Creat membership Creat membership
Sign in

Forgot password?

Confirm
  • Forgot password?
    Sign Up
  • Confirm
    Sign In
home > search

Now showing items 1 - 16 of 197560

  • A Reply to Eddie Yuen

    Download Collect
  • The 80387 and its applications: Perlmutter, D and Kin-Wah Yuen, A pp 42–57

    Download Collect
  • The 80387 and its applications: Perlmutter, D and Kin-Wah Yuen, A pp 42–57

    Download Collect
  • Design of a compact D–D neutron generator

    Zhiwu Huang   Junrun Wang   Zhanwen Ma   Xiaolong Lu   Zheng Wei   Shuangjiao Zhang   Yuguo Liu   Zimin Zhang   Yu Zhang   Zeen Yao  

    Abstract The design of a compact D–D neutron generator with a neutron yield greater than 1 × 1 0 8 n/s is presented in this paper. A duoplasmatron ion source is used to supply the deuteron beam. Deuterium ions are extracted and accelerated by a single-gap accelerating column and then bombard onto a drive-in molybdenum target where neutrons are produced through D–D fusion reactions. The target is cooled by the circulating deionized water. The extraction-accelerating electrode and the target system are enclosed inside a stainless steel vacuum vessel. The ion source is at ground potential, and the target is biased to a negative potential. The electric field distribution inside the vacuum vessel, the ion beam optic, the thermal analysis of the target and the effect of secondary electron suppression are calculated. And these calculation results are used to optimize and evaluate the designed scheme. Calculation results show that the design of the neutron generator satisfies necessary engineering requirements.
    Download Collect
  • Radiation effect of neutrons produced by D–D side reactions on a D

    J. Bahmani  

    One of the most important characteristics in D–3He fusion reactors is neutron production via D–D side reactions. The neutrons can activate structural material, degrading them and ultimately converting them into high-level radioactive waste, while it is really costly and difficult to remove them. The neutrons from a fusion reactor could also be used to make weapons-grade nuclear material, rendering such types of fusion reactors a serious proliferation hazard. A related problem is the presence of radioactive elements such as tritium in D–3He plasma, either as fuel for or as products of the nuclear reactions; substantial quantities of radioactive elements would not only pose a general health risk, but tritium in particular would also be another proliferation hazard. The problems of neutron radiation and radioactive element production are especially interconnected because both would result from the D–D side reaction. Therefore, the presentation approach for reducing neutrons via D–D nuclear side reactions in a D–3He fusion reactor is very important. For doing this research, energy losses and neutron power fraction in D–3He fusion reactors are investigated. Calculations show neutrons produced by the D–D nuclear side reaction could be reduced by changing to a more 3He-rich fuel mixture, but then the bremsstrahlung power loss fraction would increase in the D–3He fusion reactor.
    Download Collect
  • D/A CONVERTER AND A/D CONVERTER

    A D/A converter for converting a digital signal having a predetermined number of bits into an analog signal comprises: a plurality of constituent element groups which include a plurality of constituent elements constituting the D/A converter, and which are connected, in a predetermined order, to an output unit for outputting the analog signal; and a start position modification unit which, when generating a single analog signal corresponding to the digital signal, modifies a start position of the plurality of constituent element groups to be used for generating the single analog signal, using a predefined shift pattern.
    Download Collect
  • A memristive dual-slope A/D converter

    Yang, Le   Zeng, Zhigang   Ma, Zhansong   Shan, Wenqi  

    As an emerging device, memristor has several excellent properties like changeable memristance, nonvolatility, and nanoscale. Based on complementary metal-oxide-semiconductor (CMOS) dual-slope analog-to-digital (A/D) converter, this paper proposes a memristive dual-slope A/D converter. Owing to the usage of memristor, the proposed memristive A/D converter not only has more compact circuit structure and simpler control timing than the CMOS one but also has advantages over the existing memristive conversion circuits in circuit design and application. For the memristive A/D converter, a conversion process consists of two count procedures. By means of controlling the memristance change in the two count procedures, the A/D converter converts an analog signal to the corresponding digital count value. Meanwhile, the conversion result is inferred according to the circuit structure of the A/D converter. Then, combining the conversion process and PSPICE simulation, this paper analyzes the anti-interference performance of the A/D converter. Further, the robustness of the A/D converter is presented, applying the similar analysis methods. The analysis results demonstrate that the proposed A/D converter has good anti-interference and robustness performances.
    Download Collect
  • A theory of R(D-*, D) anomaly with right-handed currents

    Babu, K. S.   Dutta, Bhaskar   Mohapatra, Rabindra N.  

    We present an ultraviolet complete theory for the R(D-*) and R(D) anomaly in terms of a low mass W +/- gauge boson of a class of left-right symmetric models. These models, which are based on the gauge symmetry SU(3)(c) x SU(2)(L) x SU(2)(R) x U(1)(B - L), utilize vector-like fermions to generate quark and lepton masses via a universal seesaw mechanism. A parity symmetric version as well as an asymmetric version are studied. A light sterile neutrino emerges naturally in this setup, which allows for new decay modes of B-meson via right-handed currents. We show that these models can explain R(D-*) and R(D) anomaly while being consistent with LHC and LEP data as well as low energy flavor constraints arising from KL-KS,Bd,s-Bd,s,D- mixing, etc., but only for a limited range of the W-R mass: 1.2 (1.8) TeV MWR 3 TeV for parity asymmetric (symmetric) Yukawa sectors. The ratio R(D)/R(D-*) is predicted to be similar or equal to 1.16, which is the same as in the Standard Model. The light sterile neutrinos predicted by the model may be relevant for explaining the MiniBoone and LSND neutrino oscillation results. The parity symmetric version of the model provides a simple solution to the strong CP problem without relying on the axion. It also predicts an isospin singlet top partner with a mass M-T =3D (1.5 - 2.5) TeV.
    Download Collect
  • Une lettre d\"Euler à d\"Alembert retrouvée

    Hug, Vanja   Steiner, Thomas  

    Download Collect
  • A theory of R(D*, D) anomaly with right-handed currents

    Babu, K. S.   Dutta, Bhaskar   Mohapatra, Rabindra N.  

    Download Collect
  • A new D–D–π–A dye for efficient dye-sensitized solar cells

    Yu, Xiaoqiang   Jiang, Huailing   Wang, Yi   Shi, Yantao   Ma, Tingli   Bao, Ming  

    Download Collect
  • DIFFERENTIAL-OUTPUT D/A CONVERTER AND A/D CONVERTER

    A differential-output D/A converter according to the present disclosure is provided with: decoders (2p, 2n) for converting inputted data into thermometer code; a positive-side capacitor array (3p, 3Ap, 3Bp, 3Cp) comprising a plurality of unit capacitors (Cp) having one end connected to a positive-side output terminal, and a switch (SWp) for switching the other end of the unit capacitors so as to connect to a positive-side reference voltage or a negative-side reference voltage in accordance with the thermometer code; and a negative-side capacitor array (3n, 3An, 3Bn, 3Cn) comprising a plurality of unit capacitors (Cn) having one end connected to a negative-side output terminal, and a switch (SWn) for switching the other end of the unit capacitors so as to connect to the positive-side reference voltage or the negative-side reference voltage in accordance with the thermometer code. The positive-side and negative-side capacitor arrays are disposed in an discretionary first direction. The unit capacitors constituting each of the arrays are arranged in a second direction orthogonal to the first direction. The unit capacitors corresponding to the thermometer code in the positive-side and negative-side capacitor arrays are disposed so as to be point-symmetrical with respect to the center of the arrays as the symmetry point.
    Download Collect
  • A method for determining d–D neutron energies in a large sample

    Junhua Luo  

    Highlights • The method is proposed to determine the d–D neutron energy irradiating on the large sample. • The theoretical formula for the calculation of the mean neutron energy is obtained. • Using the proposed equations, the average neutron energies in the Ti–D solid and D 2 gas targets were calculated. • The results of theoretical calculation compared with the literature values. Abstract The energy of monoenergetic neutrons generated by the D(d,n) 3 He reaction was determined as a function of emergent angle and incidence energy of d + -beam, E n ( θ , E d ). Based on the geometric size of the experimental sample, position of the sample relative to the Ti–D solid or D 2 gas targets, volume distribution of D 2 gas targets, theoretical formulas were obtained for calculating the mean neutron energy required to irradiate a large sample. Using these formulas, the mean neutron energies of the Ti–D solid and D 2 gas targets irradiating a large sample were calculated under various conditions. The results were compared to those reported in the literature. The formulas obtained in this study were found to be applicable for the determination of mean neutron energy irradiating a large sample for the Ti–D solid and D 2 gas targets.
    Download Collect
  • D. D. Gomes Casseres: Biographical approach to a transnational Colombian

    Camacho Navarro, Enrique  

    Download Collect
  • A/D CONVERTER AND A/D CONVERSION APPARATUS

    An A/D converter is provided with: a first wiring layer including a first A/D conversion circuit including a first capacitor group in which a plurality of weighted unit capacitors are connected in parallel and a second capacitor group which is connected in parallel with the first capacitor group and in which a plurality of unit capacitors are connected in parallel; and a second wiring layer including a second A/D conversion circuit including a third capacitor group in which a plurality of weighted unit capacitors are connected in parallel and a fourth capacitor group which is connected in parallel with the third capacitor group and in which a plurality of unit capacitors are connected in parallel. The first wiring layer and the second wiring layer are stacked so that the first A/D conversion circuit and the second A/D conversion circuit are arranged at overlapping positions.
    Download Collect
  • D. D. Gomes Casseres: Biographical approach to a transnational Colombian

    Camacho Navarro, Enrique  

    Download Collect
1 2 3 4 5 6 7 8 9 10

Contact

If you have any feedback, Please follow the official account to submit feedback.

Turn on your phone and scan

Submit Feedback