Please select the most similar patent number from A, B, C and D. Which number is?
A thermostatic safety apparatus comprising an upper cover connecting element (1), an upper nickel-titanium alloy spring (2), a spherical silicone pad (3), a sealing valve (4), a lower nickel-titanium alloy spring (5), and a spherical container (6). When the temperature of a liquid in the container is greater than 41 °C ± 2 °C, the lower nickel-titanium alloy spring (5) in the spherical container (6) extends under the effects of temperature, the upper nickel-titanium alloy spring (2) contracts under the effects of temperature and force, the lower nickel-titanium alloy spring (5) pushes the sealing valve (4) and the spherical silicone pad (3) to block a circular water outlet of the cover connecting element (1); when the temperature of the liquid is less than 36 °C, the lower nickel-titanium alloy spring (5) contracts, the upper nickel-titanium alloy spring (2) extends, and the upper nickel-titanium alloy spring (2) pushes the sealing valve and the spherical silicone pad to allow the liquid to pass through the circular water outlet of the cover connecting element.
A: A nickel titanium alloy gradient flexible root canal file, comprising a root canal file tip part (F1), a root canal file middle part (F2) and a root canal file root part (F3) divided along the axis of the nickel titanium alloy gradient flexible root canal. The internal tissue of the root canal file tip part (F1) is a martensite M phase; the internal tissue of the root canal file middle part (F2) is an R phase; and the internal tissue of the root canal file root part (F3) is an austenite A phase. Further disclosed is a manufacturing method for the nickel titanium alloy gradient flexible root canal file. The beneficial effect is that the safety of using the file is effectively improved.
B: Provided are a nonlinear temperature compensation device (1), an optical module and a method. The device (1) comprises a driving rod (101) and a two-way shape memory alloy spring (103), wherein the driving rod (101) is provided with an elastic structure (102), two ends of the two-way shape memory alloy spring (103) are connected to the driving rod (101), and the two-way shape memory alloy spring (103) is connected to the elastic structure (102) in parallel; the two-way shape memory alloy spring (103) is made of a material capable of realizing a two-way shape memory behavior, and the length thereof changes with temperature non-linearly; and the optical module uses the nonlinear temperature compensation device (1) to compensate the AWG wavelength non-linearly. According to the nonlinear behavior of the two-way shape memory alloy material changing with temperature, the two-way shape memory alloy spring (103) is used for compensating the change of the AWG wavelength with temperature, and the structure is simple and the manufacture is easy; and compared with linear compensation, the wavelength drift is smaller, and the applicable temperature range is wider.
C: A fixing clip, comprising a fixing clip body (1). The fixing clip body (1) has a clipping space (11) and a clipping opening (12) in communication with same, and comprises a hardware spring fastener (2) and an elastic rubber base (3) integrally formed at the periphery of the hardware spring fastener (2) and matching same in the appearance. The elastic rubber base (3) has a clipping space (11) and a clipping opening (12). The hardware spring fastener (2) is used as a frame for the fixing clip body so as to improve the elastic clipping force. The elastic rubber base (3) is integrally fixed at the periphery of the hardware spring fastener (2), and is elastic to open or close over the hardware spring fastener (2). During use, the clipping opening (12) of the fixing clip body (1) is enabled to face towards a tube or a pillar, is pushed hard to open to form the elastic restoring force, and is reset under the elastic restoring force after the tube or the pillar is placed into the clipping space, so that the fixing clip body is stably clipped on the tube or the pillar, is not easy to detach, and is easy to operate.
D: An emergency shut-off valve integrating electromagnetic, manual, and temperature-sensing self-actuated shut-off approaches. When a handle (20) is manually pressed to drive a temperature-sensing element (21) to push a push rod (28) to move downward or when the temperature-sensing element (21) is influenced by the ambient temperature to push the push rod (28) to move downward, the push rod (28) drives a protection slider (29), a pressure relief protection spring (31), and a small push rod (32) to slide downward; a steel bead interior securing member (6) is driven by the small push rod (32) to move downward; then a steel bead (7) enters the place between a snap beads connection member (3) and the steel bead interior securing member (6); the snap beads connection member (3) is, after the steel bead (7) moves away, driven by a sealing spring (37) to move downward simultaneously with a sealing member (38) and a sealing sheet (39) so as to shut off a valve. The self-actuated emergency shut-off valve can be turned off in a self-actuated manner when the ambient temperature abnormally rises to a preset temperature, or can be manually turned off, or can also be remotely controlled as required.
Answer: D