Pub Date : 2016-01-01Epub Date: 2016-11-04DOI: 10.1117/12.2235822
Tomohiro Taniguchi, Julie Grollier, M D Stiles
We propose an experimental scheme to determine the spin-transfer torque efficiency excited by the spin-orbit interaction in ferromagnetic bilayers from the measurement of the longitudinal magnetoresistace. Solving a diffusive spin-transport theory with appropriate boundary conditions gives an analytical formula of the longitudinal charge current density. The longitudinal charge current has a term that is proportional to the square of the spin-transfer torque efficiency and that also depends on the ratio of the film thickness to the spin diffusion length of the ferromagnet. Extracting this contribution from measurements of the longitudinal resistivity as a function of the thickness can give the spin-transfer torque efficiency.
{"title":"Spin-transfer torque in ferromagnetic bilayers generated by anomalous Hall effect and anisotropic magnetoresistance.","authors":"Tomohiro Taniguchi, Julie Grollier, M D Stiles","doi":"10.1117/12.2235822","DOIUrl":"10.1117/12.2235822","url":null,"abstract":"<p><p>We propose an experimental scheme to determine the spin-transfer torque efficiency excited by the spin-orbit interaction in ferromagnetic bilayers from the measurement of the longitudinal magnetoresistace. Solving a diffusive spin-transport theory with appropriate boundary conditions gives an analytical formula of the longitudinal charge current density. The longitudinal charge current has a term that is proportional to the square of the spin-transfer torque efficiency and that also depends on the ratio of the film thickness to the spin diffusion length of the ferromagnet. Extracting this contribution from measurements of the longitudinal resistivity as a function of the thickness can give the spin-transfer torque efficiency.</p>","PeriodicalId":23290,"journal":{"name":"Transactions of The Faraday Society","volume":"20 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5207049/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80178591","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-01-01DOI: 10.3978/j.issn.2224-4336.2012.12.01
Marry M van den Heuvel-Eibrink, Saskia L Gooskens, Filippo Spreafico
{"title":"Omitting pulmonary radiotherapy in selected stage IV nephroblastoma patients with pulmonary metastases.","authors":"Marry M van den Heuvel-Eibrink, Saskia L Gooskens, Filippo Spreafico","doi":"10.3978/j.issn.2224-4336.2012.12.01","DOIUrl":"10.3978/j.issn.2224-4336.2012.12.01","url":null,"abstract":"","PeriodicalId":23290,"journal":{"name":"Transactions of The Faraday Society","volume":"55 1","pages":"46-7"},"PeriodicalIF":2.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4728941/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80454563","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-08-01DOI: 10.1177/000348940111000801
E G Cohen, A M Soliman
Angioedema can be a life-threatening event presenting to otolaryngologists, emergency medicine physicians, and other physicians. Recent reports suggest an increasing role of angiotensin-converting enzyme inhibitors (ACEIs) in the causation of angioedema. Sixty-four cases occurring between 1994 and 1998 were identified and examined retrospectively. Fifty-eight percent of patients presenting with angioedema were using ACEIs. Ninety-four percent of patients overall, and 92% of patients with ACEI-associated angioedema, were African-American. Tongue, lip, facial, and supraglottic edema were most common. Treatment included intubation in 13% and intensive care unit monitoring in 20%. Nearly all patients were treated with corticosteroids and antihistamines. There were no deaths. Angioedema associated with ACEI use appears to be much more common than previously reported. African-American patients may be at higher risk for angioedema with ACEI use. Successful management was achieved with observation, expectant airway management, corticosteroids, and discontinuation of ACEIs. Patients without airway obstruction or pharyngeal or laryngeal edema who improved with treatment and observation were successfully treated as outpatients.
{"title":"Changing trends in angioedema.","authors":"E G Cohen, A M Soliman","doi":"10.1177/000348940111000801","DOIUrl":"10.1177/000348940111000801","url":null,"abstract":"<p><p>Angioedema can be a life-threatening event presenting to otolaryngologists, emergency medicine physicians, and other physicians. Recent reports suggest an increasing role of angiotensin-converting enzyme inhibitors (ACEIs) in the causation of angioedema. Sixty-four cases occurring between 1994 and 1998 were identified and examined retrospectively. Fifty-eight percent of patients presenting with angioedema were using ACEIs. Ninety-four percent of patients overall, and 92% of patients with ACEI-associated angioedema, were African-American. Tongue, lip, facial, and supraglottic edema were most common. Treatment included intubation in 13% and intensive care unit monitoring in 20%. Nearly all patients were treated with corticosteroids and antihistamines. There were no deaths. Angioedema associated with ACEI use appears to be much more common than previously reported. African-American patients may be at higher risk for angioedema with ACEI use. Successful management was achieved with observation, expectant airway management, corticosteroids, and discontinuation of ACEIs. Patients without airway obstruction or pharyngeal or laryngeal edema who improved with treatment and observation were successfully treated as outpatients.</p>","PeriodicalId":23290,"journal":{"name":"Transactions of The Faraday Society","volume":"63 1","pages":"701-6"},"PeriodicalIF":0.0,"publicationDate":"2001-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80576069","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-01-01DOI: 10.1002/14651858.CD003013
S Burgess, J Geddes, K Hawton, E Townsend, K Jamison, G Goodwin
<p><strong>Background: </strong>Mood disorders are common, disabling and tend to be recurrent. They carry a high risk of suicide. Maintenance treatment, aimed at the prevention of relapse, is therefore of vital importance. Lithium has been used for some years as the mainstay of maintenance treatment in bipolar affective disorder, and to a lesser extent in unipolar disorder. However, the efficacy and effectiveness of prophylactic lithium therapy has been disputed. Low suicide rates in lithium-treated patients have led to claims that lithium has a specific anti-suicidal effect. If so, this is of considerable importance as treatments for mental disorders in general have not been shown convincingly to be effective in suicide prevention.</p><p><strong>Objectives: </strong>1. To investigate the efficacy of lithium treatment in the prevention of relapse in recurrent mood disorders. 2. To examine the effect of lithium treatment on consumers' general health and social functioning, its acceptability to consumers, and the side-effects of treatment. 3. To investigate the hypothesis that lithium has a specific effect in reducing the incidence of suicide and deliberate self-harm in persons with mood disorders.</p><p><strong>Search strategy: </strong>The Cochrane Collaboration Depression, Anxiety and Neurosis Controlled Trials Register (CCDANCTR) and The Cochrane Controlled Clinical Trials Register (CCTR) were searched. Reference lists of relevant papers and major text books of mood disorder were examined. Authors, other experts in the field and pharmaceutical companies were contacted for knowledge of suitable trials, published or unpublished. Specialist journals concerning lithium were hand searched.</p><p><strong>Selection criteria: </strong>Randomised controlled trials comparing lithium with placebo, where the stated intent of treatment was maintenance or prophylaxis. Participants were males and females of all ages with diagnoses of mood disorder. Discontinuation studies (in which all participants had been stable on lithium for some time before being randomised to either continued lithium treatment or placebo substitution) were excluded.</p><p><strong>Data collection and analysis: </strong>Data were extracted from the original reports independently by two reviewers. The main outcomes studied were related to the objectives stated above. Data were analysed for all diagnoses of mood disorder and for bipolar and unipolar disorder separately. Data were analysed using Review Manager version 4.0.</p><p><strong>Main results: </strong>Nine studies were included in the review, reporting on 825 participants randomly allocated to lithium or placebo. Lithium was found to be more effective than placebo in preventing relapse in mood disorder overall, and in bipolar disorder. The most consistent effect was found in bipolar disorder (random effects OR 0.29; 95% CI 0.09 to 0.93 ). In unipolar disorder, the direction of effect was in favour of lithium, but the result (when het
背景：情绪失调是一种常见的致残性疾病，而且往往反复发作。它们具有很高的自杀风险。因此，旨在预防复发的维持治疗至关重要。多年来，锂一直被用作双相情感障碍的主要维持治疗药物，其次是单相情感障碍。然而，预防性锂疗法的疗效和有效性一直存在争议。锂盐治疗患者的自杀率较低，因此有人声称锂盐具有特定的抗自杀作用。如果是这样的话，这一点就相当重要了，因为一般的精神障碍治疗在预防自杀方面并没有令人信服的效果：1.研究锂治疗对预防复发性情绪障碍复发的疗效。2.2. 研究锂治疗对患者一般健康和社会功能的影响、患者的接受程度以及治疗的副作用。3.3. 研究锂对降低情绪障碍患者自杀和蓄意自残发生率的特殊效果这一假设：检索策略：检索了 Cochrane 协作抑郁症、焦虑症和神经症对照试验登记册（CCDANCTR）和 Cochrane 对照临床试验登记册（CCTR）。查阅了相关论文的参考文献目录和有关情绪障碍的主要教科书。与作者、该领域的其他专家和制药公司取得联系，了解已发表或未发表的合适试验。人工检索了有关锂的专业期刊：将锂与安慰剂进行比较的随机对照试验，治疗目的为维持或预防。参与者为所有年龄段的男性和女性，诊断为情绪障碍。停药研究（所有参与者在随机接受继续锂剂治疗或安慰剂替代治疗前，已稳定服用锂剂一段时间）不包括在内：数据由两名审稿人独立从原始报告中提取。研究的主要结果与上述目标相关。对所有情绪障碍诊断以及双相情感障碍和单相情感障碍的数据分别进行了分析。数据使用 Review Manager 4.0 版进行分析：综述共纳入九项研究，报告了随机分配给锂或安慰剂的 825 名参与者的情况。研究发现，与安慰剂相比，锂能更有效地预防情绪障碍和躁狂症的复发。双相情感障碍的疗效最为一致（随机效应 OR 0.29；95% CI 0.09 至 0.93）。在单相情感障碍中，影响的方向有利于锂，但结果（考虑到研究之间的异质性）未达到统计学意义。在所有患者组别中，不同研究之间存在很大的异质性。所有研究的影响方向相同；没有研究发现锂对患者有负面影响。异质性可能是由于参与者的选择不同，以及在研究前阶段接触锂的情况不同，导致停药效应的影响不同。关于参与者在不同治疗条件下的整体健康和社会功能，以及参与者自己对治疗的看法，报告数据很少。描述性分析表明，对总体健康和社会功能的评估通常倾向于锂剂。由于死亡和自杀的绝对人数较少，且缺乏非致命自杀行为的数据，因此无法就锂疗法在预防自杀方面的作用得出有意义的结论：这篇系统综述指出，锂是治疗躁郁症的有效维持疗法。单相情感障碍的疗效证据则不那么有力。本综述并不包括锂剂与其他维持治疗方法相比的相对疗效，这一点目前尚不清楚。关于锂是否具有抗自杀作用，本综述没有明确的证据。有必要进行系统回顾和大规模随机研究，比较锂与其他维持治疗（如抗惊厥药、抗抑郁药）的效果。日後所有有關情緒障礙的維持治療研究，均應包括與死亡及自殺行為有關的結果。
{"title":"Lithium for maintenance treatment of mood disorders.","authors":"S Burgess, J Geddes, K Hawton, E Townsend, K Jamison, G Goodwin","doi":"10.1002/14651858.CD003013","DOIUrl":"10.1002/14651858.CD003013","url":null,"abstract":"<p><strong>Background: </strong>Mood disorders are common, disabling and tend to be recurrent. They carry a high risk of suicide. Maintenance treatment, aimed at the prevention of relapse, is therefore of vital importance. Lithium has been used for some years as the mainstay of maintenance treatment in bipolar affective disorder, and to a lesser extent in unipolar disorder. However, the efficacy and effectiveness of prophylactic lithium therapy has been disputed. Low suicide rates in lithium-treated patients have led to claims that lithium has a specific anti-suicidal effect. If so, this is of considerable importance as treatments for mental disorders in general have not been shown convincingly to be effective in suicide prevention.</p><p><strong>Objectives: </strong>1. To investigate the efficacy of lithium treatment in the prevention of relapse in recurrent mood disorders. 2. To examine the effect of lithium treatment on consumers' general health and social functioning, its acceptability to consumers, and the side-effects of treatment. 3. To investigate the hypothesis that lithium has a specific effect in reducing the incidence of suicide and deliberate self-harm in persons with mood disorders.</p><p><strong>Search strategy: </strong>The Cochrane Collaboration Depression, Anxiety and Neurosis Controlled Trials Register (CCDANCTR) and The Cochrane Controlled Clinical Trials Register (CCTR) were searched. Reference lists of relevant papers and major text books of mood disorder were examined. Authors, other experts in the field and pharmaceutical companies were contacted for knowledge of suitable trials, published or unpublished. Specialist journals concerning lithium were hand searched.</p><p><strong>Selection criteria: </strong>Randomised controlled trials comparing lithium with placebo, where the stated intent of treatment was maintenance or prophylaxis. Participants were males and females of all ages with diagnoses of mood disorder. Discontinuation studies (in which all participants had been stable on lithium for some time before being randomised to either continued lithium treatment or placebo substitution) were excluded.</p><p><strong>Data collection and analysis: </strong>Data were extracted from the original reports independently by two reviewers. The main outcomes studied were related to the objectives stated above. Data were analysed for all diagnoses of mood disorder and for bipolar and unipolar disorder separately. Data were analysed using Review Manager version 4.0.</p><p><strong>Main results: </strong>Nine studies were included in the review, reporting on 825 participants randomly allocated to lithium or placebo. Lithium was found to be more effective than placebo in preventing relapse in mood disorder overall, and in bipolar disorder. The most consistent effect was found in bipolar disorder (random effects OR 0.29; 95% CI 0.09 to 0.93 ). In unipolar disorder, the direction of effect was in favour of lithium, but the result (when het","PeriodicalId":23290,"journal":{"name":"Transactions of The Faraday Society","volume":"67 1","pages":"CD003013"},"PeriodicalIF":8.4,"publicationDate":"2001-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7005360/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79632230","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A microwave-pulse temperature-jump relaxation technique is described. Temperature rises of about 0.5 K may be produced in non-polar solvent media in about 1 µs. Spectrophotometric detection is used to monitor the resulting chemical relaxation. A conductimetric detection system is also described and applied to the measurement of relaxation times in the millisecond range in an aqueous solution.
{"title":"Study of fast reactions in solution using a dielectric-heating relaxation technique","authors":"K. J. Ivin, J. McGarvey, E. Simmons","doi":"10.1039/TF9716700097","DOIUrl":"https://doi.org/10.1039/TF9716700097","url":null,"abstract":"A microwave-pulse temperature-jump relaxation technique is described. Temperature rises of about 0.5 K may be produced in non-polar solvent media in about 1 µs. Spectrophotometric detection is used to monitor the resulting chemical relaxation. A conductimetric detection system is also described and applied to the measurement of relaxation times in the millisecond range in an aqueous solution.","PeriodicalId":23290,"journal":{"name":"Transactions of The Faraday Society","volume":"67 1","pages":"97-103"},"PeriodicalIF":0.0,"publicationDate":"1971-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1039/TF9716700097","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57612915","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The Laplace transform of the ring current transient is easier to interpret theoretically than the transient itself. A simple unit for carrying out the transformation is described. Results from the application of the technique are in good agreement with theory.
{"title":"Ring-disc electrodes. Part 13.—The Laplace transformation of transients","authors":"W. Albery, J. S. Drury, M. Hitchman","doi":"10.1039/TF9716700166","DOIUrl":"https://doi.org/10.1039/TF9716700166","url":null,"abstract":"The Laplace transform of the ring current transient is easier to interpret theoretically than the transient itself. A simple unit for carrying out the transformation is described. Results from the application of the technique are in good agreement with theory.","PeriodicalId":23290,"journal":{"name":"Transactions of The Faraday Society","volume":"67 1","pages":"166-169"},"PeriodicalIF":0.0,"publicationDate":"1971-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1039/TF9716700166","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57613734","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Microwave absorption of COS adsorbed on finely powdered NaCl has been investigated in the 9000 MHz region. From the T tan δ against temperature dependence, the relaxation time and free energy of activation for orientation were calculated. The energy of interaction of the molecule with the solid adsorbent was computed for different adsorption sites and orientations of the adsorbate and as a function of angle of rotation. The calculated values of heat of adsorption and potential barrier for orientation were in good agreement with the experimental ones.
{"title":"Microwave absorption and potential barrier for orientation in COS adsorbed on NaCl","authors":"I. Lubezky, M. Folman","doi":"10.1039/TF9716700222","DOIUrl":"https://doi.org/10.1039/TF9716700222","url":null,"abstract":"Microwave absorption of COS adsorbed on finely powdered NaCl has been investigated in the 9000 MHz region. From the T tan δ against temperature dependence, the relaxation time and free energy of activation for orientation were calculated. The energy of interaction of the molecule with the solid adsorbent was computed for different adsorption sites and orientations of the adsorbate and as a function of angle of rotation. The calculated values of heat of adsorption and potential barrier for orientation were in good agreement with the experimental ones.","PeriodicalId":23290,"journal":{"name":"Transactions of The Faraday Society","volume":"67 1","pages":"222-230"},"PeriodicalIF":0.0,"publicationDate":"1971-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1039/TF9716700222","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57613996","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper reports work on the influence on the kinetics of the first stage of decomposition of solid poly(vinylidene chloride) of pre-irradiation with u.-v. and γ-radiation, and of the chemical nature of the ambient atmosphere (vacuum, N2, air, O2, HCl, NO, ethylene, propylene, water vapour). The results lend support to the mechanism of the reaction proposed in part 1.
{"title":"Kinetics of dehydrochlorination of poly(vinylidine chloride). Part 2.—Effect of pre-irradiation with U.-V. and γ-rays and the Influence of the chemical nature of the ambient atmosphere","authors":"D. H. Everett, D. Taylor","doi":"10.1039/TF9716700402","DOIUrl":"https://doi.org/10.1039/TF9716700402","url":null,"abstract":"This paper reports work on the influence on the kinetics of the first stage of decomposition of solid poly(vinylidene chloride) of pre-irradiation with u.-v. and γ-radiation, and of the chemical nature of the ambient atmosphere (vacuum, N2, air, O2, HCl, NO, ethylene, propylene, water vapour). The results lend support to the mechanism of the reaction proposed in part 1.","PeriodicalId":23290,"journal":{"name":"Transactions of The Faraday Society","volume":"67 1","pages":"402-413"},"PeriodicalIF":0.0,"publicationDate":"1971-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1039/TF9716700402","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57614499","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Magnetic susceptibilities (77 to 700 K) and e.p.r. spectra (100 to 573 K ) have been measured for a series of spinel solid solutions MgCrxAl2–xO4 with x varying from 0.002 to 2. The Racah parameter B has been obtained from optical reflectance spectra. All the solutions obey the Curie-Weiss law and the effective magnetic moments lie in the region 3.87 ± 0.05µβ except at x= 1.5 where (below 500 K)µeff= 4.1µβ. Solutions dilute in chromium give e.p.r. spectra characteristic of chromium ions isolated in the spinel lattice (Iµ resonance). At x= 0.2 a broad resonance ϕ replaces the Iµ resonance between x= 0.4 and x= 2. These results, together with the temperature variation of the e.p.r. resonance ϕ, are correlated with the susceptibility and optical measurements. The interpretation of the results is based on the variations in cation-cation interaction with increasing chromium content. The results obtained for the spinel series of solid solutions are compared with those obtained for the corundum series in part 1.
{"title":"Magnetic properties of chromium ions in oxide matrices. Part 1.—Cr2O3-Al2O3 solid solutions","authors":"F. Stone, J. Vickerman","doi":"10.1039/TF9716700316","DOIUrl":"https://doi.org/10.1039/TF9716700316","url":null,"abstract":"Magnetic susceptibilities (77 to 700 K) and e.p.r. spectra (100 to 573 K ) have been measured for a series of spinel solid solutions MgCrxAl2–xO4 with x varying from 0.002 to 2. The Racah parameter B has been obtained from optical reflectance spectra. All the solutions obey the Curie-Weiss law and the effective magnetic moments lie in the region 3.87 ± 0.05µβ except at x= 1.5 where (below 500 K)µeff= 4.1µβ. Solutions dilute in chromium give e.p.r. spectra characteristic of chromium ions isolated in the spinel lattice (Iµ resonance). At x= 0.2 a broad resonance ϕ replaces the Iµ resonance between x= 0.4 and x= 2. These results, together with the temperature variation of the e.p.r. resonance ϕ, are correlated with the susceptibility and optical measurements. The interpretation of the results is based on the variations in cation-cation interaction with increasing chromium content. The results obtained for the spinel series of solid solutions are compared with those obtained for the corundum series in part 1.","PeriodicalId":23290,"journal":{"name":"Transactions of The Faraday Society","volume":"67 1","pages":"316-328"},"PeriodicalIF":0.0,"publicationDate":"1971-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1039/TF9716700316","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57614643","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The decomposition, in the temperature range 195–455 K, of hydrazine chemisorbed on tungsten films at 195 K has been studied under isothermal conditions, and also when the temperature of decomposition was increased linearly with time. Decomposition occurs by two main processes: (i) by dissociative chemisorption to form adsorbed amide radicals, followed by further surface dissociation, thereby producing adsorbed imide radicals (or even nitrogen adatoms) and mobile hydrogen adatoms; these latter combine and subsequently desorb as hydrogen molecules; (ii) by associative chemisorption of the hydrazine molecule to surface tungsten atoms; the activated surface complex so formed breaks down to give ammonia and nitrogen, largely by the reaction: 3N2H4→ 4NH3+ N2. A study of the decomposition on tungsten films (i) contaminated by the products of a previous decomposition; (ii) presaturated with hydrogen; (iii) partially saturated by both presorption and postsorption of either carbon monoxide or ammonia, indicated that the molecular adsorption takes place on the (110) plane and that the other planes are active for the dissociative adsorption. On the (110) plane, the hydrazine molecule appears to be attached to a single tungsten atom; on the other planes, it occupies four adjacent surface sites. This dual mechanism is consistent with previous results on the heterogeneous decomposition of hydrazine on a wide variety of different surfaces.
{"title":"Heterogeneous decomposition of hydrazine on tungsten films","authors":"R. C. Cosser, F. Tompkins","doi":"10.1039/TF9716700526","DOIUrl":"https://doi.org/10.1039/TF9716700526","url":null,"abstract":"The decomposition, in the temperature range 195–455 K, of hydrazine chemisorbed on tungsten films at 195 K has been studied under isothermal conditions, and also when the temperature of decomposition was increased linearly with time. Decomposition occurs by two main processes: (i) by dissociative chemisorption to form adsorbed amide radicals, followed by further surface dissociation, thereby producing adsorbed imide radicals (or even nitrogen adatoms) and mobile hydrogen adatoms; these latter combine and subsequently desorb as hydrogen molecules; (ii) by associative chemisorption of the hydrazine molecule to surface tungsten atoms; the activated surface complex so formed breaks down to give ammonia and nitrogen, largely by the reaction: 3N2H4→ 4NH3+ N2. A study of the decomposition on tungsten films (i) contaminated by the products of a previous decomposition; (ii) presaturated with hydrogen; (iii) partially saturated by both presorption and postsorption of either carbon monoxide or ammonia, indicated that the molecular adsorption takes place on the (110) plane and that the other planes are active for the dissociative adsorption. On the (110) plane, the hydrazine molecule appears to be attached to a single tungsten atom; on the other planes, it occupies four adjacent surface sites. This dual mechanism is consistent with previous results on the heterogeneous decomposition of hydrazine on a wide variety of different surfaces.","PeriodicalId":23290,"journal":{"name":"Transactions of The Faraday Society","volume":"67 1","pages":"526-544"},"PeriodicalIF":0.0,"publicationDate":"1971-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1039/TF9716700526","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57614856","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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