Application of the concept of criterion of a complex stress state to a simple tension for appraisal of resistance of fatigue of structural materials. Part 2. Drawing up criterion and its checking on compliance to experimental data

The criterion for appraisal of resistance of fatigue of structural material at action on it of repeatedly variables loads and static loads in the form of a bend or tensioncompression together with torsion, and also at action of loads, which create two-axis regular change of stress state in a dangerous point of material is constructed. The received criterion will acceptable be coordinated with the known experimental data. Keywords: dangerous point of material, regular cycle of loading, equivalent amplitude, equivalent average stress, chart of extreme amplitudes of stresses. [email protected]

Magnetic anisotropy and phohotoluminescence properties of amorphous CexFeyOn nanowire arrays

Amorphous Ce[Formula: see text]Fe[Formula: see text]O[Formula: see text] nanowire arrays with diameters about 100 nm were fabricated in porous anodic aluminum oxide (AAO) template channels by chemical co-precipitation assisted by suction filtration. Ce[Formula: see text]Fe[Formula: see text]O[Formula: see text] nanowire arrays have distinct magnetic anisotropy behavior, and the axis parallel to the nanowire is magnetically “easy.” The magnetic properties of Ce[Formula: see text]Mn[Formula: see text]O[Formula: see text] and Ce[Formula: see text]Fe[Formula: see text]Mn[Formula: see text]O[Formula: see text] nanowire arrays were investigated to compare with Ce[Formula: see text]Fe[Formula: see text]O[Formula: see text] nanowire arrays. The fluorescence spectra of Ce[Formula: see text]Fe[Formula: see text]O[Formula: see text] nanowires arrays mixed with Eu, Tb, Sm showed that their emission intensity displays regular change with the increase of the mole fraction of mixture. The emission intensity reached maximum with increasing of Eu or Sm-mixing from 2 mol% to 10 mol% at 591 nm, 709 nm or 607 nm, then decreased gradually. However, there is no obvious influence to fluorescence of Tb mixed Ce[Formula: see text]Fe[Formula: see text]O[Formula: see text] nanowire arrays, only one visible weak emission peak is present at 486 nm.

STRUCTURE AND DYNAMICS OF LARCH STANDS IN THE UPPER PART OF THE MOUNTAIN-FOREST BELT OF THE MASSIF DRY MOUNTAINS (PUTORANA PLATEAU)

Общеизвестно, что каждое из трех последних десятилетий характеризовалось более высокой тем- пературой у поверхности Земли по сравнению с любым предыдущим десятилетием начиная с 1950 г. На фоне этих изменений в научной литературе в последнее время появляется все большее количество работ, свидетельствующих об экспансии древесных и кустарниковых видов в арктические и высокогор- ные экосистемы. В статье приведены результаты исследования формирования древостоев верхней гра- ницы леса и зарослей крупных кустарников в одном из малоизученных регионов центрального сектора Субарктики России – плато Путорана. Объектом исследования явились древостои лиственница Гмелина Larix gmelinii Rupr. и заросли ольхи кустарниковой Duschekia fruticosa (Rupr) Pouzar. Показано, что на фоне современных изменений климата в последнем столетии (особенно во второй половине) происхо- дило смещение верхней границы распространения древесной и кустарниковой растительности выше в горы. Доказательством данных процессов служит закономерное изменение морфометрических параметров и среднего возраста изучаемых видов по мере продвижения в гору в последнем столетии. It is well known that each of the last three decades has been characterized by a higher temperature at the Earth’s surface compared to any previous decade since 1950. Against the background of these changes, an increasing number of works have recently appeared in the scientifi c literature, indicating the expansion of tree and shrub species into Arctic and high-altitude ecosystems. The article presents the results of a study of the formation of stands of the upper border of the forest and thickets of large shrubs in one of the poorly studied regions of the central sector of the Subarctic of Russia – the Putorana plateau. The object of the study was stands of Gmelin larch (Larix gmelinii Rupr.) and thickets of shrub alder (Duschekia fruticosa (Rupr) Pouzar). It is shown that against the background of modern climate changes in the last century (especially in the second half), the upper limit of the distribution of woody and shrubby vegetation was shifted higher into the mountains. The proof of these processes is the regular change in morphometric parameters and the average age of the studied species as they move uphill in the last century.

COMPARATIVE ANALYSIS OF THE STATE OF FRAGMENTS COENOPOPULATIONS OF CHAMAECYTISUS RUTHENICUS (FISCH. EX WOL.) KLASS.

Статья посвящена комплексной оценке состояния ракитника русского Chamaecytisus ruthenicus на основе онтогенетических, популяционных, морфометрических и виталитетных параметров данного вида в природных и антропогенных ландшафтах Режевского района Свердловской области. В индивидуаль- ном развитии Chamaecytisus ruthenicus выделены 3 периода и 6 онтогенетических состояний. Характер- ным типом онтогенетического спектра является одновершинный центрированный спектр. Особенностью в условиях антропогенного воздействия на шлаковом отвале и в водоохраной зоне р. Реж является пол- ное отсутствие прегенеративных особей, о чем свидетельствуют индексы восстановления и замещения. По совокупности всех параметров установлено, что оптимальные условия для существования складыва- ются в природном ландшафте в водоохранной зоне р. Бобровки, несмотря на низкие организменные зна- чения. Преобладающая часть изученных местообитаний ракитника отличается высокой численностью и не- полночленным онтогенетическим спектром, связанным с быстрым отмиранием растений после заверше- ния генеративного периода. По нашим наблюдениям, состояние фрагментов ценопопуляции не только зависит от эколого-ценотических условий в местообитаниях, но связано в первую очередь с антропоген- ными воздействиями. Отсутствие антропогенного влияния способствует увеличению плотности особей в ценопопуляции, и за счет регулярной смены поколений ракитник русский способен удерживать занятую им территорию. The article is devoted to a comprehensive assessment of the condition of Chamaecytisus ruthenicus on the basis of ontogenetic, population, morphometric and vital parameters of this species in natural and anthropogenic landscapes of the Rezhevsky district of the Sverdlovsk region. There are 3 periods and 6 ontogenetic States in the individual development of Chamaecytisus ruthenicus. A characteristic type of ontogenetic spectrum is a single-vertex centered spectrum. Especially in the conditions of anthropogenic impact on the slag dump and in the water protection zone of the river. However, we can distinguish the complete absence of pregenerative individuals, as evidenced by the recovery and replacement indices. Based on the totality of all parameters, it was found that the optimal conditions for existence are formed in the natural landscape in the water-protected zone of the Bobrovka river, despite the low organizational values. The predominant part of the studied Chamaecytisus ruthenicus habitats are characterized by a high number and incomplete ontogenetic spectrum associated with the rapid death of plants after the generative period. According to our observations, the state of coenopopulation fragments not only depends on the ecological and coenotic conditions in the habitats, but is primarily associated with anthropogenic impacts. The absence of anthropogenic infl uence contributes to an increase in the density of individuals in the coenopopulation and due to the regular change of generations, the Chamaecytisus ruthenicus is able to hold the territory occupied by it.

Analysis of the Influence of Water-cement Ratio on Concrete Strength

In this paper, the main strength of the relationship between water-cement ratio and concrete, and it uses the contrast test of different water cement ratio, finally, it gets the regular change between water cement ratio and concrete strength. The test results show that: cement. when the ratio of large stone: small stone: water: admixture is 340: 618: 1009: 433: 139: 6.8, the water-cement ratio of concrete is within the range of 0.371-0.479. The concrete strength of the sample decreases with the increase of the water-cement ratio. Finally, the relationship between the concrete strength and the water-cement ratio is obtained by fitting.

Successional structure and useful condition of mowing-and-grazing landscapes

The paper presents data on the indicators of livestock production, the number of farm animals and poultry in the Tyumen region. The characteristics and significance of near-village forage lands are given. The studied forage lands are assigned to the forest-steppe lowland latitudinal-zonal area of the Kurgan province and contain valuable species of herbs: Calamagrostis epigejos, Bromopsis inermis, Festuca pratensis, Vicia villosa Roth, Trifolium rubens L., Medicago falcata. The territory of pastures is used for mowing and grazing animals of the individual sector, which prevents sodding and degeneration and has a significant impact on the consistent regular change of the biological community (phytocoenosis, microbial community, etc.). The hay yield is 14.7 c/ha, which corresponds to natural meadows without cultivation. To improve the quality of hay and yield, the authors suggest carrying out agrotechnical measures: compliance with the terms of mowing the grass - a week before flowering or at the beginning of flowering of meadow grasses; introduction of potash fertilizers, which will increase the content of grasses in the herbage and will reduce the specific weight of forbs; application of nitrogen fertilizer in a mixture with potash and complete mineral fertilization, which will reduce the level of forbs by almost half; undersowing of leguminous grasses.

Collaborative Writing Activity Using Google Docs: Non-English Major Students Perspectives and Difficulties

One of the most challenging skills for non-English major students is writing an essay since they have to pay attention to the language structure and must be able to transfer their thoughts and ideas into the target language. In regard to solving this problem, regular change and development are needed in teaching English writing. One of the methods that increased to be used is collaborative writing using Google Docs. This study aims to investigate the non-English major students’ perspectives and difficulties in collaborative writing through Google Docs. This study examined 22 students from a state polytechnic in Makassar who have involved in collaborative writing activity through Google Docs. A convergent parallel design was applied in this study, where the data collected by using a questionnaire which consists of closed- open-ended questions and interview. The closed-ended questions data were analyzed quantitatively using descriptive statistic with SPSS. Further, the collected data from the open-ended questions and the interview was analyzed qualitatively using a narrative method. The results show that the students have positive perspectives on collaborative writing activity through Google Docs and did not encounter many difficulties when they were involved in this activity.

A SiPM-Based Trinal Spectral Sensor Developed for Detecting Hazardous Discharges in High-Voltage Switchgear

Electric discharges seriously threat the safety of high-voltage switchgear. In this paper, a spectrum-based optical method is proposed for hazardous discharge monitoring. A SiPM-based trinal spectral sensor is developed with good performances in terms of sensitivity, defect resolution, and risk evaluation. Experiments carried out on two types of artificial discharges (i.e., partial discharge and arc discharge) demonstrate that the light intensities coupled in the three spectral bands account for different proportions and the ratio among the three components generally experiences a regular change with increase in severity of discharge. The typical spectral ratio values are then acquired for hazard rating of discharge and recognition of discharge types with high confidence.