防老剂对HTPB-IPDI高燃速推进剂性能影响研究(Ⅱ)

采用高温加速老化方法 ,研究了胺类防老剂 H(N,N′-二苯基对苯二胺 )和酚类防老剂甲叉 44 2 6 -S(硫代双 -3,5 -二叔丁基 -4 -羟苄基 )对 HTPB/ IPDI高燃速推进剂贮存性能的影响。实验结果表明 ,随着贮存时间的延长 ,推进剂的常温抗拉强度升高 ,常温、高温、低温下的伸长率降低 ,加入甲叉 44 2 6 -S的 HTPB/ IPDI推进剂的高温贮存性能优于防老剂 H。

固体推进剂空穴损伤的理论与实验分析

在空穴累积损伤和微孔洞形核、长大和汇合损伤二种损伤模式分析的基础上 ,提出一个空穴损伤细观力学模型 ,根据粘弹性对应原理和数学分析 ,求得空穴损伤演变的二个理论数学表达式。采用空穴损伤非接触诊断专利技术 ,进行老化药柱的空穴损伤实验研究 ,求得一种固体复合推进剂的空穴损伤演变的实验曲线和使用寿命。因为贮存失效临界点是实测的 ,对比实验分析表明 :若药柱贮存时间超过贮存失效临界点 ,则药柱要出现裂纹 ,超过的时间越长则药柱中的裂纹就越大。

美在发现——奇石审美漫谈

奇石又称观赏石,在自然美审美领域中属于地质物体的观赏。地质物体从观赏角度可以分为四大类:矿物、岩石、地层及山水体。前二者构成观赏石的审美客体,后二者则构成风景美的审美客体。观赏石体量小,具备可搬运性、可储存性、性态稳定性,作为商品还具备可收集性。观赏石的这些特性又形成了其可以长期集中陈列展览的审美欣赏方式。风景美体量大,具备不可搬运性、无限时空性、自然综合性。

三峰具体小 应是华山孙——奇石审美漫谈

有幸参观新加坡华侨张荣光先生与颐和园合作举办的"天下奇石陈列展",深感这个奇石展实在是自然美美育的一本难得的实物教材! 奇石又称观赏石,在自然美审美领域中属于地质物质的观赏。它体量小,具备可搬运性、可储存性、性态稳定性。

Correlation of Cooperatively Localized Rearrangement on the ＂Fluidized Domain＂ of Polymers to Their Nonexponentially Viscoelastic Behavior and Lifetime at Double Aging Processes II： Estimation of Long-term Mechanical Behavior and Lifetime of Polymeric Materials from Short-time Creep and Stress Relaxation Tests

Three kinds of polymeric materials are taken as example for the verification of linear ex-trapolation method from unified master lines with reduced universal equations on creep and stress relaxation tests. The theoretical values of long-term mechanical behavior and lifetime for a cured epoxide, polypropylene, poly（methyl-methacrylate）, and SBR rubber are directly evaluated with the universal equations on reduced creep compliance and reduced stress relax-ation modulus and are compared with their predicted values by the linear extrapolation from the unified master lines of creep and stress relaxation. The results show that the theoretical values of dimensional stability, bearing ability and lifetime are in an excellent agreement with the predicted values, it shows that the linear extrapolation method is more simple and reliable. The dependences of long-term mechanical behaviors and lifetime on the different aging times are discussed.

Techno-Economic Challenges of Fuel Cell Commercialization

As resource scarcity, extreme climate change, and pollution levels increase, economic growth must rely on more environmentally friendly and efficient production processes, Fuel cells are an ideal alternative to internal combustion （IC） engines and boilers on the path to greener industries because of their high effi- ciency and environmentally friendly operation, However, as a new energy technology, significant market penetration of fuel cells has not yet been achieved, In this paper, we perform a techno-economic and environmental analysis of fuel cell systems using life cycle and value chain activities, First, we investigate the procedure of fuel cell development and identify what activities should he undertaken according to fuel cell life cycle activities, value chain activities, and end-user acceptance criteria, Next, we present a unified learning of the institutional barriers in fuel cell commercialization, The primary end-user accep- tance criteria are function, cost, and reliability; a fuel cell should outperform these criteria compared with its competitors, such as IC engines and batteries, to achieve a competitive advantage, The repair and maintenance costs of fuel cells （due to low reliability） can lead to a substantial cost increase and decrease in availability, which are the major factors for end-user acceptance, The fuel cell industry must face the challenge of how to overcome this reliability barrier, This paper provides a deeper insight into our work over the years on the main barriers to fuel cell commercialization, and discusses the potential pivotal role of fuel cells in a future low-carbon green economy, It also identifies the needs and points out some direc- tions for this future low-carbon economy, Green energy, supplied with fuel cells, is truly the business mode of the future, Striving for a more sustainable development of economic growth by adopting green public investments and implementing policy initiatives encourages environmentally responsible indus- trial investments.

The Effect of Exogenous Sodium Nitroprusside Treatment on Broccoli Quality During the Storage Process

[Objective] The aim was to provide certain theoretical basis for the protection of broccoli. [Method] Exogenous sodium nitroprusside was used to in the experiment. Under the condition of 20 ℃ and RH 95%, the optimal SNP concentration of broccoli was determined. [Result] The exogenous SNP could effectively maintain the quality of broccoli, inhabited the yellowing of broccoli and the increasing of cell membrane permeability, and maintain the soluble solids content, decreased the degradation rate of chlorophyll and delayed the loss of VC. [Conclusion] Exogenous sodium nitroprusside can effectively maintain the quality of broccoli to keep it fresh.

3D-metal-embroidered electrodes:dreaming for next generation flexible and personalizable energy storage devices

Flexible and Personalizable battery is a promising candidate for energy storage, but suffers from the weldablity and large-scale producibility of the electrode. To address the issues, we design a nickel foam catalyzed electroless deposition (NFED) derived 3D-metal-pattern embroidered electrodes. This is the first attempt to utilize this type of electrode in battery field. It is found that the current collector can be embroidered on any selected areas of any complex-shape electrodes, with high controllability and economical feasibility. As a result, the electronic conductivity of the flexible electrodes can be improved by nearly one order of magnitude, which can be easily and firmly weldded to the metal tab using the industry generic ultrasonic heating process. The embroidered electrodes could substantially promote the electrochemical performance under bending deformation, with both Li-S and Li-Li FePO4batteries as the models. This innovation is also suitable to embroider all the VIII group elements on any electrodes with personalized shapes, which is widely attractive for the development of next generation flexible and personalizable energy storage devices.

A reliable power management scheme for consistent hashing based distributed key value storage systems

Distributed key value storage systems are among the most important types of distributed storage systems currently deployed in data centers. Nowadays, enterprise data centers are facing growing pressure in reducing their power consumption. In this paper, we propose GreenCHT, a reliable power management scheme for consistent hashing based distributed key value storage systems. It consists of a multi-tier replication scheme, a reliable distributed log store, and a predictive power mode scheduler （PMS）. Instead of randomly placing replicas of each object on a number of nodes in the consistent hash ring, we arrange the replicas of objects on nonoverlapping tiers of nodes in the ring. This allows the system to fall in various power modes by powering down subsets of servers while not violating data availability. The predictive PMS predicts workloads and adapts to load fluctuation. It cooperates with the multi-tier replication strategy to provide power proportionality for the system. To ensure that the reliability of the system is maintained when replicas are powered down, we distribute the writes to standby replicas to active servers, which ensures failure tolerance of the system. GreenCHT is implemented based on Sheepdog, a distributed key value storage system that uses consistent hashing as an underlying distributed hash table. By replaying 12 typical real workload traces collected from Microsoft, the evaluation results show that GreenCHT can provide significant power savings while maintaining a desired performance. We observe that GreenCHT can reduce power consumption by up to 35%-61%.

A reliable and energy-efficient storage system with erasure coding cache

In modern energy-saving replication storage systems, a primary group of disks is always powered up to serve incoming requests while other disks are often spun down to save energy during slack periods. However, since new writes cannot be immediately synchronized into all disks, system reliability is degraded. In this paper, we develop a high-reliability and energy-efficient replication storage system, named RERAID, based on RAID10. RERAID employs part of the free space in the primary disk group and uses erasure coding to construct a code cache at the front end to absorb new writes. Since code cache supports failure recovery of two or more disks by using erasure coding, RERAID guarantees a reliability comparable with that of the RAID10 storage system. In addition, we develop an algorithm, called erasure coding write （ECW）, to buffer many small random writes into a few large writes, which are then written to the code cache in a parallel fashion sequentially to improve the write performance. Experimental results show that RERAID significantly improves write performance and saves more energy than existing solutions.

Hf_(0.5)Zr_(0.5)O_(2)-based ferroelectric memristor with multilevel storage potential and artificial synaptic plasticity

Memristors are designed to mimic the brain’s integrated functions of storage and computing,thus breaking through the von Neumann framework.However,the formation and breaking of the conductive filament inside a conventional memristor is unstable,which makes it difficult to realistically mimic the function of a biological synapse.This problem has become a main factor that hinders memristor applications.The ferroelectric memristor overcomes the shortcomings of the traditional memristor because its resistance variation depends on the polarization direction of the ferroelectric thin film.In this work,an Au/Hf0.5Zr0.5O2/p+-Si ferroelectric memristor is proposed,which is capable of achieving resistive switching characteristics.In particular,the proposed device realizes the stable characteristics of multilevel storage,which possesses the potential to be applied to multi-level storage.Through polarization,the resistance of the proposed memristor can be gradually modulated by flipping the ferroelectric domains.Additionally,a plurality of resistance states can be obtained in bidirectional continuous reversibility,which is similar to the changes in synaptic weights.Furthermore,the proposed memristor is able to successfully mimic biological synaptic functions such as long-term depression,long-term potentiation,paired-pulse facilitation,and spike-timing-dependent plasticity.Consequently,it constitutes a promising candidate for a breakthrough in the von Neumann framework.

Extending attributes page:a scheme for enhancing the reliability of storage system metadata

In an object-based storage system,a novel scheme named EAP(extending attributes page) is presented to enhance the metadata reliability of the system by adding the user object file information attributes page for each user object and storing the file-related attributes of each user object in object-based storage devices.The EAP scheme requires no additional hardware equipments compared to a general method which uses backup metadata servers to improve the metadata reliability.Leveraging a Markov chain,this paper compares the metadata reliability of the system using the EAP scheme with that using only metadata servers to offer the file metadata service.Our results demonstrate that the EAP scheme can dramatically enhance the reliability of storage system metadata.

Use of near-infrared spectroscopy and least-squares support vector machine to determine quality change of tomato juice

Near-infrared (NIR) transmittance spectroscopy combined with least-squares support vector machine (LS-SVM) was investigated to study the quality change of tomato juice during the storage. A total of 100 tomato juice samples were used. The spectrum of each tomato juice was collected twice: the first measurement was taken when the tomato juice was fresh and had not undergone any changes, and the second measurement was taken after a month. Principal component analysis (PCA) was used to examine a potential capability of separating juice before and after the storage. The soluble solid content (SSC) and pH of the juice samples were determined. The results show that changes in certain compounds between tomato juice before and after the storage period were obvious. An excellent precision was achieved by LS-SVM model compared with discriminant partial least-squares (DPLS), soft independent modeling of class analogy (SIMCA), and discriminant analysis (DA) models, with 100% of a total accuracy. It can be found that NIR spectroscopy coupled with LS-SVM, DPLS, SIMCA, and DA can be used to control the quality change of tomato juice during the storage.

Topological quantum memory interfacing atomic and superconducting qubits

We propose a scheme to manipulate a topological spin qubit which is realized with cold atoms in a one-dimensional optical lattice.In particular, by introducing a quantum opto-electro-mechanical interface, we are able to first transfer a superconducting qubit state to an atomic qubit state and then to store it into the topological spin qubit. In this way, an efficient topological quantum memory could be constructed for the superconducting qubit. Therefore, we can consolidate the advantages of both the noise resistance of the topological qubits and the scalability of the superconducting qubits in this hybrid architecture.

通信枢纽楼能耗运行分析研究

如何在业务量不断增加,电源容量无法扩容的情况下,更好地解决供电能力紧张、机房装机位不足、机房散热等问题,是本论文的研究意义所在。本文通过对S省通信枢纽楼能耗运行分析,给出以上难点的合理化建议和建设指导原则。