电动自行车中轴扭矩传感器

电动自行车归属于非机动车类，它既不能在汽车道上行驶，也不能在人行道上行驶，只能在非机动车道上行驶。作为一种介于摩托车和费力型脚踏自行车之间的新型产品，它的发展方向只能是“省力型轻便自行车”。电动自行车在行驶过程中，其电力只能是辅助性的。因此，如何去科学测量人的脚蹬力，也就是如何开发出能准确地测量出人的脚蹬力的传感器进而给人以适中的电力辅助的问题成为电动助力自行车的研究重点。

深念

十年前应王德昌、李元同志之嘱,为《张钰哲论文选》作序。捧卷凝思,睹文生情,一幕幕往事夹着情感,不自觉地渗入笔端。序写好后,觉得颇不中矩,却是把许多思念都寄放在字里行间了。今值纪念张先生诞辰一百周年,谨在此重录原文,再表其中深深的思念。

剪得掉的商标,剪不断的爱

编辑导语记得儿子小时候,为他买来的每一件小衣服,无论是内衣还是外衣,我都要细心地拆去商标,再把衣服翻过来,剪断所有浮着的线头,最后再仔细地将衣服用皂粉手洗一遍,放在太阳下晒干,才会拿给儿子穿。那样的过程,是烦琐的,是麻烦的,甚至在外人的眼中,是多余的。但,一个母亲的心,又岂是人人都能懂的呢?

超级享受,Amuza VIP Limousine

我们常人以为日本这个东方国度造车一贯是中规 中矩,其实不然,有时也很另类！

Altered profiles of nuclear matrix proteins during the differentiation of human gastric mucous adenocarcinoma MGc80-3 cells

AIM： To find and identify specific nuclear matrix proteins associated with proliferation and differentiation of carcinoma cells, which will be potential markers for cancer diagnosis and targets in cancer therapy. METHODS： Nuclear matrix proteins were selectively extracted from MGcS0-3 cells treated with or without hexamethylamine bisacetamide （HMBA）, and subjected to 2-D gel electrophoresis. The resulted protein patterns were analyzed by Melanie software. Spots of nuclear matrix proteins differentially expressed were excised and subjected to in situ digestion with trypsin. Peptide masses were obtained by matrix-assisted laser-desorption/ ionization time of flight mass spectrometry （MALDI-TOFMS） analysis and submitted for database searching using Mascot tool. RESULTS： The MGc80-3 cells were induced into differentiation by HMBA. There were 22 protein spots which changed remarkably in the nuclear matrix, from differentiation of MGcS0-3 cells compared to control. Eleven of which were identified. Seven proteinsactin, prohibitin, porin 31HL, heterogeneous nuclear dbonucleoprotein A2/B1, vimentin, ATP synthase, and heat shock protein 60 were downregulated, whereas three proteins - heat shock protein gp96, heat shock protein 90-beta, and valosin-containing protein were upregulated, and the oxygen-regulated protein was only found in the differentiated MGc80-3 cells. CONCLUSION： The induced differentiation of carcinoma cells is accompanied by the changes of nuclear matrix proteins. Further characterization of those proteins will show the mechanism of cellular proliferation and differentiation, as well as cancer differentiation.

Horizontal gas mixing in rectangular fluidized bed:A novel method for gas dispersion coefficients in various conditions and distributor designs

In a rectangular fluidized bed combustor, the tracer gas is injected continuously into the bed from a point source at the center of the distributor plate. In this study, a general governing equation is formulated for tracer gas dispersion in the bed. An analytical solution is derived to estimate the dispersion coefficients, Dxand Dy, in a horizontal plane. The concentration profiles at different sampling heights with various gas velocities are plotted.Subsequently, to estimate the dispersion coefficients, surface fitting of the obtained analytical solution to the experimental data is performed. The dispersion coefficients obtained from this model are compared with those of a conventional model. Additionally, the effect of walls, bed height and gas injection rate on the dispersion coefficients in a horizontal plane is investigated, and the effect of distributor design on the dispersion coefficients in a horizontal plane is investigated with different tracer positions. It is found that Dxand Dyare nearly equivalent at a lower tracer gas ratio of the injected gas to the total gas flow rate. It is also demonstrated that the effect of bed height on Dxis minor. This model is also able to estimate the dispersion coefficients in the case of a multihorizontal nozzle distributor.

On the Centrosymmetric and Centroskewsymmetric Solutions to a Matrix Equation over a Central Algebra

Let Ω be a finite dimensional central algebra and chart Ω≠2 .The matrix equation AXB-CXD=E over Ω is considered.Necessary and sufficient conditions for the existence of centro(skew)symmetric solutions of the matrix equation are given.As a particular case ,the matrix equation X-AXB=C over Ω is also considered.

Bi-large Neutrino Mixing See-Saw Mass Matrix with Texture Zeros and Leptogenesis

We study constraints on neutrino properties for a class of bi-large mixing See-Saw mass matrices with texture zeros and with the related Dirac neutrino mass matrix to be proportional to a diagonal matrix of the form diag （e, 1, 1）. Texture zeros may occur in the light （class a）） or in the heavy （class b）） neutrino mass matrices. Each of these two classes has 5 different forms which can produce non-trivial three generation mixing with at least one texture zero. We tind that two types of texture zero mass matrices in both class a and class b can be consistent with present data on neutrino masses and mixing. None of the neutrinos can have zero masses and the lightest of the light neutrinos has a mass larger than about 0.046 eV for class a and 0.0027 eV for class b. In these models although the CK.M CP violating phase vanishes, the non-zero Majorana phases can exist and can play an important role in producing the observed baryon asymmetry in our universe through leptogenesis mechanism. The requirement of producing the observed baryon asymmetry can further distinguish different models and also restrict the See-Saw scale to be in the range of 10^12- 10^15 GeV. We also discuss RG effects on V^13.

Perihelion Precession,in Gravitational Field of Center Mass with Electric Charge and Magnetic Moment

With a perfect mathematical method by us, we obtain some expressions of the orbital effect for a test particle and some meaningful results in the gravitational field of the center mass with electric charge and magnetic moment.

Full Graph Methods of Switched Current Circuit Solution

Circuits with switched current are described by an admittance matrix and seeking current transfers then means calculating the ratio of algebraic supplements of this matrix. As there are also graph methods of circuit analysis in addition to algebraic methods, it is clearly possible in theory to carry out an analysis of the whole switched circuit in two-phase switching exclusively by the graph method as well. For this purpose it is possible to plot a Mason graph of a circuit, use transformation graphs to reduce Mason graphs for all the four phases of switching, and then plot a summary graph from the transformed graphs obtained this way. First the author draws nodes and possible branches, obtained by transformation graphs for transfers of EE （even-even） and OO （odd-odd） phases. In the next step, branches obtained by transformation graphs for EO and OE phase are drawn between these nodes, while their resulting transfer is 1 multiplied by z^1/2. This summary graph is extended by two branches from input node and to output node, the extended graph can then be interpreted by the Mason＇s relation to provide transparent current transfers. Therefore it is not necessary to compose a sum admittance matrix and to express this consequently in numbers, and so it is possible to reach the final result in a graphical way.

Estimates of Central Moments for One Kind of Exponential-Type Operators

In this paper,the explicit estimates of central moments for one kind of exponential-type operators are derived.The estimates play an essential role in studying the explicit approximation properties of this family of operators.Using the proposed method,the results of Ditzian and Totik in 1987,Guo and Qi in 2007,and Mahmudov in 2010 can be improved respectively.

Focal Mechanism of the Xianyou Earthquake Sequence,Fujian,China

1,209 earthquakes occurred in Xianyou,Fujian from August 4,2010 to October 4,2013.The largest earthquake was M L5. 0 on September 4,2013. In order to study the Xianyou earthquake sequence and understand the causative structure and stress field of Xianyou,the focal mechanism solutions of six earthquakes( M L> 3. 5) in the Xianyou earthquake sequence are calculated using the broadband digital data of the Fujian Seismic Network with the seismic moment tensor inverse method. The results show that the focal faults of the six earthquakes are similar,which are all strike-slip faults striking to the northwest with high dip angles. The direction of the principal compressive stress axes is near SN,which is different from the stress field of Fujian region. The Xianyou earthquake sequence may have been induced by the stress adjustment after the impoundment of Jinzhong reservoir.

Study of Top Quark FCNC

We study the one-loop contribution of the effective flavor changing neutral couplings （FCNC） tcZ on the charm quark electric dipole moment. Using the known limits on the top and charm quarks electric dipole moments, we place limits on these FCNC anomalous couplings.

A Negative Donor D^- in a Magnetic Field

Using the method of numerical matrix diagonalization within the effective-mass approximation, we investigated a D^--center quantum dot system subjected to a Gaussian potential confinement. We obtain the dependence of binding energies of the ground-states of the D^--center on the depth of Gaussian potential and the magnetic field strength. The result shows clearly that the binding energies of the ground-states of the D^--center are rather sensitive to the depth of potential and the strength of magnetic field.

Risks Matrixes Risks Assessment Tools of Small and Medium-Sized Enterprises： The Case of Latvia

The enterprises need to assess the risk dynamic of financial instability and its impact on small and medium-sized enterprises＇ development, because it is important for enterprises to extend commercial activity and to open a new structural subdivision. We have researched types of risks, their identification, classification, and assessment possibilities in activities of small and medium-sized enterprises. We have used our own algorithm of identification, classification, and assessment of enterprises＇ risks. The goal of this research is to study the economic and financial risks＇ impact on small and medium-sized enterprises＇ development in Latvia. For study purpose, we have carried out the questionnaire of representative small and medium-sized enterprises about the economic and financial risks＇ impact on enterprises＇ development in Latvia. We have created classification of Latvian services sectors＇ economic and financial risks in the period from 2011 to 2012. Those risks have been included in the questionnaire. The risks matrix is a quantitative assessment tool of risks. We have created Latvian service sector economic and financial risks matrix. We have arranged risks by their sizes of possible losses for enterprises. For each risk has been assessed its probability of realization. We have created Latvian accommodations （hotel） and food services technological process risks map. Several parts of the risk map （segments） make it possible to assess each type of the risk separately in its segment. Risks matrix can be used to choose enterprises＇ strategy of risk management. Enterprise＇s strategy of risk management is developed by analysing zones of risk level.

Frame Dragging Effect on Properties of Rotating Neutron Stars with Strong Magnetic Field

The general relativistic frame dragging effect on the properties,such as the moments of inertia and the radiiof gyration of fast rotating neutron stars with a uniform strong magnetic field,is calculated accurate to the first orderin the uniform angular velocity.The results show that compared with the corresponding non-rotating static sphericalsymmetric neutron star with a weaker magnetic field,a fast rotating neutron star(millisecond pulsar)with a strongermagnetic field has a relative smaller moment of inertia and radius of gyration.

Influence of Soft Filler on Stress Concentration Factor of Elliptic Holes in a Rectangular Plate

Finite element models were established to analyze the influence of soft filler on stress concentration for a rectangular plate with an elliptic hole in the center. The influence was quantified by means of stress concentration factor (SCF). Seven shape factors of the elliptic hole and three levels of elasticity modulus of the soft filler were considered. The reduction coefficient and sensitivity index of SCF are the two indicators in evaluating the influence of soft filler. It was found that the reduction coefficient of SCF increases significantly as the shape factor and the elasticity modulus of the filler increase, indicating that soft filler can reduce the concentrated stress effectively, especially when the shape factor is great. Analysis for the sensitivity index of SCF indicates that SCF is more sensitive to materials with small elasticity modulus than to materials with large one.

Embodied Pollution in China-U.S.Trade——An Empirical Study Based on Estimation of Input-Output Technology Matrix

Using input-output tables of China and the U.S., this paper has calculated the pollution embodied in trade and structure of pollution, the balance of emissions embodied in trade （BEET） and the pollution terms of trade （PTT） for 18 manufacturing sectors of China and the US. between 2001 and 2010. The calculation aims to verify whether China has become a ＂pollution haven＂ in bilateral trade with developed countries represented by the U.S., and whether Chinese exports are ＂dirtier＂ compared with imports from the U.S., and further conducting an industry structure analysis and effect decomposition study on pollution embodied in trade in industrial goods between China and U.S.. Result of our research indicates that according to our calculation of the BEET, China remains a country with environmental deficits in bilateral trade with the U.S. while the gaps between pollution embodied in China＇s export and import are narrowing. Pollution embodied in China＇s export has the tendency of increase before decline while pollution embodied in import demonstrates no significant tendency of decline. Through effect decomposition, we further found that the effect of technology arising from the substantial decline of pollution intensity effectively lowered pollution embodied in export and narrowed the environmental deficits of China in its bilateral trade. The effect of scale arising from growing export volumes significantly increased China＇s environmental deficits while the structural effect arising from changes in the structure of import and export is insignificant in reducing environmental deficits. Our calculation of the PTT led to the finding that China＇s export goods are more pollution intensive compared with import goods and that the structure of US exports to China is cleaner than the structure of Chinese exports to the US., which requires further improvements of China＇s import and export structure.

Analysis of Sampled Fiber Bragg Grating Based on the Photonic Crystal Theory

One of the most basic characteristics of photonic crystal is frequency band gap. When defects are introduced into the periodic photonic crystal, a number of defect modes appear in the stop band. In this paper, we exploit transfer matrix method based on photonic crystal theory, and assume the sampled fiber Bragg grating as one-dimensional dual photonic crystal with a large size defect. Characteristics of the sampled fiber Bragg grating are analyzed. Experimental results show that the sampled fiber Bragg grating has many reflective peaks. Its reflectivity, center wavelength, reflective peak intervals and band width all change with the grating parameters, including grating length, duty ratio of the material with high dielectric constant, and index modulation depth and period. Results agree with the conventional couple mode theory which can be used when analyzing other characteristics of the sampled fiber Bragg grating or applying it into practice.

Passivity-based control of synchronous motors in mine hoist systems

An adaptive PBC strategy for SM with a time-varying load torque to track fluxand speed trajectories was proposed.The key point of this method was the identificationof terms,known as workless forces,which appeared in the dynamic equations of SM buthad no effect on the energy balance equation of the closed loop.PBC,combined withadaptive control schemes,not only preserved the advantages of PBC such as nonexistenceof singularity,but also rejected the flux and speed tracking error caused by statorand rotor resistance variation.The rotor currents of SM were estimated via a state observer.This algorithm simplified the control structure and enhanced the robustness of thecontrol system.The feasibility and effectiveness were confirmed by experimental resultsbased on dSPACE.