A tele-monitoring system for gait rehabilitation with an inertial measurement unit and a shoe-type ground reaction force sensor

In this paper, a tele-monitoring system is proposed, using an inertial measurement unit (IMU) and a shoe-type ground reaction force (GRF) sensor called a Smart Shoe to measure a patient’s walking data, and transmitting the measured data via the Internet. In our previous work, a mobile gait-monitoring system was developed, which provided visual feedback based on GRFs measured by a Smart Shoe (used as a mobile platform). However, the limited information provided by the Smart Shoe alone may not be adequate for a tele-monitoring system using the Internet. In the present tele-monitoring system for gait rehabilitation, a Smart Shoe is combined with an IMU for detailed monitoring of walking motions. By analyzing the signals from the IMU and the Smart Shoe, foot trajectories, walking distance, length of stride, etc., can be estimated. A user-friendly graphic interface displays the measured or estimated data on separate computers at the patient’s location and the physical therapist’s office. Thus, using the proposed system, it is possible to monitor a patient’s walking motion via the Internet, without restrictions on time or place.     

应用置换反应制备高效SERS活性基底研究

利用预处理的铝片和铜片还原硝酸银溶液的方法获得了具有不同表面形貌的银纳米结构.扫描电子显微镜(SEM)图表明反应产物分别为花样和树枝状的银纳米结构.以对羟基苯甲酸(PHBA)作为探针分子,对这种新体系的表面增强拉曼散射(SERS)活性进行了研究,发现该体系是一种非常高效的SERS活性增强基底,并且其SERS活性优于用化学方法制备的银胶.本文对这种新型SERS活性基底的增强机制进行了讨论.     

铝液对石墨润湿过程的研究

铝-石墨复合材料制造中的突出问题是铝液与石墨的润湿能力很差,为此大多在工艺上采取措施,如石墨表面喷涂Ti-B,Ni或Cu涂层,或采用流变铸造等。然而这些措施使得工艺复杂、成本提高,因而推广应用受到限制。为改善铝液与石墨的润湿能力,有必要深入研究铝液对石墨的润湿过程。国内外这方面报道甚少,而且所报道的结果差别较大。我们通过长时间的保温试验,仔细地研究了不同温度下铝液对石墨的润湿过程,发现了一些新的现象。     

Covalent 0D–2D Heterostructuring of Co9S8–MoS2 for Enhanced Hydrogen Evolution in All pH Electrolytes

Ultrasmall Co₉S₈ nanoparticles are introduced on the basal plane of MoS₂ to fabricate a covalent 0D–2D heterostructure that enhances the hydrogen evolution reaction (HER) activity of electrochemical water splitting. In the heterostructure, separate phases of Co₉S₈ and MoS₂ are formed, but they are connected by Co–S–Mo type covalent bonds. The charge redistribution from Co to Mo occurring at the interface enhances the electron‐doped characteristics of MoS₂ to generate electron‐rich Mo atoms. Besides, reductive annealing during the synthesis forms S defects that activates adjacent Mo atoms for further enhanced HER activity as elucidated by the density functional theory (DFT) calculation. Eventually, the covalent Co₉S₈–MoS₂ heterostructure shows amplified HER activity as well as stability in all pH electrolytes. The synergistic effect is pronounced when the heterostructure is coupled with a porous Ni foam (NF) support to form Co₉S₈–MoS₂/NF that displays superior performance to those of the state‐of‐the‐art non‐noble metal electrocatalysts, and even outperforms a commercial Pt/C catalyst in a practically meaningful, high current density region in alkaline (>170 mA cm^?2) and neutral (>60 mA cm^?2) media. The high HER performance and stability of Co₉S₈–MoS₂ heterostructure make it a promising pH universal alternative to expensive Pt‐based electrocatalysts for practical water electrolyzers.     

Engineering Surface Atomic Architecture of NiTe Nanocrystals Toward Efficient Electrochemical N2 Fixation

Efficient N₂ fixation at ambient condition through electrochemical processes has been regarded as a promising alternative to traditional Haber–Bosch technology. Engineering surface atomic architecture of the catalysts to generate desirable active sites is important to facilitate electrochemical nitrogen reduction reaction (NRR) while suppressing the competitive hydrogen evolution reaction. Herein, nickel telluride nanocrystals with selectively exposed {001} and {010} facets are synthesized by a simple process, realizing the manipulation of surface chemistry at the atomic level. It is found that the catalysts expose the {001} facets coupled with desirable Ni sites, which possess high Faraday efficiency of 17.38 ± 0.36% and NH₃ yield rate of 33.34 ± 0.70 μg h^?1 mg^?1 at ‐0.1 V vs RHE, outperforming other samples enclosed by {010} facets (8.56 ± 0.22%, 12.78 ± 0.43 μg h^?1 mg^?1). Both experimental results and computational simulations reveal that {001} facets, with selectively exposed Ni sites, guarantee the adsorption and activation of N₂ and weaken the binding for *H species. Moreover, the enhanced reduction capacity and accelerated charge transfer kinetics also contribute the superior NRR performance of {001} facets. This work presents a novel strategy in designing nonprecious NRR electrocatalyst with exposed favorable active sites.     

One‐Pot Synthesis of Framework Porphyrin Materials and Their Applications in Bifunctional Oxygen Electrocatalysis

Organic framework materials constructed by covalently linking organic building blocks into framework structures are highly regarded as paragons to precisely control the material structure at the atomic level. Herein, a direct synthesis methodology is proposed as a guidance for the bulk synthesis of organic framework materials. Framework porphyrin (POF) materials are one‐pot synthesized to demonstrate the advances of the direct synthesis methodology. The as‐synthesized POF materials are intrinsically 2D and exhibit impressive versatility in composition, structure, morphology, and function, delivering a free‐standing POF film, hybrids of POF and nanocarbon, and cobalt‐coordinated POF. When applied as electrocatalysts for oxygen reduction reaction and oxygen evolution reaction, the cobalt‐coordinated POF exhibits excellent bifunctional electrocatalytic performances comparable with noble‐metal‐based electrocatalysts. The direct synthesis methodology and resultant POF materials demonstrate the ability of controlling materials at the atomic level for energy electrocatalysis.     

Embedding RhPx in N,P Co‐Doped Carbon Nanoshells Through Synergetic Phosphorization and Pyrolysis for Efficient Hydrogen Evolution

Rational design and controllable synthesis of well‐defined nanostructures with high stability and Pt‐like activity for hydrogen evolution reaction (HER) are critical for renewable energy conversion. Herein, a unique pyrolysis strategy is demonstrated for the synthesis of RhP_x nanoparticles (NPs) in N, P co‐doped thin carbon nanoshells (RhP_x@NPC nanoshells) that display high electrocatalytic activity and stability over a wide pH range. This strategy involves simultaneous phosphorization and pyrolysis processes that can produce highly‐dispersed RhP_x NPs within N, P co‐doped carbon nanoshells and at the same time induce thinning of carbon nanoshells from inside out. The resulting RhP_x@NPC nanoshells not only possess Pt‐like activity for HER with low overpotentials to achieve 10 mA cm^?2 (22 mV in 0.5 m H₂SO₄, 69 mV in 1.0 m KOH, and 38 mV in 1.0 m phosphate buffered saline (PBS)) but also provide long‐term durability in a wide pH range. The remarkable HER performance of RhP_x@NPC nanoshells is ascribed to the high surface area, abundant mesoporosity, strong catalyst–support interaction, ultrathin carbon encapsulation, and N, P co‐doping. This work provides an effective strategy for designing heterostructured electrocatalysts with high catalytic activity and stability desired for reactions that may occur under harsh conditions.     

初论聚酯生产中DEG的影响因素

分析了ＰＴＡ与ＥＧ酯化反应过程中ＤＥＧ的成因．并对控制ＤＥＧ含量提出相应的方法。     

Enterotoxigenic Escherichia coli detected in foods by PCR and an enzyme-linked oligonucleotide probe

A polymerase chain reaction (PCR) and an enzyme-linked oligonucleotide probe hybridization assay were developed for the detection of enterotoxigenic Escherichia coli (ETEC) in ground beef, chicken, pork and raw milk. Two synthetic primers, one of which was biotinylated, were used in the PCR to amplify a fragment of the E. coli heat-labile enterotoxin (LT) gene. The identity of the amplified products was confirmed by liquid hybridization using a horseradish peroxidase-linked internal oligonucleotide probe in a 96-well microplate coated with streptavidin. The final quantitation of the PCR products was performed by a colorimetric reaction. Under established conditions (including l min at 60 °C for primer annealing and extension in PCR cycles), this method detected all 7 LT-producing E. coli pathogenic for humans, but did not detect all 7 LT-positive E. coli of animal origin, 3 E. coli strains that do not produce LT, and 9 other bacteria. Under less stringent PCR conditions (55 °C for annealing and extension), 2 strains of LT-producing E. coli of porcine origin were detected while the results of other bacterial strains remained unchanged. In pure cultures, the detection limit of the method was 1.4 colony forming units (CFU). Prior to PCR amplification, all food samples inoculated with an LT-producing ETEC, were subjected to enrichment in brain heart infusion broth for 8 h at 37 °C. From these cultures, 10 μ1 was heated at 95 °C for 10 min and directly used in the PCR. An initial inoculum of as few as 1.2 to 12 CFU of the LT-producing ETEC per 25 g (or ml) of food sample gave a positive reaction.