是在萃取完成后于一个滤膜中进行,因此无法确定金属中每种夹杂物的具体位置。为了确定金属中夹杂物的具体位置,将卤-醇的光蚀刻方法用于以Ti和Al除氧的钢样品表面附近出现的夹杂颗粒,使用扫描电子显微技术和俄歇电子能谱(AES)对精细夹杂物颗粒形貌、尺寸和元素的偏析进行评估,不过卤醇却和钢铁中的金属钛和金属铝发生还原反应。对微小夹杂物颗粒的成分的形态、分离进行估测,然后,使用一种低加速能-扫描电子显微技术和俄歇电子能谱(AES)对用聚焦离子束制备微小夹杂物颗粒截面上元素的微观偏析进行评定。在这些研究结果基础上讨论了多元夹杂物颗粒的形成机理。    相似文献   
9.
High‐precision stages require high‐speed and high‐precision control to improve their production throughput and quality. However, their motion speed and accuracy are expected to reach a limit in the near future if the conventional high‐precision stage structure is used. Therefore, the authors designed and fabricated a “catapult stage,” which has a structure that can be decoupled into a fine stage and coarse stage. The catapult stage is different from conventional dual stages in which the fine stage is disturbed by the coarse stage because they contact each other. This paper proposes a novel control system design for the catapult stage and a control method that shortens the settling time by using final state control (FSC). So far, FSC has mainly been used for applications such as hard disk drives, for which the initial states are zero. However, it is important to consider the initial states for the catapult stage because the initial position, velocity, and acceleration of the catapult stage are not equal to zero. Simulations and experiments were performed to demonstrate the effectiveness of the proposed methods.  相似文献   
10.
The d.c. conductivity (σ) of (a) glasses prepared by the press-quenching method and (b) glass-ceramics (crystallized glass) produced by post-heat treatment was investigated in the system Sb2O3–CaO–V2O5 and their conduction mechanism was studied. The glasses were n-type semiconductors with σ = 2.6 × 10-6 ∼ 2.8 × 10-5 S cm-1 at 333 K for varying glass compositions. The conduction was attributed to small polaron hopping in the adiabatic regime. The estimated carrier density was 1.7 ∼ 3.8 × 1021 cm-3 for V2O5 = 70 ∼ 80 mol% and the mobility was 3.5 × 10-9 to 6.9 × 10-8 cm2 V-1 s-1. Crystallization raised the conductivity by a factor of 103. The crystalline product in the glass-ceramics was Ca0.17V2O5. The glass-ceramics were n-type semiconductors, and the conduction was interpreted by a superposition of the small polaron hopping in the crystalline and glassy phases. This revised version was published online in November 2006 with corrections to the Cover Date.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司    京ICP备09084417号-23

京公网安备 11010802026262号