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In recent years, with the rapid development of agricultural Internet of things, many different agricultural and sideline products can be bought easily which from different regions, but it also brings about more problems of foods safety (production and sale of fake eggs, water injection Pork, etc.). These issues affect social development and people’s health seriously. According these issues, all stages of agricultural products should be monitor and control. This paper introduces the traceability system which integrates RFID and EPC technologies, and uses ONS database to store key information. The tracing information can be queried that user login in traceability system and identify the two-dimensional code. People use the mobile scan to encrypted the QR code to get the information of agriculture and food products they need. The traceability system guarantees the safety of meat in all aspects of the supply chain. The system should be developed and promoted in society.

To understand EXO70 gene duplication in Brassica rapa and B. oleracea genomes, we identified and analyzed 39 BrEXO70 and 45 BoEXO70 genes. EXO70s from B. rapa show the same pattern of high interspecies conservation as those from B. oleracea . The number of exons differs among EXO70 genes, with the greatest number observed in EXO70A . Although each encoded EXO70 contains a highly conserved pfam03081 domain, the domains differ from one another in amino acid composition. The gene duplication mechanism of BoEXO70 is more complex than that of BrEXO70 . Although few differences in synonymous codon preference exist between BoEXO70 and BrEXO70 , obvious differences in codon preference are present among different EXO70 types. We conclude that EXO70 has been duplicated multiple times during the evolution of both B. rapa and B. oleracea . More duplications have occurred in B. oleracea than in B. rapa , even though the same modes of gene duplication are found in both BoEXO70 and BrEXO70 . In addition, high conservation is exhibited by the same types of EXO70 genes in both B. oleracea and B. rapa . We also propose that the pfam03081 domain plays an essential role in EXO70 functional determination. Finally, EXO70 evolutionary divergence is evident in both B. rapa and B. oleracea .

EXO70, an important component of the exocyst complex, is encoded by a single gene in humans, mice and yeast. To understand EXO70 gene duplication in plant genomes, we identified and analyzed all OsEXO70 and AtEXO70 genes in Arabidopsis thaliana and Oryza sativa . A total of 23 different EXO70 genes were identified in the A. thaliana genome, of which 15 were present on the ‘-’ strand. We detected 27 different mature mRNAs of EXO70 arising from alternative splicing. In O. sativa , 38 OsEXO70 genes coding for proteins comprising more than 412 amino acids were found to be distributed across the 12 rice chromosomes. Of these genes, 29 were located on the ‘+’ strand. Interestingly, a product of large-scale genome duplication—an approximately 2-Mbp-long fragment including both OsEXO70H3 and OsEXO70H4 , was highly conserved between chromosomes 11 and 12. The gene duplication mode of OsEXO70 is more complex than that of AtEXO70 . Although synonymous codon bias exists in both AtEXO70 and OsEXO70 , codon preferences differ between them. All EXO70 proteins contain a pfam03081 domain, indicating that these proteins may have the same or similar functions. We conclude that EXO70 has been duplicated multiple times during the evolution of both A. thaliana and O. sativa , with more duplications occurring in O. sativa than in A. thaliana . Additionally, a greater number of gene duplication mechanisms are operative for OsEXO70 than for AtEXO70 . We also propose that the pfam03081 domain may play an essential role in EXO70 functional determination. Finally, many differences in synonymous codon preference exist between AtEXO70 and OsEXO70 .

Bent function is an important nonlinear function in design of stream cipher and S-box. More than eight variables Bent functions can only be generated by construction, up to now, most of these functions are still not found. In this paper, the Bent function search algorithm based on truth table is presented via analyzing the value distribution and run length property of the Bent function. Compared with other searching algorithms, the algorithm proposed in this paper has weak storage complexity and is easy to be implemented by parallel computing.

with the rapid development of science and technology, modern agriculture has made great progress. But frequent agricultural safety incidents have affected people's trust in agricultural production. These incidents (such as mad cow disease, avian flu) have seriously affected the situation of agricultural production in a region or product, and even affected the economic and social development. Based on the study of the existing traceability products, we constructs the agricultural traceability system of agricultural products based on Internet of things through the Internet of things technology information security technology and cloud computing technology in this paper. Through the system customers can effectively understand the detailed process and risk status of every phase of agricultural products, such as cultivation, processing, storage and sale, and the problem of counterfeiting in the process of production and circulation can be solved. Finally, the agricultural traceability system can provide effective basis for agricultural trade, logistics and safe consumption.

Based on the LEACH protocol and the Single-hop protocol, this paper proposes a new method to predict the lifetime and reliability of wireless sensor network directly. That is to say, the sensor nodes can be directly deployed without further simulation. Through a series of experiments to compare the two protocols have been several key conclusions: With the increase in sensor density, although the LEACH protocol life cycle is also increasing, but the maximum is always lower than the life cycle remains basically the same single-hop protocol. And compare the network reliability of the two can be seen, with the sensor density increases, LEACH protocol reliability is reduced. However, the reliability of the Single-hop protocol is always higher than that of the LEACH protocol. Thus, in this limited experimental environment, Single-hop protocol is better than LEACH protocol.

This study investigated the feasibility of stabilizing lead sludge by reaction with iron sludge via the formation of PbFe12O19 through a thermal treatment process. Lead hydroxide was used to simulate lead-laden sludge and the sintering procedure was performed by firing a mixture of this simulated sludge together with iron sludge at a Fe/Pb molar ratio of 12 over the temperature range from 650 to 1400 °C. The accompanying phase transformations as well as the surface characteristic of sintered samples were observed by XRD and SEM, while the leaching behavior of the stabilized sludge in an acidic environment was evaluated by a modified Toxicity Characteristic Leaching Procedure (TCLP) test. The results confirmed that PbFe12O19 acts as a stabilization phase for lead, and showed that the formation of a PbFe12O19 phase began at 750 °C with the lead completely incorporated into the PbFe12O19 phase at 1050 °C. Above 1100 °C, the PbFe12O19 phase began to decompose, accompanied by the reappearance of Fe2O3. The volumes of compressed sludge samples were reduced significantly after thermal treatment, with accompanying volume reductions of 40% at 1050 °C. This study compared the leaching of lead from PbO and sintered sludge samples using a prolonged TCLP test, and the data showed that the PbFe12O19 phase was superior to the PbO and that the sintered sludge sample exhibited very high stability under acidic environments. These results suggest a promising and reliable method of reducing lead sludge mobility and toxicity has been identified.

Triboelectrification-enabled self-powered flexible electronic/optical systems have aroused a new surge of interest in recent years. All-in-one integration of such a system, which could significantly improve its adaptability, operability, and portability, still remains a challenge due to the absence of suitable architectures and integration schemes. Herein, a previously reported self-powered optical switch (OS) is thoroughly remolded and upgraded to a fully integrated contact-sliding-triboelectrification-driven dynamic optical transmittance modulator (OTM). The OTM is constructed with a multilayered structure, comprising a transparent triboelectrification top layer, a SiO2 -spaced polymer dispersed liquid crystal (PDLC) intermediate layer, and a flexible transparent conductive substrate. The working mechanism is that an alternating electric field can be induced once contact-sliding occurs upon the OTM, rendering the PDLC layer immediately switching its initial translucent state to an instantaneous transparent state. As such, a decent dimming range with the relative transmitted light intensity from 0.17 to 0.72 can be achieved at low mechanical thresholds of contact pressure (≈20 kPa) and sliding velocity (≈0.3 m s-1 ). Moreover, for practical applications, demonstrations of information covering and selective visualization are successfully implemented without any extra optical elements nor external power supplies, explicitly showing great potential for the OTM in various self-powered optical interactive applications.

For the medical industry, there are problems such as poor sharing of medical data, tampering, and leakage of private data. In view of these problems, a blockchain-based electronic medical record access control research scheme based on the role-based access control model is proposed in this article. First, the appropriate access control strategy is adopted to solve the leakage problem of the user’s medical privacy information during the access process. Then, the information entropy technology is used to quantify the medical data, so that the medical data can be effectively and maximally utilized. Using the distributed general ledger characteristics of blockchain and its inherent security attributes, data islands can be eliminated, data sharing among medical systems can be promoted, access records can be prevented from being tampered with, and medical research and precise medical treatment can be better supported. Through this research, not only can user’s medical privacy information protection be realized during the service process but also patients can manage their own medical data autonomously, which is beneficial to privacy protection under the medical data sharing.

A popular construction of stream ciphers is to combine several LFSRs and nonlinear components, such as a Nonlinear Feedback Shift Register (NFSR) and a Boolean function. In this paper, we present a new analysis method for stream ciphers based on the Walsh spectrum. Besides the security properties, balancedness, nonlinearity and correlation immunity of nonlinear component, our works are focused on the key points of the values of Walsh spectrum, which influence these security indicators. By this method, the weakness of nonlinear component can be found more easily and clearly. Finally, we use this method to analyze the Grain v1 and point out its’ security weakness.

从甘蓝、大白菜与甘蓝型油菜中分离出 EXO70A1 基因，对该基因的序列进行生物信息学分析, 然后转化酵母Y187, 应用半定量RT-PCR检测 BoEXO70A1 基因的表达特性。结果表明, 3种芸薹属植物 EXO70A1 序列长度均为1 917 bp，相似性97.1%, 它们的gDNA序列均为单一序列，长度分别为3 797、3 752和3 770 bp，一致度达91.0%，均由12个外显子及11个内含子组成，除了第4、第5、第6、第8个内含子外，其余内含子的保守性低于外显子; 推导的3种蛋白质序列(BnEXO70A1、BrEXO70A1和BoEXO70A1)的相似度与一致性分别达99.8%与98.1%，其二级结构、三维结构及理化特性高度相似。 EXO70A1 基因的11个内含子的剪切位点均符合“GU-AG”法则，剪切受体(AG)的前20~50个碱基存在一段保守的序列“CU(A/G)A(C/U)”; 3种芸薹属植物与拟南芥 EXO70A1 基因的12个外显子的对应序列长度完全相同，所构成的编码区的序列一致性达90.1%，相应的蛋白质序列的相似度与一致性分别达99.8%与93.7%; 分子进化分析表明, EXO70A1在整个EXO70蛋白家族中及不同的植物间表现出较高的保守性; BoEXO70A1 在酵母细胞Y187呈现弱表达; EXO70A1 在甘蓝的雄蕊、幼茎、幼嫩花瓣、雌蕊、幼根及叶片中均能表达，可能属于组成型表达基因，但是其表达量在不同发育时期的不同器官中存在差异，授粉前雌蕊中最高，雄蕊中最低。由此可知， EXO70A1 在芸薹属植物中整体高度保守, 但在酵母转化株和甘蓝各器官中的组成型表达有所差异，推测 EXO70A1 在植物细胞中具有多种重要的功能。

The orientation transition from perpendicular to parallel alignment of PEO cylindrical domains of PEO-b-PMA(Az) films has been demonstrated by extruding the block copolymer (BCP) solutions through a micropore of a plastic gastight syringe. The parallelized orientation of PEO domains induced by this micropore extrusion can be recovered to perpendicular alignment via ultrasonication of the extruded BCP solutions and subsequent annealing. A plausible mechanism is proposed in this study. The BCP films can be used as templates to prepare nanowire arrays with controlled layers, which has enormous potential application in the field of integrated circuits.

This study examined the relationships among entrepreneurial orientation (EO), experimental learning (EL) and acquisitive learning (AL), and firm performance (FP). We tested our model in China as EO is the engine that is driving firms to take advantage of opportunities in an increasingly market–oriented transitional economy. From the responses of 607 firms, we found that EO was positively related to EL but had an inverse U–shaped relationship with AL. Both EL and AL enhanced FP although the effects from AL were weaker and became nonsignificant when external knowledge was embedded into the firm's internal private knowledge.

Exfoliation from multiwalled carbon nanotubes (MWCNTs) during electrochemical insertion of lithium is shown to depend on the inner diameter of the tubes and the wall thickness. Those with core diameters of 10 nm and walls 5 nm thick showed no incorporation of solvated Li+ ions into the core and exfoliation as a result of solvated Li+ ions entering the walls; those with core diameters of 40 nm with walls 30 nm thick showed no exfoliation in an electrolyte based on ethylene carbonate (EC) and little exfoliation even in electrolytes based on propylene carbonate (PC). Exfoliation of graphene layers from a MWCNT on lithium insertion depends not only on the size of the solvated Li+ ions, but also on the concentration of the solvated Li+ ions between the graphene layers in the walls. Keywords: Multiwalled carbon nanotubes, Lithium-ion batteries, Electrochemical insertion, Exfoliation

A facile method using polystyrene-b-poly(4-vinyl pyridine) (PS-b-P4VP) micelles is demonstrated to synthesize N/FeN4-doped hollow carbon nanospheres (N/FeN4-CHNS) with high electrocatalytic activity for oxygen reduction reactions (ORRs). Uniform spherical micelles with PS core and P4VP shell are prepared by exposing PS-b-P4VP in a mixture of ethanol/tetrahydrofuran. Pyridinic N in shell cooperates with Fe3+ to induce an in situ polymerization of pyrrole. Tuning molecular composition of PS-b-P4VP can form hollow carbon spheres with controlled size down to sub-100 nm that remains challenge using traditional hard template strategies. N/FeN4-CHNS possesses a series of desirable properties as electrode materials, including easy fabrication, high reproducibility, large surface area, and highly accessible porous surface. This electrocatalyst exhibits excellent ORR activity (onset potential of 0.976 V vs reversible hydrogen electrode (RHE) and half-wave potential of 0.852 V vs RHE), higher than that of commercial Pt/C (20 wt%) in an alkaline media, and shows a good activity in an acidic media as well. In addition to its higher stability and methanol tolerance than Pt/C in both alkaline and acidic electrolytes, highly competitive single cell performance is achieved in a proton exchange membrane fuel cell. This work provides a general approach to preparing functionalized small hollow nanospheres based on self-assembly of block copolymers.

The ordered arrays of Fe–Pd binary alloy nanotubes were synthesized from the mixed metal-complex solution by a simple electrodeposition method with the assistance of nanoporous anodic alumina (AAO). The electrodeposition potentials of Fe2+ and Pd2+ can be controlled by complexing agents, which has allowed for the fabrication of the Fe–Pd nanotubes by the AAO-template-assisted electrodeposition. Furthermore, the adjustment of the cathodic current density has caused the variation of the inner diameters and Fe–Pd composition ratios of the alloy nanotubes. Although the as-prepared Fe–Pd nanotubes are comprised of f.c.c. crystal structures, the metastable phase structure has been converted to L12 supper-lattice structure by annealing. The results of this work have shown a potential applicability of AAO-template-assisted electrodeposition to the preparation of other new binary alloy nanotubes by selecting adequate complexing agents.

Multi-walled carbon nanotube/cadmium sulfide hybrid heterostructures were easily synthesized by employing a thermal decomposition of thioacetamide as a sulfide-ion source in an aqueous regime. The resulting cadmium-sulfide phase is comprised of a zinc-blende structure of spherical polycrystalline nanoparticles (cadmium-sulfide nanoclusters) with the subunits of ca. 15 nm, deposited on the nanotube surface. The formation of the cadmium-sulfide nanoparticles with zinc-blende structure (cubic crystal) suggests that the local concentrations of reacting ion species in the vicinity of the nanotube surface are different from those in the reaction solution. The cadmium-sulfide nanoparticles are comprised of a stoichiometrically ideal chemical-composition ratio (cadmium: sulfur=1:1.02) of cadmium and sulfur with the valence states of +2 and −2, respectively. The optical responses of the cadmium-sulfide phase for ultraviolet-visible light and photoluminescence spectroscopes show the proper size-effect and inherent optical properties of the cadmium-sulfide nanoparticles.

Literature revealed that an appropriate alignment between firm strategic orientation and market positioning is critical because of its impact on firm performance. The alignment is especially crucia...

The ZnS/hyperbranched polyester nanocomposite with higher refractive index was prepared by incorporating the acrylated 2-(2-mercapto-acetoxy)-ethyl ester-capped ZnS nanoparticles into the acrylated Boltorn™ H20 (H20). The acrylated 2-(2-mercapto-acetoxy)-ethyl ester-capped colloidal ZnS nanoparticles were synthesized by the reaction of zinc acetate with thioacetamide in N,N-dimethylformamide. The acrylated hyperbranched polyester was obtained by reacting acryloyl chloride with hydroxyl group of H20. The acrylated H20 plays an important role in stabilizing and dispersing ZnS nanoparticles with a diameter of 1–4 nm. The refractive indices of ZnS/hyperbranched polyester nanocomposites, depending on ZnS content, were determined to be in the ranges of 1.48–1.65.

To investigate the correlation between CT image presentations and biochemical indexes in adrenal adenomas and pheochromocytomas.We retrospectively analyzed the CT features, cortisol rhythm, supine and orthostatic hypertension and 24-h urine methoxy in 209 patients with benign adrenal tumors. The relationship between CT findings and the biochemical indexes were analyzed in patients with different benign adrenal tumors.The 209 cases analyzed included 53 cases of cortisol adenoma, 65 cases of aldosterone adenoma, 45 cases of non-functional adenoma and 46 cases of pheochromocytomas. The plain CT scan values of the 4 groups were 17.25 ± 1.81, 14.52 ± 1.57, 12.20 ± 2.05, 42.42 ± 0.97 HU, enhanced CT values (arterial phase) were 47.82 ± 3.07, 39.23 ± 2.37, 45.35 ± 6.46, and 104.93 ± 5.84 HU, respectively, and the differences between CT scan and enhanced CT values were 30.58 ± 2.29, 24.71 ± 1.55, 33.15 ± 5.18, and 62.51 ± 5.73 HU, respectively. In cortisol adenoma group, cortisol levels measured at 16:00 and 24:00 were positively correlated with plain CT scan value (r=0.506, P=0.0001; r=0.504, P=0.0001) and enhanced CT value (r=0.514, P=0.0001; r=0.554, P=0.0001). In pheochromocytoma group, plain scan CT value and the difference between plain and enhanced CT scan value were correlated with 24-h urine methoxy adrenaline (Rho;=0.342, 0.350; P=0.020, 0.017, respectively) and norepinephrine (Rho;=0.419, 0.412; P=0.004, 0.004, respectively).Plain and enhanced CT scan values and their combination have important value in differential diagnosis of adenoma and pheochromocytoma tumor, CT values combine with biochemical indexes can reduce misdiagnosis and missed diagnosis of pheochromocytoma.

Background The Tarim Basin in western China, known for its amazingly well-preserved mummies, has been for thousands of years an important crossroad between the eastern and western parts of Eurasia. Despite its key position in communications and migration, and highly diverse peoples, languages and cultures, its prehistory is poorly understood. To shed light on the origin of the populations of the Tarim Basin, we analysed mitochondrial DNA polymorphisms in human skeletal remains excavated from the Xiaohe cemetery, used by the local community between 4000 and 3500 years before present, and possibly representing some of the earliest settlers. Results Xiaohe people carried a wide variety of maternal lineages, including West Eurasian lineages H, K, U5, U7, U2e, T, R*, East Eurasian lineages B, C4, C5, D, G2a and Indian lineage M5. Conclusion Our results indicate that the people of the Tarim Basin had a diverse maternal ancestry, with origins in Europe, central/eastern Siberia and southern/western Asia. These findings, together with information on the cultural context of the Xiaohe cemetery, can be used to test contrasting hypotheses of route of settlement into the Tarim Basin. Electronic supplementary material The online version of this article (doi:10.1186/s12863-015-0237-5) contains supplementary material, which is available to authorized users.

Nickel-induced morphology change of mesostructured alumina with amorphous walls to bayerite tetrahedra when treated in water, and then to γ-alumina with worm-like mesopores topologically after it was calcined at 400 °C is reported. The catalytic activity for selective CO methanation increased significantly after this treatment.

In this study, the temperature dependence of Cr(VI) formation and reduction in the presence of CaO was examined during the thermal treatment of sludge that contains chromium. thermogravimetry–differential scanning calorimetry and X-ray diffractometry were used to characterize the thermal behavior and phase transformation, respectively. Na2CO3 leaching procedure was employed to determine the amount of Cr(VI). The result showed that CaO promoted Cr(III) oxidation, however, its influence is very dependent on heating temperature, with the extent of the effect varying with temperature. From 200–400 °C, the presence of CaO facilitated formation of intermediate product Cr2O3+x containing Cr(VI) during dehydration of chromium hydrate, while Cr2O3+x would decompose as temperature over 400 °C, accompanied by part of Cr(VI) being reduced to Cr(III). From 500 to 900 °C, Cr(III) reacted with CaO to form a leachable CaCrO4 product. This product was stable and a prolonged heating time did not reduce the amount of Cr(VI) significantly. At 1000–1200 °C, part of CaCrO4 was reduced to Ca(CrO2)2 in 1 h. While extended heating time above 1 h resulted in the Ca(CrO2)2 being oxidized reversibly to CaCrO4 at 1200 °C. Since CaCrO4 is thermodynamically less stable over 1000 °C, MgO could induce CaCrO4 to be reduced into MgCr2O4 at around 900 °C, lower than that for the reduction from CaCrO4 into Ca(CrO2)2. It suggested that adding MgO might be a potential approach for inhibiting Cr(VI) formation during heating sludge containing chromium.

PurposeHuman resource management (HRM) is seen as crucial for innovation and firm performance in China. This paper aims to carry out an empirical research to investigate the effects of main dimensions of HRM on technological innovation as well as organizational performance.Design/methodology/approachThe research uses a sample of 194 high‐tech firms surveyed in eight provinces in China.FindingsThis research finds that employee training, immaterial motivation and process control have positive effects on technological innovation, while material motivation and outcome control have a negative influence on technological innovation. It is also found that technological innovation is positively related with performance.Research limitations/implicationsThis study does not consider the different influence of every HRM dimension affecting different innovation types. This should be a future research topic.Practical implicationsThis study provides useful managerial implication for managers. First, employee training is needed to develop employees' knowledge. Second, material incentive is needed but not main motivation in Chinese high‐tech firms. Third, process control should be emphasized more than outcome control in Chinese high‐tech firms.Originality/valueThis study demonstrated that the HRM significantly contributed to technological innovation and firm performance. This study demonstrates that Chinese high‐tech firms' HRM has an important influence on technological innovation, and lead to firm's superior performance.

The mesoporous silica spheres with bimodal pore structure were successfully prepared from silica/hyperbranched polyester (Boltorn™ H20, H20) and silica/glycidoxy-propyltrimethoxysilane modified H20 (H20M) using a simple sol–gel process, and characterized with TEM, FTIR, XPS, TGA, DSC, and N2-BET computation. The effects of organic phase content on the characters of the formed mesoporous silica spheres were investigated. The results showed that the silica spheres prepared from silica/H20M have a bigger particle size, specific surface area and porous volume, and narrower bimodal pore-volume distribution compared with that formed by silica/H20.

In this study, we build a systemic conceptual model to describe the relationship among firm orientation, internal control systems and new product development, and to test empirically how market and entrepreneurship orientations affect the degree of improvement in new product development through personal control and/or output control in the Chinese transitional economy. Our research findings provide some valuable insights into new product development. Entrepreneurship orientation not only has a direct positive effect on the degree of improvement in new product development, but also indirectly has a positive effect on it through personal control. At the same time, market orientation, through output control, has a negative indirect influence.

The monodisperse submicrometer zinc sulfide (ZnS) hollow spheres were synthesized by -ray irradiation at room temperature, using monodisperse silica spheres as the templates. In order to obtain ZnS hollow spheres, the ZnS-coated SiO2 core-shell particles were prepared through -ray irradiation deposition in an aqueous containing zinc acetate and sulfide, released through the hydrolysis of thioacetamide, followed by dissolving the SiO2 cores using hydrofluoric acid. X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and UV–vis spectroscopy were used to characterize these nanoparticles, indicating the formation of core-shell colloidal spheres, as well as hollow spheres. © 2005 Elsevier B.V. All rights reserved.

Lead sulfide (PbS) nanocrystallites in the modified hyperbranched polyester matrix were prepared in situ by 60Co gamma-ray irradiation with sodium thiosulfate at room temperature, and characterized with Fourier transform infrared, X-ray diffraction (XRD), transmission electron microscopy (TEM) and photoluminescence (PL). The average diameter of PbS nanocrystallites was estimated to be 7.8 nm on the basis of analysis of the TEM image and dispersed homogeneously within the modified hyperbranched polyester matrix. The possible formation mechanism of the PbS nanocrystallites under irradiation was discussed.

A novel method for preparing PbS/hyperbranched polyester nanocomposite hollow spheres through coordination and organometallic chemistry method was presented. Their molecular structure crystallinity, shape of crystallites, and optical property were characterized with Fourier transform infrared (FTIR), X-ray diffraction, transmission electron microscopy (TEM), and photoluminescence (PL), respectively. The hollow spheres were of the external diameter of about 50–70 nm and the wall thickness of about 10–20 nm. The possible formation mechanism was also proposed.

The submicrometer monodisperse zinc sulfide (ZnS) hollow spheres were synthesized by gamma-ray irradiation at room temperature, using monodisperse poly (styrene-methyl methacrylate-acrylic acid) (PSMA) latex spheres as the templates. X-ray diffraction (XRD) spectroscopy, transmission electron microscopy, thermogravimetric analysis, and UV–vis spectroscopy were used to characterize these nanoparticles, indicating the formation of core–shell colloidal spheres, as well as hollow spheres. The TEM study for the ZnS-coated PSMA core-shell particles has revealed the uniform coating of ZnS on the PSMA core surface as a thin layer. The obtained ZnS hollow spheres are uniform having a diameter range of 365–375 nm, and wall thickness range of 25–35 nm.

To compare the properties of hyperbranched polymers with linear oligomers for preparing organic-inorganic hybrids, hyperbranched aliphatic polyester (BoltornTM H20) and linear polyester hexa-acrylate (EB830) were selected as organic components for preparing UV-curable transparent hybrid materials using 3-(trimethoxysilyl) propylmethacrylate as a coupling agent via a sol-gel process. The prehydrolyzed product of tetraethoxysilane was used as an inorganic component. The effects of inorganic content on the morphologies, thermal behaviors, photopolymerizaiton kinetics and mechanical properties of the hybrids were investigated. The results show that for hyperbranched polyester-based hybrids, the organic phase shows much better compatibility with inorganic phase even at high inorganic component content due to its special spheral shape and plenty of functional end groups, compared with linear EB830-based hybrids. Copyright © 2004 John Wiley & Sons, Ltd.

A series of organic–inorganic hybrid membranes based on phosphoric acid and hyperbranched aliphatic polyester (Boltorn™ H20) used as electrolytes for polymer electrolyte membrane fuel cells (PEMFC) operated at the temperature higher than 100 °C have been prepared via a sol–gel process, and characterized using 31 P MAS NMR. Boltorn™ H20 was doped into the hybrid membranes at different levels to provide high hydrophilic and water conservation property. A high proton conductivity was obtained with suitable H20 doping level, and the membrane with the highest proton conductivity remained a conductivity of 5 × 10 −4 S cm −1 even after holding for 7 h at 130 °C under 30% relative humidity. The TGA/DTG results have shown that the obtained hybrid membranes were stable up to 200 °C.

Detailed investigations on the self-assembly of amphiphilic star block copolymers composed of three-arm poly(ethylene oxide) (PEO) and poly(methacrylate) (PMAAz) with an azobenzene side chain (denoted as 3PEO-b-PMAAz) into stable spherical aggregates with clear lamellar stripes in solution are demonstrated. Four block copolymers, 3PEO12-b-PMA(Az)33, 3PEO22-b-PMA(Az)31, 3PEO22-b-PMA(Az)62, and linear PEO68-b-PMA(Az)31, are synthesized. The liquid crystalline properties of the block copolymers are studied by differential scanning calorimetry, polarized optical microscopy techniques, and wide-angle X-ray diffraction. The morphologies of the compound micelles self-assembled in tetrahydrofuran (THF)/water mixtures are observed by means of transmission electron microscopy and scanning electron microscopy. The size of the spherical micelles is influenced by the self-assembly conditions and the lengths of two blocks. The well-defined three-arm architecture of the hydrophilic blocks is a key structural element to the formation of stable spherical compound micelles. The micelle surface integrity is affected by the lengths of PEO blocks. The lamellar stripes are clearly observed on these micelles. This work provides a promising strategy to prepare functional stable spherical compound micelles self-assembled by amphiphilic block copolymers in solution.

Traffic is one of the most fundamental dynamical processes in networked systems. With the traditional shortest path routing (SPR) protocol, traffic congestion is likely to occur on the hub nodes on scale-free networks. In this paper, we propose an improved optimal routing (IOR) strategy which is based on the betweenness centrality and the degree centrality of nodes in the scale-free networks. With the proposed strategy, the routing paths can accurately bypass hub nodes in the network to enhance the transport efficiency. Simulation results show that the traffic capacity as well as some other indexes reflecting transportation efficiency are further improved with the IOR strategy. Owing to the significantly improved traffic performance, this study is helpful to design more efficient routing strategies in communication or transportation systems.

Nanoporous thin films with pore size of sub-10 nm are fabricated using an acid-cleavable block copolymer (BCP), a benzoic imine junction between poly(ethylene oxide) (PEO) and poly(methacrylate) (PMAAz) bearing an azobenzene side chain (denoted as PEO-bei-PMAAz) as the precursor. After a thermal annealing, the block copolymers are self-assembled to form highly ordered PEO cylinders within a PMAAz matrix normal to the film, even in the case of low BCP molecular weight due to the existing of the liquid crystalline (LC) azobenzene rigid segment. Thus, PMAAz thin films with pore size of ≈7 nm and density of ≈1012 cm−2 are obtained after removal of the PEO minor phase by breaking the benzoic imine junction under mild acidic conditions. This work enriches the nanoporous polymer films from BCP precursors and introduces the LC property as a functionality which can further enhance the mechanical properties of the films and broaden their applications.

This study investigated the feasibility of stabilizing lead sludge by reaction with iron sludge via the formation of PbFe12O19 through a thermal treatment process. Lead hydroxide was used to simulate lead-laden sludge and the sintering procedure was performed by firing a mixture of this simulated sludge together with iron sludge at a Fe/Pb molar ratio of 12 over the temperature range from 650 to 1400 °C. The accompanying phase transformations as well as the surface characteristic of sintered samples were observed by XRD and SEM, while the leaching behavior of the stabilized sludge in an acidic environment was evaluated by a modified Toxicity Characteristic Leaching Procedure (TCLP) test. The results confirmed that PbFe12O19 acts as a stabilization phase for lead, and showed that the formation of a PbFe12O19 phase began at 750 °C with the lead completely incorporated into the PbFe12O19 phase at 1050 °C. Above 1100 °C, the PbFe12O19 phase began to decompose, accompanied by the reappearance of Fe2O3. The volumes of compressed sludge samples were reduced significantly after thermal treatment, with accompanying volume reductions of 40% at 1050 °C. This study compared the leaching of lead from PbO and sintered sludge samples using a prolonged TCLP test, and the data showed that the PbFe12O19 phase was superior to the PbO and that the sintered sludge sample exhibited very high stability under acidic environments. These results suggest a promising and reliable method of reducing lead sludge mobility and toxicity has been identified.

Carbon black–silver hybrid catalysts were easily synthesized by a mixing method of acid-oxidized carbon black and the colloidal dispersion of silver nanoparticles. The silver colloidal dispersion was pre-synthesized by a chemical reduction of silver nitrate by dimethyl sulfoxide in the presence of trisodium citrate dihydrate as capping agents. In the mixing method, approx. 6.0 nm diameters of silver nanoparticles with face-centered cubic crystal structures are highly dispersed on the acid-oxidized carbon blacks due to the surface reactivity resulting from the enhancement of oxygen-containing functional groups. The hybrid catalysts were examined for electro-catalytic activity towards oxidation of hydrazine. The results clearly show that the carbon black–silver hybrid catalysts are highly active for electro-catalytic oxidation of hydrazine.

Multi-walled carbon nanotube/silver nanoparticles hybrid materials were easily synthesized by a mixing method of acid-oxidized nanotubes and the colloidal dispersion of silver nanoparticles. The silver colloidal dispersion was pre-synthesized by a chemical reduction of silver nitrate by dimethyl sulfoxide in the presence of trisodium citrate dihydrate as capping agents. In the mixing method, approx 5.0 nm diameters of silver nanoparticles with face-centered cubic crystal structures are highly dispersed on the acid-oxidized nanotubes due to the surface reactivity resulting from the enhancement of oxygen-containing functional groups. The results emphasize that the anchoring effect of the functionalized nanotube surface on silver nanoparticles originates from electrostatic metal-support interactions.