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Thanks to the complex underground environment that coal mines enjoy, drill rods for mining are vulnerable to corrosion during operation. To investigate the impact of the corrosion defects on the residual intensity of the drill rod, a relational expression of stress versus corrosion rate in the conditions of uniform and local corrosions is deduced based on the theory on mechanochemical effects; building on this, a spherical corrosion defect is developed in the joint of a φ73 mm drill rod while it is exerted with a make-up torque, an axial force and a bending moment. So it is found that, when the corrosion defect is under pressure, the bending moment plays a certain role to inhibit its increase, however when it is under tension, the bending moment plays the role to drive its increase so as to quicken its corrosion rate while the impact of the change in the corrosion detect depth is much greater than that of the radius. The result from the research provides a basis to evaluate the residual intensity of the drill rod and theoretical basis to protect drill rods from corrosion.

Introduction L'insuline peglispro (BIL) est une nouvelle insuline basale avec un profil pharmacocinétique plat, et une action hépato-préférentielle résultant d'effets périphériques diminués. Patients et Méthodes Dans cette étude de phase 3, de 52 semaines, en double aveugle, 1 114 adultes DT1, ayant une HbA 1c < 12,0 % (moyenne 7,9 %), ont été randomisés (3 :2) pour BIL ou GL au coucher associé à l'insuline prandiale lispro. Résultats À 52 semaines, BIL a entraîné une réduction supérieure de l'HbA 1c vs GL [(différence − 0,22 % ; IC 95 % − 0,32 % ; − 0,12 %) ; 7,4 % vs 7,6 % ( p < 0,001)]. Plus de patients sous BIL ont atteints une HbA 1c < 7,0 % (35,3 % vs 26,1 % ; p < 0,001). Sous BIL, étaient observés une moindre variabilité glycémique ( p < 0,01), un taux d'hypoglycémie nocturne inférieur de 47 % (ASG ≤ 3,9 mmol/l ; p < 0,001), et une perte de poids [variations de poids moyenne à 52 semaines : BIL : − 0,6 kg ; Gl : 1,2 kg ( p < 0,001)]. Le taux d'hypoglycémies totales était plus élevé de 11 % avec BIL ( p = 0,002), et le taux d'hypoglycémies sévères était similaire ( p = 0,520). Alors que la dose totale d'insuline était comparable, les patients sous BIL recevaient plus d'insuline basale et moins d'insuline bolus. Avec BIL, LDLC et triglycérides (TG) ont augmenté et le HDLC a diminué. Plus de patients sous BIL ont eu des taux d'ALAT ≥ 3xLSN (4,8 % vs 2,0 %, p = 0,021) sans cas relevant de la loi de Hy. La teneur hépatique en acides gras (LFC) en IRM chez 182 patients de 2 études BIL vs GL dans le DT1, augmentait avec BIL (5,7 ± 0,3 vs 3,5 ± 0,4, p < 0,001). Les patients sous BIL avaient plus fréquemment des réactions au site d'injection (13,3 % vs 0,2 %, p < 0,001). Conclusions Dans le DT1, le traitement par BIL vs GL a entraîné une réduction supérieure de l'HbA 1c , une réduction des hypoglycémies nocturnes et une perte de poids, avec une augmentation des ALAT, des TG, du LFC, et plus de réactions au site d'injection. [ABSTRACT FROM AUTHOR]

In order to explore the soil improvement effect of guest soil reclamation, the main physical and chemical properties of the soil in-situ extracted rare earth tailings after reclamation in Pingyuan County, Meizhou city were tested. Using 5 point sampling method, soil samples were taken from a 0-20 cm soil layer to detect NH4+ residues, pH value, content of organic matter, available N, available K, available P, and heavy metal in the soil. The results were shown that the NH4+ content in the soil decreased from 96.67 to 15.29 (mg·kg−1) after reclamation, the pH value increased from 4.58 to 5.40, and the organic matter increased from 2.12 to 2.75 (g·kg−1). However, the available N, P, and K decreased, and the soil fertility index also decreased from 0.55 to 0.49. The reclamation did not significantly improve soil fertility. The Nemero comprehensive index of non-rare earth heavy metal elements decreased from 0.58 to 0.44, but the pollution of non-rare earth heavy metals in the soil before and after reclamation was at a clean level, and there was no heavy metal pollution. The total RE (rare earth) content in tailings soil, reclaimed soil, and control soil was higher than the soil environmental background value in Guangdong Province. Heavy RE content in tailings soil exceeded 50% of total RE content, while light RE was mainly in the reclaimed soil. The pollution levels of total RE metals in soil before and after reclamation were non-pollution to moderate pollution level and non-pollution level, respectively. The control soil was the most severely polluted, reaching a strong pollution level. The three RE metals, Y, Sm and Ce, accounted for the highest proportion of the total soil REs, and the pollution levels of the latter two elements were above strong pollution in control soil. After 4 years of land reclamation, the NH4+-N pollution, soil acidification, and heavy metal pollution in the soil of tailings could be significantly improved, but the soil fertility was still low and required a long remediation process. In the future reclamation work, in addition to continuing to pay attention to the improvement of soil environment, the improvement of soil fertility and the control of RE pollution should also be strengthened, and when using foreign soil for reclamation and improvement, the quality of foreign soil, especially fertility, should also be considered.

This article examines the protection and renewal design of rural industrial heritage using the Bingcun Cement Factory in Bingcun Town, Meizhou District, Meizhou City, Guangdong Province, China as a case study. It delves into the challenges and opportunities faced by rural industrial heritage in the context of cultural preservation and rural revitalization. By conducting on-site investigations at the Bingcun Cement Plant, a comprehensive design strategy encompassing spatial layout, planning guidance, architecture, and environmental considerations was developed. The strategy focuses on spatial optimization, architectural restoration, environmental enhancement, and ecological restoration, aiming to transform industrial heritage sites into cultural attractions with educational and aesthetic value, while also fostering rural economic and cultural vibrancy. The article concludes by suggesting that sustainable development of rural industrial heritage can be achieved through heritage preservation, integration into local culture, and multifaceted regional planning.

Il existe un gradient de contractilité cardiaque à travers la paroi du ventricule gauche où les cellules du sous-endocarde (ENDO) se contractent davantage que celles du sous-épicarde (EPI). Ce gradient de contractilité est altéré au cours de l’insuffisance cardiaque ischémique et hypertrophique. L’objectif de cette étude a été de déterminer si chez le chien, le gradient de contractilité transmural peut s’expliquer par une hétérogénéité contractile cellulaire et d’évaluer l’impact d’une cardiopathie dilatée spontanée de dystrophie musculaire de Duchenne chez le chien GRMD (Golden Retriever Muscular Dystrophy) sur ce gradient transmural. Dans cette étude, la contractilité cardiaque a été explorée in vivo par échocardiographie et in vitro sur cellules perméabilisées pour évaluer les propriétés contractiles des myofilaments (i .e tension active et passive, et sensibilité au Ca2+ des myofilaments (pCa50) à deux longueurs de sarcomère). Chez le chien sain, la vitesse de contraction des couches ENDO, mesurée in-vivo, était plus élevée par rapport aux couches EPI. Au niveau cellulaire, l’augmentation consécutive à un étirement de la sensibilité des myofilaments pour le calcium (Delta pCa50) était plus élevée dans les cellules ENDO. La dystrophie musculaire (DM) a induit une baisse de la fraction de raccourcissement de la paroi ventriculaire gauche des chiens GRMD ainsi qu’une reduction importante du gradient de vitesse de contraction transmural (ENDO-EPI) principalement due à une altération des couches sousendocardique. Nous avons également observé que la DM induisait une baisse de la tension active maximale développée par les cellules ENDO. Par ailleurs, la DM a induit une augmentation de la pCa50 à faible longueur de sarcomère des cellules ENDO qui conduit à une diminution du Delta pCa50. Les cellules EPI n’étaient pas affectées par la DM. Nos résultats montrent que le gradient transmural de contractilité observé in vivo chez le chien normal s’explique en partie par une hétérogénéité contractile cellulaire. Chez le chien porteur d’une dystrophie musculaire le gradient de contractilité transmural est altéré en raison d’une atteinte préférentielle des couches sousendocardique. Cette anomalie déjà décrite dans les cardiopathies ischémiques et hypertrophique apparaît donc ubiquitaire à l’insuffisance cardiaque. [Copyright &y& Elsevier]

With the gradual depletion of the earth’s resources and people’s attention to environmental issues, the access of renewable energy has been paid more and more attention by countries around the world. Wind is one of the pollution-free energy sources, and wind power generation is forming a boom in the world, because wind power generation does not need to use fuel, nor does it produce radiation or air pollution. The power of wind power generation is characterized by volatility and intermittence. When there is disturbance in the system, the wind farm is likely to oscillate and challenge the stability of the power grid. Therefore, the wind turbine generator must be connected to SVG system to realize dynamic reactive power compensation function, so as to ensure the stability of its operation in case of fault. In addition, the cause of wind turbine oscillation needs to be analyzed in detail to ensure its stability.

Fine structural interpretation is one of the effective methods to find favorable structural traps and targets. Aiming at the fault interpretation of Jurassic Badaowan Fm in Madong area of Xiayan fault zone is not fine and structural characteristics are not implemented, the structural characteristics of Jurassic Badaowan Fm are implemented and favorable traps are found through the study of seismic, well logging and geological comprehensive methods. The results show that the structure of Jurassic Badaowan Fm in Madong area is high in the north and low in the south. The first member of Badaowan Fm is a delta front subaqueous distributary channel deposit, which is a hydrocarbon enrichment zone. Oil and gas are adjusted along the relay of deep and shallow faults, and the great fault zone and the inherited uplifting zone are favorable accumulation areas of Jurassic Badaowan Fm in Madong area. In this paper, the relationship between deep and shallow fault system and hydrocarbon distribution of Badaowan Fm in Madong area is systematically reviewed for the first time. Combined with the palaeohigh distribution, three favorable hydrocarbon accumulation zones are identified, which provides favorable targets for exploring the hydrocarbon accumulation potential of Badaowan Fm.

Under the background of high-quality development, the support of fiscal policy is important for enterprises to achieve high-quality development. As a major initiative to promote the supply-side reform in China, can tax cut policy promote the high-quality development of enterprises? In order to explore this question, based on the data of China’s listed companies from 2015-2019, this paper finds that: (i) Tax cut policy can improve the total factor productivity of enterprises and empower their high-quality development. (ii) The impact is different for companies in different regions and firms with different nature of property rights. Tax cut policy can better promote the high-quality development for companies in central regions and state-owned enterprises in China. (iii) The optimization of business environment effectively strengthens the positive effect of tax cut policy on the enterprise high-quality development. The effect of tax cut policy on total factor productivity is more obvious for companies in better business environment.

The controllability for complex network system is to find the minimum number of leaders for the network system to achieve effective control of the global networks. In this paper, the problem of controllability of the directed network for a family of matrices carrying the structure under directed hypercube is considered. The relationship between the minimum number of leaders for the directed network system and the number of the signed zero forcing set is established. The minimum number of leaders of the directed networks system under a directed hypercube is obtained by computing the zero forcing number of a signed graph.

Hyperspectral classification with limited training samples is challenging. The current work lies in two aspects: first, we change the statistical distribution of samples by iterative filtering based on the guide images. The filter is called a Simplified Bilateral Filter (SBF), which is a modified bilateral filter for clustering samples. Secondly, new structural convolution kernels are used to generate new hyperspectral data. Finally, the class label of the test sample after dimension reduction is determined by OMP classification or SVM classification. Experimental results on two hyperspectral datasets demonstrate the effectiveness of the proposed feature extraction method in improving classification accuracy with limited training samples.

The exploitation of coal mine resources has greatly contributed to China’s economic development, but it has also caused damage to the surrounding ecological environment. With the adjustment and optimization of the national energy structure, many small or unqualified mines have been closed in recent years. Thus, the environmental treatment and ecological restoration of these closed coal mines need to be carried out urgently. In this study, the causes of closed coal mines are analyzed from the perspective of macro policy. Then, the key technical difficulties of comprehensive and systematic restoration and treatment of geological and ecological problems are discussed from multiple perspectives. Finally, the successful restoration and treatment cases of closed coal mines locally and globally are showed. The findings of this study provide ideas and methods for ecological environment restoration and management of closed coal mines.

Based on the material flow analysis method, the green development index system of industrial park was constructed. By using the PSR model, 13 indexes were divided into pressure layer, state layer and response layer, the indexes were standardized, weight distribution and synthesis. The green development level of industrial park was divided into 5 grades combined with the pressure state response factors. The results show that the energy consumption per unit industrial output of a stainless-steel industrial park is 0.7116 tons of standard coal per million yuan, the water consumption per unit industrial output is 6.1466 cubic meters per million yuan, the wastewater discharge per unit industrial added value is 3.12 tons per million yuan, the reduction rate of carbon emissions per unit industrial added value is 19.53%, and the green development index is 0.65, which belongs to the third level of green development. The problems are reflected in particulate emission, resource recycling, energy efficiency, industrial structure, and park greening. In the future, the stainless-steel industrial park should focus on industrial restructuring and transformation, environmental protection infrastructure construction, new policy guidance, and ecological environment construction of the park.

With the further advent of the era of big data, the scale of social media data containing geolocation information is exploding, providing a new source of big data information and perspective for an in-depth study of the changing spatio-temporal and geographical characteristics of the current tourist population. This paper extracts data on popular attractions in the Tibet Autonomous Region using the HDBSCAN algorithm combined with the TF-IDF algorithm based on information on images with geotags shared by users in the Flickr image sharing site from 2005-2018. Social network analysis was used to explore the changes in the spatial and temporal characteristics of inbound tourism flows in Tibet. The results show that: (1) in terms of temporal characteristics, the number of inbound tourists shows obvious off-peak seasons, with relatively high sensitivity to the influence of economic, policy and infrastructure construction factors; (2) in terms of spatial distribution characteristics, the inbound tourism flow in Tibet shows an “axis-scattered” distribution. The core area is centred on Lhasa and extends in three directions: west, north and east along important roads.

In order to meet the requirements of partial discharge (PD) detection of electrical equipment in substation station area, the ultra-high frequency (UHF) antenna with broadband, high gain and horizontal plane (H-plane) omnidirectional is studied and designed as a PD sensor. By analyzing the characteristic impedance and structural characteristics of the biconic antenna, it is determined to be an UHF omnidirectional wideband antenna for detecting PD. The influence of structural parameters such as half-cone angle and vertebral body height on the antenna performance is simulated. At last, a double cone antenna is made and its bandwidth, directional pattern, gain and equivalent height are tested.

Different from the previous articles on multi-echelon cold chain system, in addition to traditional transportation/distribution, warehousing and inventory control, DC value-added services, such as joint order processing, product processing and customizing, picking and assorting, joint distribution, etc. are employed to improve the performance of the cold chain system. Case study and sensitivity analysis demonstrate that (1) DC revenue is mainly from processing and customizing service for all kinds of products; (2) Of the value added services, picking and assorting cost has a significant effect on the total profit. These conclusions present good theoretical and managerial insights.

Different from the previous articles on multi-echelon deteriorating inventory, this paper explains the economic implications of Weibull parameters for cold chain inventory rather than restricting to mathematical sense. A case study shows that DC warehousing activities and total throughput of the scale factor has a significant effect on the total profit compared with the storage technology and warehousing environment of shape factor. The improvements of DC warehousing standard and total throughput and preservation technology and warehousing environment contribute to the reduction of some DC operation costs and the increase of DC processing and customizing profit.

Considering a two-echelon supply chain consisting of one overseas warehouse logistics provider and one cross-border e-commerce retailer with cold chain products over a finite time horizon, this paper studies the optimal decision-making of logistics pricing, freshness-keeping effort level and cold chain product pricing under the Stackelberg game and the cooperative game, and makes a comparative analysis of the two models. Through two-person cooperative game of transferable payment, it is proved that (1)both the total supply chain profit and individual profit of the two parties are greater than the Stackelberg game;(2) the freshness level is higher than that of the Stackelberg game;(3) the logistics price is lower than that of the Stackelberg game;(4) e-commerce transaction scale (i.e. logistics demand scale) is higher than that of the Stackelberg game; and (5) the retail price of the cold chain product is lower than the Stackelberg game. Numerical results bear out the validity of the theoretical models.

In order to screen out the plants used to repair heavy metal pollution in the soil, five plants and surface soil were collected in the Huize lead-zinc mine area, centered on the hyperaccumulator plant Arabis alpina L. var. parviflora Franch, measured the heavy metal content of in shoot and root of plant and surface soil, and analyzed the characteristics of heavy metal accumulation in plants. The results showed that the soil Cd pollution in the Huize lead-zinc mining area was the most serious; among the five plants, the Cd bioconcentration factor(BCF) and translocation factor(TF) of A. alpina were more than 1, and the TF of Pb was more than 1; the TF of Anaphalis margaritacea, Cyananthus inflatus and Arenaria orbiculata to Cu and Zn were more than 1, the TF of Juncus effusus to Cd and Zn were more than 1. These five plants had good tolerance to heavy metals and were of great significance to the remediation and restoration of heavy metal contaminated soil in lead-zinc mining areas.

Aging is a programmed and spontaneous life course that organisms must undergo, and as an irreversible and relatively conservative process, several theories have tried to explain its causes. Among them, the somatic mutation theory, the free radical theory, the natural cross-linking of biomolecules, the immune theory, the telomere theory, the biological clock theory, and the toxic theory are among the most widely accepted hypotheses. However, no single doctrine can fully explain the aging process. Aging is mainly manifested in the structural and functional aging and decline of organisms, and as organisms continue to age, most organs will experience varying degrees of aging and irreversible damage, although it is directly related to many diseases, aging itself is generally not considered as a disease. Any organism ages slowly over time, with the most easily observable manifestations in external changes such as diminished hair color and sagging skin. Numerous studies have shown that mitochondria are instrumental in mitigating aging as the primary provider of cellular energy, providing energy for cell growth and development as well as being the center of cellular metabolism; therefore, once mitochondria become faulty, a large number of cells will lose function, age, and thus die. In this paper, we will discuss in detail the relationship between mitochondria and aging and how external interventions can promote the function of mitochondria in delaying aging.

In this paper, the performance of A1515 centrifugal pump was studied on a high parameters and precision large general test platform in combination with the Huang-jin-xia hydro-junction in Hanjiang-to-Weihe River valley water diversion project. The efficiency characteristics and cavitation performance of the pump were tested and measured respectively. All measured parameters were collected and recorded through the acquisition system. The experimental results show that the optimal efficiency and weighted average efficiency of the pump is 92.46% and 92.18%, and the design point efficiency is 92.39%, all of which meet the design requirements. After conversion to the prototype pump, the efficiency value at each working point is higher than the guaranteed value. The pump hump margin is 3.03%, which is greater than 2% of the required value and meets the requirements. In the whole normal operating range, the cavitation performance of the model pump meets the design and test requirements. The comprehensive error of model test is less than ±0.2%. The research results provide reference for the design of large centrifugal pump.

The question of what the law is may preoccupy some legal theorists. Answering it is definitely the legal professionals’ nightmare. Constitutional and statutory requirements now require Taiwan’s officials and lawyers to confront the problem of ascertaining and applying indigenous customs in the exercise of all state powers. Yet, the most widely accepted juridical concept of custom results in a choice between two evils, to wit, breaching either the general duty to uphold law or the concrete obligation to respect indigenous values. So far, efforts have only been made to document the customs, but the documentation thus produced is too ethnographic to be legally useful. The challenge, therefore, is one of translation. Values are to be carried from an indigenous world into the modern one, and the little-known form of custom is to be expressed in the language of the science of law. This paper argues for the translation of indigenous customs with conceptions available in an array of examples from European legal history. This paper explains that, in cases like Taiwan, the solutions known to the English-speaking literature all end in the dilemma I call »modern state centralism« (MSC). The solutions are divided into two types: legal pluralism and Francisco Suárez’s conception of custom. The former defeats itself in that its criticism against the state’s monopoly of law amounts to suggesting that the state tolerate all kinds of non-state normativity. The latter reduces to MSC because recent literature ignores Suárez’s legal historical references and important studies written in German. The rest of the section shows how »non-modern« legal techniques may help. This paper concludes by suggesting that the concept pair of law and custom be dissociated from four others, to wit, written and unwritten law, state and society, law in books and law in action, and, finally, alien and native law.

This paper challenges the modern legal concept of “person” by analyzing the translation problems of some Roman law fragments. It shows why the Latin word “persona” cannot be the etymon of the vernacular “person,” and argues that the modern use of “person” stems from the nineteenth-century German juridical literature, especially that of F. C. von Savigny. This paper shows that “persona” forms a phrase with verbs like gerere, tenere and sustinere (bear, carry, hold, etc.) and has no meaning by itself. Such phrases require a noun complement in genitive form, as their synonym “represent,” which is transitive, needs a direct object. On the other hand, the modern literature attributes a sense to “person,” taking it as equivalent to “human individual” and using it word with the verb “be.” This use is a modern invention and cannot be re-translated into Latin without semantic confusion.

Based on the in-depth analysis of the causes of the large-scale water supply pipe network explosion at home and abroad, the paper discusses the neural network modeling technology for quickly and accurately locating the water pipe network. Furthermore, the remedial measures of the pipe network squib in the field were adopted, and the BP neural network deep learning method was proposed to carry out the intelligent positioning of the water pipe network bursting. Based on the construction of a miniature hydraulic model based on BP neural network analysis, through the correlation analysis of the flow change of 5 positions and the pressure monitoring point change of 17 positions when the pipe network bursts, the artificial neural network deep learning is further used to diagnose the position of the pipe network where the pipe burst is located. In this paper, the small-scale water supply pipe network built by the laboratory is taken as an example to verify the research method of the pipe burst positioning.

Navigation messages are the basic data for navigation and positioning calculations in satellite navigation systems. Nowadays, there is a growing need to evaluate the protocol conformance of navigation messages. In this paper, the evaluation model and the calculation method for protocol conformance of BDS D1 navigation messages are proposed, and the example analysis of actual BDS D1 navigation messages is presented. The evaluation model is described from three aspects, including formatting conformance, verification conformance and quantization unit conformance. Every aspect is considered carefully with calculation and analysis. The results show that the model can evaluate the protocol conformance of BDS D1 navigation messages reasonably.

The paper introduces the theory and application of Power Plant's primary frequency compensation(PFC) on the unit with the supercritical forced circulation boiler. First of all,the paper gives the typical parameters Setting and logic design of PFC. Then it explains some adverse factors which affect the PFC of the unit. With some problems in the operative process, the typical control strategy and some advices are given , which can improve PFC ability of Power Plant's PFC.

This paper mainly aims at the energy reception characteristics of solar aircraft flying in the near space between the Tropics of Cancer and Capricorn. Based on the solar radiation intensity calculation model, the energy reception characteristics including maximum solar radiation intensity, daytime average solar radiation intensity, total solar radiation energy received per day on the unit area., and daytime hours of solar aircraft was calculated varying with date, longitude, and latitude. By analyzing the corresponding calculation results, it can provide some reference value for the design of solar aircraft flying in this area.

Taking a certain area of a coastal city as the research object, based on the measured data, the model of rainwater pipe network and the hydraulic model of sewage pipe network in the study area were established based on SWMM. According to the set interception target combined with the established SWMM rainwater network model, the specific volume of Rain Water in the initial stage of each Rain Water discharge port is calculated, which is given to the sewage trunk pipe in the form of time series to realize the initial Rain Water interception control and analyze the receiving capacity of the sewage pipe network. In this study, 20% of the initial Rain Water was set up in the study area, which was given in the form of time series to the nodes in the sewage pipe network model. After the initial Rain Water was cut off 20%, part of the pipe segment and the node appeared overload phenomenon, but there was no overflow. After 30% initial Rain Water interception, overflow occurred in some pipe segments.

Urban drainage pipe network is an important foundation project in urban construction. It has a vital impact on urban waterlogging prevention and water pollution. However, in the current practice, there are many hidden problems in the pipe network, and it is difficult to check the pipe network problem, which restricts the understanding of the drainage system problem to a certain extent. In order to solve the two technical problems of drainage network survey and data statistics, the monitoring technology based on Internet of things and big data is adopted in this study. Taking the sponge city pilot area of a coastal city in China as the research area, the monitoring scheme was established and the monitoring data were obtained. Based on more than 6 million monitoring data, the automatic analysis algorithm is applied to analyse the problems of mixed connection of rain and sewage and tidal backwater in the pipeline network. The results show that there are a total of 17 outlets in 160 outlets with problems of rain and sewage mixing. Among them, there are four outlets with regular domestic sewage entering the rainwater pipe network, 7 outlets with irregular sewage entering the rainwater pipe network, and 6 outlets where sewage is smuggled into the rainwater pipe network. In addition, there is a sea tidal backwater phenomenon at one of the coastal rainwater outfalls.

The utilization of voice coil motor (VCM) rotary actuator in hard disk drives (HDDs) results in skew angles between the read/write head and disk rotation direction. The system performance and achievable capacity of hard disk drives are excessively sensitive to the skew angle [1–3]. The difference in skew angle, between the ID to the OD can be as large as more than 30 degrees in conventional 3.5” and 2.5” VCM actuated HDDs. This paper presents three mechanisms, namely, a slant arm/suspension mechanism, a guider track mechanism, and a 4 link mechanism which can be designed to achieve minimum skew angle actuations for hard disk drives. The slant arm/suspension mechanism reduces the skew angle to ± 2 degrees in rotary actuated systems. The guider track mechanism further achieves the skew angle as zero degree theoretically. As an approximation of the guider track mechanism, the 4 link actuation mechanism reduces the skew angle to 0.4 degree. Their system dynamic behaviors are studied numerically using finite element modelling. Some of designs are prototyped and experimentally investigated.

A 1.5mm thickness as-cast Fe-2.7%Si strip was produced by twin-roll strip casting and the precipitates under different isothermal holding time (0.5 min–30 min) and cooling rates (1∘/s–20 ∘C/s) were investigated by thermal simulation experiment technology and electron probe micro-analyzer. The main precipitates in all specimens are AlN-MnS complex with a structure of core-edge. During isothermal holding, the number density of relatively large precipitates (≥ 0.3 μm) decrease with increase in time and the mean size of the small precipitates (≤150 nm) increases gradually. It can be attributed to the complicated interactions of dissolve, precipitation and coarsening behavior. For precipitates in strips cooling from 1380 ∘C to 20 ∘C, the mean size decreases continuously with increase in cooling rate because the corresponding growth rate and time of precipitates decrease. These results indicate that isothermal holding time and cooling rate have an important influence on size of precipitates in strip, which will be of great importance in optimizing properties of silicon steel.