Abstract: A method for preparing pinacolone is provided. Raw materials including 2-methyl-2-butene, hydrochloric acid and formaldehyde are reacted in the presence of a catalyst to produce pinacolone. The catalyst is a single lanthanide Lewis acid, a compounded lanthanide Lewis acid or a lanthanide metal oxide soluble in hydrochloric acid. The lanthanide Lewis acid is lanthanum chloride, cerium chloride, praseodymium chloride, neodymium chloride, erbium chloride, holmium chloride, dysprosium chloride or thulium chloride. The method is performed through a continuous two-step reaction. In the first reaction, 2-methyl-2-butene and hydrochloric acid are reacted to form an intermediate, which undergoes a second reaction with formaldehyde in the presence of the catalyst to produce pinacolone.

Abstract: A conformal printing device for curved-surface circuits is provided. The device includes a device body that includes a stand and a support plate movable relative to the stand. The device further includes a print-head module mounted on the support plate and a motion module mounted on the device body. The print-head module includes a piezoelectric nozzle and an airflow assisting structure for applying an assisted airflow to guide charged jet ejected from the nozzle to be precisely printed onto a curved-surface base material below the nozzle. The motion module enables a tangent of a surface, on which a printing position of the curved-surface base material to be printed is located, to be always perpendicular to a jet ejected by the nozzle, ensures that the print-head module moves following the curved-surface shape, and implements conformal printing circuits on any complex curved surfaces.

Abstract: A method for implementing an atomic clock based on NV-15N coupling spin system in diamond and a device are provided. The method includes: applying a pulse sequence to jointly initialize NV electron spins and 15N nuclear spins; performing a Ramsey interferometry to compare a RF frequency and a 15N hyperfine coupling; entangling the NV electron spin and the nuclear spin, reading out a state of nuclear spins by collecting a fluorescence signal; calculating a frequency difference between the RF frequency and the 15N hyperfine coupling according to the fluorescence signal, thereby locking the RF frequency to the 15N hyperfine coupling; and outputting the RF frequency as a frequency standard.

Abstract: The subject disclosure provides systems and methods for providing access to media content from a server based on a user interface of a client device through which the access is requested. A user may access certain media content, such as a song, album, playlist, a radio station, etc., only if a request for that content is initiated via a specific user interface, and when the user is a subscriber to a reduced subscription tier to a service of the server. To restrict the access in this way, an interface-specific token is generated at a server for each media content. The interface-specific token is received by a user device and is used for further access to the media content from the server.

Abstract: A method for preparing pinacolone is provided. Raw materials including isopentane, hydrochloric acid and formaldehyde are reacted in the presence of a catalyst to produce pinacolone. The catalyst is a single lanthanide Lewis acid, a compounded lanthanide Lewis acid or a lanthanide metal oxide soluble in hydrochloric acid. The lanthanide Lewis acid is lanthanum chloride, cerium chloride, praseodymium chloride, neodymium chloride, erbium chloride, holmium chloride, dysprosium chloride or thulium chloride. The method is performed through a continuous two-step reaction. In the first reaction, isopentene and hydrochloric acid are reacted to form an intermediate, which undergoes a second reaction with formaldehyde in the presence of the catalyst to produce pinacolone.

Abstract: A method for implementing an atomic clock based on NV-14N coupling spin system in diamond and a device are provided. The method is to lock a RF frequency using a 14N zero-field splitting and output the RF frequency as a frequency standard. The method includes: applying a pulse sequence to jointly initialize NV electron spins and 14N nuclear spins; performing a Ramsey interferometry to compare a RF frequency and a 14N zero-field splitting; entangling the NV electron spin and the nuclear spin, reading out a state of nuclear spins by collecting a fluorescence signal; calculating a frequency difference between the RF frequency and the 14N zero-field splitting according to the fluorescence signal, thereby locking the RF frequency to the 14N zero-field splitting; and outputting the RF frequency as a frequency standard.

Abstract: The present disclosure discloses a voice conversion method. The method includes: obtaining a to-be-converted voice, and extracting acoustic features of the to-be-converted voice; obtaining a source vector corresponding to the to-be-converted voice from a source vector pool, and selecting a target vector corresponding to the target voice from the target vector pool; obtaining acoustic features of the target voice output by the voice conversion model by using the acoustic features of the to-be-converted voice, the source vector corresponding to the to-be-converted voice, and the target vector corresponding to the target voice as an input of the voice conversion model; and obtaining the target voice by converting the acoustic features of the target voice using a vocoder. In addition, a voice conversion apparatus and a storage medium are also provided.

Abstract: A method for implementing an atomic clock based on NV-15N coupling spin system in diamond and a device are provided. The method includes: applying a pulse sequence to jointly initialize NV electron spins and 15N nuclear spins; performing a Ramsey interferometry to compare a RF frequency and a 15N hyperfine coupling; entangling the NV electron spin and the nuclear spin, reading out a state of nuclear spins by collecting a fluorescence signal; calculating a frequency difference between the RF frequency and the 15N hyperfine coupling according to the fluorescence signal, thereby locking the RF frequency to the 15N hyperfine coupling; and outputting the RF frequency as a frequency standard. This system is located in a stable solid environment and is not affected by environmental conditions such as an external magnetic field, electric field, and temperature, and therefore it has an excellent robustness. Various components of the device may be integrated into several chips to miniaturize a diamond atomic clock.

Abstract: A method for implementing an atomic clock based on NV-14N coupling spin system in diamond and a device are provided. The method is to lock a RF frequency using a 14N zero-field splitting and output the RF frequency as a frequency standard. The method includes: applying a pulse sequence to jointly initialize NV electron spins and 14N nuclear spins; performing a Ramsey interferometry to compare a RF frequency and a 14N zero-field splitting; entangling the NV electron spin and the nuclear spin, reading out a state of nuclear spins by collecting a fluorescence signal; calculating a frequency difference between the RF frequency and the 14N zero-field splitting according to the fluorescence signal, thereby locking the RF frequency to the 14N zero-field splitting; and outputting the RF frequency as a frequency standard.

Abstract: In accordance with implementations of the subject matter described herein, a solution for speech enhancement is proposed. In this solution, a target time-frequency representation at least indicating intensities of an input audio signal at different frequencies over time is obtained. The input audio signal comprises a speech component and a noise component. Frequency correlation information and time correlation information of the input audio signal is determined based on the target time-frequency representation. A target feature representation is generated based on the frequency correlation information, the time correlation information, and the target time-frequency representation. The target feature representation is for distinguishing the speech component and the noise component. An output audio signal is generated based on the target feature representation and the target time-frequency representation. The speech component is enhanced relative to the noise component in the output audio signal.

Abstract: A speech synthesis method includes: obtaining an acoustic feature sequence of a text to be processed; processing the acoustic feature sequence by using a non-autoregressive computing model in parallel to obtain first audio information of the text, to be processed, wherein the first audio information comprises audio corresponding to each segment; processing the acoustic feature sequence and the first audio information by using an autoregressive computing model to obtain a residual value corresponding to each segment; and obtaining second audio information corresponding to an i-th segment based on the first audio information corresponding to the i-th segment and the residual values corresponding to a first to an (i-1)-th segment, wherein a synthesized audio of the text to be processed comprises each of the second audio information, i=1, 2 . . . n, n is a total number of the segments.

Abstract: The subject disclosure provides systems and methods for providing access to media content from a server based on a user interface of a client device through which the access is requested. A user may access certain media content, such as a song, album, playlist, a radio station, etc., only if a request for that content is initiated via a specific user interface, and when the user is a subscriber to a reduced subscription tier to a service of the server. To restrict the access in this way, an interface-specific token is generated at a server for each media content. The interface-specific token is received by a user device and is used for further access to the media content from the server.

Abstract: In some implementations, a computing system can manage access to media sources associated with a user's media account. For example, the system can coordinate access to a user's media account between local and network devices such that when access to the user's media account is granted to an application on a user device, the application can access both local and network media sources associated with the user's media account. Similarly, when access to the user's media account is revoked from an application at a user device or at a network device, the application is prevented from accessing both local and network media sources associated with the user's media account.

Abstract: The present disclosure discloses a voice conversion method. The method includes: obtaining a to-be-converted voice, and extracting acoustic features of the to-be-converted voice; obtaining a source vector corresponding to the to-be-converted voice from a source vector pool, and selecting a target vector corresponding to the target voice from the target vector pool; obtaining acoustic features of the target voice output by the voice conversion model by using the acoustic features of the to-be-converted voice, the source vector corresponding to the to-be-converted voice, and the target vector corresponding to the target voice as an input of the voice conversion model; and obtaining the target voice by converting the acoustic features of the target voice using a vocoder. In addition, a voice conversion apparatus and a storage medium are also provided.

Abstract: In some implementations, a computing system can manage access to media sources associated with a user's media account. For example, the system can coordinate access to a user's media account between local and network devices such that when access to the user's media account is granted to an application on a user device, the application can access both local and network media sources associated with the user's media account. Similarly, when access to the user's media account is revoked from an application at a user device or at a network device, the application is prevented from accessing both local and network media sources associated with the user's media account.

Abstract: In some implementations, a computing system can manage access to media sources associated with a user's media account. For example, the system can coordinate access to a user's media account between local and network devices such that when access to the user's media account is granted to an application on a user device, the application can access both local and network media sources associated with the user's media account. Similarly, when access to the user's media account is revoked from an application at a user device or at a network device, the application is prevented from accessing both local and network media sources associated with the user's media account.

Abstract: A candidate sample (T) and respective features (Ft) of the candidate sample (T) are obtained. A predetermined positive integer (N) samples are selected from a classification sample library. A feature similarity (SIMi) is determined between the candidate sample (T) and each of the N samples (i), where the feature similarity (SIMi) is determined based on the respective features (Ft) of the candidate sample (T) and respective features (Fi) of each sample (i). A sample quality (Qi) of each sample (i) is obtained. As comprehensive similarity measures (Si), a comprehensive similarity measure (Si) is determined between the candidate sample (T) and each sample (i) at least based on a difference (ri) between the feature similarity (SIMi) and the sample quality (Qi). Based on the comprehensive similarity measures (Si), a determination is performed as to whether the candidate sample (T) belongs to a classification within the classification sample library.

Abstract: In some implementations, a computing system can manage access to media sources associated with a user's media account. For example, the system can coordinate access to a user's media account between local and network devices such that when access to the user's media account is granted to an application on a user device, the application can access both local and network media sources associated with the user's media account. Similarly, when access to the user's media account is revoked from an application at a user device or at a network device, the application is prevented from accessing both local and network media sources associated with the user's media account.